Introdução: Zumbido é um sintoma de alterações nas vias auditivas com etiologia variada. Muitos pacientes com perda auditiva possuem zumbido e um dos tratamentos é o uso dos aparelhos auditivos. Os aparelhos auditivos amplificam os sons externos e os pacientes passam a perceber melhor os sons do ambiente, diminuindo a percepção do zumbido e proporcionando melhora na entrada do som por meio do enriquecimento sonoro. Contudo, é visto na literatura que alguns pacientes não observam a diminuição do incômodo e da percepção do zumbido ao utilizar os aparelhos auditivos. O estudo da audição periférica nestes pacientes poderia fornecer informações sobre fatores que dificultam a redução da percepção do zumbido com o uso de aparelhos auditivos. Objetivo: Avaliar as características audiológicas de pacientes com zumbido e perda de audição e verificar se há diferenças entre o grupo que obteve redução na percepção do zumbido com o uso de aparelhos auditivos e o grupo que não obteve o mesmo benefício. Método: Foram avaliados 29 sujeitos, divididos em dois Grupos, sendo Grupo I (GI) composto por 20 sujeitos que observaram melhora na percepção do zumbido após dois meses de uso dos aparelhos auditivos, e o Grupo II (GII) composto por nove, que não observaram melhora na percepção do zumbido. A pontuação na Escala Visual Analógica (EVA) determinou a divisão dos grupos. Foram aplicados: questionários para avaliar o incômodo do zumbido (Tinnitus Handicap Inventory -THI) e a melhora da percepção auditiva (Hearing Handicap Inventory Elderly Screening Version- HHIE-S); avaliações audiológicas (audiometria de via área e óssea, índice de reconhecimento de fala, identificação do limiar diferencial de intensidade índice, emissões otoacústicas), testes de processamento auditivo temporal (Gaps-in-Noise-GIN, Teste de Detecção de Intervalo Aleatório-RGDT, testes Padrão de Frequência e Duração -TPF e TPD respectivamente) e medidas psicoacústicas do zumbido (pitch, loudness e Limiar Mínimo de Mascaramento - MML) antes da adaptação dos aparelhos auditivos e após dois meses de uso dos aparelhos auditivos. Os sujeitos tinham entre 28 e 68 anos (média 55 anos) de ambos os sexos, e usaram aparelhos auditivos da mesma marca, com as regulagens adequadas para cada sujeito. Resultados: Não houve diferença significativa entre os grupos nos testes audiológicos aplicados. Nos testes auditivos temporais, a porcentagem de acerto do Grupo I foi superior ao Grupo II, com tendência à significância estatística no TPF. Foi observada diferença estatística nos questionários THI, HHIE-S no GI e GII após o uso dos aparelhos, diminuindo a pontuação. Com relação às medidas psicoacústicas, houve diferença estatística significante entre o Loudness e MML iniciais e finais do GI e diferença entre os grupos no loudness e no MML final. Conclusão: As caraterísticas audiológicas avaliadas não foram suficientes para indicar se o paciente com perda de audição se beneficiaria com a diminuição na percepção do zumbido com dois meses de uso de aparelhos auditivos. Indivíduos com desempenho pobre no TPF tem tendência a não reduzir a percepção do zumbido com o uso de aparelhos auditivos. O presente estudo aponta para a necessidade de investigar outras características que podem estar associadas à dificuldade na redução na percepção do zumbido com o uso de aparelhos auditivos / Introduction: Tinnitus is a symptom of damage of the auditory pathways with varied etiology. Many patients with hearing loss have tinnitus and one of its treatments is the use of hearing aids. Hearing aids amplify external sounds and patients are able to better understand the sounds of the environment, reducing the perception of the tinnitus and improving sound input through enriched acoustics. However, according to literature, some patients do not observe discomfort and tinnitus perception decrease using hearing aids. The study of peripheral hearing in these patients could provide information on factors that make it difficult to reduce tinnitus perception with the use of hearing aids. Objective: To evaluate audiological characteristics of patients with tinnitus and hearing loss, and verify if there are differences between the group that obtained reduction in tinnitus perception with the use of hearing aids and the group that did not obtain the same benefit. Methods: 29 subjects, divided into two groups: Group I (GI) composed of 20 subjects who observed improvement in tinnitus perception after two months of hearing aids use and Group II (GII) with nine subjects who did not observe improvement in tinnitus perception, were evaluated. The Visual Analogue Scale (VAS) score