Orbitofrontal Epilepsies: Intracranial Electroencephalography and Surgical Aspects

Area of Science:

• Neurosurgery
• Epileptology
• Clinical Neurology

Background:

• Orbitofrontal epilepsies (OFE) present diagnostic challenges due to varied semiology and non-specific EEG patterns.
• Systematic studies on the surgical management and outcomes of OFE are limited.
• A 20-year surgical experience provides a basis for evaluating treatment strategies.

Purpose of the Study:

• To review current literature on OFE surgical management.
• To discuss intracranial EEG, microsurgical techniques, and outcomes in OFE.
• To analyze surgical outcomes based on a 20-year experience with 24 OFE patients.

Main Methods:

• Retrospective review of 24 patients with OFE undergoing surgery over 20 years.
• Classification of patients into purely orbitofrontal resections (OF-focal) and those with additional resections (OF-plus).
• Analysis of clinical characteristics, surgical extensions, and seizure outcomes (Engel I-II).

Main Results:

• No significant differences in age, epilepsy duration, or MRI lesions between OF-focal and OF-plus groups.
• High rates of no auras, generalized tonic-clonic seizures, and nocturnal seizures in both groups.
• Durable seizure control (Engel I-II) achieved in 50% of OF-focal and 57% of OF-plus patients.
• Seizure freedom in 36% of nonlesional cases, with 75% undergoing OF-plus resection.
• Malformation of cortical development was the most common etiology (58%).

Conclusions:

• Surgical resection for OFE yields seizure-free rates comparable to other neocortical epilepsies.
• Surgical intervention in OFE can be performed safely with minimal cognitive or functional impairment.
• OF-plus resections may offer improved outcomes in nonlesional cases.