Quantitative analysis of motor performance in epilepsy patients treated with valproate.

Purpose: The aim of our study was to detect objective signs of deterioration of motor performance in epilepsy patients treated with chronic valproate therapy.

Methods: We examined 14 controls and 15 epilepsy patients receiving chronic valproate monotherapy, who had no subjective complaints related to motor function. Regularity and maximum frequency of repetitive hand and finger movements, and simple reaction time were measured. Intensity and frequency characteristics of resting and postural tremor were assessed using accelerometry. Data were statistically evaluated.

Results: Repetitive hand and finger movements were significantly more irregular and the maximum frequency of repetitive movements was significantly lower in the valproate group than in controls. Resting tremor peak frequency and motor reaction time of the two cohorts did not differ.

Conclusions: This is the first study, which quantitatively assesses motor performance of patients with epilepsy on chronic valproate therapy. The results suggest significant irregularity of repetitive hand movements and finger tapping even in patients with no motor complaints. Objective methods might help to recognize valproate-induced motor performance deterioration.