Microsurgery of epileptic foci in the insular region.
OBJECTIVE
The insular region has long been neglected in the investigation and treatment of refractory epilepsy. Surgery in the insular region is rarely performed because of the risk of injury to the opercula, the arteries transiting on the surface of the insula, and the deep structures such as the basal ganglia and the internal capsule. This study was undertaken to report the results of insular surgery using modern microsurgical techniques in patients with epilepsy.


METHODS
The authors performed a retrospective study of cases involving patients who underwent surgery for insular lesions associated with epilepsy over the last 10 years. In the majority of patients, intracranial electrodes were implanted with neuronavigation guidance to confirm the localization of the epileptic foci.


RESULTS
Nine patients underwent insular surgery: 7 for refractory epilepsy with no tumor and 2 for tumors associated with seizures. Four of the resections were performed in the left hemisphere. After an average follow-up of 54 months (range 14-122 months), Engel Class IA outcome had been achieved in 6 of 7 cases in the Epilepsy Surgery Group. The remaining patient had an Engel Class III outcome after partial insular resection but later became seizurefree (Engel Class IA) following insular Gamma Knife surgery. Postoperatively, the majority of patients suffered from minor reversible hemipareses that disappeared completely within a few months. There was no surgical mortality.


CONCLUSIONS
Insular surgery is both safe and beneficial when it is well planned and performed with modern microsurgical techniques and good anatomical knowledge. Insulectomy is associated with little permanent morbidity and a high rate of seizure control. To the authors' knowledge, this is the first series of insulectomies predominantly performed for refractory epilepsy since those performed by Penfield.
Malak
Ramez
R
Departments of Neurosurgery, Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital, Montréal, Québec, Canada.
Bouthillier
Alain
A
Carmant
Lionel
L
Cossette
Patrick
P
Giard
Normand
N
Saint-Hilaire
Jean-Marc
JM
Nguyen
Dong Bach
DB
Nguyen
Dang Khoa
DK
D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D015331:Cohort Studies; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008866:Microsurgery; D038361:Neuronavigation; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult