Abstracts

Hemispherectomy for intractable epilepsy associated with unihemispheric lesions has been performed since 1928. The results of surgery in relation to age at presentation, underlying pathology, seizure type and co-existing deficits are necessary for counseling parents of candidates for epilepsy surgery. Fifty-three patients undergoing hemispherectomy between 1990 and 2003 were identified from the Children[apos]s Hospital epilepsy surgery database. Patients had received standard assessments involving clinical neurology and developmental examination, neuroradiology and neurophysiology. All patients were evaluated with MRI and video-EEG telemetry. A number of patients also underwent ictal/interictal SPECT, PET scanning and/or quantitative EEG. Twenty-one percent also had invasive EEG monitoring prior to definitive surgery.
Seizure outcome was assessed using the modified Engel scale. Pre and post-operative motor function was assessed on clinical examination. Visual field deficits were based on clinical examination and formal perimetry where possible. All children underwent formal developmental assessment by a pediatric neurologist. Behavior was assessed by neuropsychological testing or parental report.
Descriptive statistics were calculated using standard software and comparisons between groups made using non-parametric test for single and multiple group comparisons.
This study was approved by the Children[apos]s Hospital Boston Institutional Review Board. Age at surgery was 4 months to 27 years (median 2 years), with follow-up ranging from 6 months to 7 years (mean 2.5 years). Underlying pathology was acquired in 11, developmental in 22 and progressive in 20. Forty-six patients had anatomic hemispherectomy and 7 underwent functional disconnections. Twenty-three percent of patients had undergone previous surgery. At follow-up 83% were free of disabling seizures, 7% had rare disabling seizures, 2% had had worthwhile improvement and 8% had no improvement. There were 2 deaths. Seizure freedom was highest in those with developmental and progressive pathology and lowest in those with acquired pathology. Seventy-eight percent were taking 1 or less AED at follow-up. Cognitive status was improved in 66%, unchanged in 27% and worsened in 9%. Hemiplegia worsened in 70%. Fifty-three children with intractable epilepsy who underwent anatomic and functional hemispherectomy showed significant improvement in seizure outcome. Our patients overall showed improvement in cognitive and behavioral status. (Supported by the Michelle and Roger Marino Fellowship.)