Epilepsy surgery in children: results and predictors of outcome on seizures.
OBJECTIVE
To retrospectively analyze the results on seizures of surgery in children with drug-resistant focal epilepsy. To identify the factors predicting seizure control among several presurgical, surgical, and postsurgical variables.


METHODS
One hundred thirteen patients (67 male, 46 female), younger than 16 years, operated on from 1996 to 2004 and followed-up for at least 2 years were identified. Individualized microsurgical resections, aimed at removal of the epileptogenic zone, were performed according to the results of tailored presurgical evaluations, which included stereo-electroencephalographic recording with intracerebral electrodes when needed. Risk of seizure recurrence was assessed for the considered variables by bivariate and multivariate analysis.


RESULTS
Mean age at surgery was 8.8 years, mean duration of epilepsy was 5.7 years, and mean age at seizure onset was 3.1 years. One hundred eight patients (96%) had an abnormal magnetic resonance imaging. At postoperative follow-up (mean duration 55.1 month), 77 patients (68%) were in Engel's class I, with 68 patients (60%) being seizure free (Engel's classes Ia and Ic). At multivariate analysis, variables associated with a significantly lower risk of seizure recurrence were unifocal lesion at MRI and older age at seizure onset (presurgical variables), temporal unilobar resection and complete lesionectomy (surgical variables), diagnosis of glial-neuronal tumors (postsurgical variables).


CONCLUSIONS
Surgery is a valuable option for children with drug-resistant focal epilepsies which may provide excellent results in a considerable amount of cases. Since results of surgery for epilepsy strongly depend on the presurgical identification of the Epileptogenic Zone, future work should be focused on refinement and implementation of diagnostic strategies.
Cossu
Massimo
M
C. Munari, Center for Epilepsy Surgery, Ospedale Niguarda, Milan, Italy. massimo.cossu@ospedaleniguarda.it
Lo Russo
Giorgio
G
Francione
Stefano
S
Mai
Roberto
R
Nobili
Lino
L
Sartori
Ivana
I
Tassi
Laura
L
Citterio
Alberto
A
Colombo
Nadia
N
Bramerio
Manuela
M
Galli
Carlo
C
Castana
Laura
L
Cardinale
Francesco
F
D000367:Age Factors; D017668:Age of Onset; D038481:Anterior Temporal Lobectomy; D002540:Cerebral Cortex / Q000002:abnormalities / Q000601:surgery; D002648:Child; D018572:Disease-Free Survival; D004351:Drug Resistance; D004569:Electroencephalography / Q000379:methods / Q000706:statistics & numerical data; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000188:drug therapy / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008866:Microsurgery / Q000379:methods; D015999:Multivariate Analysis; D011300:Preoperative Care; D011379:Prognosis; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D013238:Stereotaxic Techniques; D013702:Temporal Lobe / Q000601:surgery; D016896:Treatment Outcome