determined the division of the groups. The questionnaires Hearing Handicap Inventory Elderly Screening (HHIE-S) and Tinnitus Handicap Inventory (THI), audiological evaluation (pure tone and bone conduction audiometry, speech recognition index, short increment sensitivity index, otoacoustic emissions), temporal auditory processing tests (Gaps-in-Noise-GIN, Random Interval Detection Test-RGDT, frequency and duration tests (PPS and DPT) and psychoacoustic measures of tinnitus (pitch, loudness and MML) before the fitting of hearing aids and after two months of use were conducted. Subjects were aged between 28 and 68 (mean age 55 years), both sexes, and used same brand hearing aids, with the appropriate fitting for each subject. Results: There was no significant difference between the groups in the audiological tests. Temporal auditory tests accuracy percentage of Group I was higher than Group II, with a tendency to statistical significance in the PPS. Statistical difference was observed in the THI, HHIE-S for GI and GII after the hearing aids use, reducing the score. Regarding psychoacoustic measures, there was significant statistical difference between initial and final loudness and MML in GI, and intergroup difference (GI and GII) in the final MML and loudness. Conclusion: The evaluated audiologic characteristics were not sufficient to indicate if the patient with hearing loss would benefit from a decrease in tinnitus perception after two months of hearing aids use. Individuals with poor PPS performance tend not to reduce tinnitus perception with hearing aids use. The present study indicates the need to investigate other characteristics that may be associated with the difficulty in reducing tinnitus perception with hearing aids use

碩士 / 國立高雄師範大學 / 電子工程學系 / 106 / In recent years, the number of tinnitus patients has continued to increase. However, the current study on the tinnitus retraining therapy, the main mode of tinnitus treatment, requires little research on the music system. Tinnitus retraining therapy requires a set of random music to prevent the human ear from adapting to music leads to poor therapeutic efficacy. How to use an easy-to-control system to achieve the goal of tinnitus treatment music is the main topic of this article. This paper is based on chaos theory to complete a system that can randomly generate tones and rhythms in music and improve it, so that the system does not need to worry about complex parameter settings. First of all, first introduce the relevant algorithms used in this paper, and according to the modules required in the architecture, use Matlab to do the program description and construction, and finally transfer the music output in Matlab to the composition software Ovrture for actual music #Chaos #Chaotic System #Tinnitus #Music

O zumbido (ou tinnitus) pode ser descrito como a percepção de um som ou ruído sem nenhuma estimulação acústica externa. Apesar de freqüente, ainda existem muitas dúvidas envolvendo o zumbido, no que se refere à sua origem e tratamento para a totalidade dos casos. Os objetivos do presente trabalho foram estudar a supressão das Emissões Otoacústicas Transitórias com estimulação contralateral e as latências, intervalos interpicos, bem como as amplitudes das ondas dos Potenciais Auditivos Evocados de Tronco Cerebral, em pacientes com zumbido e perda auditiva neurossensorial, causada possivelmente por exposição prolongada a níveis de pressão sonora elevados. Foram avaliados 30 sujeitos com zumbido (grupo Z) e 30 sujeitos sem zumbido (grupo C), ambos os grupos do sexo masculino e pareados quanto à faixa etária, tempo de exposição ao ruído e grau de perda auditiva neurossensorial em agudos. Os resultados mostraram homogeneidade dos dois grupos quanto à faixa etária, tempo de exposição ao ruído e limiares auditivos. Observou-se supressão das emissões menores para o grupo Z, com diferença estatística somente para a orelha esquerda e indícios de diferença significante para a orelha direita. Quanto aos Potenciais Auditivos Evocados de Tronco Cerebral, houve um aumento das latências e redução das amplitudes para o grupo Z, com resultados significantes para a latência de onda III da orelha direita e para as latências das ondas I e III da orelha esquerda. Com base nos achados descritos, hipotetizou-se que, nos pacientes com zumbido, o sistema auditivo eferente olivococlear medial seria possivelmente menos eficiente, já que a supressão das emissões foi menor nestes pacientes. Além disso, poder-se-ia supor a existência de uma possível alteração na atividade do Tronco Cerebral em indivíduos com zumbido, evidenciadas pelos prolongamentos