Alonso-Juarez M, et al. - The clinicians performed this study to investigate the clinical features and functional effect of valproate-induced tremor. Among patients taking valproate, the tremor was frequently observed and was severe enough to require treatment in approximately 24% of cases.

Methods

• A cohort of patients treated with anticonvulsants for neurological disorders, through blinded evaluations using the Clinical Rating Scale for Tremor (CRST) was studied.
• The frequency, severity and functional impact of drug-induced tremor were compared between patients treated with valproate and those treated with other anticonvulsants.

Results

• In this study, 171 were fully evaluated from a cohort of 218 consecutive patients.
• 118 patients were taking valproate alone or combined with other anticonvulsants and 53 patients were taking other anticonvulsants.
• At the evaluation of the cohort, mean age (±SD) was 32 ± 13 years, females represented 55.6% of cases.
• The clinicians observed tremor more frequently in patients taking valproate particularly postural upper limb tremor: 49% vs. 15% (right-side) (P < 0.001) and 48.3% vs. 13.2% (left-side), (P < 0.001).
• These patients had a higher total CRST score: 12.14 vs. 3.06 (P < 0.001), and required more frequent treatment for drug-induced tremor: 23.7% vs. 5.6% (P=0.005) compared with patients taking other anticonvulsants.
• Women had a higher total CRST score compared with men: 14.54 ± 14.9 vs. 9.56 ± 9.55 (P=0.034) among 118 patients taking valproate.
• They observed a weak correlation between the total CRST score, dose per Kg of valproate and serum levels of valproate.