Cortical Stimulation of the Epileptogenic Zone for the Treatment of Focal Motor Seizures: An Experimental Study in the Nonhuman Primate

BACKGROUND: Cortical stimulation is under investigation in clinical trials of drug-resistant epilepsy. Results are heterogeneous; therefore, more evidence from animal studies is required. OBJECTIVE: To investigate the therapeutic effects of parameters of direct stimulation of the cortical focus in a Macaca fascicularis presenting focal motor epilepsy. METHODS: We developed a model of motor seizures after intracortical injection of penicillin G in the primary motor cortex of a Macaca fascicularis. We performed electric epidural cortical stimulation at low, medium, and high frequency using continuous or short-term stimulation. Short-term stimulation was triggered on seizure onset, either visually or automatically with a seizure detection algorithm connected to a programmable stimulator. RESULTS: Automated detection could detect 100% of the seizures, but ensuing cortical electric stimulation failed to abort seizures. CONCLUSION: This study demonstrates the inefficacy of the stimulation of the cortical focus to prevent seizures induced by local injection of penicillin G. Because this model may be too severe to allow comparison to human epilepsies, further work is required in other monkey models of focal epilepsy.