Electroencephalographic study of rat hyperthermic seizures.

The behavior and EEG of rat hyperthermic convulsions was studied. We found that a long run of high-voltage slow waves without convulsions, high-voltage irregular activity consisting of spikes and waves with intermittent myoclonus, and rapid spike and wave bursts accompanied by generalized clonic convulsions occurred sequentially. This behavioral and EEG activity is analogous to human febrile convulsions and supports the usefulness of this model for studies of human febrile convulsions. Rats frequently showed arrest of locomotion concurrently with paroxysmal EEG theta bursts before development of generalized convulsions. We speculate that this paroxysmal activity is a type of seizure discharge.