Abstracts

RATIONALE: Ictal EEG has been used as the [dsquote]gold standard[dsquote] for localizing the epileptogenic zone in patients being evaluated for epilepsy surgery. Children with extratemporal lobe epilepsy and with non-lesional epilepsy are especially challenging. SISCOM has been shown to be valuable in many adult patients with difficult to localize seizures. OBJECTIVE: (1) To determine the relationship of SISCOM to intracranial ictal EEG (ICiEEG) in children with intractable epilepsy; and (2) to determine the usefulness of SISCOM in pediatric presurgical evaluation.
METHODS: SISCOM images were reviewed by two blinded reviewers. Each SISCOM was classified as focal, regional, multifocal, or non-localizing. Each focus was classified as primary, secondary, or tertiary. The results were correlated with the ICiEEG of habitual clinical seizures and classified as concordant or nonconcordant.
RESULTS: Thirty-two of 45 children ([lte]18 years of age) who had SISCOM during presurgical evaluation underwent resective surgery. A lesion was present in 19 children, and the MRI findings were normal in 13 (41%) children. An ICiEEG was obtained in 24 of the 32 children. In 20 (83%), the SISCOM was concordant with ICiEEG. Of the 8 children who did not have ICiEEG, the SISCOM was concordant with the site of surgery in 5. Twenty-five (78%) of the 32 patients were Class I.
CONCLUSIONS: These data suggest that SISCOM images correlate strongly with ICiEEG in children with medically intractable epilepsy. They also suggest that SISCOM is useful in determining the site for placement of intracranial electrodes.