Increased Incidence of Tinnitus Following a Hyperthyroidism Diagnosis: A Population-Based Longitudinal Study.

Background: An association between thyroid disease and tinnitus has been described previously but further longitudinal, population-based studies are limited. Objective: To investigate the incidence of tinnitus in patients with hyperthyroidism in a national sample, and to identify risk level and associated factors for tinnitus in hyperthyroidism patients. Design: Retrospective cohort study. Patient data were collected from the Longitudinal Health Insurance Database (LHID 2000), which includes national claims data of patient expenditures for admissions or ambulatory care from 1996 to 2011. Setting: Taiwan hospitals and clinics providing healthcare nationwide. Participants: Patients aged 20 years and older with newly diagnosed hyperthyroidism (ICD-9-CM code 242) between 2000-2010 were selected as the study cohort. Hyperthyroidism patient cohort were identified from the LHID2000. Those with tinnitus history (ICD-9-CM code 388.3) before the index date (first hyperthyroidism diagnosis), younger than 20 years, and with incomplete demographic data were excluded. The non-hyperthyroidism cohort included patients with no history of hyperthyroidism and no documented tinnitus. Main Outcomes and Measures: Incidence of tinnitus was the primary outcome. Baseline demographic factors and comorbidities possibly associated with tinnitus, including age, sex, and comorbidities of hearing loss, vertigo, insomnia and anxiety, were retrieved from the LHID 2000. Patients were followed until end of 2011. Results: During the study period, 780 (4.9%) hyperthyroidism patients and 2007 (3.2%) non-hyperthyroidism controls developed tinnitus. Incidence rate of tinnitus in the hyperthyroidism cohort was significantly higher in hyperthyroidism cohort (7.86 vs. 5.05 per 1000 person-years) than that in non-hyperthyroidism cohort. A higher proportion of patients with hyperthyroidism had comorbid insomnia (45.1% vs. 30.9%) and anxiety (14.0% vs. 5.73%) than those without hyperthyroidism. After adjusting for age, gender and comorbidities (vertigo, insomnia, anxiety, hearing loss), hyperthyroidism patients had 1.38-fold higher risk of tinnitus (95% CI = 1.27-1.50) than those without hyperthyroidism. Conclusions: This large population-based study suggests patients with diagnosed hyperthyroidism was more prone to develop tinnitus. Our findings suggest evaluation for comorbid vertigo, insomnia, anxiety and/or hearing loss may identify patients who are at high risk of developing tinnitus in patients with hyperthyroidism.

Classification of Tinnitus: Multiple Causes with the Same Name.

Tinnitus is spoken of as if it were a single thing, but there are many different causes, likely many different mechanisms, and many different subtypes. This article reviews a broad range of approaches to understand and demarcate different tinnitus subtypes, which will be critical for exploring and finding cures for different subtypes.

A review of hyperacusis and future directions: part II. Measurement, mechanisms, and treatment.

PURPOSE: Hyperacusis can be extremely debilitating, and at present, there is no cure. In this detailed review of the field, we consolidate present knowledge in the hope of facilitating future research. METHOD: We review and reference the literature on hyperacusis and related areas. This is the 2nd of a 2-part review. RESULTS: Hyperacusis encompasses a wide range of reactions to sounds, which can be grouped into the categories of excessive loudness, annoyance, fear, and pain. Reasonable approaches to assessing the different forms of hyperacusis are emerging, including brain-imaging studies. Researchers are only beginning to understand the many mechanisms at play, and valid animal models are still evolving. There are many counseling and sound-therapy approaches that some patients find helpful, but well-controlled studies are needed to measure their long-term efficacy and to test new approaches. CONCLUSIONS: Hyperacusis can make life difficult in this increasingly noisy world, forcing sufferers to dramatically alter their work and social habits. We believe this is an opportune time to explore approaches to better understand and treat hyperacusis.

Tinnitus retraining therapy: mixing point and total masking are equally effective.

