Tinnitus Type Research Articles

Effects of tinnitus retraining therapy on patients with tinnitus: a systematic review of randomized controlled trials.

This review aims to explore the influences of tinnitus retraining therapy (TRT) on patients with tinnitus. PubMed, MEDLINE, EMBASE, CINAHL, PEDro, SCOPUS, and Web of Science were screened for randomized controlled trials (RCTs) that explored the effects of TRT on patients with tinnitus from inception to June 30, 2024. The methodological quality of the included RCTs was evaluated using the physiotherapy evidence database (PEDro) scale. Fifteen studies met our eligibility criteria. A total of 2069 patients with tinnitus (mean age 52.93years; 66% male) were involved in the present review. The quality of the selected studies ranged from 5 to 8 on the PEDro scale, with a median score of 7. TRT did not provide superior effects in treating patients with tinnitus compared to tinnitus masking (TM), tinnitus educational counselling (TED), TRT with open ear hearing aids, Tailor-made notched music training (TMNMT), partial TRT, usual care, and smart TRT. TRT intervention is considered a treatment option for patients with tinnitus. Combining TRT with other interventions, such as cognitive-behavioral therapy, pharmacotherapy, or tDS, may show even greater efficacy. Additional studies are strongly required to recognize the long-term effects of TRT on tinnitus, determine who most likely would benefit from the intervention regarding tinnitus type and severity, and identify the optimal treatment protocol.

Speech intelligibility deterioration for normal hearing and hearing impaired patients with different types of tinnitus

ObjectivesMany tinnitus subjects report problems with communication, in particular, difficulties with the intelligibility of speech when it is presented in the background of noise. The type of tinnitus (tone-like, noise, etc.), its location and range in the frequency domain, and the type and degree of accompanying hearing loss can affect speech intelligibility in noise in different ways. The main purpose of this study was to determine the effects of tinnitus and degree of hearing loss on the intelligibility of speech when it is presented in a background noise. MethodsA group of 128 patients participated in the study. There were persons with tinnitus and sensorineural hearing loss as well persons with tinnitus without hearing loss. All participants were patients of the Laryngological Centre of Rehabilitation, Medical University in Poznań. The age of patients ranged from 31 to 84 years. An additional group of 10 subjects (24–50 years) with normal hearing and without tinnitus took part in this study as a control group. An initial experiment was concerned with the determination of the tinnitus type. A band of noise of different widths (Q-factor, goodness), with varying centre frequency (f) was used to match the perceived tinnitus type. The Q factor is the ratio of the centre frequency to the noise bandwidth. In the main experiment, the Speech Reception Threshold (SRT) was measured using The Polish Sentence Test (PST). In this test, short sentences were presented in a background of a so-called babble-noise reflecting the averaged spectrum of Polish speech. Resultsamong the different types of signal used by patients to match their tinnitus, the ones most often used were broadband noise in the medium frequency range (BM) and tone-like high-frequency noise (TH). The average Speech Reception Threshold (SRT) for tinnitus patients with normal hearing was 3 dB higher than that for the control group. The highest deterioration in speech intelligibility was observed for broadband tinnitus, located in the mid-frequency band (1.5–5 kHz). ConclusionsTinnitus patients with normal hearing threshold have significantly higher speech reception thresholds (SRT, on average by 3 dB) than normally hearing subjects (control group, without tinnitus), when the speech is presented in a background of babble-noise. Patients with flat audiograms had SRT values on average about 2.5 dB lower than patients with sloping type audiograms (with greater loss at higher frequencies). On average patients in the age group up to 60 years had 4 dB higher SRT values than the control group, and in the older group of patients (above 61 years) - values were 5 dB higher than in the control group. A significant effect of tinnitus located in the medium and high frequency band on the increase of SRT was noted in normally hearing patients and also in patients with mild hearing loss. For higher degrees of hearing loss, the factor that determines the deterioration of speech intelligibility is the hearing loss (moderate and severe), not tinnitus.

