Study of Auditory Brainstem Evoked Response at Varying Frequencies in Subclinical Hypothyroid Subjects

BACKGROUND: Hearing deterioration in hypothyroid subject was documented by Kemp. Cristiane et al. reported delayed waves latency in subclinical hypothyroid subjects. Recording of auditory brain stem evoked response in subclinical hypothyroid subjects at 80 dB and varying frequencies has been done. MATERIALS AND METHODS: Case control study. Group 1, N = 30 control subjects, free T3, free T4, thyroid stimulating hormone (TSH) within normal range. Group 2, N = 30 subclinical hypothyroid subjects, TSH was between 4.6-8 microIU/L. Student Unpaired t test was done. Those on epileptic, neuroleptics, depression, psychosis drugs, inflammatory, proliferative, traumatic ear disorder, smokers, on tobacco, COVID-19 positive subjects, altered sensorium, drug abuse, diabetes mellitus, neuropathy, hypertension, cardiac arrhythmia, family history of hearing disorder, and furosemide drug were excluded. Auditory brainstem evoked response (ABER) done. RESULTS: Mean ± SD of Brainstem evoked response auditory (BERA) waves III, V, interpeak latencies at 80 dB, 2, 4,6 KHz reported delay and significant in subclinical hypothyroid group as compared to control. CONCLUSION: BERA study at 6 KHz and 80 dB detects central neuropathy earlier in subclinical hypothyroid patients.