Transcallosal resection of hypothalamic hamartoma for intractable epilepsy.

PURPOSE: To present the results of transcallosal surgical resection of hypothalamic hamartoma (HH) in 26 patients with refractory epilepsy in a prospective outcome study.
METHODS: Patients with refractory epilepsy symptomatic to HH were referred for surgical resection of their HH (mean age, 10.0 years; range, 2.1-24.2 years). A transcallosal, interforniceal approach was used to remove and/or disconnect the hamartoma. Volumetry was obtained on pre- and postoperative brain MRI scans to determine percentage of resection. Outcome assessment included determination of postoperative seizure frequencies in comparison to baseline and the incidence of postoperative complications. Postoperative changes in cognitive and behavioral functioning, in comparison to baseline, were elicited by parental report.
RESULTS: The average postoperative follow-up interval was 20.3 months (range, 13-28 months). Fourteen (54%) patients were completely seizure free, and nine (35%) had at least a 90% improvement in total seizure frequency. Parents reported postoperative improvement in behavior in 23 (88%) patients and in cognition in 17 (65%) patients. Transient postoperative memory disturbance was seen in 15 (58%) patients, but persisted in only two (8%). Two (8%) patients had persisting endocrine disturbance requiring hormone replacement therapy (diabetes insipidus and hypothyroidism in one each). With univariate analysis, the likelihood of a seizure-free outcome correlated with younger age, shorter lifetime duration of epilepsy, smaller preoperative HH volume, and 100% HH resection.
CONCLUSIONS: Refractory epilepsy associated with HH can be safely and effectively treated with surgical resection by a transcallosal, interforniceal approach. Short-term memory deficits appear to be transient for most patients, and family perception of the impact of surgery on cognitive and behavioral domains is favorable. Complete resection yields the best result.