Selected abstracts

Abstracts have been organized into subcategories, with brief comment preceding each group, pointing out particularly interesting findings or their implications.

Mechanism & Models

Intensive work continues with use of various imaging techniques to delineate brain areas related to tinnitus. Melcher et al. report is new by showing tinnitus-related changes in activation at the subcortical auditory level of inferior colliculus. Notably, abnormal neuronal activity, presumably related to tinnitus, was shown in past to exist in this structure (Cheng & Jastreboff 1995). Lockwood at al. joined the investigation of gaze-evoked tinnitus and provide further support to involvement of plastic changes in the brain in development of tinnitus. Anderson at al. used lidocaine, which is well recognized for its ability to temporarily attenuate tinnitus, to delineate brain area involved in tinnitus, with results indicating areas related to auditory attention and limbic system. As tinnitus perception has aversive connotations, Mirz et al. attempt to learn more about tinnitus by finding the area of the brain which are activated by aversive auditory stimuli. In addition to auditory system, they observed activation of the prefrontal cortex, and the limbic system. All these findings further support the neurophysiological model of tinnitus, which interestingly postulated involvement of the limbic system and prefrontal cortex as well (Jastreboff 1990).

Norena et al. returns to use of Zwicker tone (auditory after image) as a potential model of tinnitus attempting to find specific mechanisms of this phenomenon. While data are not decisive there is indication that lateral inhibition might be involved.

Potential neurotransmitter / modulators systems involved in tinnitus are postulated in some papers. Bauer at al. return to importance of modifications in GAD expression and GABA(A) receptors. Sahley et al. focus on cochlear mechanisms of tinnitus and propose that natural opioid dynorphins are released from efferent axons during stressful situations and enhance function of NMDA receptors on IHC. Lin and Hand point out importance of the width of the auditory nerve fibers action potentials for normal and pathological function of the auditory periphery. More research is needed to validate these postulates, and clinical data, so far, are limited and not particularly supportive.

Clinical reports indicated link between tinnitus and hypertension. Mosnier et al. investigated an hypothesis that this effect might be due to altered blood-perilymph barrier. Their experimental results were contrary to expected and invalidated this hypothesis.

More papers appear on the subject of genetic links / basis of tinnitus and hyperacusis. Verstreken et al. report on Belgian family, 35% of which have tinnitus, with otologic problems linked to DFNA10 locus. Verhagen sugests COCH mutation (DFNA9) as linked to otologic problem. The paper of Calamandrei et al. postulating link between neurotrophin nerve growth factor (NGF) and Williams syndrome is of particular interest. It is recognized that hyperacusis is presented in 95% of children with Williams syndrome. Thus, better understanding of genetics of this disorder should provide insight into genetic basis of hyperacusis.

Electrophysiological investigations of tinnitus-related neuronal activity continue to be well represented. Komiya & Eggermont, in continuation of their work of cortical areas report reorganization of tonotopic organization after pure-tone trauma. Their results fully support cortical plasticity and the presence of reorganization, and showed increase of spontaneous activity, with not as clear results regarding modification of cross-correlation of the neuronal activity evoked by sound trauma. Several papers of Kaltenbach expand on his previous reports of the increased activity in the dorsal cochlear nucleus as a results of sound exposure. Most recent results show that this increase resembles activity evoked by external tone, but that it shows delayed onset (2 - 5 days after exposure) with further increase for next 6 months. This time course is different from those of clinically observed tinnitus resulting from overexposure to sound. And the authors postulate that mechanisms leading to measured hyperactivity are more complex than previously realized.

Lateralized tinnitus studied with functional magnetic resonance imaging: abnormal inferior colliculus activation. Melcher JR, Sigalovsky IS, Guinan JJ Jr, Levine RA. Eaton_Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston 02114, Massachusetts. J Neurophysiol 2000 Feb;83(2):1058_72

Tinnitus, the perception of sound in the absence of external stimuli, is a common and often disturbing symptom that is not understood physiologically. This paper presents an approach for using functional magnetic resonance imaging (fMRI) to investigate the physiology of tinnitus and demonstrates that the approach is effective in revealing tinnitus_related abnormalities in brain function. Our approach as applied here included 1) using a masking noise stimulus to change tinnitus loudness and examining the inferior colliculus (IC) for corresponding changes in activity, 2) separately considering subpopulations with particular tinnitus characteristics, in this case tinnitus lateralized to one ear, 3) controlling for intersubject differences in hearing loss by considering only subjects with normal or near_normal audiograms, and 4) tailoring the experimental design to the characteristics of the tinnitus subpopulation under study. For lateralized tinnitus subjects, we hypothesized that sound_evoked activation would be abnormally asymmetric because of the asymmetry of the tinnitus percept. This was tested using two reference groups for comparison: nontinnitus subjects and nonlateralized tinnitus subjects. Binaural noise produced abnormally asymmetric IC activation in every lateralized tinnitus subject (n = 4). In reference subjects (n = 9), activation (i.e., percent change in image signal) in the right versus left IC did not differ significantly. Compared with reference subjects, lateralized tinnitus subjects showed abnormally low percent signal change in the IC contralateral, but not ipsilateral, to the tinnitus percept. Consequently, activation asymmetry (i.e., the ratio of percent signal change in the IC ipsilateral versus contralateral to the tinnitus percept) was significantly greater in lateralized tinnitus subjects as compared with reference subjects. Monaural noise also produced abnormally asymmetric IC activation in lateralized tinnitus subjects. Two possible models are presented to explain why IC activation was abnormally low contralateral to the tinnitus percept in lateralized tinnitus subjects. Both assume that the percept is associated with abnormally high ("tinnitus_related") neural activity in the contralateral IC. Additionally, they assume that either 1) additional activity evoked by sound was limited by saturation or 2) sound stimulation reduced the level of tinnitus_related activity as it reduced the loudness of (i.e., masked) the tinnitus percept. In summary, this work demonstrates that fMRI can provide objective measures of lateralized tinnitus and tinnitus_related activation can be interpreted at a neural level.

The functional anatomy of gaze_evoked tinnitus and sustained lateral gaze. Lockwood AH, Wack DS, Burkard RF, Coad ML, Reyes SA, Arnold SA, Salvi RJ. Centers for Positron Emission Tomography, Veterans Administration Western New York Health Care System, Buffalo 14215, USA. alan@petnet.buffalo.edu, Neurology 2001 Feb 27;56(4):472_80

OBJECTIVE: To identify neural sites associated with gaze_evoked tinnitus (GET), an unusual condition that may follow cerebellar_pontine angle surgery. METHODS: The authors examined eight patients with GET and used PET to map the neural sites activated by lateral gaze in them and seven age_ and sex_matched control subjects. RESULTS: In patients with GET, tinnitus loudness and pitch increased with lateral gaze and, to a lesser extent, up and down gaze. Evidence for neural activity related to GET was seen in the auditory lateral pontine tegmentum or auditory cortex. GET_associated nystagmus appears to activate the cuneus and cerebellar vermis. These sites were found in addition to an extensive network that included frontal eye fields and other sites in frontal, parietal, and temporal cortex that were activated by lateral gaze in seven control subjects and the patients. The unilateral deafness in patients with GET was associated with expansion of auditory cortical areas responsive to tones delivered to the good ear. In addition to GET, unilateral deafness, end_gaze nystagmus, and facial nerve dysfunction were common. CONCLUSIONS: Patients with GET have plastic changes in multiple neural systems that allow neural activity associated with eye movement, including those associated with the neural integrator, to stimulate the auditory system. Anomalous auditory activation is enhanced by the failure of cross_modal inhibition to suppress auditory cortical activity. The time course for the development of GET suggests that it may be due to multiple mechanisms.

Regional cerebral blood flow during tinnitus: a PET case study with lidocaine and auditory stimulation. Andersson G, Lyttkens L, Hirvela C, Furmark T, Tillfors M, Fredrikson M. Department of Audiology, Uppsala University Hospital, Uppsala University, Sweden. Gerhard.Andersson@psyk.uu.se, Acta Otolaryngol 2000 Oct;120(8):967_72

Brain imaging of tinnitus has suggested central correlates of tinnitus perception. This study presents positron emission tomographic (PET) measurements of regional cerebral blood flow (rCBF) in a female tinnitus patient with bilateral left dominant tinnitus. Lidocaine infusion (75 mg during 5 min (0.2 mg/kg/min)) resulted in a 75% reduction of tinnitus and a temporary abolition of the dominant tinnitus in her left ear. Regional CBF was measured in four conditions: i) at rest while concentrating on tinnitus, ii) following maximum effect of lidocaine, iii) during sound stimulation, and iv) the following day at rest while concentrating on tinnitus. Subtraction analyses showed that tinnitus was associated with increased rCBF in the left parieto_temporal auditory cortex, including the primary and secondary auditory cortex with a focus in the parietal cortex (Brodmann areas 39, 41, 42, 21, 22). Activations were also found in right frontal paralimbic areas (Brodmann areas 47, 49 and 15). Sound stimulation resulted in bilateral activation of auditory areas. It is suggested that tinnitus is processed in primary, secondary and integrative auditory cortical areas. Tinnitus perception may involve areas related to auditory attention, while emotional processing relates to temporofrontal paralimbic areas.

Functional brain imaging of tinnitus_like perception induced by aversive auditory stimuli. Mirz F, Gjedde A, Sodkilde_Jrgensen H, Pedersen CB. Department of Otorhinolaryngology, PET_Centre, Aarhus University Hospitals, Denmark. Neuroreport 2000 Feb 28;11(3):633_7

Tinnitus is an aversive auditory percept of unknown origin. We tested the speculation that tinnitus may share neuronal processing mechanisms with aversive auditory percepts of known origin. This study revealed the functional neuroanatomy of the perception of aversive auditory stimuli. The stimuli were presented to 12 healthy volunteers so as to mimic the psychoacoustical features of tinnitus and its affective response in tinnitus sufferers. The regional cerebral blood flow distribution was measured by PET during four auditory processing conditions and one control condition. The aversive auditory stimuli activated primary and secondary auditory areas bilaterally, dorsolateral prefrontal attention areas, and structures in the limbic system which subserve emotional processing. Based on these results and findings from other functional neuroimages of tinnitus, we hypothesize that the perception of tinnitus may involve the functional linkage of these brain areas: secondary auditory cortex, dorsolateral prefrontal cortex, and limbic system.

An auditory negative after_image as a human model of tinnitus. Norena A, Micheyl C, Chery_Croze S. CNRS UMR 5020, Laboratoire 'Neurosciences and Systemes Sensoriels', Hopital Edouard Herriot, Pavillon U, Place d'Arsonval, 69437 Cedex 03, Lyon, France. Hear Res 2000 Nov;149(1_2):24_32

The Zwicker tone (ZT) is an auditory after_image, i.e. a tonal sensation that occurs following the presentation of notched noise. In the present study, the hypothesis that neural lateral inhibition is involved in the generation of this auditory illusion was investigated in humans through differences in perceptual detection thresholds measured following broadband noise, notched noise, and low_pass noise stimulation. The detection thresholds were measured using probe tones at several frequencies, within as well as outside the suppressed frequency range of the notched noise, and below as well as above the corner frequency of the low_pass noise. Thresholds measured after broadband noise using a sequence of four 130_ms probe tones (with a 130_ms inter_burst interval) proved to be significantly smaller that those measured using the same probe tones after notched noise at frequencies falling within the notch, but larger for frequencies on the outer edges of the noise. Thresholds measured following low_pass noise using the same sequence of probe tones were found to be smaller at frequencies slightly above the corner, but larger at lower, neighboring frequencies. This pattern of results is consistent with the hypothesis that the changes in auditory sensitivity induced by stimuli containing sharp spectral contrasts reflect lateral inhibition processes in the auditory system. The potential implications of these findings for the understanding of the mechanisms underlying the generation of auditory illusions like the ZT or tinnitus are discussed.

Effects of chronic salicylate on GABAergic activity in rat inferior colliculus. Bauer CA, Brozoski TJ, Holder TM, Caspary DM. Southern Illinois University School of Medicine, Springfield, IL 62794_9662, USA. cbauer@siumed.edu. Hear Res 2000 Sep;147(1_2):175_82

It is well accepted that salicylate ototoxicity results in reversible tinnitus in humans. Salicylate_induced tinnitus may be an example of plasticity of the central auditory system and could potentially serve as a model to further understand mechanisms of tinnitus generation. This study examined levels of glutamic acid decarboxylase (GAD) and the binding characteristics of the GABA(A) receptor in auditory brainstem structures of Long_Evans rats chronically treated with salicylate. Western blotting revealed a significant 63% (P<0.008) elevation of GAD levels in the inferior colliculus (IC) of salicylate_treated subjects. This occurred in subjects demonstrating behavioral evidence of tinnitus. Muscimol saturation analysis was indicative of a salicylate_related increase in receptor affinity. Linear regression of [(3)H]muscimol saturation analysis data revealed a significant (P<0.05) reduction in K(d) values in whole IC (_48%), as well as in the central nucleus of IC (CIC, _58%) and combined external and dorsal cortex of IC (E/DCIC, _46%). The number of GABA(A) binding sites (B(max)) were also significantly (P<0.05) decreased. These changes were observed only in central auditory structures. This suggests that GAD expression and GABA(A) receptor binding characteristics may be altered with chronic exposure to sodium salicylate and these changes may represent aberrant plasticity clinically experienced as tinnitus.

A biochemical model of peripheral tinnitus(1). Sahley TL, Nodar RH. Hear Res 2001 Feb;152(1_2):43_54

Subjective tinnitus may be defined as the perceptual correlate of altered spontaneous neural activity occurring in the absence of an externally evoking auditory stimulus. Tinnitus can be caused or exacerbated by one or more of five forms of stress. We propose and provide evidence supporting a model that explains, but is not limited to, peripheral (cochlear) tinnitus. In this model, naturally occurring opioid dynorphins are released from lateral efferent axons into the synaptic region beneath the cochlear inner hair cells during stressful episodes. In the presence of dynorphins, the excitatory neurotransmitter glutamate, released by inner hair cells in response to stimuli or (spontaneously) in silence, is enhanced at cochlear N_methyl_D_aspartate (NMDA) receptors. This results in altered neural excitability and/or an altered discharge spectrum in (modiolar_oriented) type I neurons normally characterized by low rates of spontaneous discharge and relatively poor thresholds. It is also possible that chronic exposure to dynorphins leads to auditory neural excitotoxicity via the same receptor mechanism. Finally, the proposed excitatory interactions of dynorphins and glutamate at NMDA receptors need not be restricted to the auditory periphery.

Computer_simulation studies on roles of potassium currents in neurotransmission of the auditory nerve. Lin X, Hant J. Section on Neurobiology, Department of Cell and Molecular Biology, House Ear Institute, 2100 West Third St., 90057, Los Angeles, CA, USA. Hear Res 2001 Feb;152(1_2):90_9

Our previous work showed that action potentials (APs) fired in spiral ganglion (SG) neurons broaden gradually as a result of cumulative inactivation of the potassium current (I(K)), or with the application of a tinnitus_inducing drug (quinine). These results led us to speculate that AP width could affect neurotransmission of the auditory nerve under both normal and pathological conditions. This study used both experimental and theoretical approaches to test this hypothesis. We first measured the effect of AP broadening on Ca(2+) entry into SG neurons. The effect of pre_synaptic AP broadening on post_synaptic responses was then assessed using computer_simulations. Results showed that wider presynaptic APs augmented responses of all types of postsynaptic glutamatergic receptors mainly by amplifying responses of postsynaptic receptors whose locations were not well aligned with the presynaptic release sites. A cumulative inactivation of I(K) in SG neurons significantly enhanced the responses of kainate receptors at all spike rates, while the augmentations for the alpha_amino_3_hydroxy_5_methylisoxazole_4_propionic acid and N_methyl_D_aspartic acid receptors were most prominent below 100 spikes/s. These modeling results suggest that, in addition to the AP firing rate and timing, the width of APs could affect the neurotransmission of the auditory nerve under both normal and pathological conditions.

Effects of acute and chronic hypertension on the labyrinthine barriers in rat. Mosnier I, Teixeira M, Loiseau A, Fernandes I, Sterkers O, Amiel C, Ferrary E. INSERM U.426, Faculte Xavier Bichat, Univesite Paris 7, France. Hear Res 2001 Jan;151(1_2):227_236

Hearing loss, vertigo, and tinnitus have been related to arterial hypertension. The aim of the present work was to study the permeability of the blood_perilymph and of the labyrinthine barrier, between endolymph and perilymph, to small molecules during chronic and acute hypertension. Experiments were performed in normotensive Wistar_Kyoto (WKY) and spontaneously hypertensive rats (SHR). Acute hypertension was induced by phenylephrine. Perilymph was sampled from the first turn of the scala vestibuli and the Na, K, urea, and radioactive concentrations ((14)C_urea and (3)H_mannitol) were measured. In another experimental set, the endocochlear potential was recorded from the basal turn of scala media, before and after phenylephrine injection. The composition of the perilymph and the kinetic constants for (14)C_urea and (3)H_mannitol were similar in WKY and SHR, and not modified after acute hypertension. In endolymph, the endocochlear potential in SHR (+80+/_2.7 mV, n=24) was lower (P<0.001) than in WKY (+98+/_1.5 mV, n=29). The endocochlear potential was decreased by 40 mV during acute hypertensive peak in seven out of 19 WKY but not in SHR rats (n=13). In conclusion, chronic or acute hypertension did not severely alter the permeability to small molecules of the blood_perilymph barrier. The relationship between the low endocochlear potential and hypertension in SHR remains to be evaluated. After acute hypertensive peak, the presence of vascular protective mechanisms in the cochlea could account for the stable endocochlear potential recorded in SHR and 60% of normotensive rats.

Audiometric analysis of a Belgian family linked to the DFNA10 locus. Verstreken M, Declau F, Schatteman I, Van Velzen D, Verhoeven K, Van Camp G, Willems PJ, Kuhweide EW, Verhaert E, D'Haese P, Wuyts FL, Van de Heyning PH. University Department of Otorhinolaryngology, University of Antwerp, Belgium. Am J Otol 2000 Sep;21(5):675_81

OBJECTIVE: To report the otologic and audiometric characteristics of a nonsyndromic postlingual sensorineural hearing impairment in a Belgian family linked to DFNA10. STUDY DESIGN: Retrospective study of the otologic and audiometric data of 17 genetically affected persons. SETTING: Tertiary referral center. PATIENTS: All members of a Belgian kindred who carried the haplotype linked to the inherited hearing impairment of DFNA10. INTERVENTIONS: Diagnostic otologic and audiometric analysis. MAIN OUTCOME MEASURES: Pure_tone audiometry. RESULTS: To find the frequencies that were most affected by the genetic defect, the excess hearing loss of the 17 patients was calculated per frequency in comparison with the respective p50 and p95 thresholds of the normal population. CONCLUSIONS: The genetically affected persons of a Belgian family shared a progressive symmetric sensorineural hearing loss that started in the first to fourth decade. Thirty_five percent of the affected family members had tinnitus, and only one patient had very mild vestibular complaints. At onset, hearing losses were mainly situated at the midfrequencies. With increasing age, all frequencies became affected. The hearing loss was initially mild, with a spontaneous evolution to a moderate or severe hearing impairment. The progression of the hearing loss for the pure_tone average (between 0.5 and 4 kHz) was 1.08 dB/year for this family, compared with 0.50 dB/year and 0.35 dB/year at the 95th and 50th percentiles of the normal population, respectively.

Familial progressive vestibulocochlear dysfunction caused by a COCH mutation (DFNA9). Verhagen WI, Bom SJ, Huygen PL, Fransen E, Van Camp G, Cremers CW. Department of Neurology, Canisius_Wilhelmina Hospital, PO Box 9015, 6500 GS, Nijmegen, The Netherlands. knf@cwz.nl. Arch Neurol 2000 Jul;57(7):1045_7

OBJECTIVE: To describe the decline of vestibulocochlear function in a man with vestibulocochlear dysfunction caused by a Pro51Ser mutation within the COCH gene on chromosome 14q12_13 (DFNA9). METHODS: A follow_up of more than 15 years was performed in a single case. Clinical investigations were supplemented by oculomotor, vestibular, and auditory tests. RESULTS: A 50_year_old man had had progressive sensorineural hearing loss and dysequilibrium for 15 years; he had been asymptomatic at the age of 35 years. He suffered from instability in the dark, head movement_dependent oscillopsia, paroxysmal positional vertigo, and vertigo with and without nausea. Hearing impairment started unilaterally, predominantly in the high frequencies. He also reported tinnitus. Disease progressed to severe bilateral high_frequency hearing impairment and vestibular areflexia. Fluctuation of vestibulocochlear function was documented and mentioned by the patient. CONCLUSIONS: Our patient proved to suffer from an autosomal dominant vestibulocochlear disorder caused by a COCH gene mutation. The remarkable medical history has some features in common with Meniere disease; however, there are also different clinical and neurophysiological features. In the family, phenotypic variability is present.

Serum NGF levels in children and adolescents with either Williams syndrome or Down syndrome. Calamandrei G, Alleva E, Cirulli F, Queyras A, Volterra V, Capirci O, Vicari S, Giannotti A, Turrini P, Aloe L. Laboratorio di Fisiopatologia di Organo e di Sistema, Istituto Superiore di Sanita, Rome, Italy. Dev Med Child Neurol 2000 Nov;42(11):746_50

The neurotrophin nerve growth factor (NGF) is a major regulator of peripheral and central nervous system development. Serum NGF was measured in normally developing control children (n=26) and in individuals affected by congenital syndromes associated with learning disability: either Williams syndrome (WS; n=12) or Down syndrome (DS; n=21). Participants were assessed at three distinct developmental stages: early childhood (2 to 6 years), childhood (8 to 12 years), and adolescence (14 to 20 years). A sample was taken only once from each individual. Serum NGF levels were markedly higher in participants with WS, than DS and control participants. In addition, different developmental profiles emerged in the three groups: while in normally developing individuals NGF levels were higher in early childhood than later on, children with WS showed constantly elevated NGF levels. When compared to control participants, those with DS showed lower NGF levels only during early childhood. Neuropsychological assessment confirmed previously reported differences among the three groups in the development of linguistic/cognitive abilities. Some features of individuals with WS, such as hyperacusis and hypertension, could be related to high_circulating NGF levels.

Spontaneous firing activity of cortical neurons in adult cats with reorganized tonotopic map following pure_tone trauma. Komiya H, Eggermont JJ. Department of Physiology, University of Calgary, Alberta, Canada. Acta Otolaryngol 2000 Sep;120(6):750_6

We hypothesized that moderate sensorineural hearing loss resulting from acoustic trauma would cause (i) a change in the cortical tonotopic map, (ii) an increase in spontaneous activity in the reorganized region and (iii) increased inter_neuronal synchrony within the reorganized part of the cortex. Five kittens were exposed to a 126 dB sound pressure limit tone of 6 kHz for 1 h at both 5 and 6 weeks of age. Recordings were performed 7_16 weeks after the exposure. Auditory brainstem response thresholds for frequencies above 12 kHz were increased by 30 dB on average relative to those in normal cats. Tonotopic maps in the primary auditory cortex were reorganized in such a way that the area normally tuned to frequencies of 10_40 kHz was now entirely tuned to 10 kHz. Spontaneous firing rates were significantly higher in reorganized areas than in normal areas. In order to test for changes in inter_neuronal synchrony, cross_correlation analysis was done on 225 single_unit pairs recorded in the traumatized cats. For the single_ and dual_electrode pairs there was no significant difference in peak cross_correlation coefficients for the firings of simultaneously recorded cells between normal and reorganized areas. However, the percentage of correlations that differed significantly from zero was higher in the reorganized area than in the normal area. This suggests a potential correlation between cortical reorganization, increased spontaneous firing rate and inter_neuronal synchrony that might be related to tinnitus found in high_frequency hearing loss induced by acoustic trauma.

Neurophysiologic mechanisms of tinnitus. Kaltenbach JA. Department of Otolaryngology__Head and Neck Surgery, Wayne State University, Detroit, Michigan 48201, USA. J Am Acad Audiol 2000 Mar;11(3):125_37

Research over the past decade has provided new insights into the neural mechanisms likely to produce the false percepts of sound associated with tinnitus. These insights have emerged mainly as a result of electrophysiologic studies, examining changes in brain activity, and behavioral studies, examining changes in perception, in animals that have been treated with well_known tinnitus inducers such as salicylates, quinine, and intense sound. The available evidence, based on electrophysiologic studies, suggests that tinnitus is associated with disturbances in spontaneous neural activity in the auditory system. These abnormalities include increases in spontaneous activity (hyperactivity), changes in the timing of neural discharges (i.e., the temporal firing properties of neurons), and an increase in bursting activity of neurons. Parallel studies using behavioral testing methods have demonstrated that agents, which produce these neural changes, also cause tinnitus in animals. This article reviews the literature concerned with both behavioral evidence for tinnitus in animal models and the associated changes that occur at peripheral and central levels of the auditory system.

Plasticity of spontaneous neural activity in the dorsal cochlear nucleus after intense sound exposure. Kaltenbach JA, Zhang J, Afman CE. Department of Otolaryngology, 5E_UHC, Wayne. State University, Detroit, MI 48201, USA. jkalten@med.wayne.edu. Hear Res 2000 Sep;147(1_2):282_92

Increases in multiunit spontaneous activity (hyperactivity) can be induced in the dorsal cochlear nucleus (DCN) by intense sound exposure. This hyperactivity has been observed in the hamster and rat following exposure to a 10 kHz tone at a level of 125_130 dB SPL for a period of 4 h. The present study demonstrates that the onset of this hyperactivity is not immediate, but develops in the DCN between 2 and 5 days after exposure. Mean rates of multiunit spontaneous activity increased sharply from below normal levels at day 2 to higher than normal levels at day 5. The mean magnitude of activity continued to increase more gradually over the next 6 months. During this period, changes in the distribution of hyperactivity across the tonotopic array were also noted. The hyperactivity was more broadly distributed across the DCN at the early post_exposure times (5 and 14 days) than at later post_exposure recovery times (30 and 180 days), and peak activity was found at increasingly more medial positions over this time frame. These changes over time indicate that the mechanisms leading to hyperactivity following intense sound exposure are more complex than previously realized.

Hyperactivity in the dorsal cochlear nucleus after intense sound exposure and its resemblance to tone_evoked activity: a physiological model for tinnitus. Kaltenbach JA, Afman CE. Department of Otolaryngology, Wayne State University, 5E_UHC, Detroit, MI 48201, USA. jkalten@med.wayne.edu Hear Res 2000 Feb;140(1_2):165_72

Intense tone exposure induces increased spontaneous activity (hyperactivity) in the dorsal cochlear nucleus (DCN) of hamsters. This increase may represent an important neural correlate of noise_induced tinnitus, a condition in which sound, typically of very high pitch, is perceived in the absence of a corresponding acoustic stimulus. Since high pitch sounds are thought to be represented in central auditory structures by the place of activation across the tonotopic array; it is therefore possible that the high pitch of noise_induced tinnitus occurs because intense sound exposure induces a tonotopic distribution of chronic hyperactivity in the DCN similar to that normally evoked only under conditions of high frequency stimulation. To investigate this possibility we compared this tone_induced hyperactivity with the activity evoked in normal animals by presentation of a tone. This comparison revealed that the activity in the DCN of animals which had been exposed to an intense 10 kHz tone 1 month previously showed a striking similarity to the activity in the DCN of normal animals during presentation of low to moderate level tonal stimuli of the same frequency. In both test conditions similar patterns were seen in the topographic distribution of the increased activity along the tonotopic axis. The magnitude of hyperactivity in exposed animals was similar to the evoked activity in the normal DCN responding to a stimulus at a level of 20 dB SL. These results suggest that the altered DCN following intense tone exposure behaves physiologically as though it is responding to a tone in the absence of a corresponding acoustic stimulus. The relevance of these findings to noise_induced tinnitus and their implications for understanding its underlying mechanisms are discussed.

Clinical Research

Tinnitus in children attract more attention. Kentish et al. data show that tinnitus can have the same impact on children lives as in adults. Notably, children with hearing loss found tinnitus less troublesome that children with normal hearing.

As majority of epidemiological data were gathered in UK, Germany, and Sweden, there is still great need for epidemiological data from various countries. Vallianatou et al., report preliminary data from Greece. Results from Brazil (Pitcher et al.) describe prevalence of sensorineural hearing loss and tinnitus in patients with sickle cell, showing the presence of positive correlation.

The recurrent question of tinnitus treatment with low-intensity laser was addressed in randomized, prospective, double-blind, placebo-controlled trial (Mirz et al.). As in previous well controlled studies, there was no positive effect of laser, and the authors conclude that previous positive reports may be explained by the placebo effect.

There is no consensus on the method to evaluate tinnitus. Two studies were aimed at checking relative validity of various questionnaires. Baguley et al., evaluated correlation of findings from the tinnitus handicap inventory (THI) with tinnitus questionnaire (TQ), and concluded that both questionnaires provide convergent results. Meric et al., studied English and French version of Tinnitus Reaction Questionnaire and concluded that French version is equally valid as English original.

Children's experience of tinnitus: a preliminary survey of children presenting to a psychology department. Kentish RC, Crocker SR, McKenna L. Nuffield Hearing and Speech Centre, Royal National Throat, Nose and Ear Hospital, London, UK. Br J Audiol 2000 Dec;34(6):335_40

Tinnitus has been much researched within adult populations with consideration of prevalence as well as the impact of tinnitus on individual's lives. Although the literature highlights the prevalence of tinnitus in children, there is little information on its effects from a psychological perspective. This small_scale preliminary study looked at 24 children (50% with normal hearing and 50% with a hearing loss) who presented to the Psychology Department with troublesome tinnitus. In line with adult studies, preliminary results suggested that tinnitus can have as marked an effect on children's lives as it is reported to have on adults. Insomnia, emotional distress, listening and attention difficulties are the main psychological factors associated with tinnitus in children. These, in turn, may have an effect upon their school performance. Differences were found between children with normal hearing and those with some degree of hearing loss. Overall, children with normal hearing found tinnitus more troublesome and presented with higher levels of anxiety than those with some level of hearing impairment. The present study suggests that children who complain of tinnitus should be taken seriously. In terms of management, individual intervention packages were found to be useful in alleviating anxiety and other associated factors. Recommendations are made on areas for future research.

Audiologic and psychological profile of Greek patients with tinnitus_Preliminary findings. Vallianatou NG, Christodoulou P, Nestoros JN, Helidonis E. Department of Otorhinolaryngology, Laboratory of Audiology and Neurotology, University Hospital of Heraklion, Crete, Greece. Am J Otolaryngol 2001 Jan_Feb;22(1):33_7

Tinnitus is a common complaint among people who suffer from auditory disorders. Altering the patients' response to tinnitus and the development of coping techniques are the most important goals of the therapeutic or suppression methods. This is the first study in the Greek population to investigate the personality characteristics and coping techniques of tinnitus patients. We have studied the relation between the subjective assessment of tinnitus intensity with factors such as sex, age, duration of symptom, and degree of hearing loss. We have also studied the possible relation between the patients' personality characteristics on their attitude towards tinnitus. The participants were 80 tinnitus sufferers, men and women, between 18 and 65 years of age. The personality characteristics were assessed with the Minnesota Multiphasic Personality Inventory (MMPI). The mean MMPI scores in both men and women were within the normal range. The duration of symptoms did not prove to be an important factor for the patients' subjective assessment of the tinnitus intensity. Most patients showed "effective" coping style, were well adjusted to tinnitus, and had no significant interference in their everyday functioning. The above are discussed in the context of the influence of geographical, climatological, economic, social, and cultural factors that influence psychological functioning.

Sensorineural hearing loss among sickle cell disease patients from southern Brazil. Piltcher. O, Cigana L, Friedriech J, Ribeiro FA, da Costa SS. Hospital de Clinicas de Porto Alegre and the Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo, Brazil. Am J Otolaryngol 2000 Mar_Apr;21(2):75_9

PURPOSE: A case_control study was done to confirm the higher prevalence of sensorineural hearing loss (SNHL) among sickle cell patients (HbSS) from southern Brazil. PATIENTS AND METHODS: Twenty_eight patients and 28 matched normal controls were studied. Besides complete anamneses and physical otolaryngological examination, all individuals had audiometric and tympanometric testings to determine the presence of SNHL or middle ear problems. The only significant difference between groups was the presence of a positive history of otologic symptoms (hearing loss, dizziness or tinnitus) and neurological sequelae in the HbSS patients. RESULTS: Six patients (21.4%) presented with SNHL compared with one control (3.6%) (Fisher's one_tailed P = .05; OR, 7.36 (95% CI, 0.82, 65.83). The average age of HbSS diagnosis was higher among the patients with SNHL (10 years +/_ 8.3) than those without SNHL (5.43 years +/_ 5.65), but this was not significant (analysis of variance P > .05). More patients 25 years and older on the examination date had SNHL than younger patients (Fisher's 2_tailed P < .05). Sixty_seven percent of the patients with SNHL had alterations in the acoustic reflex, and a surprising 27% of the patients without NSHL also presented with some elevation or an absence of acoustic reflex. CONCLUSIONS: These data indicate that patients with HbSS from southern Brazil are more predisposed to the development of sensorineural hearing problems than the general population.

