Parietal Lobe Epilepsy: Surgical Treatment and Outcome

Abstract

Objective: 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. Methods: 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. Results: 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%). Conclusion: 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.

Surgical treatment of parietal lobe epilepsy

“…20,21 Nearly all (37 [97%] of 38 patients) underwent invasive intracranial monitoring to determine the epileptogenic zone. In this series, there was a higher proportion of cortical dysplasia (94%) than in other studies.…”

“…Many authors have grouped parietal, occipital, and occipitotemporal epilepsies together as posterior cortex epilepsies, 2,3,8,9 whereas others have separately analyzed parietal lobe lesional epilepsies. 4,11,16,20,21,38 No matter the grouping, seizure freedom has been reported in ~ 40-60% of patients; however, the diversity of pathological findings, inclusion criteria, and outcome classification scales makes comparisons difficult.…”

Long-term outcome of lesional posterior cortical epilepsy surgery in adults

“…As no clear anatomical or neurophysiological distinctions are apparent between posterior cortical areas, epilepsies originating from these areas are probably better analysed and understood when grouped together 1 – 4. Surgery is becoming increasingly popular in PCE patients, and the superiority of surgical treatment has been proved 5 6…”

Longitudinal Change in Outcome of Frontal Lobe Epilepsy Surgery

“…20 Although ictal SPECT theoretically is a very good diagnostic method, the changeover to a postictal hypoperfusion state may occur very quickly in FLE. 3,14,24 To obtain an exact ictal SPECT, the isotope should be injected at the time of seizure. 5,14,24 Without an automated injector or standby medical personnel, this is difficult, and the results sometimes are misleading.…”

“…3,14,24 To obtain an exact ictal SPECT, the isotope should be injected at the time of seizure. 5,14,24 Without an automated injector or standby medical personnel, this is difficult, and the results sometimes are misleading. 5,14,24 That may explain the low diagnostic value of ictal SPECT observed in our study.…”