Second operation after the failure of previous resection for epilepsy

Area of Science:

• Neurosurgery
• Epileptology
• Clinical Neurology

Background:

• Epilepsy surgery aims to resect epileptogenic zones but can result in recurrent seizures.
• Identifying the source of recurrent seizures after initial surgery is crucial for planning subsequent interventions.

Purpose of the Study:

• To evaluate the surgical outcomes of second operations in patients with recurrent intractable partial seizures post-epilepsy surgery.
• To analyze the location and characteristics of residual epileptogenicity contributing to seizure recurrence.

Main Methods:

• Retrospective review of 15 patients undergoing a second epilepsy surgery.
• Detailed video-electroencephalography (EEG) with invasive electrodes in 11 patients to localize ictal onset.
• Assessment of residual structural lesions and epileptogenic zones.

Main Results:

• Recurrent seizures originated remotely from previous resection in 3 patients (extratemporal) and within or near the previous resection site in 12 patients (temporal or extratemporal).
• Residual structural lesions were associated with recurrences in 5 cases (2 extratemporal, 3 temporal).
• Post-second surgery, 47% of patients were seizure-free, and 33% had >90% seizure frequency reduction, with no mortality or significant morbidity.

Conclusions:

• The extent and distribution of residual epileptogenicity after failed epilepsy surgery are highly variable.
• Second epilepsy surgery can offer significant seizure control for selected patients with recurrent intractable partial seizures.
• Accurate localization of residual epileptogenic foci is key to successful reoperation.