EFFECTS OF ANXIETY AROUSAL AND MENTAL STRESS ON THE VESTIBULOOCULAR REFLEX

Although the subjective reports of patients suggest that anxiety may a ggravate vertigo and imbalance, there has been little research into ho w anxiety might directly affect balance system functioning. We conduct ed two studies to examine the effect of anxiety and arousal on the ves tibule-ocular reflex (VOR). In the first study, pre-test fear ratings were obtained from 20 normal subjects and 36 anxious subjects immediat ely prior to rotation and caloric testing. Fear ratings were significa ntly correlated with the maximum slow-phase velocity (SPV) of nystagmu s induced by caloric testing. In the second study, we assessed the VOR response to rotation of 36 normal subjects under 3 task conditions: a ) minimal alerting (counting backwards during rotation); b) physical a rousal (induced by exertion prior to rotation); c) mental arousal (ind uced by performance of stressful mental tasks during rotation). Both t he physical and mental tasks induced a significant increase in heart r ate compared with the alerting condition. The maximum SPV of the nysta gmus induced by rotation was significantly greater during performance of the mental task than in the other two conditions. These combined re sults indicate that anxiety may influence the gain of the VOR.