Associação do zumbido e a hipertensão arterial sistêmica autorreferida: estudo retrospectivo

ABSTRACT Purpose To describe data on hearing loss, systemic arterial hypertension and tinnitus of individuals, and to verify the association between self-reported systemic arterial hypertension and tinnitus, as well as to correlate other variables present in the sample: hearing loss and tinnitus, age and tinnitus and age and systemic arterial hypertension. Methods Quantitative, descriptive and inferential, retrospective research with data collection from 473 medical records of adults and elderly people treated between 2008 and 2018. Selected were information on age, gender, result of pure tone audiometry, tinnitus, tinnitus type and frequency, presence of SAH and use of medication to control the disease. Results No association was found between systemic arterial hypertension and tinnitus or between hearing loss and tinnitus and between age and tinnitus, however, an association was observed between age and systemic arterial hypertension using the Chi - Square test. The most common type of tinnitus was wheezing and most individuals who reported feeling more than one type of tinnitus were hypertensive. Conclusion The results found and the literature suggest that systemic arterial hypertension may be an additional factor or an aggravating factor of preexisting factors in the generation of tinnitus, but not the primary cause.

Association of tinnitus and self-reported systemic arterial hypertension: a retrospective study.

To describe data on hearing loss, systemic arterial hypertension and tinnitus of individuals, and to verify the association between self-reported systemic arterial hypertension and tinnitus, as well as to correlate other variables present in the sample: hearing loss and tinnitus, age and tinnitus and age and systemic arterial hypertension. Quantitative, descriptive and inferential, retrospective research with data collection from 473 medical records of adults and elderly people treated between 2008 and 2018. Selected were information on age, gender, result of pure tone audiometry, tinnitus, tinnitus type and frequency, presence of SAH and use of medication to control the disease. No association was found between systemic arterial hypertension and tinnitus or between hearing loss and tinnitus and between age and tinnitus, however, an association was observed between age and systemic arterial hypertension using the Chi - Square test. The most common type of tinnitus was wheezing and most individuals who reported feeling more than one type of tinnitus were hypertensive. The results found and the literature suggest that systemic arterial hypertension may be an additional factor or an aggravating factor of preexisting factors in the generation of tinnitus, but not the primary cause.

Repetitive Transcranial Magnetic Stimulation for Tinnitus Treatment in Vestibular Schwannoma: A Pilot Study.

Background: Vestibular schwannomas (VS) are brain tumors affecting the vestibulocochlear nerve. Thus, VS patients suffer from tinnitus (TN). While the pathophysiology is mainly unclear, there is an increasing interest in repetitive transcranial magnetic stimulation (rTMS) for TN treatment. However, the results have been divergent. In addition to the methodological aspects, the heterogeneity of the patients might affect the outcome. Yet, there is no study evaluating rTMS exclusively in VS-associated tinnitus. Thus, the present pilot study evaluates low-frequency rTMS to the right dorsolateral pre-frontal cortex (DLPFC) in a VS-associated tinnitus.Methods: This prospective pilot study enrolled nine patients with a monoaural VS-associated tinnitus ipsilateral to the tumor. Patients were treated with a 10-day rTMS regime (1 Hz, 100% RMT, 1,200 pulses, right DLPFC). The primary endpoint of the study was the reduction of TN distress (according to the Tinnitus Handicap Inventory, THI). The secondary endpoint was a reduction of TN intensity (according to the Tinnitus Matching Test, TMT) and the evaluation of factors predicting tinnitus outcome (i.e., hearing impairment, TN duration, type of tinnitus).Results: No complications or side effects occurred. There was one drop-out due to a non-responsiveness of the complaint. There was a significant acute effect of rTMS on the THI and TMT. However, there was no significant long-term effect after 4 weeks. While the THI failed to detect any clinically relevant acute effect of rTMS in 56% of the patients, TMT revealed a reduction of TN intensity for more than 20 in 89% and for more than 50 in 56% of the patients. Notably, the acute effect of rTMS was influenced by the TN type and duration. In general, patients with a tonal TN and shorter TN duration showed a better response to the rTMS therapy.Conclusion: The present pilot study is the first one to exclusively evaluate the effect of low-frequency rTMS to the right DLPFC in a VS-associated tinnitus. Our results prove the feasibility and the efficacy of rTMS in this patient cohort. There is a significant acute but a limited long-term effect. In addition, there is evidence that patients with a tonal tinnitus and shorter tinnitus duration might have the strongest benefit. A larger, randomized controlled study is necessary to prove these initial findings.

