Impact of stereotactic interstitial radiosurgery on cognition in ten juvenile epilepsy patients with hypothalamic hamartoma

Cognitive impairment as well as behavioral disturbances are associated with the epileptic syndrome of hypothalamic hamartomas. We assessed cognitive functions – including attention, verbal and visual short-term and working memory, verbal and figural declarative memory, phonematic fluency, planning, and visuoconstruction – before and after interstitial radiotherapy in ten juvenile patients with a mean age of 15.5 years and gelastic seizures due to hypothalamic hamartomas. Neuropsychological assessment was carried out before temporary implantation of a 125I-seed and at least three months after seed excision. After a mean of 8 months, the patients showed a significant improvement in selective attention and a decline in visuoconstructive abilities. The remaining cognitive domains revealed no significant changes. The impairment in postoperative visuoconstructive functions was accompanied by a higher number of secondarily generalized seizures after seed explantation. Thus, the stereotactical implantation of 125I-seeds in this patient group with gelastic seizures due to hypothalamic hamartoma provides a well tolerated minimal invasive method in the treatment of this severe epileptic syndrome.