[Treatment of tinnitus with low_intensity laser]. [Article in Danish] Mirz F, Zachariae B, Andersen SE, Nielsen AG, Johansen LV, Bjerring P, Pedersen CB. Arhus Universitetshospital, Arhus Kommunehospital, ore_naese_halsafdeling H. mirz@dadlnet.dk Ugeskr Laeger 2000 Jun 19;162(25):3607_10

This study evaluated the effect of low_power laser in the treatment of tinnitus in a randomized, prospective, double_blind, placebo_controlled trial. The active laser applied 50 mW (cw, 830 nm) over a period of 10 minutes per session. Forty_nine patients were included. The main outcome was measured using psychoacoustical match of tinnitus loudness, Visual Analog Scale (VAS) ratings of subjective loudness, annoyance and attention involved, scores on tinnitus_specific questionnaires, and a number of psychosocial questionnaires. Only few subjects (18%) experienced subjective improvement. There were no statistically significant differences between the effects of the active laser and placebo treatments. CONCLUSION: Low_power laser treatment is not indicated in the treatment of tinnitus. Reports of significant benefits of this treatment in previous studies may be explained by the placebo effect.

Convergent validity of the tinnitus handicap inventory and the tinnitus questionnaire. Baguley DM, Humphriss RL, Hodgson CA. Department of Audiology, Addenbrooke's Hospital, Cambridge, UK. dmb29@cam.ac.uk J Laryngol Otol 2000 Nov;114(11):840_3

For research into tinnitus to be robust and credible, the use of well_validated instruments of self_perceived tinnitus handicap as outcome measures is essential. The tinnitus handicap inventory (THI) and the tinnitus questionnaire (TQ) are two such instruments which are in widespread use. Both questionnaires were administered by mail to 100 consecutive new patients of the Cambridge Tinnitus Clinic, and completed in randomized order. These patients had been referred by the otolaryngology team and had not undergone any tinnitus therapy. The response rate was 78 per cent, neither questionnaire being more acceptable to patients than the other. The convergent validity of the instruments was high, with total and subscale scores all being significantly correlated at the five per cent level (Spearman correlation coefficients). A number of subscale scores were not significantly correlated at the one per cent level however. In particular, the sleep disturbance element of the TQ was demonstrated to have some discriminant validity from the THI and from other elements of the TQ at the one per cent significance level. The THI and TQ have been demonstrated to have high convergent validity and are both suitable for tinnitus outcome studies involving the quantification of self_perceived tinnitus handicap. For research that aims to determine the specific effect of an intervention on tinnitus_related sleep disturbance, the TQ sleep subscale has potential utility. The hypothetical constructs of tinnitus handicap underlying the psychologist_developed TQ and the audiologist_developed THI have been shown to be convergent.

Validation assessment of a French version of the tinnitus reaction questionnaire: a comparison between data from English and French versions. Meric C, Pham E, Chery_Croze S.

UMR CNRS, Lyon, France. J Speech Lang Hear Res 2000 Feb;43(1):184_90

The present study compares the results obtained on original and French versions of the TRQ (Tinnitus Reaction Questionnaire) initially published by Wilson, Henry, Bowen, and Haralambous (1991) in English to evaluate the psychological distress of tinnitus sufferers. Reliability and validity of the French translation were determined using data from 173 normal hearing or hearing_impaired patients with tinnitus lasting from 1 month to 41 years. They completed the translated questionnaire and a short version of the Minnesota Multiphasic Personality Inventory. The results indicated good internal consistency (Cronbach's alpha = .94), and the reliability of the French version of the TRQ was demonstrated, except for items 5 and 20. High statistically significant correlations were found between the TRQ and Depression, Psychaesthenia, and Anxiety Mini_Mult subscales. The validation demonstrates only minor effects of language. The French version of the TRQ thus is an equally valid tool as the original English version for evaluating tinnitus distress of a patient.

Audiology

The variability of repetitive evaluation of tinnitus loudness was proposed as one of method to validate the presence of tinnitus (particularly for legal cases). Jacobson et al. have shown that the underlying this approach assumption of larger variability in people who imagine tinnitus, versus those who actually experience it, is not correct, and consequently study of the variability has no value for proving existence of tinnitus. On the technical side Henry at al., proposed a computerized system for psychoacoustical tinnitus evaluation.

Another paper from Henry & Meikle confirmed one of postulates of the neurophysiological model of tinnitus that neither loudness nor other psychoacoustic measures of tinnitus have a consistent relation to the severity or perceived loudness of tinnitus. On the other hand, Holgers et al., reports that severity of tinnitus, measured by absence from work related to tinnitus, could be related to depression and physical immobility. Fowler et al., relate tinnitus severity to insomia, anxiety and depression, furthermore making analogy to chronic pain.

Effects of unilateral sudden hearing loss were investigated by Chiossoine-Kerdel et al. Tinnitus was found in 67% of cases with handicap present in 57% of subject with tinnitus. Hearing handicap was noted in 86% of patients. Notably, there was no correlation between the extent of audiometric loss and hearing or tinnitus handicap. The authors concluded that handicap in these patients results form both tinnitus and hearing loss.

Interesting occupational hearing loss was reported by Merchant at al., in rickshaw drivers. In addition to heairng loss they were twice as likely to develop tinnitus.

Attempt to detect some features related to tinnitus in DPOAE was reported by Linke et al. Unfortunately, the authors were not able to document any positive findings.

Katzenell & Segal review literature related to hyperacusis, list various medical problems and conditions accompanied by hyperacusis, and suggest dominance of central mechanism.

A re_evaluation of tinnitus reliability testing. Jacobson GP, Henderson JA, McCaslin DL. Division of Audiology, Henry Ford Hospital, Detroit, Michigan 48202, USA. J Am Acad Audiol 2000 Mar;11(3):156_61

The purposes of these investigations were to (1) evaluate tinnitus loudness measures of unskilled normal listeners asked to imagine that they are experiencing a constant monaural tonal tinnitus and (2) compare the performance of these listeners to that of a sample of patients with tinnitus. Subgroups of 24 patients participated in two investigations. Results suggest that (1) normal subjects asked to imagine a high_pitched, tonal tinnitus show significantly greater tinnitus loudness matching levels (a) when they do not have an external reference, (b) after a 1_week interval, and (c) for low_frequency matching tones; (2) patients with high_pitched tinnitus did not demonstrate statistically significant differences in tinnitus loudness judgments within or between sessions or frequencies; (3) tinnitus patients do not differ significantly from normals feigning tinnitus in the variability of tinnitus loudness matching levels within a single session (two measures) or after a 1_week interval (one measure); and (4) normals feigning tinnitus tended to choose significantly greater loudness matching levels than did tinnitus subjects.

Computer_automated clinical technique for tinnitus quantification. Henry JA, Fausti SA, Flick CL, Helt WJ, Ellingson RM. Veterans Affairs RR&D National Center for Rehabilitative Auditory Research, Portland VA Medical Center, OR, USA. henryj@ohsu.edu Am J Audiol 2000 Jun;9(1):36_49

This study addresses the need for uniformity in techniques for clinical quantification of tinnitus. Because automation can be an effective means to achieve standardization, this laboratory is developing techniques to perform computer_automated tinnitus testing. The present study was conducted to demonstrate the feasibility of obtaining reliable tinnitus measures using a fully automated system. A computer_controlled psychoacoustical system was developed to quantify tinnitus loudness and pitch using a tone_matching technique. Hearing thresholds were also obtained as part of the procedure. The system generated test stimuli and simultaneously controlled a notebook computer positioned in the sound chamber facing the patient. The notebook computer displayed instructions for responding and relayed response choices through on_screen "buttons" that the patient touched with a pen device. Twenty individuals with tinnitus were evaluated with the technique over two sessions, and responses were analyzed for test_retest reliability. Analyses revealed good reliability of thresholds, loudness matches, and pitch matches. These results demonstrate that use of a fully automated system to obtain reliable measurements of tinnitus loudness and pitch is feasible for clinical application.

Psychoacoustic measures of tinnitus. Henry JA, Meikle MB. VA RR&D National Center for Rehabilitative Auditory Research, Portland VA Medical Center, Oregon 97207, USA. J Am Acad Audiol 2000 Mar;11(3):138_55

This report reviews research from the 1930s to the present that has extended our understanding by investigating the characteristics of tinnitus that can be studied using psychoacoustic techniques. Studies of tinnitus masking and residual inhibition began in the 1970s, leading to the therapeutic use of tinnitus masking and a consequent increase in research devoted to tinnitus measurement. In 1981, the CIBA Foundation symposium on tinnitus advocated general adoption of four tinnitus measures: (1) pitch, (2) loudness, (3) maskability, and (4) residual inhibition. Since then, psychoacoustic research into all four topics has proliferated, yielding many valuable insights and controversies concerning the details of measurement techniques. A consensus has emerged that neither the loudness nor other psychoacoustic measures of tinnitus bear a consistent relation to the severity or perceived loudness of tinnitus. Nevertheless, quantification is needed in clinical trials of proposed treatments and in a variety of other types of tinnitus research. Standardization of techniques for specifying the acoustic parameters of tinnitus thus continues to be an important research goal.

Predictive factors for the severity of tinnitus Holgers KM, Erlandsson SI, Barrenas ML.

Department of Audiology, Sahlgrenska University Hospital, Goteborg University, Sweden. Audiology 2000 Sep;39(5):284_91

The majority of patients with tinnitus experience a lessening of their symptoms during an 18_month period after their first consultation. The exception to this rule is severe incapacitating tinnitus, the sometimes very troublesome symptoms of which show no sign of diminishing with time. The aim of the present study was to investigate risk factors for incapacitating tinnitus, as measured by absence from work related to tinnitus (AWT) of more than 1 month during an 18_month period after the first visit to the tinnitus clinic. Audiometric data and the scores from the Tinnitus Severity Questionnaire and the Nottingham Health Profile at the first visit to the clinic were correlated to AWT by a logistic regression model. By using this risk model, an individual risk score for AWT could be estimated. Depression and physical immobility were strong predictors of AWT, and hearing loss was moderate. Based on these results, we suggest that the aetiology of tinnitus severity could be described as depression_/anxiety_related, somatic, and auditory tinnitus.

Chronic tinnitus as phantom auditory pain. Folmer RL, Griest SE, Martin WH. Tinnitus Clinic, Oregon Hearing Research Center, Department of Otolaryngology, Oregon Health Sciences University. Otolaryngol Head Neck Surg 2001 Apr;124(4):394_400

OBJECTIVES: To investigate similarities between patients who experience chronic tinnitus or pain and to formulate treatment strategies that are likely to be effective for patients who experience phantom auditory pain. Study design: A total of 160 patients rated the severity and loudness of their tinnitus and completed the State_Trait Anxiety Inventory (STAI) and an abbreviated version of the Beck Depression Inventory (aBDI). Patients received counseling, audiometric testing, and matched the loudness of their tinnitus to sounds played through headphones. SETTING: A specialized tinnitus clinic within an urban medical center. RESULTS: Tinnitus severity was highly correlated with patients' degree of sleep disturbance, STAI, and aBDI scores. The self_rated (on a 1_to_10 scale)_but not the matched_loudness of tinnitus was correlated with tinnitus severity, sleep disturbance, STAI, and aBDI scores. CONCLUSIONS: The severity of chronic tinnitus is correlated with the severity of insomnia, anxiety, and depression. These relationships are the same for many patients with chronic pain. Treatment recommendations are discussed in reference to these results.

