title: Efficacy and safety of radiosurgical callosotomy: a retrospective analysis.
abstract: OBJECTIVE
  Anterior callosotomy is a surgical option for the treatment of generalized tonic or atonic seizures associated with drop attacks. Besides open surgery, a radiosurgical callosal disconnection using the gamma knife (GK) also can be performed, but reliable data about tolerability and efficacy are sparse.
  
  
  METHODS
  Eight patients (three female, five male age range, 5 to 69 years) with severe generalized epilepsy associated with disabling drop attacks underwent GK callosotomy between 1993 and 2004. In six patients, the anterior third of the corpus callosum was radiosurgically disconnected. In one patient a second procedure with GK treatment of the middle third of the corpus callosum was added 17 months later. In two patients posterior GK callosotomy had followed partial hemispherotomy.
  
  
  RESULTS
  Drop attacks (DAs) were completely abolished in three patients, and two patients had a marked DA seizure reduction of 60%. Two of four patients with additional generalized tonic-clonic seizures showed a reduction of 100%, and the remaining, a 50% and 60% decrease, respectively. Other seizure types responded less well to the radiosurgical treatment. In both patients with posterior GK callosotomy after hemispherotomy, partial seizures decreased. Beside transient headache in two patients, no immediate or long-term postradiosurgical side effects were observed.
  
  
  CONCLUSIONS
  Palliative radiosurgical callosotomy is an efficient and safe noninvasive alternative to the open procedure with comparable results. No signs of postradiosurgical side effects were noted within an up to 12-year posttreatment period.
authors.affiliation: Department of Neurology, Medical University Graz, Graz, Austria. mi.feichtinger@meduni-graz.at
authors.forename: Michael
authors.initials: M
authors.lastname: Feichtinger
authors.forename: Oskar
authors.initials: O
authors.lastname: Schröttner
authors.forename: Hans
authors.initials: H
authors.lastname: Eder
authors.forename: Hans
authors.initials: H
authors.lastname: Holthausen
authors.forename: Tom
authors.initials: T
authors.lastname: Pieper
authors.forename: Frank
authors.initials: F
authors.lastname: Unger
authors.forename: Alexander
authors.initials: A
authors.lastname: Holl
authors.forename: Lucia
authors.initials: L
authors.lastname: Gruber
authors.forename: Eva
authors.initials: E
authors.lastname: Körner
authors.forename: Eugen
authors.initials: E
authors.lastname: Trinka
authors.forename: Franz
authors.initials: F
authors.lastname: Fazekas
authors.forename: Erwin
authors.initials: E
authors.lastname: Ott
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000473:pathology / Q000601:surgery*; D004829:Epilepsy, Generalized / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000473:pathology; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000473:pathology; D016634:Radiosurgery / Q000009:adverse effects* / Q000379:methods*; D012720:Severity of Illness Index; D013575:Syncope / Q000517:prevention & control; D016896:Treatment Outcome