das latências e redução das amplitudes. / Tinnitus can be described as a perception of a particular sound or noise without any external acoustic stimulation. Though frequent, there are still many unanswered questions regarding tinnitus, the origin and treatment for all cases. The aim of this work was to study the suppression of Transitory Otoacoustic Emissions with contralateral stimulus and the latencies, interpeak intervals and amplitudes of Auditory Brainstem Response waves in patients with tinnitus and sensorineural hearing loss, possibly caused by prolonged exposition to high sound pressure levels. For that purpose, 30 individuals with tinnitus (group Z) and another 30 without it (group C) were studied. Both groups formed by males matched according with age, time exposed to noise and high-frequency sensorineural hearing loss. The results show homogeneous age, noise exposure time and hearing thresholds of both groups. Weaker suppression of emissions in group Z was observed, with significant statistical difference only for left ear and indicia of significant difference for the right ear. As for auditory brainstem response, there was an increase in latencies and reduction of amplitudes for group Z, with significant results for wave III latency of right ear and for I and III waves of left ear. Based on these findings, the theory is that in patients with tinnitus the medial olivocochlear efferent auditory system could possibly be less efficient, since the emission suppression was weaker in such patients. Besides, an assumption could be made that a possible alteration of brainstem activity takes place in patients with tinnitus, made clear by prolonged latencies and reduction of amplitudes in that group.

O objetivo deste estudo foi avaliar o efeito de placas oclusais com guias anteriores de desoclusão e placas oclusais com contatos bilaterais e anteriores simultâneos durante os movimentos excursivos da mandíbula em pacientes com disfunção temporomandibular (DTM) e zumbido subjetivo. Foram avaliados 264 pacientes encaminhados para tratamento da DTM na FORP/USP e selecionados 32 mulheres com DTM muscular, associada ou não a DTM articular, e zumbido subjetivo que preencheram os critérios de inclusão. O diagnóstico da DTM foi realizado com o Research Diagnostic Criteria for Temporomadibular Disorders (RDC/TMD). As pacientes foram divididas randomicamente em dois grupos para utilizarem um dos dois tipos de placas. As avaliações incluíram dor à palpação, limiar de dor a pressão com algômetro, medidas da amplitude dos movimentos mandibulares, eletromiografia de superfície, relato da intensidade da dor e da loudness do zumbido em escala visual analógica (EVA) e das características do zumbido. Os pacientes também responderam a um questionário para quantificação da frequência e severidade dos sinais e sintomas de DTM (ProDTMMulti) e para a avaliação do impacto do zumbido no dia-a-dia (Tinnitus Handicap Inventory - THI). A avaliação eletromiográfica foi realizada em várias atividades com e sem placa oclusal (apertamento máximo voluntário, movimentos excursivos mandibulares, repouso e mastigação habitual) e comparada com um grupo de 13 mulheres assintomáticas. As avaliações foram realizadas inicialmente (A1), no dia de instalação das placas oclusais, após 60 dias da avaliação inicial (A2) e após 90 dias de uso da placa oclusal (A3). O período entre as avaliações A1 e A2 foi considerado um período controle. Os resultados mostraram uma significante melhora da dor relatada pelo pacientes e aumento da amplitude da abertura bucal sem dor nos dois grupos, sem diferença entre eles. A atividade eletromiográfica foi significativamente reduzida durante apertamento máximo voluntário com a placa oclusal em comparação com o apertamento em máxima intercuspidação habitual, para as demais atividades realizadas durante o exame não houve diferença significante. A avaliação do zumbido mostrou que em muitos pacientes houve remissão do sintoma após o tratamento com placa oclusal. Não houve diferença entre os grupos para todas as avaliações realizadas. Baseados nesses achados, pode-se concluir que o tratamento com ambas as placas promoveu melhora na sintomatologia dos pacientes, sem diferenças entre elas, e houve em muitos pacientes uma remissão do zumbido relatado durante o tratamento. / The aim of this study was to assess the effect of anterior guidance and bilateral balanced splints in patients with temporomandibular disorders (TMD) and subjective tinnitus. A total of 264 subjects referred for treatment of TMD in FORP/USP were evaluated and 32 women with muscular TMD with or without the diagnosis of articular TMD, who met the inclusion criteria, were selected. TMD diagnosis was performed according to Research Diagnostic Criteria for Temporomadibular Disorders (RDC/TMD). The patients were randomly divided into two groups: anterior guidance splint group and bilateral balanced splints group. The assessments included pain to palpation, pressure pain threshold with algometer, measurement of amplitude of mandibular movements, surface electromyography, pain intensity and loudness of tinnitus reports in visual analogue scale (VAS) and characteristics of tinnitus. The patients also answered a questionnaire to quantify the frequency and severity of signs and symptoms of TMD (ProDTMMulti) and to assess the impact of tinnitus on a day-to-day (Tinnitus Handicap Inventory - THI). The electromyography evaluation was performed in different activities with and without occlusal splint (maximum voluntary clenching, excursive jaw movements, resting and habitual chewing) and compared to a group of 13 asymptomatic women. The assessments were performed initially (A1), at the day of installation of the occlusal splints, after 60 days of the initial assessment (A2) and after 90 days of occlusal splint therapy (A3). The period between A1 and A2 assessments was considered a control period. The results showed a significant improvement in pain reported by patients and an increase in the amplitude of mouth opening without pain in both groups, without difference between them. The electromyographic activity was significantly reduced during maximum voluntary clenching with occlusal splint compared to clenching in maximal habitual intercuspation, to the other activities performed during the examination there was no significant difference. The tinnitus evaluation showed that in many patients there was remission of symptom after treatment with occlusal splint. There was no difference among groups for all assessments. Based on these findings it is possible to conclude that treatment with both splints promoted improvement in symptoms of patients, without differences among them, and many patients had a remission of reported tinnitus during the treatment.

碩士 / 國立成功大學 / 醫學工程研究所 / 91 / Most people have tinnitus experiences with various degree, and one-third of the elderly are suffered from tinnitus. The statistical data of American Tinnitus Association shows that there are forty-one million tinnitus patients in America. Twelve million patients have severe tinnitus. Unfortunately, most conventional treatments fail to improve the symptoms of tinnitus. Many patients feel aborted, confused and depressed. Until 1980, neurophysiologist Pawel Jastreboff and Dr. Vernon have proposed a Tinnitus Retraining Therapy and a Tinnitus Masking treatment for the tinnitus, respectively. These therapies consist of clinical consultation by physicians and applying noise generator for rehabilitation treatment. Based on the plasticity and habituation of neuron, the implementation of noise generator is to accelerate the period of habituation to improve the symptoms of tinnitus. Most imported commercial noise generators provide primarily broadband noises for the treatment ; unfortunately, the devices and their corresponding treatment are without considering the clinical evidence that among 70% of tinnitus patients are complicated with hearing loss. Except white noise with only volume adjustment from noise generators providing inefficacious outcomes for some tinnitus patients, it always takes a prolong period for treatment and even is at high risk for hearing loss damage. Moreover, the imported noise generators are too expensive for many domestic patients in need to obtain medicinal treatment. Recently, Advanced technology of digital signal processing in both hardware makes the implementation of many complex algorithms becoming possible. Based on the concept and underlying mechanisms of Tinnitus Retraining Therapy and Tinnitus Masking, this research project, which applies theories of statistical digital signal processing and modeling, is aimed to develop and establish a PC-based platform for evaluation and rehabilitation of tinnitus. This platform, which provides the measuring and evaluation of physical parameters of hearing state and tinnitus, is able to prescribe the customized noise of treatment with specified spectrum. The evaluation and rehabilitation platform for tinnitus treatment are completely developed with four main modules including PTA module, narrow-band noise production module, tinnitus-sound approaching module, and noise with specified spectrum production module. There are pure tones of 250, 500, 1k, 2k, 4k