An investigation of the audiologic handicap associated with unilateral sudden sensorineural hearing loss. Chiossoine_Kerdel JA, Baguley DM, Stoddart RL, Moffat DA. Department of Otolaryngology, Addenbrooke's Hospital, Cambridge, UK. Am J Otol 2000 Sep;21(5):645_51

OBJECTIVE: To determine the incidence of tinnitus and associated handicap after unilateral sudden sensorineural hearing loss (SSNHL); in addition, to determine the hearing handicap experienced as a consequence of such a loss. STUDY DESIGN: Identification of patients and determination of demographic and audiologic data by retrospective case review; determination of handicap and distress by postal questionnaire. SETTING: Teaching hospital department of otolaryngology. PATIENTS: Thirty_eight patients were identified as having been treated for a unilateral sudden sensorineural hearing loss in the period 1988 through 1997. Of those, 21 (55.3%) replied to the questionnaire. MAIN OUTCOME MEASURES: Audiometric data at admission and at 4_week follow_up, Tinnitus Handicap Inventory (THI), visual analogue scales of tinnitus loudness and distress, Hearing Handicap Inventory in Adults (HHIA). RESULTS: The questionnaire responder group did not significantly differ from the questionnaire nonresponder group on demographic nor audiometric variables, and hence were considered to be a representative sample. Tinnitus was present in 14 patients (67%). Hearing handicap was found in 86% of patients (of the 21 questionnaire responders) and tinnitus handicap in 57% (of the 14 with tinnitus). Correlations were found between tinnitus loudness, distress, and handicap. There was no correlation between time elapsed since SSNHL and tinnitus or hearing handicap, nor was there a correlation between the extent of audiometric loss and hearing or tinnitus handicap. A strong negative correlation was, however, found between recovery in audiometry in the first 4 weeks after onset and tinnitus and hearing handicap. The audiometric status of the contralateral ear correlated with hearing handicap. CONCLUSIONS: A majority of patients after unilateral SSNHL have a perceived handicap associated with tinnitus and hearing. Although this condition is an otologic emergency, careful thought should be given to the audiologic rehabilitation of this patient group.

What is the effect of riskshaw noise on its driver? Merchant AT, Lalani I, Afridi ZH, Latif N, Malik TA, Merchant SS, Momin IA, Moizuddin SS, Motiei A, Motiwala S, Munir A, Sethi AK. Department of Community Health Sciences, Medical College, Aga Khan University, Karachi. J Pak Med Assoc 2000 Apr;50(4):124_8

OBJECTIVE: Occupational hearing loss is common in the industrialized world. Road noise is a major contributor to perceived environmental noise. The objective of this study was to assess hearing loss in rickshaw drivers due to rickshaw noise. METHODS: Hearing loss in rickshaw drivers and taxi drivers of Karachi who were 50 years of age or younger was estimated, with a Smith Hearing Screening (SHS) questionnaire that was modified, translated into the national language, Urdu and field tested prior to administration. RESULTS: Interviews for 91 rickshaw drivers and 94 taxi drivers were completed. All subjects were male; mean ages were 34 and 33 years for rickshaw and taxi drivers respectively. None of the rickshaws were fitted with silencers. Rickshaw drivers were about thrice as likely to be screened as hearing impaired by the SHS questionnaire (RR 2.9, 95% confidence interval 1.6, 5.0), twice as likely to report tinnitus (RR 2.2, 95% confidence interval, 1.1, 3.3) and two and a half times as likely to have difficulty in following telephonic conversations (RR 2.4, 95% confidence interval 1.2, 4.8). CONCLUSION: There is loss of hearing and tinnitus among rickshaw drivers that could be attributed to their trade. Use of silencers by rickshaw drivers could result in less hearing loss among rickshaw drivers and less noise in the environment for the other 11 million residents in the city.

[Distortion products of otoacoustic emissions (DPOAE) in acute tinnitus aurium]. [Article in German] Linke R, Mazurek B, Matschke RG. Hals_Nasen_Ohren_Klinik, Klinikum Schwerin. Laryngorhinootologie 2000 Sep;79(9):517_22

BACKGROUND: The origin of subjective tinnitus is not really known yet. It is possible to investigate the function of outer hair cells by means of the distortion products of otoacoustic emissions (DPOAE). METHODS: DPOAE of 56 patients were analysed in a prospective study (tinnitus without any loss of hearing n = 34; hearing loss with a maximum of 35 dB and tinnitus n = 22). There was always a normal tympanogram and in no case a conductive hearing loss. The relation of the primary tones f2/f1 was 1.22, the levels of the primary tones were 70 dB. RESULTS: DPOAE_amplitudes were reduced distinctly in both groups of patients. But there was no general difference and no difference at the frequency of tinnitus between the ear with tinnitus and the contralateral ear (no hearing loss) or there was a small reduction related to the normal ear (distinct hearing loss). DPOAE_amplitudes did not change in patients without hearing loss after a treatment with Pentoxifylline i.v., also not at the frequency of tinnitus, although there was a subjective reduction of tinnitus. In patients with hearing loss DPOAE_amplitudes enhanced like the improvement of hearing threshold at the frequency of tinnitus. CONCLUSIONS: The low DPOAE_amplitudes are a sign of damaged outer hair cells of the patients. But there is a symmetry of the DPOAE_amplitudes and there is no change of DPOAE after a therapy with Pentoxifylline i.v. in patients without hearing loss.

Hyperacusis: review and clinical guidelines. Katzenell U, Segal S. Department of Otolaryngology, Wolfson Medical Center, Holon, Israel. katzudi@zahav.net.il Otol Neurotol 2001 May;22(3):321_6; discussion 326_7

OBJECTIVE: To review the current known causes of hyperacusis and the different hypotheses concerning its etiology, and to suggest clinical guidelines. DATA SOURCE: A review of the literature with the aid of the MEDLINE database, using the following key words: hyperacusis, intolerance to sound, loudness discomfort level, and phonophobia. DATA EXTRACTION: The data collected included clinical studies, case reports and laboratory studies. CONCLUSION: Hyperacusis was shown to be caused by pathologic conditions of the peripheral auditory system, diseases of the central nervous system diseases, and hormonal and infectious diseases. In some cases there was no known cause. The pathophysiology of hyperacusis probably involves a central mechanism rather than a peripheral one. Suggested clinical guidelines and treatment are discussed.

Habituation based therapies

Two contrasting papers were published recently; one representing group of German psychologist strongly criticizing TRT, and the other by PJ & MM Jastreboff providing outline of the present status of the method. Future will show if “German concept” or TRT survive the test of time.

[An assessment of tinnitus retraining therapy]. [Article in German] von Wedel H, von Wedel UC. Abteilung fur Audiologie und Padaudiologie, Klinik und Poliklinik fur Hals_, Nasen_ und Ohrenheilkunde der Universitat zu Koln, Joseph Stelzmann_Strasse 9, 50924 Koln. hasso.von.wedel@uni_koeln.de HNO 2000 Dec;48(12):887_901

Based on the neurophysiological model of tinnitus developed by Jastreboff and Hazell [39] there have been some important developments in understanding and therapy of tinnitus over the last decade. The clinical applications of this model are known as "tinnitus retraining therapy", which has the objective of reducing both the distress associated with tinnitus and the tinnitus perception itself. As a form of systematic, repeated and skilled counselling over a long period of up to 2 years supported by sound therapy (hearing aid or noise generator) the evidence for their high degree of effectiveness is overwhelming. On the basis of a "German concept" of tinnitus retraining therapy developed and proposed by the ADANO (Arbeitsgemeinschaft deutschsprachiger Audiologen und Neurootologen) the current status of this treatment will be briefly reviewed including some actual studies of Goebel et al. [14] that confirm the world wide critical comments on the recent developments in the management of tinnitus especially with regard to tinnitus retraining therapy [79].

Tinnitus Retraining Therapy (TRT) as a method for treatment of tinnitus and hyperacusis patients. Jastreboff PJ, Jastreboff MM. Tinnitus and Hyperacusis Center, Department of Otolaryngology, Emory University School of Medicine, Atlanta, Georgia 30322, USA. J Am Acad Audiol 2000 Mar;11(3):162_77

The aim of this paper is to provide information about the neurophysiologic model of tinnitus and Tinnitus Retraining Therapy (TRT). With this overview of the model and therapy, professionals may discern with this basic foundation of knowledge whether they wish to pursue learning and subsequently implement TRT in their practice. This paper provides an overview only and is insufficient for the implementation of TRT.

Pharmacology

Treating tinnitus with medications attract would be very welcome, however so far none of the drugs pass the test of offering clear help without profound side effects. A case report presents potential beneficial effect of gabapentin (Zapp) while detailed, well controlled study dispose with hope of effectiveness of Ginkgo biloba (Drew & Davies).

The list of drug reported to have tinnitus as a side effect is long. Valproate is reported to induce tinnitus which disappear after discontinuation of the drug which indicates potential causal relation (Reeves et al.). This finding is of interest as the drug is used for treatment of bipolar disorder, which would make tinnitus treatment more complex.

So far no medications were reported to be effective for hyperacusis. A case study (Gopat et al.) suggest potential for use of selective serotonin reuptake inhibitors, which are cominly used as antidepressant. While typical hyperacusis is relatively easy treated and cured with TRT, it is more difficult when hyperacusis is accompanied by hypersensitivity in other sensory modalities. Therefore, if this finding is confirmed by double blind study, this would be of clear interest.

Gabapentin for the treatment of tinnitus: a case report. Zapp JJ. Pain Institute of Northeast Florida, 2021 Kingsley Ave., Suite 102, Orange Park, FL 32073, USA. Ear Nose Throat J 2001 Feb;80(2):114_6

The objective of this article is to discuss the clinically effective use of gabapentin in patients with tinnitus. The author describes the case of a man who came to the office complaining of tinnitus of 10 months' duration. The patient was started on gabapentin and maintained on a regimen of 500 mg/day in divided doses. Subsequently, he reported that he was free of tinnitus approximately 23 days a month and that he experienced a 75% decrease in symptoms during the remaining days. At 2 years' follow_up, he remains noise_ and pain_free on 500 mg/day of gabapentin.