Differences in Clinical Characteristics and Brain Activity between Patients with Low- and High-Frequency Tinnitus.

This study was aimed at delineating and comparing differences in clinical characteristics and brain activity between patients with low- and high-frequency tinnitus (LFT and HFT, respectively) using high-density electroencephalography (EEG). This study enrolled 3217 patients with subjective tinnitus who were divided into LFT (frequency < 4000 Hz) and HFT (≥4000 Hz) groups. Data regarding medical history, Tinnitus Handicap Inventory, tinnitus matching, and hearing threshold were collected from all patients. Twenty tinnitus patients and 20 volunteers were subjected to 256-channel EEG, and neurophysiological differences were evaluated using standardized low-resolution brain electromagnetic tomography (sLORETA) source-localized EEG recordings. Significant differences in sex (p < 0.001), age (p = 0.022), laterality (p < 0.001), intensity (p < 0.001), tinnitus type (p < 0.001), persistent tinnitus (p = 0.04), average threshold (p < 0.001), and hearing loss (p = 0.028) were observed between LFT and HFT groups. The tinnitus pitch only appeared to be correlated with the threshold of the worst hearing loss in the HFT group. Compared with the controls, the LFT group exhibited increased gamma power (p < 0.05), predominantly in the posterior cingulate cortex (PCC, BA31), whereas the HFT group had significantly decreased alpha1 power (p < 0.05) in the angular gyrus (BA39) and auditory association cortex (BA22). Higher gamma linear connectivity between right BA39 and right BA41 was observed in the HFT group relative to controls (t = 3.637, p = 0.027). Significant changes associated with increased gamma in the LFT group and decreased alpha1 in the HFT group indicate that tinnitus pitch is crucial for matching between the tinnitus and control groups. Differences of band frequency energy in brain activity levels may contribute to the clinical characteristics and internal tinnitus “spectrum” differences.

Therapeutic Effect of Electrical Stimulation on Chronic Tinnitus: A Double Blind Randomized Controlled Trial

Chronic tinnitus is a disturbing condition that may affect different aspects of life. In this study, the therapeutic effect of electrical stimulation on chronic tinnitus was assessed. This was a clinical trial on 49 patients with persistent tinnitus for more than 6 months without a proper response to routine treatments. They were randomly allocated into two groups: the case group was treated with electrical stimulation for 6 sessions over 6 consecutive days, and the control group received a placebo. Before the intervention, one week and three months after the treatment sessions, patients were evaluated by comprehensive audiological assessments and hearing tests. The mean age of the participants was 40.37±9.32 and 41.35±9.24 in treatment and placebo groups, respectively. Tinnitus intensity was significantly decreased in the case group one week and three months after the treatment (P&lt;0.05). Tinnitus handicap inventory score significantly decreased in the treatment group one week and three months after the treatment (P&lt;0.05). There was no significant difference in tinnitus intensity after treatment, considering gender, age, tinnitus duration, and tinnitus type. Electrical stimulation could significantly reduce the severity of the tinnitus regardless of age, gender, duration, and type of tinnitus. © 2020 Tehran University of Medical Sciences. All rights reserved. Acta Med Iran 2020;58(1):4-8.

Analysis of the effect and influencing factors of customized sound on tinnitus

Objective:To explore the effect and influencing factors of customized sound on tinnitus. Method:303 patients with tinnitus who received customized sound therapy for 6 months were enrolled in this study. Tinnitus handicap inventory (THI) was used to evaluate the treatment effect before treatment, 1 month, 2 months, 3 months, 4 months, 5 months and 6 months after treatment, and the influencing factors of sound treatment effect were analyzed. Result:The THI score decreased at the 1, 2, 3, 4, 5 and 6 months after treatment (P<0.01), compared with that before treatment. Gender, tinnitus type and presence or absence of voice allergy had no effect on THI score before treatment and 6 months after treatment (P>0.05). Conclusion:Customized sound therapy can reduce the score of THI in tinnitus patients, which supports that sound therapy can reduce the negative impact and disturbances produced by tinnitus, and its curative effect is not affected by gender, tinnitus type and presence or absence of voice allergy..

