title: Minimally invasive magnetic resonance imaging-guided stereotactic radiofrequency thermocoagulation for epileptogenic hypothalamic hamartomas.
abstract: OBJECTIVE
  To validate the safety and efficacy of magnetic resonance imaging (MRI)-guided stereotactic radiofrequency thermocoagulation (SRT) for epileptogenic hypothalamic hamartoma (HH), we evaluated surgical outcomes and revised the MRI classification.
  
  
  METHODS
  We retrospectively reviewed 25 consecutive patients with HH (age range, 2-36 years; mean age, 14.8 years) with gelastic seizures. Other seizure types were exhibited in 22 patients (88.0%), precocious puberty in 8 (32.0%), behavioral disorder in 10 (40.0%), and mental retardation in 14 (56.0%). We classified HH into 3 subtypes according to coronal MRI: intrahypothalamic, parahypothalamic, and mixed hypothalamic type. Maximum diameter ranged from 8 to 30 mm (mean, 15.3 mm). All patients underwent SRT (74 degrees C, 60 seconds) for HH.
  
  
  RESULTS
  HH subtype and size were correlated with precocious puberty, mental retardation, and behavioral disorder. Thirty-one SRT procedures were performed, requiring 1 to 8 tracks (mean, 3.8 tracks) and involving 1 to 18 lesions (mean, 7.2 lesions). There were no adaptive limitations, regardless of size or subtype. Mixed-type HHs needed more tracks and more lesions. No permanent complications persisted after SRT, and gelastic seizures disappeared in all but 2 patients. Complete seizure freedom was achieved in 19 patients (76.0%). These patients had not only disappearance of all seizure types and behavioral disorder but also intellectual improvement.
  
  
  CONCLUSIONS
  The present SRT procedure has favorable efficacy and invasiveness and has no adaptive limitations. SRT should therefore be considered before adulthood. The new HH classification is useful to understand clinical symptoms and to determine surgical strategies.
authors.affiliation: Department of Functional Neurosurgery, Epilepsy Center, Nishi-Niigata Chuo National Hospital, Niigata, Japan. kameyama@masa.go.jp
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kameyama
authors.forename: Hiroatsu
authors.initials: H
authors.lastname: Murakami
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Masuda
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sugiyama
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004564:Electrocoagulation / Q000379:methods; D004569:Electroencephalography / Q000379:methods; D004827:Epilepsy / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D005260:Female; D006222:Hamartoma / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D006801:Humans; D007027:Hypothalamic Diseases / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D053798:Magnetocardiography / Q000379:methods; D008297:Male; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D055815:Young Adult