Can vestibular-evoked myogenic potentials be used in the assessment of reflex habituation? A preliminary report

Background: Vestibular-evoked myogenic potentials (VEMPs) provide an electrophysiological evaluation of vestibular reflexes. The aim of the study was to search for the habituation of ocular and cervical VEMPs (cVEMPs). Materials and Methods: A total of 20 healthy volunteers (10 men and 10 women), with a mean age of 32.4 years (range: 25-45 years) were included in the study. cVEMP and ocular VEMP (oVEMP) tests were performed using "click stimuli." In cVEMP and oVEMP tests, the latency and amplitude of the responses recorded with 100 and 250 stimulus sequences were compared. Results: When the traces recorded with 100 repetitions for both tests were compared with the traces obtained with 250 repetitions, it was observed that the latencies increased while the amplitudes decreased with increasing number of stimuli, which was statistically significant. Conclusion: Our results showed that an increase in the number of stimuli in oVEMP and cVEMP tests in healthy individuals led to a decrease in amplitude and an increase in latency. As noninvasive, short, and inexpensive evaluation methods, VEMP tests may be used in evaluating the "habituation response" and may find new areas of investigation.