Valproate-induced rest tremor and parkinsonism

Area of Science:

• Neurology
• Pharmacology

Background:

• Valproate is known to cause tremor and parkinsonism.
• The specific relationship between rest tremor and parkinsonism in valproate-treated patients remains unclear.

Purpose of the Study:

• To investigate the association between rest tremor and other parkinsonian signs in patients taking valproate.
• To determine the frequency of valproate-induced parkinsonism and rest tremor.

Main Methods:

• A cohort of 125 patients treated with valproate for epilepsy or migraine was evaluated.
• The Fahn-Tolosa-Marin Tremor Rating Scale (FTM-TRS) was used for assessment.
• Patients were assessed for rest tremor and signs of parkinsonism.

Main Results:

• Rest tremor was identified in 11.2% of the patients (14 out of 125).
• Patients with rest tremor showed significantly higher FTM-TRS scores (P < 0.001).
• Only one patient was diagnosed with parkinsonism, suggesting rest tremor is not always indicative of parkinsonism.

Conclusions:

• Rest tremor is a notable side effect in 11.2% of patients on valproate.
• Valproate-induced tremor burden, rather than parkinsonism, is associated with rest tremor.
• Valproate may cause parkinsonism or worsen existing Parkinson's disease motor features.