Audiological Profile in Patients with Hypothyroidism and Hyperthyroidism

Abstract

Aim of the study: Thyroid hormone is important for the normal function of the auditory system. The aim and objective of the study were to investigate the audiological profile in hypothyroidism (group 1) and hyperthyroidism (group 2), to compare the audiological profile between the hypothyroidism and hyperthyroidism. Material and methods: There were 30 subjects in control group (CG) and 42 subjects (22-hypothyroidism and 20-hyperthyroidism) in study group between age ranges 18-45 years. Impedance audiometry, acoustic reflex, OAE, PTA, extended high frequency audiometry and ABR were performed on all subjects. Results: Subjects had type-A tympanogram were enrolled in the study. Acoustic reflex thresholds of group 1 and group 2 were elevated both ipsilaterally and contralaterally as compared to CG. In otoacoustic emission, TEOAEs showed decreased SNR in group 1 and group 2 as compared to CG in both ears. However no significant difference was observed between two study groups viz. group 1 and 2. Whereas significant difference (p<0.05) was observed in DPOAEs among CG, group 1, and 2. 77.3% of the subjects in group 1 and 84.6% of the subjects group 2 had minimal hearing loss. Extended high frequency thresholds showed elevated thresholds in group 2 and 3 as compared to group 1. Highly significant (<0.01) difference was observed for absolute latency of wave I and a significant (p<0.05) for waves III and V between CG and group 1 in both ears. No significant (p>0.05) difference was found for interpeak latency between waves I-III, I-V and III-V in either ears in either group. Conclusion: Both hypothyroidism and hyperthyroidism have auditory impairment with minimal degree and it mainly affects cochlea not the external and middle ear. In hypothyroidism cases auditory brainstem is involved. Auditory impairment is more in hypothyroidism as compared to hyperthyroidism.