Assessment of vestibulo-ocular reflex with video head impulse test in epilepsy patients undergoing carbamazepine monotherapy.

OBJECTIVE: Carbamazepine may cause clinical effects such as dizziness and nystagmus. This may depend on the duration of use. The aim of this study is to measure the effect of carbamazepine monotherapy on the vestibular system electrophysiologically by using Video Head Impulse Test (VHIT) and to compare the numerical and objective data obtained between the groups.

PATIENTS AND METHODS: In this study, in which 55 people (110 ears) participated, Video Head Impulse Test (VHIT) was performed to evaluate the vestibulo-ocular reflex (VOR) in the epilepsy patients and a healthy control group consisting of healthy individuals. In addition, patients were analyzed in two groups to demonstrate the long-term effects of carbamazepine (<10 years and >10 years). Right/left lateral, anterior, posterior semi-circular canals (SCCs) VOR gains, lateral, left anterior right posterior, and right anterior right posterior gain asymmetries were measured between groups.

RESULTS: Lateral SCCs VOR gains were 0.878±0.057 and 0.921±0.045 between the patient and healthy control groups, respectively (p=0.024). A decrease in the right and left lateral SCCs VOR gains (0.885±0.062 and 0.868±0.063) was detected in the patients (p=0.011 and p=0.001). Those using carbamazepine for >10 years had a decrease in lateral SSCs VOR gains (0.843±0.055) compared to those using the drug for <10 years (0.902±0.046) (p=0.008).

CONCLUSIONS: A relative reduction in lateral (right/left) SCCs VOR gains was found in epilepsy patients using carbamazepine and in the group of patients using this drug for a long time (>10 years).