Effectiveness of Ginkgo biloba in treating tinnitus: double blind, placebo controlled trial. Drew S, Davies E. Pharmacology Department, Division of Neuroscience, University of Birmingham, Birmingham B15 2TT, UK. s.j.drew@bham.ac.uk BMJ 2001 Jan 13;322(7278):73

OBJECTIVE: To determine whether Ginkgo biloba is effective in treating tinnitus. DESIGN: Double blind, placebo controlled trial using postal questionnaires. PARTICIPANTS: 1121 healthy people aged between 18 and 70 years with tinnitus that was comparatively stable; 978 participants were matched (489 pairs). Intervention: 12 weeks' treatment with either 50 mg Ginkgo biloba extract LI 1370 three times daily or placebo. MAIN OUTCOME MEASURES: Participants' assessment of tinnitus before, during, and after treatment. Questionnaires included items assessing perception of how loud and how troublesome tinnitus was. Changes in loudness were rated on a six point scale. Changes in how troublesome were rated on a five point scale. RESULTS: There were no significant differences in primary or secondary outcome measures between the groups. 34 of 360 participants receiving active treatment reported that their tinnitus was less troublesome after 12 weeks of treatment compared with 35 of 360 participants who took placebo. CONCLUSIONS: 50 mg Ginkgo biloba extract LI 1370 given 3 times daily for 12 weeks is no more effective than placebo in treating tinnitus.

Valproate_induced tinnitus misinterpreted as psychotic symptoms. Reeves RR, Mustain DW, Pendarvis JE. Department of Psychiatry, Montgomery VA Medical Center, USA. South Med J 2000 Oct;93(10):1030_1

Valproate sodium is an anticonvulsant medication, which has also been shown to be effective in the treatment of bipolar disorder. We report a case of valproate_induced tinnitus that was initially misinterpreted as increasing psychotic symptoms, which began approximately 2 days after initiation of valproate therapy. Tinnitus worsened during the next 6 days of treatment until it was recognized that this symptom was related to valproate. After discontinuance of the medication, the tinnitus gradually resolved over a period of 10 days with no residual effects. Although it is a rare adverse effect, valproate_induced tinnitus should be included in the differential diagnosis for tinnitus in patients receiving this medication. Tinnitus may be difficult to recognize in patients with active psychosis or mania.

Effects of selective serotonin reuptake inhibitors on auditory processing: case study. Gopal KV, Daly DM, Daniloff RG, Pennartz L. Department of Speech and Hearing Sciences, University of North Texas, Denton 76203, USA. J Am Acad Audiol 2000 Sep;11(8):454_63

Auditory sensitivity and processing ability were evaluated in a patient who suffered from hyperacusis, difficulty understanding speech, withdrawn depression, lethargy, and hypersensitivity to touch, pressure, and light. Treatment with fluvoxamine and fluoxetine (selective serotonin reuptake inhibitors) reversibly alleviated complaints. Testing while medicated and unmedicated (after voluntary withdrawal from medication for several weeks) revealed no difference in pure_tone thresholds, speech thresholds, word recognition scores, tympanograms, or acoustic reflex thresholds. Medicated SCAN_A (a screening test for central auditory processing disorders) results were normal, and unmedicated results were abnormal. Unmedicated transient otoacoustic emissions and auditory brainstem response waves I, III, and V were significantly larger bilaterally. Uncomfortable loudness levels indicated greater tolerance during the medicated condition. Central processing and vigilance were evaluated with analog_synthesized three_formant consonant_vowel syllables. While medicated, responses to stimuli at each ear revealed well_defined, labeling crossovers of about 90 msec. Vowel identification matched normal subject responses; labeling of /gE/jE/ and /bE/wE/ continua was well defined but all crossover points differed from normals (p < .0001). During unmedicated testing, responses to /gE/jE/ began at medicated levels but approached chance levels for the entire continuum within 10 min; labeling of /bE/wE/ was consistent with medicated responses throughout with earlier than normal crossover points.

Medical approaches

Large variety of papers addressed medical issues related to tinnitus. Another modification for treating Ménière’s disease is presented. Several issues related to vestibular neuroma such as its prevalence, confirming other reports that tinnitus occurs less often with increasing tumor size (Heerma et al.), and recommendation of a conservative management of unilateral vestibular schwannomas which coming from the group of Dr. Ugo Fisch has a special meaning (Tschudi et al.). Potential causes of tinnitus, from perilymphatic fistula to lighting and car air bags explosion are presented. Various source of somatosounds are reported as well. These papers mainly confirm and expand previous findings.

Effects of exposing the opened endolymphatic sac to large doses of steroids to treat intractable Meniere's disease. Kitahara T, Takeda N, Mishiro Y, Saika T, Fukushima M, Okumura S, Kubo T. Department of Otolaryngology, Osaka Rosai Hospital, Sakai, Japan. Ann Otol Rhinol Laryngol 2001 Feb;110(2):109_12

To enhance the effect of treatment for intractable Meniere's disease, we exposed the opened endolymphatic sac to high concentrations of steroids. This technique__endolymphatic sac drainage and steroid instillation surgery__involves the application of a mass of prednisolone followed by absorbable gelatin sponges soaked in a high concentration of dexamethasone into a sac lumen opened and expanded with a bundle of absorbable gelatin film. These sponges are also placed around the sac and coated with biochemical adhesive so that the medicine is slowly delivered into the sac over a prolonged period of time by means of a natural sustained_release vehicle. The short_term results (6 to 14 months) in 12 patients with Meniere's disease, including those in stage IV, treated by the above techniques showed that definitive spells were completely controlled in all cases. Hearing was improved, and annoyance due to tinnitus was decreased in all cases except one.

Clinical picture of vestibular schwannoma. Kentala E, Pyykko I I. Department of Otolaryngology, Helsinki University Central Hospital, PO Box 220, 00029 HYKS, Helsinki, Finland. Auris Nasus Larynx 2001 Jan;28(1):15_22

Purpose: To characterize the clinical picture with vestibular schwannoma, we retrieved 122 patients with vestibular schwannoma from the vestibular unit of the Helsinki University Central Hospital. Procedures: The patients filled out a questionnaire concerning their symptoms, earlier diseases, accidents, and the use of tobacco and alcohol. This information was then completed with results of audiometric, neurotologic and imaging studies. The data were prospectively stored to the database of neurotologic expert system called ONE. Results: The average tumor size was 21 mm. Most of the patients had hearing loss (94%) and tinnitus (83%) but only half of them (49%) had vertigo attacks. The most common initial symptom was hearing loss combined with tinnitus (34%, n=44). Vertigo only was the initial symptom for 12 patients. The mean duration of a vertigo attack was from 5 min to 4 h and the intensity of the attack was regularly mild (37%) or moderate (32%). The vertigo of the vestibular schwannoma patients differed from vertigo in other diseases by the absence (63%) or low intensity (18%) of nausea. Spontaneous nystagmus was present in 56 patients (46%), and caloric asymmetry (>25%) was observed in 66% (n=69). Caloric asymmetry increased with tumor size. The prevalence of headache was 18% (n=21). Sudden slips seldom (7%) occurred. Conclusion: Hearing loss and tinnitus are the main symptoms of vestibular schwannoma. Only half of patients have vertigo. Screening to detect vestibular schwannoma is more yielding in sudden deafness patients rather than in patients with Meniere's disease.

Immediate neurological deterioration after gamma knife radiosurgery for acoustic neuroma. Case report. Tago M, Terahara A, Nakagawa K, Aoki Y, Ohtomo K, Shin M, Kurita H. Department of Radiology, University of Tokyo Hospital, Japan. TAGO_RAD@h.u_tokyo.ac.jp J Neurosurg 2000 Dec;93 Suppl 3:78_81

The authors describe acute deterioration in facial and acoustic neuropathies following radiosurgery for acoustic neuromas. In May 1995, a 26_year_old man, who had no evidence of neurofibromatosis Type 2, was treated with gamma knife radiosurgery (GKS; maximum dose 20 Gy and margin dose 14 Gy) for a right_sided intracanalicular acoustic tumor. Two days after the treatment, he developed headache, vomiting, right_sided facial weakness, tinnitus, and right hearing loss. There was a deterioration of facial nerve function and hearing function from pretreatment values. The facial function worsened from House_Brackmann Grade 1 to 3. Hearing deteriorated from Grade 1 to 5. Magnetic resonance (MR) images, obtained at the same time revealed an obvious decrease in contrast enhancement of the tumor without any change in tumor size or peritumoral edema. Facial nerve function improved gradually and increased to House_Brackmann Grade 2 by 8 months post_GKS. The tumor has been unchanged in size for 5 years, and facial nerve function has also been maintained at Grade 2 with unchanged deafness. This is the first detailed report of immediate facial neuropathy after GKS for acoustic neuroma and MR imaging revealing early possibly toxic changes. Potential explanations for this phenomenon are presented.

Conservative management of unilateral acoustic neuromas. Tschudi DC, Linder TE, Fisch U. Department of Otolaryngology, University Hospital of Zurich, Switzerland. Am J Otol 2000 Sep;21(5):722_8

OBJECTIVE: The aim of this study was to analyze the natural course of unilateral acoustic neuromas and to evaluate the advantages and disadvantages of an initial conservative approach. METHODS: Between 1989 and 1994, 74 consecutive patients with the diagnosis of unilateral acoustic neuroma were evaluated at the Department of Otorhinolaryngology, University of Zurich. Their charts and magnetic resonance imaging scans were retrospectively analyzed regarding duration and type of symptoms, initial tumor size, tumor growth pattern, and audiometric data. RESULTS: Of the 74 tumors, 68.9% (51/74) did not grow during a mean follow_up of 35 months. Eight (16%) of these tumors had radiologically documented tumor regression. Twenty_three tumors did grow, 16 of them (70%) with a growth rate of <2 mm/year. There was a statistically significant correlation between the first_year and the total growth rate, indicating that the tumor's behavior in the first year is highly predictive of its subsequent growth pattern. Patients with progressive hearing loss as a first symptom had a significantly lower tumor growth than those presenting with tinnitus, sudden hearing loss, or dizziness. Patients with tumor growth showed a greater tendency for hearing loss, although this trend was significant only for isolated frequencies. In 12% of the cases (9/74), the initial conservative approach had to be abandoned in favor of surgery. CONCLUSION: Watchful expectation can be regarded as a safe approach for selected cases of acoustic neuromas. Surgery or irradiation is indicated in patients with proven growth of their tumors.

[Effect of microneurosurgical operation in acoustic neurinoma on symptoms of vertigo and tinnitus]. [Article in German] Heerma H, Braun V, Richter HP. Neurochirurgische Klinik, Universitat Ulm. HNO 2000 May;48(5):372_7

After exstirpation of an acoustic neuroma one trends to concentrated on the preservation of hearing and facial function. But how does the surgical removal for an acoustic neuroma, influence the symptoms of tinnitus and vertigo? Our report follows a retrospective evaluation of 78 patients. Based on these results we will also discuss aspects of the origin of these symptoms. Our patients suffered from tinnitus at a rate of 73% preoperatively and 59% postoperatively. With increasing tumor size tinnitus occurred less often, therefore we considered the size of the tumor exclusively. Also, an intraoperative dissection of the cochlear nerve often did not result in an improvement of the symptoms. Vertigo was stated prooperatively in 44% of the cases, postoperatively in 22%. Again as with tinnitus, there was an inverse relationship between the size of the tumor and the severity of the symptoms. In conclusion a deafferention_like syndrome has to be considered as the major causative factor for the tinnitus in patients with acoustic neuromas. However, in the vertigo cases, the symptoms seem to be caused vestibularily due to the increasing tumor and then after a temporary compensation a cerebellar ataxia occurred which the patients often perceive as vertigo.