Tinnitus: A Stepchild in Our Specialty

Many patients are not satisfied with their doctor's answer when they complain about tinnitus. The proposed classification can be used to communicate with patients as well as guide future research. Type A itemizes the treatable causes of tinnitus. Type B itemizes tinnitus with a lack of medical explanation. Type C tinnitus is caused by diagnosable and treatable conditions, as listed in tinnitus type A, but the tinnitus persists after the successful treatment of the other symptoms.

Cochlear implantation as a long-term treatment for ipsilateral incapacitating tinnitus in subjects with unilateral hearing loss up to 10 years

IntroductionThe authors previously demonstrated that tinnitus resulting from unilateral hearing loss (UHL) can be treated with electrical stimulation via a Cochlear Implant (CI). The study aimed to do a long-term (LT) evaluation of CI in subjects suffering from UHL and accompanied incapacitating tinnitus up to 10 years. The primary focus of the study is on LT tinnitus reduction. SubjectsLT evaluation was derived from 23 subjects suffering from UHL and accompanied incapacitating tinnitus (Pre-operative Tinnitus Loudness Visual Analogue Scale (VAS) score >6/10). They were cochlear implanted at a median age of 55 years (22–71 yr) and had 8 years (3–10 yr) experience with their CI at the LT testing. The subjects were categorized into two groups: a Single-Sided Deaf Group (SSD) and an Asymmetric Hearing Loss Group (AHL). The SSD group comprises subjects with contralateral normal hearing (i.e. air conduction pure tone average (PTA0.5, 1, 2 and 4 kHz) ≤ 30 dB HL) and the AHL group subjects with contralateral mild to moderate hearing loss (i.e. air conduction PTA0.5, 1, 2 and 4 kHz > 30 dB HL). MethodsIn order to obtain a LT structural overview of the CI use in UHL subjects, a structured interview was conducted including questions about daily amount of CI use, residual inhibition of the tinnitus after switch off, tinnitus type, etc. The VAStinnitus loudness and the Tinnitus Questionnaire were obtained pre-operatively, one, three, six, 12, and 36-months post-operatively and at the long-term test interval (8 (3–10 years) post-operative). The Hyperacusis Questionnaire was administered in the CION and the CIOFF condition. ResultsThe structural interview revealed that all patients (23/23) still wear their CI seven days a week, eight (3–10) years after cochlear implantation. It appeared that in all subjects but one CI switch-on is the first act when rising and CI switch-off is the last act before bedtime. In the SSD group, tinnitus suppression is still the primary benefit reported (83%), whereas in the AHL the majority of the subjects (55%) report that the primary benefit shifted to improved hearing. In the majority of the subjects the tinnitus reduction starts within 1 min (in 70% of the cases) and the residual inhibition after CI switch-off is less than a minute (in 65% of the cases). The VAS and TQ scores significantly improved up to three months after the first-fitting and remain stable up to the LT test interval. The median score on the Hyperacusis Questionnaire was 17 (7–36) in the CIOFF condition and improved to 23,5 (12–39) in the CION condition in the SSD group. ConclusionThis is the first study to report on LT results in a large number of UHL CI users, up to 10 years. Structured interviews shows that 100% of the subjects wears their CI seven days a week. The tinnitus reduces significantly up to three months after the first-fitting and the tinnitus reduction remain stable up to the LT test interval. The SSD group report tinnitus reduction as the primary benefit, whereas the majority of the AHL group report improved hearing as the primary benefit, eight (3–10) years after implantation. In addition to the tinnitus reduction, the CI provides also a benefit regarding reported.

