Abstracts

Rationale: The routine evaluation for epilepsy surgery often includes SPECT imaging. There are age-dependent changes in physiology that lead to differences in SPECT utility between children and adults. The subset of very young children may be different as well, and has not been previously reported in a sizable cohort. Methods: We retrospectively summarized all infants who underwent a SPECT injections for epilepsy surgery prior to the age of 1 year. Most children had more than one SPECT, and all available SPECT data was included. Resection completeness was determined using two criteria: EEG/MRI completeness and SPECT completeness. We compared the SPECT findings to outcome data regarding seizure freedom and histopathology. Results: Thirteen infants underwent SPECT as part of the evaluation for epilepsy surgery. Thirty-two SPECT studies were performed (average of 2.5 SPECT scans per patient). Age at the time of first SPECT varied between 40 days and 354 days. Outcome after the first epilepsy surgery was seizure free in 30% (n=4) and 50% or less seizure reduction in 70% (n=9). Completeness was achieved by both criteria in 15% (n=2) patients; MRI/EEG completeness was present in another 15%, and SPECT completeness alone in another 7% (n=1). None of the patients with incomplete resection by both criteria (n=8) were improved after surgery. Most (80%; n=4) of the complete resections by one or more criteria were seizure free. Conclusions: The outcome of epilepsy surgery in infants was bimodal, with all subjects either seizure free, or minimally improved (with <= 50% reduction). The completeness of resection was judged by MRI/EEG and SPECT criteria independently, and being complete in either respect was a necessary condition for seizure freedom. This is the first cohort of infants with SPECT data, and although the numbers were too small to compare the criterion of resection completeness, SPECT appears to have a valuable role in the management of infants with intractable epilepsy.