title: Outcome and predictors of interstitial radiosurgery in the treatment of gelastic epilepsy.
abstract: BACKGROUND
  Gelastic epilepsy due to hypothalamic hamartomas is usually a severe condition encompassing both epileptic seizures and an epileptic encephalopathy associated with behavioral and cognitive impairments. Here we report the effects of interstitial radiosurgery in the treatment of this generally pharmacoresistant epilepsy syndrome.
  
  
  METHODS
  Twenty-four consecutive patients (3-46 years of age, 7 women, mean age 21.9 years, mean duration of epilepsy 17.6 years) with gelastic epilepsy due to MR-ascertained hypothalamic hamartoma and a minimum follow-up period of 1 year were included in this evaluation. Treatment was performed by interstitial radiosurgery using stereotactically implanted (125)I seeds. Effects of treatment on seizure frequency and possible side effects were assessed prospectively. Factors influencing outcome and side effects were analyzed statistically.
  
  
  RESULTS
  After a mean 24-month follow-up period following the last radiosurgical treatment, 11/24 patients were seizure free or had seizure reduction of at least 90% (Engel class I and II), in some cases only after repeated treatment. The duration of epilepsy prior to radiosurgery negatively influenced outcome. Treatment was well tolerated in most patients. Headache, fatigue, and lethargy were transient side effects associated with the development of brain edema extending from the implantation site in five patients. Four patients had a weight gain of more than 5 kg which was severe in two patients. The majority of those patients whose cognitive functions initially deteriorated showed subsequent recovery of cognitive functions, but episodic memory in two patients showed persistent decline at 1 year follow-up. Longer disease duration increased the risk for cognitive side effects, and larger hamartoma size and eccentric seed positioning increased the risk for radiogenic brain edema. Neither perioperative mortality nor neurologic impairments, visual field defects, or endocrinologic disturbances were encountered following treatment.
  
  
  CONCLUSIONS
  Interstitial radiosurgery was efficacious in significantly improving gelastic epilepsy in about half of the patients treated in this series. Weight gain may occur as a side effect, whereas other severe side effects reported following microsurgical removal of the hamartoma were absent. The study results strongly suggest early causal treatment, as chances for seizure control are higher and the risk for cognitive side effects is lower in patients with shorter disease duration.
authors.affiliation: Epilepsy Center, Neurocentre, University Hospital Freiburg, Breisacher Str. 64, D-79106 Freiburg, Germany. andreas.schulze-bonhage@uniklinik-freiburg.de
authors.forename: A
authors.initials: A
authors.lastname: Schulze-Bonhage
authors.forename: M
authors.initials: M
authors.lastname: Trippel
authors.forename: K
authors.initials: K
authors.lastname: Wagner
authors.forename: T
authors.initials: T
authors.lastname: Bast
authors.forename: F V
authors.initials: FV
authors.lastname: Deimling
authors.forename: A
authors.initials: A
authors.lastname: Ebner
authors.forename: C
authors.initials: C
authors.lastname: Elger
authors.forename: T
authors.initials: T
authors.lastname: Mayer
authors.forename: R
authors.initials: R
authors.lastname: Keimer
authors.forename: B J
authors.initials: BJ
authors.lastname: Steinhoff
authors.forename: J
authors.initials: J
authors.lastname: Spreer
authors.forename: S
authors.initials: S
authors.lastname: Fauser
authors.forename: C
authors.initials: C
authors.lastname: Ostertag
mesh_terms: D000293:Adolescent; D000328:Adult; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data*; D001929:Brain Edema / Q000209:etiology / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D015331:Cohort Studies; D004828:Epilepsies, Partial / Q000209:etiology / Q000503:physiopathology / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006222:Hamartoma / Q000150:complications / Q000473:pathology / Q000532:radiotherapy*; D006261:Headache / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D007027:Hypothalamic Diseases / Q000150:complications / Q000473:pathology / Q000532:radiotherapy*; D007031:Hypothalamus / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D053609:Lethargy / Q000209:etiology / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020127:Recovery of Function / Q000502:physiology / Q000528:radiation effects; D013238:Stereotaxic Techniques; D016896:Treatment Outcome; D015430:Weight Gain / Q000502:physiology / Q000528:radiation effects
chemical_list: D007457:Iodine Radioisotopes