Abstracts

Rationale: Parietal lobe epilepsy in children is often difficult to treat surgically due to variable semiology, poorly localizing scalp EEG, and a high risk of functional deficit following surgery. We studied the surgical outcome and prognostic factors related to the surgical treatment of parietal lobe epilepsy in children. Methods: We retrospectively reviewed the medical records of children who underwent cortical resection of parietal lobe between 1992 and 2006 at the Children’s Medical Center, Medical College of Georgia. The extents of resection were parietal lobe only (n=16), parietal + temporal lobe (n=10), and multi-lobe resections consisting of parietal/temporal/occipital/frontal regions (n=10). We examined demographic data, clinical history, ictal semiology, interictal/ictal scalp EEG, intracranial EEG, MRI, ictal SPECT, PET, pathology, and 1-year post-operative follow up. Results: A total of 36 patients were included. The mean age of seizure onset was 34 months. The mean age at surgery was 104 months. Seventy-eight percent (28/36) had a favorable outcome (Engel’s classification I-II) including 69% (25/36) seizure free at one year post-operative evaluation. MRI was abnormal in 56% (20/36). Pathology revealed developmental malformations in 31% (11/36), mature lesions in 19% (7/36), gliosis in 39% (14/36), and 4 specimens were not available. The presence of MRI abnormality and pathological findings did not affect the surgical outcome (p=.97; p=.39 respectively). Interictal and ictal scalp EEG was localizing only in 17% (6/36). Localizing scalp EEG predicted a favorable outcome (p=.02). Out of 36 patients, 33 (92%) required intracranial EEG monitoring which revealed focal onset in 15% (5/33), regional onset in 61% (20/33), and unlocalizing in 24% (8/33) (i.e. diffuse or multifocal). There was no difference in seizure freedom between the three groups (p=0.88). Limited resection in parietal lobe only or parietal + temporal lobe predicted better outcome than the wider multi-lobe resection (p = .01). Conclusions: Our result shows that the overall surgical outcome of parietal lobe epilepsy in children is comparable to that of temporal lobe epilepsy with the development of advanced neuroimaging and aggressive utilization of intracranial EEG. Longer follow-up with a larger cohort will be necessary to confirm our findings.