Abstracts

RATIONALE: Hypothalamic hamartoma is often associated with gelastic epilepsy. Due to the delicate site in which the tumor is located, surgery is associated with considerable risks. Stereotactic radiosurgery is a noninvasive procedure that effectively treats patients with vascular malformations and brain tumors. While preliminary results are promising, data concerning it[ssquote]s efficacy for gelastic epilepsy is limited.
METHODS: In the three cases presented, gamma knife radiosurgery was applied as a safe and noninvasive alternative to microsurgery in an attempt to obtain seizure control. Three patients, a 13-year-old girl, a 6- year-old girl and a 5-year-old boy, presented with medically intractable gelastic epilepsy. Abnormal behavior and cognitive impairment were also evident. Magnetic Resonance (MR) imaging revealed hypothalamic hamartomas in all of them.
Radiosurgical treatment was performed with the Gamma Knife model C system in Marseille (October 2001 for the first two and February 2002 for the third). The procedures were performed under general anesthesia. A complex multi-isocentric highly conformal dose-planning was performed relying on stereotactic imaging ( MR and CT). Two small lesions in the third ventricles were treated with 17 Gy at the margin. The third lesion (larger in and under the floor of the ventricle) was treated with 14 gy.
RESULTS: Follow-up evaluations revealed a marked improvement in seizure frequency and global functioning. Patients are currently able to attend public school. There were no significant complications from the radiosurgical therapy.
CONCLUSIONS: Our findings suggest that gamma knife surgery is a potentially safe and valuable treatment modality for children with hypothalamic hamartomas and drug-resistant gelastic epilepsy.