Epileptiform activity in chronically isolated cerebral cortex in humans.

The ability of neuronally isolated human cerebral cortex to sustain epileptiform rhythms over long time intervals is unknown. We report here two patients after functional hemispherectomy for infantile hemiplegia and infantile meningoencephalitis. Both patients had intractable seizures. EEG performed early and up to 3 years after surgery showed persistent epileptiform activity in the isolated frontal cortex in both cases. This indicates that human isolated cortex retains its epileptogenic potential for years, independently of subcortical influences. Previous related animal and human studies are briefly reviewed.