Abstract:
Aim and Objectives: The present study aimed to measure the auditory brainstem response (ABR) to a paired click stimulus paradigm in individuals with vestibular migraine (VM). The response waveforms were measured and compared with the age and gender matched controls to detect the possible subclinical auditory dysfunction in VM patients.
Methods: The standard group comparison consisted of two groups in the age range of 18 – 50 years. Group 1 included normal hearing individuals without VM, and Group 2 consisted of normal hearing individuals with VM. ABR with a paired click stimulus paradigm at five different inter-click intervals (ICI = 0 ms, 3 ms, 5 ms, 7 ms, and 10 ms) was measured for all the participants. The absolute latencies and amplitudes of ABR peaks I, III, and V, the latency delay and amplitude reduction of the second click response, along with the peak I/V amplitude ratios and root mean square post-peak 1 (RMS post-P1) amplitude, were measured across the ICIs and compared between the groups.
Results and Discussion: Group 1 was found to have significantly delayed peak latencies for earlier peaks (I and III), whereas the Peak V latency remained the same for both groups. The peak amplitude and I/V amplitude ratios did not vary significantly between the groups. However, the RMS post-P1 amplitude was significantly lower for Group 1 compared to that of Group 2, especially for shorter ICIs. A significant ICI effect was also observed where shorter ICIs had poorer responses in Group 1, indicating the compromised auditory neural recovery in these patients.
Conclusion: The present study provides evidence of paired click stimuli as an electrophysiological measure of subclinical auditory processing abnormalities in VM. The use of paired click ABR, especially with a shorter ICI (<7 ms), proves to be a valuable tool in detecting subtle auditory nerve dysfunctions that may not be evident in standard audiological or behavioural assessments.