Perilymph fistula _ 45 case analysis. Goto F, Ogawa K, Kunihiro T, Kurashima K, Kobayashi H, Kanzaki J. Department of Otolaryngology, School of Medicine, Keio University, Tokyo, Japan. Auris Nasus Larynx 2001 Jan;28(1):29_33

Purpose of the study: Though perilymph fistula (PLF) is not a rare disease, preoperative diagnosis still remains to be established. Some new diagnostic methods are challenging, but there is still no established diagnostic method except exploratory tympanotomy that verifies the occurrence of leakage. Early diagnosis of PLF is fully depending on history taking and some clinical examinations. To know the clinical features of PLF is one of the greatest helps to make both earlier and accurate diagnosis. In spite of some innovations in clinical examinations classic diagnostic procedure is thought to be still reliable. Procedures: We investigated the clinical symptoms, basic tests results and therapeutic results in patients with PLF. Results: From 1983 to 1998 PLF was identified in 44 patients (45 ears) with exploratory tympanotomies in our hospital. With respect to clinical history the predisposing factors such as blowing the nose, lifting heavy goods, and landing in an airplane were found in almost half of the patients, while the rest of them had no clear inducing factors. Their major symptoms included hearing loss (93%), vertigo and dizziness (91%), tinnitus (76%), and aural fullness (31%). The patients who have a clear predisposing factor tended to make diagnosis easily; on the other hand the rest of the patients who do not have clear etiology had some diagnostic difficulty. Subjective positive fistula signs were observed in 71% of patients. Vestibular symptoms improved in 80% of patients after closure of PLF. Conclusions: These results suggest that the variety of clinical manifestation make diagnosis more difficult. At the moment meticulous clinical history taking and close follow_up applying repeating fistula tests are the most important for not only earlier but also accurate diagnosis.

[Ear dysfunction due to air bag detonation]? [Article in German] Brehmer D, Geidel O, Hesse G, Laubert A. Universitats_HNO_Klinik Witten/Herdecke, St. Marien_Hospital, Katholisches Krankenhaus Hagen gGmbH. HNO 2000 Oct;48(10):768_72

Air bags are among the latest developments in extensive automobile safety systems. They successfully have saved the lives of car occupants in road accidents. Many additional injuries caused by air bags from minor to severe have been reported. With the help of two acceleration sensors, the electronic tuner amplifier records the vehicle's deceleration. This is the adequate trigger for air bag deployment, which creates an intense noise of up to 170 dB sound pressure level. This noise level can cause cochlear damage. We present two patients with otologic symptoms after spontaneous air bag deployment.

[Bilateral acoustic trauma after air bag inflation]. [Article in German] Fahimi_Weber S, Kessler A, Bakkal E, Siegert R. Klinik fur Hals_Nasen_Ohren_Heilkunde, Kopf_ und Hals_Chirurgie, Prosper Hospital Recklinghausen. s.fahmi_weber@ruhr_uni_bochum.de HNO 2000 Oct;48(10):765_7

Airbag inflation is associated with a loud noise. This very short noise has a peak amplitude of 170 dB sound pressure level and can make otologic injuries. We report a case of acoustic trauma after airbag inflation. The 24_year_old man has hearing loss both side in the 3000_ to 6000_Hz range and in the deep_frequency. The possibility of acoustic trauma from airbag noise are probably much more common and need more attention in the clinic.

Syndrome of cerebral spinal fluid hypovolemia: clinical and imaging features and outcome. Chung SJ, Kim JS, Lee MC. Department of Neurology, University of Ulsan, Asan Medical Center, Seoul, South Korea. Neurology 2000 Nov 14;55(9):1321_7

OBJECTIVE: To investigate clinical, MRI, and radioisotope findings and therapeutic outcome of the syndrome of CSF hypovolemia. METHODS: Retrospective review was performed of 30 consecutive patients (10 men, 20 women; mean age 37 years) with the syndrome of CSF hypovolemia. RESULTS: All patients had an orthostatic headache, which was alleviated to a variable extent on recumbency. Additional clinical symptoms included nausea, dizziness, neck stiffness, blurring of vision, tinnitus, plugged ear, hearing difficulties and radicular pain of the arm. Eighty_two percent of the patients had CSF opening pressure less than 60 mm H2O, 59% had CSF pleocytosis, and 95% had increased CSF protein. Brain MRI showed diffuse pachymeningeal gadolinium enhancement on T1_weighted image in 83%, which was seen as hyperintense signals on T2_weighted imaging. Other features included subdural hematoma/hygroma in 17% and descent of the brain in 48% of the patients. Radioisotope cisternographic results identified CSF leakage sites in 52%, most often at the lumbar region. Also observed were limited ascent of the tracer to the cerebral convexity (91%), early appearance of radioisotope in the bladder (65%), and early soft tissue uptake of radioisotope (43%). Epidural blood patches were performed in 23 patients, which produced complete resolution of headaches in 70%. Two patients underwent drainage of subdural hematoma. None died or were disabled during hospitalization. CONCLUSIONS: Patients with CSF hypovolemia frequently have distinct MRI and radioisotope cisternographic abnormalities and often respond favorably to an epidural blood patch.

Role of angiography in the evaluation of patients with pulsatile tinnitus. Shin EJ, Lalwani AK, Dowd CF. Department of Otolaryngology__Head and Neck Surgery, University of California, San Francisco, USA. Laryngoscope 2000 Nov;110(11):1916_20

OBJECTIVES/HYPOTHESIS: Pulsatile tinnitus in the face of normal findings on otoscopy is a common otological diagnostic dilemma and can be due to serious vascular malformations such as transverse or sigmoid sinus dural arteriovenous fistula (transverse or sigmoid sinus [TS] DAVF). Left untreated, TS DAVF may result in significant morbidity and mortality. TS DAVF can be suspected or diagnosed with computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance angiography (MRA), with the gold standard being angiography. Our objective was to assess the utility of these various diagnostic modalities in the diagnosis of dural arteriovenous fistula. STUDY DESIGN: Retrospective clinical review. METHODS: Between 1986 and 1996, 54 patients were evaluated and treated for TS DAVF. Between 1996 and 1999, an additional 33 patients underwent MRI combined with MRA for the evaluation of pulsatile tinnitus. A retrospective review of the medical records for both groups, with special attention to clinical presentation, diagnostic evaluation, therapy, and outcome, was performed. RESULTS: All patients had pulsatile tinnitus with normal findings on otoscopy. CT scan was relatively insensitive in the detection of TS DAVF. MRI and MR/MRA were significantly more sensitive than CT. In the evaluation of patients with subjective pulsatile tinnitus, MRI/MRA defined anatomical abnormalities that may contribute to pulsatile tinnitus in 63% of patients. CONCLUSIONS: In the absence of objective pulsatile tinnitus, MRI/MRA is an appropriate initial diagnostic step. When a patient has an objective bruit, the clinician may choose to proceed directly to angiography to make certain that a TS DAVF is not missed.

Trigeminal neuralgia due to an acoustic neuroma in the cerebellopontine angle. Matsuka Y, Fort ET, Merrill RL. Division of Oral Biology and Medicine, UCLA School of Dentistry, Los Angeles, California, USA. J Orofac Pain 2000 Spring;14(2):147_51

This case report first reviews the intracranial tumors associated with symptoms of trigeminal neuralgia (TN). Among patients with TN_like symptoms, 6 to 16% are variously reported to have intracranial tumors. The most common cerebellopontine angle (CPA) tumor to cause TN_like symptoms is a benign tumor called an acoustic neuroma. The reported clinical symptoms of the acoustic neuroma are hearing deficits (60 to 97%), tinnitus (50 to 66%), vestibular disturbances (46 to 59%), numbness or tingling in the face (33%), headache (19 to 29%), dizziness (23%), facial paresis (17%), and trigeminal nerve disturbances (hypesthesia, paresthesia, and neuralgia) (12 to 45%). Magnetic resonance imaging with gadolinium enhancement or computed tomography with contrast media are each reported to have excellent abilities to detect intracranial tumors (92 to 93%). This article then reports a rare case of a young female patient who was mistakenly diagnosed and treated for a temporomandibular disorder but was subsequently found to have an acoustic neuroma located in the CPA.

Pulsatile tinnitus in patients with morbid obesity: the effectiveness of weight reduction surgery. Michaelides EM, Sismanis A, Sugerman HJ, Felton WL 3^rd. Department of Otolaryngology/Head Neck Surgery, Medical College of Virginia of Virginia Commonwealth University, Richmond 23298, USA. Am J Otol 2000 Sep;21(5):682_5

BACKGROUND: Morbid obesity is increasing in the United States population. Morbidly obese patients may have disabling pulsatile tinnitus (PT) secondary to pseudotumor cerebri syndrome and often seek treatment from otolaryngologists because of this symptom. OBJECTIVE: To determine the effectiveness of weight reduction surgery (WRS) for relief of PT in patients with morbid obesity. STUDY DESIGN: Retrospective study of morbidly obese patients with associated PT. SETTING: Academic tertiary referral center. PATIENTS: Sixteen women with morbid obesity and associated PT who underwent WRS. RESULTS: Median age was 34 years (range 24_45 years). Average preoperative body mass index was 45 kg/m2 (range 33_70 kg/m2). Average weight loss was 45+/_17 kg (range 25_99 kg). Average postoperative weight was 75+/_14 kg (range 57_105 kg). The average preoperative cerebrospinal fluid pressure was 344+/_103 mm H2O (range 220_520 mm H2O). Postoperative measurements of cerebrospinal fluid, obtained on 4 patients, revealed an average decrease in pressure of 198 mm H2O (range 120_400 mm H2O). Thirteen patients experienced complete resolution of their PT (81%). Three patients continued to have PT despite significant weight reduction. CONCLUSIONS: Weight reduction surgery was effective in relieving PT in morbidly obese patients with associated pseudotumor cerebri syndrome and should be considered when conservative management has failed.

Middle_ear myoclonus. Zipfel TE, Kaza SR, Greene JS. Department of Otolaryngology_Head and Neck Surgery, Penn State Geisinger Medical Center, USA. J Laryngol Otol 2000 Mar;114(3):207_9

Tinnitus produced by repetitive contraction of the middle_ear muscles is a rare condition. We present an interesting case of bilateral middle_ear myoclonus causing incapacitating tinnitus in a patient with multiple sclerosis. Otological examination demonstrated rhythmic involuntary movement of the tympanic membrane. These movements correlated with a rhythmic 'rushing wind' noise perceived by the patient. Oropharyngeal examination showed no evidence of palatal myoclonus. Impedance audiometry confirmed rhythmic change in the middle_ear volume. Medical management was unsuccessful. The patient's tinnitus was subsequently cured with bilateral sectioning of the tensor tympani and stapedial tendons.

Bilateral defects of the tegmen tympani associated with brain and dural prolapse in a patient with pulsatile tinnitus. Kale SU, Pfleiderer AG, Cradwick JC. Department of Otolaryngology, Edith Cavell Hospital, Peterborough, UK. J Laryngol Otol 2000 Nov;114(11):861_3

A pulsating ear drum is a rare otological finding and usually indicates a vascular pathology. We report the case of a woman who presented with pulsatile tinnitus following an upper respiratory tract infection. She was found to have bilateral pulsating tympanic membranes on otological examination, in association with bilateral dehiscence of the tegmen tympani and a spontaneous encephalocele on the right side and a meningocele on the left side, demonstrated on computerized tomography (CT) scan of her temporal bones.

