Levetiracetam is not effective for essential tremor

Objective: To determine if levetiracetam is efficacious in the treatment of essential tremor. Methods: Fifteen patients (3 women), aged 35 to 83 years, with essential tremor were studied in a doubleblind, placebo-controlled crossover trial of levetiracetam. During the 2 treatment periods, levetiracetam or placebo was titrated from 500 to 3000 mg/d during a 5-week titration phase, as tolerated, and the maximum tolerated dosage was then maintained for 4 weeks. There was a 3-week washout phase between the 2 treatment periods. Patients were assessed with the Fahn-Tolosa-Marin tremor rating scale (TRS), and tremor in the spiral and line drawings of 7 patients was quantified with a computerized digitizing tablet. Changes in other antitremor medications (10 patients) were not permitted during the study. Results: The planned enrollment of 45 patients was stopped when an interim analysis of the first 15 patients revealed no efficacy. One patient failed to achieve the 3000-mg/d dosage of levetiracetam. Three patients dropped out of the study due to lack of efficacy and other side effects. The analysis of TRS data with these three patients excluded and after imputing their missing data (last value carried forward) revealed a statistically insignificant trend for all TRS and tablet measures to be worse when patients were taking levetiracetam. There was no period effect or treatment-period interaction for any measure of tremor. The results were the same for the 5 patients taking no other antitremor medications. Conclusions: Levetiracetam is not beneficial in the treatment of essential tremor.