Can sharp waves localized at the sphenoidal electrode accurately identify a mesio-temporal epileptogenic focus?

Area of Science:

• Neurosurgery
• Epilepsy Research
• Clinical Neurology

Background:

• Antero-temporal lobectomy is a surgical option for refractory epilepsy.
• Accurate localization of the seizure onset zone is crucial for successful surgical outcomes.
• Interictal scalp EEG findings can sometimes be difficult to interpret for precise localization.

Purpose of the Study:

• To investigate the predictive value of a unilateral sphenoidal/antero-temporal interictal focus for seizure onset location.
• To assess the correlation between this EEG finding and surgical outcomes following antero-temporal lobectomy.

Main Methods:

• Retrospective analysis of 20 patients who underwent antero-temporal lobectomy.
• All patients had normal computed tomography (CT) scans.
• Invasive electroencephalography (EEG) recordings using subdural electrode arrays were performed.

Main Results:

• A unilateral sphenoidal/antero-temporal interictal focus was identified in all 20 patients.
• This scalp EEG finding correctly predicted the mesiobasal/anterotemporal location of interictal sharp waves and ictal onset on subdural arrays for all patients.
• Seventy-five percent of patients achieved an excellent outcome after temporal lobectomy.

Conclusions:

• The presence of a unilateral sphenoidal/antero-temporal interictal focus is a reliable predictor of seizure origin in the mesiobasal/anterotemporal region.
• This EEG pattern is associated with favorable outcomes following antero-temporal lobectomy.
• Invasive EEG monitoring confirms the predictive value of scalp EEG findings in epilepsy surgery planning.