Introduction: Clinical observations have suggested an anti-dyskinetic effect for levetiracetam and experiments in primates show improvement of dyskinesia in the MPTP-induced model of parkinsonism.
Hypothesis: Levetiracetam possesses clinically useful anti-dyskinetic effects in Parkinson’s disease.
Methodology: This was a randomized, double blinded, placebo controlled cross-over prospective cohort study. Participants were assigned to take levetiracetam or placebo in two 6 week study phases, with a 4 week washout period. The levetiracetam dose was titrated to a maximum of 2000mg per day. Patients recorded involuntary movements in a diary kept during the last week of each treatment phase. Objective measurements consisted of hourly videotaped dyskinesia assessments scored by the Goetz method, and hourly UPDRS motor subscale scoring. This was performed on one day at the end of each treatment phase on usual medication. Mann-Whitney Rank Sum t test was used for statistical comparisons.
Study results: 16 participants with PD and levodopa-induced dyskinesia were enrolled in the study. Mean age was 66±7.36 and mean disease duration was 11±3.9 years. The Goetz dyskinesia total signed rank was 55 for levetiracetam and 51 for placebo (P=0.26), and the sum of dyskinesia rank from patient diaries was 30 and 25 (P=0.10) respectively. Parkinsonism was slightly worse on levetiracetam by UPDRS scores (P=0.05). The hypothesis was rejected (CI: 95%)
Conclusion: We could detect no anti-dyskinetic effect for levetiracetam. Many of our subjects had moderate dyskinesia, so any future efforts to look for role for this drug in PD should probably concentrate on patients disabled by severe levodopa-induced dyskinesia.