Drug-resistant temporal lobe epilepsy with temporal encephaloceles: How far to resect

Area of Science:

• Neurosurgery
• Epileptology
• Neuroradiology

Background:

• Drug-resistant temporal lobe epilepsy (DR-TLE) with temporal encephaloceles (TE) presents diagnostic and surgical challenges.
• Temporal encephaloceles are often missed on initial imaging, requiring expert review or advanced techniques for detection.

Purpose of the Study:

• To evaluate the impact of surgical extent on seizure outcomes in patients with DR-TLE and TE.
• To assess the effect of surgical extent on neuropsychometric outcomes, particularly verbal memory, in a subset of patients with dominant DR-TLE.

Main Methods:

• Retrospective single-institution study of 34 patients with DR-TLE and TE (January 2008 - December 2020).
• Comparison of seizure and neuropsychometric outcomes between limited resection and standard anterior temporal lobectomy and amygdalohippocampectomy (ATLAH).

Main Results:

• Temporal encephaloceles were frequently overlooked, detected via expert re-review or advanced imaging in 91% of cases.
• No significant difference in seizure-free outcomes (Engel I/II) between limited resection (47%) and ATLAH (53%).
• Verbal memory decline was more frequent after ATLAH compared to limited resection in dominant DR-TLE cases (p=0.014).

Conclusions:

• Improved identification of TE through expert imaging review and multi-modal techniques is crucial.
• Surgical extent does not statistically influence seizure-free outcomes in DR-TLE with TE.
• Limited resection may be preferable in dominant temporal lobe cases to preserve verbal memory.