and 8k Hz in the PTA module to measure subject’s hearing thresholds. In narrow-band noise production module, it provides 18 sub-bands covering from 20 to 20k Hz of noise to evaluate the frequency band ,minimum masking level(MML) and mixing point(MP) of tinnitus. The tinnitus-sound approaching module offers noise with adjustable bandwidth to resolve the limitation of fixed band of narrow-band noise production module. The noise with specified spectrum production module produces the noise of tinnitus rehabilitation and treatment with specified spectrum according to the measured hearing parameters. The calibration and testing of the platform system has been conducted . The results of frequency calibration of pure tones indicate that all the relative errors for 250, 500, 1k, 2k, 4k and 8k Hz are less than 0.1%. The mapping table of setup volume in this system to sound level meter output is also conducted. Output volume of pure tones or noise of the platform could be converted to be in dB SPL by this mapping table. The calibration results of volume output of the system relative to sound level meter show that the mean value of correlation coefficients between nominal value and system output volume is 0.9724±.3445. This PC-based platform could provide the noise with bandwidth ranging from 20 to 20k Hz and volume up to 117.58 dB SPL for evaluation and rehabilitation of tinnitus. A pilot study is conducted to clinically implement the system for measuring and evaluation of tinnitus patients. A total of 21 tinnitus patients are in involved at this stage. For the PTA measurements, 7 of 21 patients have show high frequency loss type. 10 of 21 patients are Left-side tinnitus . There is no obvious trend in the distribution of tinnitus frequency, it might be resulted from small size of sampling. Using this platform 20 of 21 patients are frequency matching in tinnitus, and 15 of 20 patients are volume matching. The mean and standard deviation of volume values for MML and MP are 97.27±18.8 dB and 86.18±16.7 dB ,respectively. This system provides the prediction capability for the value of MP through regression analysis of MML and MP with equation y=.839x+7.266 (x : MML; y : MP), correlation coefficient=0.972 at p<.05. This platform works well so far by the results of clinic trial stage and responses of subjects. The future system research and development are recommended as following: (1) to download the customized noise to MP3 player as a noise generator and to setup the experimental group with customized-noise generator and control group with imported white noise generator for the comparison and analysis of the results of both methods; and (2) to implement the noise generator by DSP chip with linear prediction coefficients calculated by this platform system.

碩士 / 國立成功大學 / 生理學研究所 / 100 / In estimating the presence of tinnitus in animals, a conditioned behavior (polydipsia avoidance) and a reflexive behavior (pre-pulse inhibition acoustic startle reflex) are commonly used. Both of them have strength and weakness: polydipsia avoidance is more accurate, but requires long period of training; acoustic startle reflex requires no training but it only occurs at high sound intensity levels (〉90 dB SPL), way above that of tinnitus percept (〈 35 dB SPL). Hence, the use of other kinds of acoustic reflexes that can be elicited at low intensities would be very beneficial. However, the characterization of other acoustic reflexes (head orienting reflex, pinna reflex, freezing reflex) has not been done especially at low intensity levels where tinnitus is typically perceived. Here an imaging system is developed to study three acoustic reflexes. To minimize habituation, a host of acoustic signals are presented (including a set of pre-recorded environmental sounds with broad spectra). In the control adult rats: (a) head orienting reflex was often observed at a longer latency (~150 ms); (b) concurrent with this, pinna movements that are ipsi-lateral to sound source with response latency ~50 ms; (c) vibrissa freezing response that appeared with much shorter latency (~80 ms). The different response latencies are consistent with the different central neural pathways underlying these reflexes. Most importantly, all of these reflexes could be induced by sounds at levels below 40 dB SPL. Preliminary study on a putative tinnitus animal model (early sound exposure) indicated a trend of threshold elevation suggesting the presence of masking likely due to tinnitus or hearing loss. Results strongly suggested that these acoustic reflexes could be potentially useful as a simple and objective means of probing the tinnitus.

碩士 / 國立臺北護理健康大學 / 聽語障礙科學研究所 / 100 / Tinnitus is the subjective perception of sound within the ears or brain in the absence of corresponding external sound or electrical stimulation. Epidemiological studies have shown that 10.1% of adults in the general population experienced long-term tinnitus which may cause various degrees of distress, and 0.5% of the population sufferred from severe tinnitus which may affect their quality of life. Tinnitus is one of the symptoms of auditory system dysfunction and closely associated with hearing loss. Aging, noise exposure and ototoxic drugs often resulted in high-frequency hearing loss which may increase the prevalence of tinnitus. Therefore, an inquiry of tinnitus and its associated symptoms may be needed. Tinnitus retraining therapy (TRT) was developed base on the neurophysiologic model of tinnitus by Jastreboff in 1990. The therapy involved with two parts: firstly, psychological counseling which provided the patients with knowledge of tinnitus in order to minimize the conditioned reflex from negative perception. Secondly, Jastreboff proposed low-level and broadband noise masking treatment which increased the background neuronal activity and reduced the amplitude of tinnitus level which may minimize the conditioned reflex. It was believed that narrowband noise masking at lower level encompassing the main tinnitus frequency may be effective. In order to understand the response of tinnitus patients to narrowband and broadband noises, this study collected 73 patients (117 ears) with high-frequency hearing impairment and unilateral or bilateral persistent tinnitus for more than 6 months from the tinnitus counseling out-patient clinic at Kuangtien General Hospital. Patients with outer or middle ear diseases were excluded. All patients received audiological evaluation including UCL, acoustic reflex, DPOAE, pitch matching test, MML for narrowband and broadband noise stimulation, as well as RI, respectively. The purpose of audiological evaluation is to describe the characteristics of tinnitus. The data obtained from these evaluations were analyzed using SPSS 20 and R for statistical analyses includingχsquare, and Pearson’s product moment correlation coefficient. The results showed that the poor tinnitus ears match the ears with poor hearing and the pitches of tinnitus coincide with the frequencies of hearing impairment. When comparing the responses to narrowband and broadband noise masking, broadband noise needs lower level than narrowband noise to mask tinnitus, and the level lower than the hearing thresholds of patients to MML in those who with profound high-frequency hearing loss. It was observed that broadband noise masking resulted in more patients with complete RI than narrowband noise masking, which resulted in more partial or no RI response. However, the observed RI duration is longer with narrowband noise masking than those with broadband noise masking. There is no linear relationship between the existence of RI and narrowband or broadband noise, gender, age, the varying degrees of hearing impairment in different frequencies (4000 and 8000 Hz), and the tinnitus frequencies; neither is the duration of RI with these variables.

碩士 / 靜宜大學 / 食品營養研究所 / 99 / Tinnitus is a phantom sensation of sound in the absence of external stimulations. Serious tinnitus may affect emotion, concentration, and even the quality of life. However, the treatments of tinnitus need further study. The purpose of this study was to develop a behavioral model of conscious tinnitus with SAMP8 mice induced by salicylate, and evaluated the effects of Spiulina water extract on relative receptors. Three-month-old SAMP8 mice were randomly divided into normal control, tinnitus with intraperitoneal injection of salicylate (300 mg/kg BW), and Spiulina water extract (1000 mg/kg BW) with salicylate-induced tinnitus groups. Body weight were recorded and active avoidance test were performed during the experimental period. The biochemical values was analyzed after sacrificed, and the cannabinoid receptor 1 (CB1 receptor), vanilloid receptor type 1 (VR1 receptor), dopamine D1A receptor and γ-amino butyric acid (GABA) Aβ3 receptor mRNA expressions of brain stem, frontal lobe, hippocampus, temporal lobe and inner ear were also examined. Our results demonstrated that both salicylate and Spiulina water extract did not affect the liver and kidney functions of SAMP8 mice. Salicylate-induced tinnitus led significant increase in the number of false positive response while the percentage of correct response tented to reduce and Spiulina water extract could improve the trend. Salicylate significantly reduced the cannabinoid receptor 1 (CB1 receptor) and γ-amino butyric acid (GABA) Aβ3 receptor mRNA expression in brain stem, frontal lobe, hippocampus, temporal lobe and inner ear, while Spiulina water extract significantly increased their expression. In addition, salicylate significantly increased the dopamine D1A receptor expression in brain stem, hippocampus, temporal lobe and inner ear, and Spiulina water extract could significantly lessen their expression. Salicylate significantly increased the VR1 receptor expression in brain stem, frontal lobe, hippocampus and temporal lobe, and Spiulina water extract also significantly reduced the expression. In summary, we conclude that the Spiulina water extract could improve the salicylate-induced conscious tinnitus in SAMP8 mice, which might due to regulate the expression of tinnitus related receptor.

