Abstract
Background:
Migraine, the second most common type of primary headache disorder, is a complex neurological syndrome exhibiting a cyclical pattern. The attacks which are frequently associated with phonophobia, predispose patients to inflammatory auditory damage. Therefore, they remain hypersensitive to sound even during the headache free period. Frequent attacks increase the risk of otologic comorbidities early in life. Brainstem Evoked Response Audiometry (BERA), the most sensitive electrophysiological test of central nervous system dysfunction, was selected for this study to identify signal conduction defects within the auditory pathway up to brainstem projections during the interictal phase.

Aim:
This study aimed to evaluate Brainstem Auditory Evoked Potentials in terms of wave absolute latencies and interpeak latencies among migraine patients and compare them to healthy matched controls.

Methods:
This comparative, cross-sectional study was performed in the Physiology Department of SMS Medical College, Jaipur, Rajasthan, between April 2023 and June 2024 using click stimuli with rarefaction polarity. Seventy consenting participants, aged 20–40 years of both genders were divided into case and control groups, comprising of diagnosed migraine patients during the interictal phase recruited from the Neurology OPD, SMS hospital, Jaipur, and age and gender-matched healthy employees of SMS medical college, Jaipur, respectively. The brainstem potentials in terms of wave absolute and interpeak latencies were recorded at 60 dB above the sensation level (SL) binaurally. Data were analyzed using the unpaired Student’s t-test.

Results:
Migraineurs exhibited significantly longer absolute latencies of wave III and wave V as well as inter-peak latencies of waves I-V and III-V (p < 0.05) during the interictal phase compared to age- and gender-matched healthy controls. However, no significant differences were observed between the case and control groups regarding Wave I parameters.

Conclusion:
We concluded that the extent of inflammatory insult to auditory neurons causing signal conduction deficit is more pronounced within the central than a peripheral auditory pathway. BERA promises to be an efficient tool for the detection of neural dysfunction within the subcortical auditory pathway before the appearance of clinically evident signs and symptoms of impaired hearing, so as to protect them against further damage during the interictal phase.

Key words: Brainstem, Evoked Response, Migraine disorders, Headache, Hearing loss