SEEG guided hippocampus-sparing resection in mesial temporal lobe epilepsy

Area of Science:

• Neurosurgery
• Epileptology
• Neurophysiology

Background:

• Mesial temporal lobe epilepsy (MTLE) is a common epilepsy syndrome.
• Anterior temporal lobectomy (ATL) is a standard surgical treatment for MTLE.
• Hippocampal involvement in seizure onset is a key factor in surgical decision-making.

Purpose of the Study:

• To describe the clinical, neurophysiological, and radiological characteristics of patients undergoing hippocampus-sparing anterior temporal lobectomy (hs-ATL).
• To emphasize the role of stereoelectroencephalography (SEEG) in guiding the decision to spare the hippocampus.
• To evaluate the efficacy and safety of hs-ATL in selected MTLE patients.

Main Methods:

• Retrospective analysis of four patients with mesial TLE who underwent hs-ATL and SEEG at a single center.
• Detailed reporting of clinical history, presurgical evaluation, neuroimaging, and SEEG findings.
• Analysis of post-operative seizure control and neuropsychological outcomes.

Main Results:

• Three patients had SEEG-documented seizures originating from the amygdala before hippocampal involvement.
• One patient had habitual seizures induced by amygdala stimulation during SEEG.
• All four patients achieved seizure freedom (Engel IA or IB) after hs-ATL.
• Post-operative neuropsychological assessments showed stable or improved deficits.

Conclusions:

• Hippocampus-sparing anterior temporal lobectomy is a safe and effective treatment for MTLE when the hippocampus is not the seizure onset zone.
• Stereoelectroencephalography (SEEG) is crucial for identifying the seizure onset zone and guiding the decision to spare the hippocampus.
• A multidisciplinary approach integrating SEEG, neuroimaging, and neuropsychological data is essential for optimal patient selection and surgical planning.