Cognitive functions, epileptic syndromes and antiepileptic drugs

Abstract

Cognitive function of patients on monotherapy specific for their epileptic syndrome has been studied infrequently. We evaluated 7 patients with symptomatic localised epilepsies (SEL) on phenytoin aged 30 +/- 12 (mean +/- standard deviation) years, 8 with idiopathic generalised epilepsies on sodium valproate aged 18 +/- 4 years, 16 with SEL on carbamazepine aged 28 +/- 11 years, and 35 healthy controls aged 27 +/- 11 years. All subjects were of normal intelligence, educated appropriately to age, and led productive lives in the community. Two of the patients on carbamazepine and one on valproate had less than five partial, absence or myoclonic seizures monthly, the remaining were controlled. Carbamazepine serum concentrations were 12 +/- 5 micrograms/ml, phenytoin were 23 +/- 7, and valproate were 62 +/- 23 (mean +/- sd). Tests included immediate recall and recognition for pictures, Stroop test, delayed recall and recognition of pictures. Patients on phenytoin and valproate performed significantly worse than controls on immediate recall, and patients on carbamazepine performed significantly worse than controls in Stroop test (p < 0.01). The results indicate relatively minor effects of the epileptic syndromes and of phenytoin, carbamazepine and valproate on cognition of patients with controlled epilepsy leading productive lives in the community. We conclude that the cognitive deficit found in chronic epileptic patients on poly-therapeutic drug regimen must be multifactorial, and that future studies need to control for all possible variables in order to achieve meaningful results.

Neuropsychological and behavioural aspects in children and adolescents with idiopathic epilepsy at diagnosis and after 12 months of treatment

“…Verbal, non-verbal and also deferred memory abilities appeared to be improved after 12 months of treatment, to the same extent in patients treated with valproic acid and carbamazepine. Bittencourt et al 49 showed a similar improvement, especially in patients treated with carbamazepine, while Schouten et al 50 considered the impact of treatment on memory functions in a pediatric population to be non-influential. In our cases, a marked favorable impact of treatment was also registered on executive functions.…”

A comparative study of effect of phenytoin, topiramate, and zonisamide in learning and memory of albino rats

“…Since the discovery of the powerful anticonvulsant properties of phenytoin, it has been used extensively in the treatment of tonic-clonic and partial seizures. [6][7][8] Recent evidence suggests that despite the success in controlling these types of seizures, phenytoin has negative effects on learning and memory processes. 9 Topiramate (TPM), as an antiepileptic drug (AED).…”