EEG predicts surgical outcome in lesional frontal lobe epilepsy.
BACKGROUND
Because of the relatively poor results of frontal lobe epilepsy (FLE) surgery, identification of prognostic factors for surgical outcome is of great importance.


METHODS
To identify predictive factors for FLE surgery, we analyzed the data of 61 patients (mean age at surgery 19.2) who had undergone presurgical evaluation and resective surgery in the frontal lobe. Postoperative follow-up ranged from 0.5 to 5 years (mean 1.78). Fifty-nine patients had MRI-detectable lesions. Histopathologic examination showed dysplasia (57.4%), tumor (16.4%), or other lesions (26.2%). Thirty postoperatively seizure-free patients were compared with 31 non-seizure-free patients with respect to clinical history, seizure semiology, EEG and neuroimaging data, resected area, and postoperative data including histopathology.


RESULTS
Three preoperative and two postoperative variables were related to poor outcome: generalized epileptiform discharges, generalized slowing, use of intracranial electrodes, incomplete resection detected by MRI, and postoperative epileptiform discharges. The only preoperative factor associated with seizure-free outcome was the absence of generalized EEG signs. Multivariate analysis showed that only the absence of generalized EEG signs predicts the outcome independently. Moreover, the occurrence of a somatosensory aura, secondarily generalized seizures, and negative MRI was identified as additional independent risk factors for poor surgical results.


CONCLUSIONS
The absence of generalized EEG signs is the most predictive variable for a seizure-free outcome in FLE surgery. Furthermore, nonlesional MRI, somatosensory aura, and secondarily generalized seizures are risk factors for poor surgical results.
Janszky
J
J
Epilepsy Surgery Department, Epilepsy Center Bethel, Bielefeld, Germany.
Jokeit
H
H
Schulz
R
R
Hoppe
M
M
Ebner
A
A
D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000601:surgery; D002648:Child; D018572:Disease-Free Survival; D004569:Electroencephalography / Q000379:methods; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005625:Frontal Lobe / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012640:Seizures / Q000175:diagnosis; D017678:Sex Distribution; D016896:Treatment Outcome