Single-pulse electrical stimulation identifies epileptogenic frontal cortex in the human brain.

Area of Science:

• Neuroscience
• Epileptology
• Neurosurgery

Background:

• Presurgical assessment is crucial for epilepsy surgery planning.
• Identifying the epileptogenic zone is key to successful surgical outcomes.
• Frontal lobe epilepsy presents unique diagnostic challenges.

Purpose of the Study:

• To evaluate the utility of single-pulse electrical stimulation (SPES) in localizing the frontal epileptogenic cortex.
• To determine if SPES can aid in presurgical assessment for frontal epilepsy.
• To correlate SPES findings with surgical outcomes.

Main Methods:

• Single-pulse electrical stimulation (SPES) was applied to 30 patients with intracranial electrodes in the frontal lobes.
• Patients were categorized into frontal epilepsy (17) and extrafrontal epilepsy (13) groups.
• Responses to SPES were analyzed, categorizing them into early and late responses (delayed and repetitive).

Main Results:

• Late responses to SPES, specifically delayed and repetitive responses, were observed in frontal and extrafrontal areas.
• Frontal late responses were more frequently seen in patients with frontal epilepsy (13/17) and correlated with neuropathologic abnormalities.
• Resection of abnormal SPES areas in frontal epilepsy patients led to favorable postsurgical seizure control.

Conclusions:

• Single-pulse electrical stimulation (SPES) is a valuable tool for identifying frontal epileptogenicity during presurgical evaluation.
• SPES can assist in cases with unclear seizure origins, normal imaging, or limited telemetry data.
• This technique enhances the localization of epileptogenic cortex, potentially improving surgical planning and outcomes.