O zumbido (ou tinnitus) pode ser descrito como a percepção de um som ou ruído sem nenhuma estimulação acústica externa. Apesar de freqüente, ainda existem muitas dúvidas envolvendo o zumbido, no que se refere à sua origem e tratamento para a totalidade dos casos. Os objetivos do presente trabalho foram estudar a supressão das Emissões Otoacústicas Transitórias com estimulação contralateral e as latências, intervalos interpicos, bem como as amplitudes das ondas dos Potenciais Auditivos Evocados de Tronco Cerebral, em pacientes com zumbido e perda auditiva neurossensorial, causada possivelmente por exposição prolongada a níveis de pressão sonora elevados. Foram avaliados 30 sujeitos com zumbido (grupo Z) e 30 sujeitos sem zumbido (grupo C), ambos os grupos do sexo masculino e pareados quanto à faixa etária, tempo de exposição ao ruído e grau de perda auditiva neurossensorial em agudos. Os resultados mostraram homogeneidade dos dois grupos quanto à faixa etária, tempo de exposição ao ruído e limiares auditivos. Observou-se supressão das emissões menores para o grupo Z, com diferença estatística somente para a orelha esquerda e indícios de diferença significante para a orelha direita. Quanto aos Potenciais Auditivos Evocados de Tronco Cerebral, houve um aumento das latências e redução das amplitudes para o grupo Z, com resultados significantes para a latência de onda III da orelha direita e para as latências das ondas I e III da orelha esquerda. Com base nos achados descritos, hipotetizou-se que, nos pacientes com zumbido, o sistema auditivo eferente olivococlear medial seria possivelmente menos eficiente, já que a supressão das emissões foi menor nestes pacientes. Além disso, poder-se-ia supor a existência de uma possível alteração na atividade do Tronco Cerebral em indivíduos com zumbido, evidenciadas pelos prolongamentos das latências e redução das amplitudes. / Tinnitus can be described as a perception of a particular sound or noise without any external acoustic stimulation. Though frequent, there are still many unanswered questions regarding tinnitus, the origin and treatment for all cases. The aim of this work was to study the suppression of Transitory Otoacoustic Emissions with contralateral stimulus and the latencies, interpeak intervals and amplitudes of Auditory Brainstem Response waves in patients with tinnitus and sensorineural hearing loss, possibly caused by prolonged exposition to high sound pressure levels. For that purpose, 30 individuals with tinnitus (group Z) and another 30 without it (group C) were studied. Both groups formed by males matched according with age, time exposed to noise and high-frequency sensorineural hearing loss. The results show homogeneous age, noise exposure time and hearing thresholds of both groups. Weaker suppression of emissions in group Z was observed, with significant statistical difference only for left ear and indicia of significant difference for the right ear. As for auditory brainstem response, there was an increase in latencies and reduction of amplitudes for group Z, with significant results for wave III latency of right ear and for I and III waves of left ear. Based on these findings, the theory is that in patients with tinnitus the medial olivocochlear efferent auditory system could possibly be less efficient, since the emission suppression was weaker in such patients. Besides, an assumption could be made that a possible alteration of brainstem activity takes place in patients with tinnitus, made clear by prolonged latencies and reduction of amplitudes in that group.

INTRODUÇÃO: As terapias mais eficazes para zumbido são baseadas nos modelos psicológico e neurofisiológico, que teorizam que o incômodo existente é resultado da interação dinâmica dos centros auditivos, sistemas límbico e nervoso autônomo. Embora sejam amplamente aceitos na prática clínica, ainda necessitam validação científica. A ressonância magnética funcional (RMf) é um método objetivo capaz de identificar as áreas cerebrais descritas pelos modelos, como também a rede neural relacionada à percepção de estímulos emocionais, que ainda não foi investigada em estudos de zumbido. OBJETIVOS: 1) Baseado nos modelos que explicam o incômodo do zumbido, analisar as áreas corticais auditivas e não-auditivas em adultos normo-ouvintes com e sem zumbido, ativadas durante estimulação auditiva desagradável; 2) de acordo com a teoria da percepção de um estímulo emocional, avaliar se os pacientes com zumbido recrutavam a mesma rede neural para a percepção de sons desagradáveis que os indivíduos sem zumbido. MÉTODOS: Quinze pacientes com zumbido subjetivo crônico não-pulsátil (grupo zumbido, GZ) e 20 voluntários sem zumbido (grupo controle, GC), pareados por sexo e idade, foram submetidos à RMf (1.5 T). Os critérios de inclusão foram: indivíduos destros, audiometria normal, inventário de