Evaluation of hearing loss in patients with Graves’ disease

Abstract

Hearing loss has commonly been reported in association with thyroid disorders and during treatment with propylthiouracil. The relationship between hyperthyroidism and the auditory system has not been previously investigated. The aim of this cross-sectional, case-control study was to investigate hearing loss in patients with Graves' disease (GD). The study population consisted of patients with newly diagnosed GD and healthy controls. Pure tone audiometry at frequencies of 250, 500, 1000, 2000, 4000 and 8000 Hz, along with immittance measures including tympanometry and acoustic reflex tests, were performed in all participants. Twenty-two GD patients and 22 healthy controls consented to inclusion in the study. The differences between groups with regards to age and gender distribution were statistically insignificant (P = 0.567 and P = 0.757, respectively). The hearing thresholds of right and left ears were also similar in both groups (P > 0.05). When single-ear evaluations were taken into account (total of 44 ears for both groups), hearing thresholds in the GD group were significantly higher than healthy controls at all frequencies (P < 0.05). Following testing at the designated frequencies, the only significant effect of thyrotoxicosis was observed with frequencies of 4000 and 8000 Hz. The odds ratio for having hearing loss at a frequency of 8000 HZ associated with GD was 14.97 (95% confidence interval 4.03-55.64). In patients with GD, right and left pure tone audiometric findings at a frequency of 8000 Hz correlated positively with FT3, FT4 and negatively with TSH. Our results are highly suggestive of a decrease in hearing ability in patients with GD, particularly at high frequencies. Further studies are needed to help elucidate the mechanisms behind hearing loss which develops in association with GD.

Association between Sudden Sensorineural Hearing Loss and Preexisting Thyroid Diseases: A Nationwide Case-Control Study in Taiwan

“…Moreover, studies have indicated that thyroid dysfunction is related to hypercoagulability and venous thrombosis, which may impair the cochlear circulation, thus causing SSNHL [28,29]. Impaired hearing ability has been reported in patients with autoimmune-related hyperthyroidism, particularly at high frequencies [30]. Both subclinical and overt hyperthyroidism modified the coagulation-fibrinolytic balance and induced a prothrombotic state [31,32], which may also have increased the risk of SSNHL [33,34].…”

Audiological Profile in Patients with Hypothyroidism and Hyperthyroidism

“…No study could be found in the literature reporting comparison between hypothyroidism and hyperthyroidism on extended high frequency hearing sensitivity. However, Berker et al [13] studied 22 subjects with Grave's disease had also reported sensorineural hearing loss especially at higher frequency in the majority of the subjects. [13] The auditory brainstem evoked response audiometry showed significant difference for absolute latency of wave I and III in both ears and wave V for right ear.…”

“…However, Berker et al [13] studied 22 subjects with Grave's disease had also reported sensorineural hearing loss especially at higher frequency in the majority of the subjects. [13] The auditory brainstem evoked response audiometry showed significant difference for absolute latency of wave I and III in both ears and wave V for right ear. Karlos & Chandrasekhar et al [12,20] have also reported the increased absolute latencies of waves that might be due to decreased metabolism of tissues which may result in slow conduction of periphery and poor recruitment of neuronal pool of the generators of the waves in brainstem.…”

“…Thornton AR and Jarvis SJ in a comparative study of hearing profile in hypothyroidism and hyperthyroidism in 35 patients, reported that 14 patients had same audiometric configuration at four frequencies average and 21 patients had hearing threshold above 25 dB and found that there was no significant difference between hyperthyroidism and control group's auditory profile. But they concluded that there was a significant involvement of retrocochlear auditory system in hypothyroidism patients [13].…”

Endocrine glands and hearing: Auditory manifestations of various endocrine and metabolic conditions

“…[20] Exact mechanisms are yet to be elucidated. There have also been reports of ototoxicity secondary to ANCA-positive vasculitis in patients treated with propylthiouracil, which manifests as sensorineural hearing loss.…”