Intratympanic and systemic dexamethasone for Meniere's disease. Hirvonen TP, Peltomaa M, Ylikoski J. Department of Otorhinolaryngology, Helsinki University Central Hospital, Helsinki, Finland. timo.hirvonen@huch.fi ORL J Otorhinolaryngol Relat Spec 2000 May_Jun;62(3):117_20

Intratympanic and systemic dexamethasone treatment of Meniere's disease (MD) was evaluated in a prospective study. Seventeen patients (6 men and 11 women) with MD (5 right_sided, 11 left_sided and 1 bilateral) were treated with three 0.2_ to 0.4_ml injections of intratympanic dexamethasone hyaluronate (16 mg/ml) during a week and with an initial intramuscular dexamethasone injection of 15 mg. Most of patients were in stage 3, and the mean duration of MD was 5. 3 years. Pure_tone and speech audiometry and the symptom scale of the patients were followed up for 1 year after the treatment. Symptoms of aural fullness, hearing loss, tinnitus and vertigo did not improve significantly. However, sufficient control of vertigo was achieved in 76% of the patients. In conclusion, no definite treatment effect has yet been shown for intratympanic and systemic dexamethasone treatment. Therefore, the clinical use of dexamethasone in MD needs further investigation. Copyright 2000 S. Karger AG, Basel

Impairments, disabilities, and handicaps after acoustic neuroma surgery. Bateman N, Nikolopoulos TP, Robinson K, O'Donoghue GM. Department of Otorhinolaryngology/Head and Neck Surgery, University Hospital, Queen's Medical Centre, Nottingham, UK. Clin Otolaryngol 2000 Feb;25(1):62_5

The measurement of a patient's health_related quality of life following acoustic neuroma surgery is important because the surgery itself can impose significant symptoms postoperatively. This study describes the most common problems experienced by the patients, using an open_ended questionnaire mailed to a series of 70 patients who had undergone acoustic neuroma surgery. Patient responses were classified by impairment, disability and handicap, according to the World Health Organization (WHO) classification. Results showed that this group of patients had a wide variety of symptoms and concerns, and particularly highlighted the relative importance of visual (49% of the patients) and psychosocial problems (34% of the patients) associated with surgery in contrast to tinnitus that seemed to be of minor importance. Open_ended questionnaires are useful in assessing outcomes from a quality of life perspective.

Ear injuries caused by lightning: report of 18 cases. Gluncic I, Roje Z, Gluncic V, Poljak K. Department of Otorhinolaryngology, University Hospital Split, Croatia. J Laryngol Otol 2001 Jan;115(1):4_8

The clinical management and long_term outcome in lightning survivors with substantial ear damage treated at the Department of Otorhinolaryngology, University Hospital Split during the 1984_1999 period are reviewed. Results of clinical management and outcomes of lightning ear damage in 18 patients (mean age 35.3 +/_ 5 years) were retrospectively analyzed. On admission, all patients complained of severe pain, tinnitus and hearing impairment. Otomicroscopy revealed tympanic membrane rupture in 12 patients. The active therapeutic approach included immediate otomicroscopy, aseptic aspiration toilet, and eversion of perforation edges. In all patients, the ruptures healed well, and restitution of the hearing function was achieved. Follow_up examination performed in 1999 (13.2 +/_ 2.9 years later) in 11 patients (mean age 52.3 +/_ 6.1 years) revealed an almost identical audiogram as on discharge from the hospital, however, neuropsychological testing revealed numerous sequelae. Tympanic injury caused by lightning should be actively treated. Lightning survivors require additional psychotherapeutic treatment.

Aneurysm of a dural sigmoid sinus: a novel vascular cause of pulsatile tinnitus. Houdart E, Chapot R, Merland JJ. Department of Neuroradiology and Therapeutic Angiography, Hopital Lariboisiere, Paris, France. Ann Neurol 2000 Oct;48(4):669_71

We report a newly evidenced cause of venous pulsatile tinnitus__the aneurysm of a dural sigmoid sinus. A 33_year_old patient presented with an incapacitating pulsatile tinnitus of 6 months' duration in the left ear. The radiological workup evidenced an aneurysm of the left sigmoid sinus. Selective endovascular coil occlusion of the aneurysm was followed by complete resolution of the tinnitus.

Palatal myoclonus: report of two cases. Fabiani G, Teive HA, Sa D, Kay CK, Scola RH, Martins M, Werneck LC. Hospital de Clinicas, Universidade Federal do Parana, Curitiba, Brazil. giorgiof@osite.com.br Arq Neuropsiquiatr 2000 Sep;58(3B):901_4

We describe two cases of palatal myoclonus (PM), one essential and another secondary to a stroke. Case 1: a 64 years old female who developed clicking sounds in both ears after a stroke and three years later on noticed a progressive involuntary movement of the throat associated with rhythmic contractions of the soft palate, muscles of tongue and throat. MRI showed an ischemic area in brainstem. The patient had a partial response to the use of sumatriptan 6 mg subcutaneously. Case 2: a 66 years old female who began with ear clicking at left ear that worsed slowly associated with tinnitus and arrhythmic movements of soft palate and an audible click at left ear. Brain MRI was normal; audiometry showed bilateral neurosensory loss. She was prescribed clonazepan 1 mg daily with complete recovery. Primary and secondary palatal myoclonus share the same clinical features but probably have different pathophysiological underlying mechanisms.

Psychology

Erlandson & Hallberg published interesting study correlating quolity of life with number of variables. While several of them were predictable on the base of common sense (feeling depressed, negative attitudes, etc.) unrespectably, fluctuation in tinnitus, vertigo and headache did not contributed significantly to decrease of life quality. Note, that even listed 6 variables explain only 65% of the variance. While this is statistically significant the possibility that other important factors were omitted need to be considered.

Possibility that tinnitus patients have impaired cognitive performance was explored by Andersson et al. The results indicate that this indeed might be a case, however, due to methodology of the study, there is a possibility that hearing loss, and not tinnitus, is responsible for the results.

Another study by Andersson et al. assess long term follow-up of tinnitus complaints in patients seen by a psychologist. The interesting findings was that tinnitus maskability could be used as a prognostic factor of future annoyance. As maskability is not a factor in case of TRT treatment, this difference might be helpful in better understanding differences of mechanisms involved in psychological treatments versus TRT.

Prediction of quality of life in patients with tinnitus. Erlandsson SI, Hallberg LR. Department of Psychology, University of Goteborg, Sweden. Soly.Erlandsson@htu.se Br J Audiol 2000 Feb;34(1):11_20

According to epidemiological studies of tinnitus prevalence, 0.5_1% of respondents report that tinnitus severely affects their ability to lead a normal life. In the present investigation quality of life and its association with tinnitus_related factors: psychological, psychosomatic and audiological, was studied based on a sample of 122 patients, who attended the hearing clinic for distress due to tinnitus. A stepwise regression analysis was performed with quality of life as a dependent variable. Six of 13 variables included in the model proved to be significant regressors and to explain 65% of the variance. The six predictor variables were: impaired concentration, feeling depressed, perceived negative attitudes, hypersensitivity to sounds, average hearing level (best ear) and tinnitus duration (the shorter the duration of tinnitus the more negative impact on quality of life). The three most significant predictors were directly related to perceived psychological distress and explained most of the variance in quality of life in tinnitus patients included in this study. An unexpected finding was that fluctuations in tinnitus, vertigo, headache or perceived social support did not prove to belong to the significant regressors. The results are discussed in view of the construct of quality of life, depressive cognitions and social support in general, as well as in tinnitus_specific life circumstances.

Tinnitus and cognitive interference: a stroop paradigm study. Andersson G, Eriksson J, Lundh LG, Lyttkens L. Department of Psychology, Uppsala University, Sweden. gerhard.andersson@psyk.uu.se J Speech Lang Hear Res 2000 Oct;43(5):1168_73

The aim of this study was to investigate cognitive interference caused by tinnitus by means of a modified version of the Stroop color_word test. In a mixed_design study, the performances of tinnitus patients (n = 23) and healthy controls with normal hearing (n = 23) were compared on three versions of the Stroop test: the original version, a modified version including physical_threat words, and a tinnitus version for which tinnitus words (descriptors of tinnitus; e.g., peep) were derived empirically. Matched control conditions (words) were included for all three versions, yielding a total of six screens that were presented on a computer. Participants in the control group were matched with the patients for age and gender. Main dependent measures were performance on the Stroop tests in terms of total time for completing each test. Also included were the Tinnitus Questionnaire (TQ), the Beck Depression Inventory (BDI), the state version of the Spielberger Trait State Anxiety Inventory (STAI_S), and a subtest from the Wechsler Adult Intelligence Scale measuring verbal ability. Results showed that tinnitus patients performed significantly slower on all six test conditions. The classical Stroop color_word interference was replicated in both groups. Also, an effect for physical_threat words was found for both groups. Our expected tinnitus word interference could not be established. Patients scored significantly higher than controls on the BDI and the STAI, but these measures did not correlate with the Stroop results. In conclusion, the results indicate that tinnitus patients have impaired cognitive performance overall, as measured by these variations of the Stroop paradigm, but hearing impairment cannot be excluded as a possible confounder.

Longitudinal Follow_up of Tinnitus Complaints. Andersson G, Vretblad P, Larsen HC, Lyttkens L

Department of Psychology, Uppsala University, Box 1225, SE_751 42 Uppsala, Sweden. Gerhard.Andersson@ psyk.uu.se Arch Otolaryngol Head Neck Surg 2001 Feb;127(2):175_179

OBJECTIVE: To investigate the long_term outcome of patients with tinnitus, the long_term effects of cognitive behavioral therapy, and what properties of tinnitus predict distress at follow_up. DESIGN: A longitudinal follow_up of a consecutive sample of patients with tinnitus initially seen by a clinical psychologist. SETTING: Department of Audiology, University Hospital, Uppsala, Sweden. PARTICIPANTS: A consecutive series of 189 patients with tinnitus treated between January 1988 and March 1995 were sent a postal questionnaire booklet. One hundred forty_six (77 women and 69 men) provided usable responses, in all yielding a 77% response rate. MAIN OUTCOME MEASURES: A questionnaire was derived from a structured interview "Questions About Your Tinnitus." Also included were the Tinnitus Reaction Questionnaire and tinnitus_matching data. RESULTS: Questionnaire data showed that many patients with tinnitus still experienced distress an average of 4.9 years after admission. Tolerance of tinnitus increased over time overall. For patients who had received cognitive behavioral therapy (59%), there was a reduction in tinnitus_related distress. Further, an open_ended question showed that the benefits from treatment outnumbered the deficits. Multiple regression analysis showed that tinnitus maskability at admission was a significant predictor of distress at follow_up. CONCLUSIONS: Severe tinnitus shows some signs of improvement over time, especially when psychological treatment has been given. Tinnitus maskability is an important prognostic factor of future tinnitus annoyance.