Hemispherotomy: efficacy and analysis of seizure recurrence.
OBJECTIVE
Hemispherotomy generally is performed in hemiparetic patients with severe, intractable epilepsy arising from one cerebral hemisphere. In this study, the authors evaluate the efficacy of hemispherotomy and present an analysis of the factors influencing seizure recurrence following the operation.


METHODS
The authors performed a retrospective review of 49 patients (ages 0.2-20.5 years) who underwent functional hemispherotomy at their institution. The first 14 cases were traditional functional hemispherotomies, and included temporal lobectomy, while the latter 35 were performed using a modified periinsular technique that the authors adopted in 2003.


RESULTS
Thirty-eight of the 49 patients (77.6%) were seizure free at the termination of the study (mean follow-up 28.6 months). Of the 11 patients who were not seizure free, all had significant improvement in seizure frequency, with 6 patients (12.2%) achieving Engel Class II outcome and 5 patients (10.2%) achieving Engel Class III. There were no cases of Engel Class IV outcome. The effect of hemispherotomy was durable over time with no significant change in Engel class over the postoperative follow-up period. There was no statistical difference in outcome between surgery types. Analysis of factors contributing to seizure recurrence after hemispherotomy revealed no statistically significant predictors of treatment failure, although bilateral electrographic abnormalities on the preoperative electroencephalogram demonstrated a trend toward a worse outcome.


CONCLUSIONS
In the present study, hemispherotomy resulted in freedom from seizures in nearly 78% of patients; worthwhile improvement was demonstrated in all patients. The seizure reduction observed after hemispherotomy was durable over time, with only rare late failure. Bilateral electrographic abnormalities may be predictive of posthemispherotomy recurrent seizures.
Limbrick
David D
DD
Department of Neurosurgery, St. Louis Children's Hospital, Washington University School of Medicine, St. Louis, Missouri 63110-1077, USA. limbrickd@nsurg.wustl.edu
Narayan
Prithvi
P
Powers
Alexander K
AK
Ojemann
Jeffrey G
JG
Park
Tae Sung
TS
Bertrand
Mary
M
Smyth
Matthew D
MD
D000293:Adolescent; D038481:Anterior Temporal Lobectomy / Q000379:methods; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000601:surgery; D004827:Epilepsy / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D038421:Hemispherectomy / Q000379:methods*; D006624:Hippocampus / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008866:Microsurgery / Q000379:methods; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D012008:Recurrence; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult