Effects of dimenhydrinate on computerized dynamic posturography

Objective: Previous studies have demonstrated that sedatives and antiemetics commonly used by patients suppress the vestibule-ocular reflexes during electronystagmography, making it more difficult to quantify function in such patients. The effects of these medications on computerized dynamic posturography (CDP) have not been studied, and the influences, if any, on the vestibulospinal reflexes are not known. We aimed to study the influence, if any, of dimenhydrinate on CDP performance. Design: A double-blinded study using a randomized protocol to compare the effects of dimenhydrinate and placebo on CDP performance in normal subjects. Setting: A tertiary/quaternary care facility using a standardized CDP assessment protocol. Methods: After a CDP training session (one assessment) to rule out any learning effect, 10 subjects underwent CDP assessment on 2 separate days after ingestion of either a standard single dose of dimenhydrinate or placebo. Main Outcome Measures: Pre- and post-medication CDP performance was measured using Sensory Organization Test (SOT) composite scores and also scores on CDP conditions particularly sensitive to measurement of vestibular impairment (SOT conditions 5 and 6). Results: Analysis of data showed no significant effect on CDP performance of normal subjects after dimenhydrinate administration, although there may be a trend toward a slight effect on performance. Conclusions: There seems to be no significant effect of dimenhydrinate on CDP performance in normal subjects, although there may be a trend. Further studies using a dose causing more significant symptoms or using a higher number of subjects may clarify this.