Surgical outcomes in lesional and non-lesional epilepsy: a systematic review and meta-analysis.
OBJECTIVE
To provide evidence-based quantitative summary estimates of seizure outcomes in patients with non-lesional and lesional epilepsy treated with surgery, and to assess the consistency of results among published studies.


METHODS
An exhaustive literature search identified articles published since 1995, describing outcomes according to lesional status in patients of any age who underwent resective epilepsy surgery. Two reviewers independently assessed study eligibility and extracted the data. Disagreements were resolved through discussion. Random effects meta-analyses were used after assessing the dataset for heterogeneity.


RESULTS
Forty articles fulfilled eligibility criteria and described outcomes in 697 patients with non-lesional epilepsy and 2860 patients with lesional epilepsy. Overall, the odds of being seizure-free after surgery were 2.5 times higher in patients with lesions on MRI or histopathology (OR 2.5, 95%CI 2.1, 3.0, p<0.001). In patients with temporal lobe epilepsy surgery the odds were 2.7 times higher in those with lesions (OR 2.7, 95%CI 2.1, 3.5, p<0.001). In patients with extratemporal epilepsy surgery the odds were 2.9 higher in those with lesions (OR 2.9, 95%CI 1.6, 5.1, p<0.001). Outcomes were similar in children, adults, and studies that used MRI or histopathology to identify lesions.


CONCLUSIONS
Overall, the odds of seizure freedom after surgery are two to three times higher in the presence of a lesion on histopathology or MRI. The results are clinically and statistically significant, consistent across various subgroups, and quite homogeneous across studies.
Department of Medicine, Division of Neurology, University of Saskatchewan, Saskatoon, Canada. jft084@mail.usask.ca
José F
JF
Téllez-Zenteno
Lizbeth
L
Hernández Ronquillo
Farzad
F
Moien-Afshari
Samuel
S
Wiebe
D000328:Adult; D001921:Brain / Q000473:pathology / Q000601:surgery*; D002648:Child; D016001:Confidence Intervals; D004827:Epilepsy / Q000209:etiology / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D004833:Epilepsy, Temporal Lobe / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D009493:Neurosurgery / Q000379:methods*; D016017:Odds Ratio; D011184:Postoperative Period; D011379:Prognosis; D012640:Seizures / Q000503:physiopathology / Q000601:surgery; D013702:Temporal Lobe / Q000601:surgery; D016896:Treatment Outcome