Tinnitus

Patients visiting the department of Otorhinolaryngology-Head and Neck Surgery often recite tinnitus as the primary complaint. Frequently, tinnitus is accompanied by other symptoms such as hyperacusis and hearing loss. The present study is a cross-sectional study analyzing the relationships between tinnitus, hearing loss, and hyperacusis by the use of the audiologic measurements performed in a clinical practice. All patients visiting the Otorhinolaryngology-Head and Neck Surgery department of the University Hospital Antwerp with complaints of tinnitus (sometimes accompanied by hyperacusis) during the year of 2012, were looked up (n = 588). All patients underwent audiometry and filled out the Tinnitus Questionnaire (TQ) and Hyperacusis Questionnaire (HQ), and tinnitus analysis was performed. The relationships between all measurements were examined by use of correlations, multinomial logistic regression analyses, and descriptive statistics. Scores on the TQ and HQ were significantly positively correlated (r = 0.5, p < 0.001). In general, patients with a combination of tinnitus and hyperacusis showed significantly higher TQ scores (p < 0.001) and higher ratings on the VAS for loudness and distress (p < 0.001) compared with tinnitus patients without hyperacusis. Furthermore, an age-dependent influence on the audiometric configuration and tinnitus type was found. Tinnitus and hyperacusis are two frequent symptoms recited at a consultation. The present study found that patients with a high TQ grade more often also perceive hyperacusis compared with patients with a low TQ grade. Tinnitus and hyperacusis are two frequent symptoms recited at a consultation. We have to point out that also other issues, such as additional health problems and stress, may influence tinnitus severity. In addition, tinnitus type seems to be age dependent as younger patients more often experience a pure tone tinnitus and older patients more often experience a noise-like tinnitus.

The auditory and non-auditory brain areas involved in tinnitus. An emergent property of multiple parallel overlapping subnetworks

Tinnitus is the perception of a sound in the absence of an external sound source. It is characterized by sensory components such as the perceived loudness, the lateralization, the tinnitus type (pure tone, noise-like) and associated emotional components, such as distress and mood changes. Source localization of quantitative electroencephalography (qEEG) data demonstrate the involvement of auditory brain areas as well as several non-auditory brain areas such as the anterior cingulate cortex (dorsal and subgenual), auditory cortex (primary and secondary), dorsal lateral prefrontal cortex, insula, supplementary motor area, orbitofrontal cortex (including the inferior frontal gyrus), parahippocampus, posterior cingulate cortex and the precuneus, in different aspects of tinnitus. Explaining these non-auditory brain areas as constituents of separable subnetworks, each reflecting a specific aspect of the tinnitus percept increases the explanatory power of the non-auditory brain areas involvement in tinnitus. Thus, the unified percept of tinnitus can be considered an emergent property of multiple parallel dynamically changing and partially overlapping subnetworks, each with a specific spontaneous oscillatory pattern and functional connectivity signature.

The Distressed Brain: A Group Blind Source Separation Analysis on Tinnitus

BackgroundTinnitus, the perception of a sound without an external sound source, can lead to variable amounts of distress.MethodologyIn a group of tinnitus patients with variable amounts of tinnitus related distress, as measured by the Tinnitus Questionnaire (TQ), an electroencephalography (EEG) is performed, evaluating the patients' resting state electrical brain activity. This resting state electrical activity is compared with a control group and between patients with low (N = 30) and high distress (N = 25). The groups are homogeneous for tinnitus type, tinnitus duration or tinnitus laterality. A group blind source separation (BSS) analysis is performed using a large normative sample (N = 84), generating seven normative components to which high and low tinnitus patients are compared. A correlation analysis of the obtained normative components' relative power and distress is performed. Furthermore, the functional connectivity as reflected by lagged phase synchronization is analyzed between the brain areas defined by the components. Finally, a group BSS analysis on the Tinnitus group as a whole is performed.ConclusionsTinnitus can be characterized by at least four BSS components, two of which are posterior cingulate based, one based on the subgenual anterior cingulate and one based on the parahippocampus. Only the subgenual component correlates with distress. When performed on a normative sample, group BSS reveals that distress is characterized by two anterior cingulate based components. Spectral analysis of these components demonstrates that distress in tinnitus is related to alpha and beta changes in a network consisting of the subgenual anterior cingulate cortex extending to the pregenual and dorsal anterior cingulate cortex as well as the ventromedial prefrontal cortex/orbitofrontal cortex, insula, and parahippocampus. This network overlaps partially with brain areas implicated in distress in patients suffering from pain, functional somatic syndromes and posttraumatic stress disorder, and might therefore represent a specific distress network.

