Gamma knife radiosurgery for hypothalamic hamartomas in patients with medically intractable epilepsy and precocious puberty - Report of two cases

Hamartoma of the hypothalamus represents a well-known but rare cause of cen tral precocious puberty and gelastic epilepsy. Due to the delicate site in which the tumor is located, surgery is often unsuccessful and associated wi th considerable risks. In the two cases presented, gamma knife radiosurgery was applied as a safe and noninvasive alternative to obtain seizure contro l. Two patients, a 13-year-old boy and a 6-year-old girl, presented with medic ally intractable gelastic epilepsy and increasing episodes of secondary gen eralized seizures. Abnormal behavior and precocious puberty were also evide nt. Magnetic resonance (MR) imaging revealed hypothalamic hamartomas measur ing 13 and 11 mm, respectively. After general anesthesia had been induced i n the patients, radiosurgical treatment was per-formed with margin doses of 12 Gy to 90% and 60% of isodose areas, covering volumes of 700 and 500 mm( 3), respectively. After follow-up periods of 54 months in the boy and 36 months in the girl, progressive decrease in both seizure frequency and intensity was noted (Eng el outcome scores IIa and IIIa, respectively). Both patients are currently able to attend public school. Follow-up MR imaging has not revealed signifi cant changes in the sizes of the lesions. Gamma knife radiosurgery can be an effective and safe treatment modality fo r achieving good seizure control in patients with hypothalamic hamartomas.