BACKGROUND Tremor frequently occurs in patients taking valproate and may resemble that observed in patients with essential tremor (ET). We aimed to compare the distribution, severity, and functional impact of both types of tremor. METHODS Among 118 consecutive individuals taking valproate, we identified 28 patients with valproate-induced tremor severe enough to require pharmacological treatment; through evaluations using the Clinical Rating Scale for Tremor (CRST), they were compared with 29 consecutive patients with ET. RESULTS Patients with valproate-induced tremor were significantly younger than those with ET: 35.6 ± 15.4 vs 58.8 ± 20.5 years (P
