Parietal lobe epilepsy: surgical treatment and outcome

Parietal lobe epilepsy (PLE) is neither common nor easily diagnosed because of its variable clinical features. To elucidate its characteristics and surgical outcome, the authors reviewed their surgical experiences.

Between September 1994 and August 2001, 38 patients with PLE received surgical treatment at the Seoul National University Hospital. All patients underwent resection, mainly involving the parietal lobe.

Preoperatively, over 60% of the cases were not considered to be PLE, even though PLE was the most common diagnosis (15/38, 39.8%). An invasive study was performed in 37 of the 38 patients. Awake operations under regional anesthesia were performed in 20 patients (52.6%). Seizure disappeared in 15 (Engel's classification I, 39.5%), and rare seizure remained in 5 (Engel II, 13.2%). Thirteen patients showed a worthwhile improvement (Engel III, 34.2%), whereas 5 exhibited no worthwhile improvement (Engel IV, 13.2%). Pathologies were diverse, the most common being cortical dysplasia (94.3%).

Since PLE is difficult to diagnose preoperatively, an invasive study covering the parietal lobe is mandatory, if PLE is suspected. Cortical dysplasia was the most common etiology, thus awake operation under regional anesthesia and intraoperative brain mapping is helpful during extensive resection in order to spare the eloquent cortex.