depressão de Beck < 20 pontos e escolaridade equivalente ao segundo grau completo. O paradigma incluiu sons do catálogo IADS (International Affective Digitized Sounds), validados para valência emocional e grau de estímulo, associado à escala análogo-visual SAM (Self Assessment Manikin), modificada para RMf. O paradigma foi praticado previamente em um simulador de RMf. A aquisição de imagens e a apresentação de estímulos foram realizadas através da técnica de seqüência de pulso com ruído acústico minimizado (SPRAM). RESULTADOS: O hipocampo esquerdo foi a área mais ativada no GC e não demonstrou atividade neural no GZ, no qual a maior ativação foi localizada na ínsula esquerda. Áreas auditivas (giro temporal superior e região ínfero-posterior do lobo temporal) e límbicas (ínsula) foram ativadas pelos sons desagradáveis em ambos os grupos. Na análise comparativa, a maior ativação no GZ ocorreu no cerebelo direito (p < 0,05) e, no GC, no giro temporal superior esquerdo e giro frontal inferior esquerdo (p < 0,05). CONCLUSÕES: A ativação paralela dos sistemas auditivo e límbico aos sons desagradáveis foi demonstrada nos pacientes com e sem zumbido. Entretanto, na comparação entre grupos, áreas límbicas e préfrontais não foram significantemente mais ativadas em pacientes com zumbido. Sugere-se que o cerebelo direito, recentemente relacionado à função cognitiva, pode ser a área não-auditiva envolvida no incômodo do zumbido. Especula-se que o incômodo do sintoma esteja relacionado a anormalidades na percepção emocional, seja pela identificação exacerbada (via ínsula) de sons desagradáveis ou pela ausência de regulação da resposta afetiva (via hipocampo) a este estímulo / INTRODUCTION: The most successful tinnitus therapies are based on the psychological and the neurophysiological models, which suggest that tinnitus-related annoyance results from the dynamic interaction of auditory brain centers, limbic and autonomic nervous systems. Although these models have been largely accepted in clinical practice, they lack experimental support and validation. Functional magnetic resonance imaging (fMRI) offers the opportunity to identify those brain regions pertinent to each model, and studies the neural network involved in the theory of emotion perception of stimuli. The latter has not been thoroughly investigated in tinnitus. OBJECTIVES: 1) Based on the models of developing tinnitus-related annoyance, analyze the cortical areas (auditory and non-auditory) in normal hearing individuals with and without tinnitus, activated by unpleasant auditory stimulation; and 2) according to the theory of emotion perception of acoustic stimulus, evaluate whether the patients with tinnitus were using the same neural network for perception of unpleasant sounds than the subjects without tinnitus. METHODS: Fifteen subjects with chronic subjective non-pulsatile tinnitus (tinnitus group, TG), and 20 healthy volunteers (control group, CG), matched for gender and age, were submitted to 1.5 T fMRI. Inclusion criteria consisted of normal pure-tone audiogram, righthandedness, Beck depression inventory < 20 points, and formal education level > 11 years. The paradigm comprised sounds from IADS (International Affective Digitized Sounds) with validated emotional valence and arousal, and a modified visual-analog Self Assessment Manikin (SAM) scale. All individuals previously practiced the task in a mock scanner. Image acquisition and stimuli presentation were designed using the silent event-related method, in which the scanner acoustic noise effects were minimized during brain activation detection. RESULTS: The left insula presented the highest neuronal activity in the TG, which showed no activity in the hippocampus. In the CG, the activation was markedly present in the left hippocampus, and was barely found in the insula. Unpleasant sounds activated auditory areas (superior temporal gyrus, inferior-posterior temporal lobe) and the limbic system (insula) in both groups. When the groups were compared, the right cerebellum was the most activated brain area in the TG (p < 0.05), and CG showed the highest activation in the left superior temporal gyrus and the left inferior frontal gyrus (p < 0.05). CONCLUSIONS: Parallel activation of auditory and limbic systems was demonstrated in both tinnitus and control patients. However, limbic and prefrontal areas were not significantly more activated in patients with tinnitus. The right cerebellum, recently described to have cognitive function, may be responsible for integrating the brain centers involved in the annoyance of tinnitus. In addition, we suggested that tinnitus-related annoyance may be secondary to emotion perception abnormalities, either a higher identification of emotional significance of the unpleasant sounds (via insula), or a lack of regulation of individual affective reaction (via hippocampus)