Is valproate encephalopathy under-recognised in older people? A case series

Abstract

Background: Valproate (VPA) is an antiepileptic drug with a broad spectrum of efficacy. Although usually well-tolerated, it may have side-effects of which encephalopathy is one of the most serious. Objective: To describe the clinical characteristics of valproate encephalopathy (VE) in five older patients with remote symptomatic seizures treated with rapid VPA loading. Design: Case series. Setting: Teaching hospital Patients: Five patients (71-89 years old) with underlying cerebrovascular diseas or dementi and symptomatic seizures. Results: VE was characterised by decline in conscious level and (in some cases) increase in seizure frequency. Three of the five patients had elevated ammonia levels. EEG showed generalised slow activity, in some cases accompanied by additional epileptic discharges. The condition was reversible in four patients after VPA discontinuation. One patient died. Conclusions: Older people may be at particular risk of VE because of co-morbid pathology, age-related metabolic changes and co-medication. Copyright © The Author 2007. Published by Oxford University Press on behalf of the British Geriatrics Society.