Abstracts

Rationale: The study is done to determine ASL lateralization in lesional epilepsy, and assess the role of lesion type and seizure frequency in ASL co-lateralization.Methods: From the epilepsy surgery database, patients with lesional epilepsy (temporal and extra-temporal) were identified. A total of 17 patients with unilateral MRI lesion and ASL study prior to surgery were included in the study. Clinical, imaging, and pathologic reports were reviewed from medical records. ASL study was reviewed qualitatively by a neuroradiologist blinded to the patient information. Focal cortical dysplasia was diagnosed based on MRI and pathology report.Results: 17 patients, 10/17 (59%) female and 7/10 (41%) male, had ASL data prior to surgery. The median age at first surgery is 7.7 years (0.2-17.1 years). Only 2 (12%) patients had temporal lobe lesion; the rest, 15 (88%), had extra-temporal lesion. Twelve patients had cortical migrational abnormalities including focal cortical dysplasia. In 9 out of 17 children (53%), the ASL abnormality (hypo or hyperperfusion) was concordant with the lesion lateralization on MRI. ASL concordance with MRI was higher in cortical migrational abnormalities, 58 %( 7/12) as compared to 40% (2/5) in other lesions. In 8 out of 12 children (67%) with daily seizures the ASL abnormality co-lateralized with the side of the lesion as compared to 2 out of 5 children (40%) in children with less than daily seizures.Conclusions: ASL co-lateralization appears to be higher in cortical dysplasia and in children with frequent seizures. Future studies should look into the utility of ASL as part of pre-surgical evaluation in lesional and non-lesional epilepsy.