title: Clinical significance of ictal high frequency oscillations in medial temporal lobe epilepsy.
abstract: OBJECTIVE
  To clarify the clinical significance of ictal high frequency oscillations (HFO) in the medial temporal lobe.
  
  
  METHODS
  This study included 19 patients who underwent intracranial electrode implantation in bilateral temporal lobes and had at least one seizure recorded at 1kHz sampling rate. The characteristics of ictal HFO in the medial temporal lobe, and the relations between the presence of HFO, pathology, and postoperative seizure outcome were analyzed.
  
  
  RESULTS
  Ictal HFO were detected from medial temporal structures in 11 patients with medial temporal lobe epilepsy (MTLE). Among eight patients without HFO, only three were diagnosed with MTLE. Ictal HFO were detected from unilateral medial temporal structures ipsilateral to the side of hippocampal sclerosis (HS). In one patient with bitemporal independent seizure onset, ictal HFO were detected only on the side of HS. HS was detected in all 11 patients with HFO, but in only one of four patients without HFO. Seizure outcome did not differ between patients with and without HFO.
  
  
  CONCLUSIONS
  Ictal HFO in the medial temporal lobe may be a specific marker for MTLE with HS.
  
  
  CONCLUSIONS
  Recording of ictal HFO in the medial temporal lobe may be useful for presurgical evaluation of MTLE.
authors.affiliation: National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, Shizuoka, Japan. n-usui@szec.hosp.go.jp
authors.forename: Naotaka
authors.initials: N
authors.lastname: Usui
authors.forename: Kiyohito
authors.initials: K
authors.lastname: Terada
authors.forename: Koichi
authors.initials: K
authors.lastname: Baba
authors.forename: Kazumi
authors.initials: K
authors.lastname: Matsuda
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Nakamura
authors.forename: Keiko
authors.initials: K
authors.lastname: Usui
authors.forename: Miyako
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Takayasu
authors.initials: T
authors.lastname: Tottori
authors.forename: Shuichi
authors.initials: S
authors.lastname: Umeoka
authors.forename: Shigeru
authors.initials: S
authors.lastname: Fujitani
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Mihara
authors.forename: Yushi
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D000293:Adolescent; D000328:Adult; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D012598:Sclerosis; D012640:Seizures / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D055815:Young Adult