Cochlear implantation as a durable tinnitus treatment in single-sided deafness

IntroductionSevere tinnitus can seriously impair patients in their activities in daily life and reduce their quality of life. The aims of this prospective clinical study were to assess the long-term effects of cochlear implantation (CI) on tinnitus in patients with single-sided deafness and ipsilateral incapacitating tinnitus, and to investigate whether CI could treat various types of tinnitus.Materials and methodsTwenty-six subjects with unilateral severe-to-profound sensorineural hearing loss received a CI. Patients suffered from severe tinnitus greater than 6/10 on a visual analogue scale (VAS) due to unilateral deafness. Assessment consisted of a tinnitus analysis including determination of tinnitus type, frequency, and loudness. A tinnitus questionnaire (TQ) measured tinnitus distress. VAS and TQ were administered pre-implantation and post-implantation.ResultsAll 26 patients reported a subjective benefit from CI. Tinnitus loudness reduced significantly after CI from 8.6 to 2.2 on the VAS (scale: 0–10). The TQ total score decreased significantly and the mean tinnitus degree decreased from severe to mild. No differences were observed between patients with pure-tone tinnitus, narrow band noise tinnitus, or polyphonic tinnitus. The degree of tinnitus loudness reduction remained stable after CI.ConclusionsCI can successfully be used as treatment of severe tinnitus in patients with single-sided deafness and is equally effective for pure tone, narrow band noise, and polyphonic tinnitus. Long-term results show that implantation provides durable tinnitus relief in these patients. These results support the hypothesis that physiopathological mechanisms after peripheral deafferentation are reversible when hearing is restored. Single-sided deafness accompanied by severe tinnitus is a new indication for CI.

Burst transcranial magnetic stimulation: which tinnitus characteristics influence the amount of transient tinnitus suppression?

Transcranial Magnetic Stimulation (TMS) is a method capable of temporarily suppressing tinnitus by delivering tonic or burst stimuli. Burst TMS has a high interindividual variability and low effect size. Tinnitus type and laterality, tinnitus-related distress, and tinnitus duration might contribute to this large individual variation. The effect of burst TMS on the auditory cortex in 100 male individuals is evaluated with coil placed over the auditory cortex. For unilateral tinnitus, this coil was placed contralaterally to the tinnitus, whilst for bilateral tinnitus the coil was placed over the right auditory cortex. The site of maximal tinnitus suppression is determined using 1-Hz stimulation with five pulses per burst (intensity of the stimulation set at 90% of the motor threshold). When tinnitus suppression is noted, the patients are asked to estimate the decrease in tinnitus in percentage using the numeric rating scale. The procedure is repeated with stimulations at 5, 10 and 20 Hz, each stimulation session consisting of 200 pulses. Results demonstrate that burst stimulation can decrease the perceived tinnitus intensity transiently in 57.83% of the patients. Patients with bilateral tinnitus respond better to burst TMS than patients with unilateral tinnitus and highly distressed patients presenting with unilateral pure tone tinnitus fail to bust TMS. Burst TMS modulates both unilateral and bilateral tinnitus, both high and low distress and both pure tones and narrow band tinnitus. However, the suppression effect is moderated by tinnitus type and laterality, tinnitus-related distress, and tinnitus duration.

Bilateral dorsolateral prefrontal cortex modulation for tinnitus by transcranial direct current stimulation: a preliminary clinical study

Tinnitus is considered as an auditory phantom percept. Preliminary evidence indicates that transcranial direct current stimulation (tDCS) of the temporo-parietal area might reduce tinnitus. tDCS studies of the prefrontal cortex have been successful in reducing depression, impulsiveness and pain. Recently, it was shown that the prefrontal cortex is important for the integration of sensory and emotional aspects of tinnitus. As such, frontal tDCS might suppress tinnitus as well. In an open label study, a total of 478 tinnitus patients received bilateral tDCS on dorsolateral prefrontal cortex (448 patients anode right, cathode left and 30 anode left, cathode right) for 20 min. Treatment effects were assessed with visual analogue scale for tinnitus intensity and distress. No tinnitus-suppressing effect was found for tDCS with left anode and right cathode. Analyses show that tDCS with right anode and left cathode modulates tinnitus perception in 29.9% of the tinnitus patients. For these responders a significant reduction was found for both tinnitus-related distress and tinnitus intensity. In addition, the amount of suppression for tinnitus-related distress is moderated by an interaction between tinnitus type and tinnitus laterality. This was, however, not the case for tinnitus intensity. Our study supports the involvement of the prefrontal cortex in the pathophysiology of tinnitus.

