Monthly Case

A 83-year-old female patient had her first two focal seizures with impaired awareness (previously termed: complex-partial seizure) some weeks ago. CCT demonstrated moderate vascular leukencephalopathy, but the patient did not suffer from clinically relevant cognitive deficits. Two unprovoked epileptic seizures are associated with an increased risk for further seizures, this defines epilepsy and generally presents an indication for antiepileptic drug treatment.

In another hospital, the patient was administered valproic acid, the dose was stepwisely increased to 1,200 mg per day. Timely, the family observed that the patient‘s mental capabilities were significantly impaired. On admission to our hospital, the serum concentration of valproic acid was 130 mg/l (reference: 40 – 100 mg/l). We assumed vaproate encephalopathy and changed the medication to monotherapy with lacosamide 75 twice daily. Within days, the patient’s cognitive impairment normalized.

This case illustrates the limitations of valproic acid. These not only comprise teratogenicity if taken by woman of child-bearing potential, but also the risk of encephalopathy in elderly patients.

Valproic acid is an excellent anticonvulsant in generalized genetic epilepsies (previously termed: idiopathic generalized epilepsy), but these generally do not manifest in the second half of life. In focal epilepsies, this compound has approval but there is a plethora of more suitable drugs; the guidelines of the German Society for Neurology recommend for monotherapy lamotrigine and levetiracetam, but also eslicarbazepineacetate, lacosamide and zonisamide.

In summary, valproic acid should be administered to elderly patients only with caution, new treatment with this anticonvulsant should be avoided at all due to lack of a clear indication and the profile of adverse events.

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