Intraperitoneal dizocilpine induces cortical spike-wave seizure discharges in rats

Dizocilpine has been shown to be anticonvulsant in several experimental models of epilepsy. Nevertheless, 0.3 or 0.5 mg/kg intraperitoneal (i.p.) dizocilpine produced cortical spike-wave discharges (SWDs) in four of seven rats. The SWDs were accompanied by behavioral arrest, and also showed: a narrow range of induction times (around 25 min post-injection); hippocampal spikes closely correlated with the cortical spikes of the SWDs; a precipitous drop out of fast (45-100 Hz) cortical EEG; myoclonic bursts in nuchal EMG that began during the cortical slow waves. These findings suggest that patients being treated experimentally for stroke with non-competitive N-methyl-D-aspartate (NMDA) cation channel blockers should be monitored for seizures.