OBJECTIVES: Habituation to tinnitus cannot occur with total masking, an argument made by proponents of "tinnitus retraining therapy." We also compared the effectiveness of retraining therapy with mixing-point masking, total masking, and with counseling alone. DESIGN: Forty-eight tinnitus patients were randomly assigned to one of three groups: counseling, counseling plus bilateral noise generators set to completely mask the tinnitus, or counseling plus bilateral noise generators with a focus on the mixing point (partial masking just below total masking). A picture-based counseling protocol was used to assist in providing similar counseling among all three groups. The Tinnitus Handicap Questionnaire was administered before and after about 12 months of treatment. RESULTS: After 12 months, in the counseling group, three of 18 patients benefited significantly, in the mixing-point group, six of 19 patients benefited, and in the total masking group, four of 11 patients benefited from the treatment. The average decrease in the questionnaire was 16.7% for the counseling group, 31.6% for the retraining group, and 36.4% for the total masking group. No significant average differences among groups were observed. CONCLUSIONS: One premise of retraining therapy is incorrect; a focus on mixing-point masking is not required for habituation.

Hyperacusis, sound annoyance, and loudness hypersensitivity in children.

The objective of the present study was to estimate the prevalence of hyperacusis among school-aged children. We define hyperacusis as lowered loudness discomfort levels (LDL) associated with an abnormal annoyance to sounds. We used questionnaires, interviews, and estimates of LDL in a study of 506 children from 5 to 12 years of age from 15 different schools. Participants with LDL in the lowest 5th percentile were classified as having loudness hypersensitivity; an abnormal annoyance to sounds if they responded "yes" to the question "Are you bothered by any kind of sounds or noise?" could describe the sound, and were able to identify at least 10 sounds from a list of 20 as being annoying. Phonophobia was defined as a fear of sound. Children with LDL in the lowest 5th percentile typically had LDLs lower than 90 dB HL; 42% of the participants in this group were bothered by sounds and 3.2% had hyperacusis. Fifty percent of the participants with hyperacusis had tinnitus and mild hearing loss in the left ear was an associated risk factor. Phonophobia was experienced by 9% of the children. It is concluded that hyperacusis in children is prevalent, and should be considered in clinical examinations.

Tinnitus in children and associated risk factors.

The objective of the study was to estimate the prevalence of tinnitus and explore the risk factors in school-aged children age 5-12 years. For that we asked "Do you hear a noise inside your ears/head?" and required children to be able to describe the sounds perceived and their location. We refer to this as tinnitus sensation. Additionally, we asked "Does it bother or annoy you?" and "In what situations does it bother or annoy you?" to determine if this experience was bothersome. We refer to this as tinnitus annoyance. Associations to demographic and audiological factors were studied. Approximately 37% of children reported tinnitus sensation and 17% reported tinnitus annoyance. Related factors were age, hearing loss, and history of noise exposure, motion sickness and hyperacusis. Estimates of the prevalence of tinnitus clearly depend on how tinnitus is defined. In the present study, participants were asked "Do you hear a noise inside your ears/head?" but we did not make distinctions regarding the duration or character of their tinnitus. Our estimates of tinnitus annoyance were also broad, and did not attempt to quantify the degree of annoyance.

Zinc as a possible treatment for tinnitus.

Zinc is an essential trace element present in all organs, tissues, fluids, and secretions of the body and it is widely distributed in the central nervous system, including the auditory pathway in synapses of the VIII nerve and in the cochlea. Zinc is an essential component of Cu/Zn superoxide dismutase (SOD) and in certain enzymes and it is important for proper function of the immune system. Three possible mechanisms have linked zinc to tinnitus; cochlear Cu/Zn SOD activity, synaptic transmission, and depression. Evidences in the literature suggest prevalence rates of zinc deficiency in individuals with tinnitus from 2 to 69%, affecting elderly individuals more frequently. Four among five small studies indicate that administration of zinc has a beneficial effect on tinnitus but these results still have to be confirmed in clinical trials with larger samples using a cross-over design, validated tinnitus handicap questionnaires, measurements of tinnitus magnitude, and accessing the coexistence of other symptoms such as depression, phonophobia, and hyperacusis.