Effect of valproic acid on spike and wave discharges in patients with absence seizures

Abstract

Twenty-five patients with absence seizures were treated with valproic acid in doses from 17 to 62.5 mg per kilogram per day. Nineteen patients experienced reduction of spike and wave discharges; in 11 it was greater than 75 percent. Twenty-one patients had a reduction of the total time of spike and wave discharge. Four patients had increase of spike and wave discharges. Nineteen patients had fewer absence seizures. There was no correlation between plasma concentration of valproic acid and EEG change, but clinical improvement occurred when plasma levels of valproic acid reached 50 to 60 microgram per milliliter.

Treatment of idiopathic generalized epilepsy – a review of the evidence

“…This, however, is mostly based on clinical experience with scant evidence-based data derived from controlled clinical trials. For instance, one of the studies supporting the efficacy of valproate against absence seizures was based on a single-blind study that showed a reduction in the frequency of generalized epileptiform discharges on the EEG of 25 patients with absence seizures [12]. In addition, three small trials indicated comparable efficacy between valproate and ethosuximide against absence seizures [13][14][15].…”

Quantitative EEG Effects and Plasma Concentration of Sodium Valproate: Acute and Long-Term Administration to Epileptic Patients

“…spikes; spike and wave discharges) [Simon and Penry, 1975;Pinder et al, 1977;Levy, 1984, for general bibliography], sodium valproate (NaVPA) is re ported to modify the patients' background EEG signal. The evidence relative to this effect [Miribel and Marinier, 1968;Adams et al, 1978;Villareal et al, 1978;Rosadini and Sannita, 1979;Sackellares et al, 1980;Benninger et al, 1985] is in part anecdotal and the find ings are controversial, with incongruities among studies of the 'profile' and time course of the EEG effects, which are possibly due to methodological differences (e.g. pa tient selection; NaVPA dose, administration, and asso ciation with other antiepileptic compounds; modalities of EEG recording, etc.).…”

“…pa tient selection; NaVPA dose, administration, and asso ciation with other antiepileptic compounds; modalities of EEG recording, etc.). Two studies report no effect [Benninger et al, 1985;Villareal et al, 1978], The appli cation of quantitative, computer-assisted procedures for background EEG analysis has been limited to four stud ies [Rosadini and Sannita, 1979;Sackellares et al, 1980;Saletu and Grunberger, 1984;Benninger et al. 1985] notwithstanding the extensive use of this method in human neuropharmacology [Fink, 1969[Fink, , 1978aItil, 1974;Herrmann, 1982;Sannita, 1986 for general bibli ography], and recommended application in the study of antiepileptic drug [Sannita, 1984;van Wieringen et al, 1987],…”

Clinical neurophysiology of epilepsy

“…Further, some antiepileptic medications, including benzodiazepines, barbiturates, and valproate, may decrease the occurrence of IEDs [13]. Valproate, in particular, may suppress spontaneous generalized IEDs and photoparoxysmal responses [14,15].…”