Amygdalohippocampal involvement in tinnitus and auditory memory

Conclusion: The preliminary results suggest that in chronic unilateral tinnitus the contralateral amygdalohippocampal complex does seem to be involved in tinnitus perception of pure tones. Objectives: Functional neuroimaging studies have revealed that the hippocampus and amygdala are involved in tinnitus perception. The amygdala and hippocampus are supplied by the anterior choroidal artery. Selective amobarbital injections in the anterior choroidal artery result in a non-functional amygdalohippocampal area for 10 min. The aim of this study was to assess the influence of this procedure on tinnitus perception. Patients and methods: Amobarbital (80 mg in total) was injected selectively in two sessions in the left and right anterior choroidal artery in six male patients with tinnitus: four with unilateral tinnitus, two with bilateral tinnitus. Of the patients with unilateral tinnitus, three had right-sided tinnitus and one had left-sided tinnitus. The average age was 57.3 years (range 43–69). Average tinnitus duration was 5.3 years (range 1–10). The differences in visual analogue scale (VAS) scores before and after the amytal tests were analysed. Results: Amytal injection ipsilateral to the side where the tinnitus was perceived resulted in a maximum of 30% tinnitus suppression, whereas amytal injection contralateral to the tinnitus side yielded a 60–70% tinnitus suppression in three patients with unilateral chronic tinnitus (>4 years). Only pure tone tinnitus was suppressed, white noise was not. Two patients with bilateral tinnitus had no suppression, irrespective of the tinnitus type. A third patient without clinical tinnitus suppression had tinnitus of more recent origin (1.5 years).

Towards an objectification by classification of tinnitus

Objectives: The objectives of this study are to identify the presence of tinnitus and classify its different forms, in terms of changes in noise.Methods: Late auditory evoked responses (LAERs) were recorded from Fz in response to 1000 Hz tone bursts of various intensities, in 13 tinnitus-free subjects and in 25 tinnitus sufferers (16 bilateral and 9 unilateral tinnitus sufferers). A classification of different forms of tinnitus, in terms of changes in noise, was also undertaken. N1-P2 component amplitudes and N1 and P2 latencies were measured.Results: Objective identification of the affected ear in unilateral tinnitus sufferers was found feasible on the basis of N1-P2 intensity-dependence and N1-P2 amplitude. The bilateral tinnitus group was found to differ from controls by greater intensity-dependence of the N1-P2 component and shorter N1 latency. These characteristics varied with tinnitus type: a classification on the basis of intensity-dependence and latencies proved feasible. The group of patients showing improved tinnitus in noise had greater intensity-dependence and longer N1 latency than did the group showing aggravated tinnitus in noise.Conclusions: Data are discussed in light of the inhibitory role of frontal cortex on the sensory inputs and the modulatory function of central serotonergic system on the processing of auditory information.

Clinical and Audiological Characteristics of Tonal and Noise Tinnitus

A study was made of the clinical and audiological characteristics of tonal and noise tinnitus through a correlation of detailed patient interviews, comprehensive neurootological examination results, and clinical data on tinnitus type, frequency, loudness and bandwidth obtained with our newly developed tinnitus-measuring device. Of the 205 cases studied, 61% had noise tinnitus and 39% had tonal tinnitus. Higher incidences of noise tinnitus were discovered in patients aged over 50 years as well as in those with longer tinnitus histories and higher-level hearing losses; noise bandwidths in these patients also tended to be larger. Our data indicated that cases with noise tinnitus, especially those with wider bandwidths, tended to be associated with wide-range cochlear damage.