title: The significance of insular hypometabolism in temporal lobe epilepsy in children.
abstract: OBJECTIVE
  Temporal lobe epilepsy is one of the most common forms of medically refractory epileptic syndromes. In a small percentage, temporal lobectomy fails to control the seizures in patients with epilepsy of clear temporal origin, and in some of these patients, seizures originating from the insular cortex is believed to be the cause behind the surgical failures. We retrospectively analyzed the [(18)F]FDG-positron emission tomography (PET) results of patients who received temporal lobe surgery for presence of insular hypometabolism, and compared the surgical outcome to verify whether insular hypometablism was related with difference in post-operative results.
  
  
  METHODS
  13 patients were enrolled, and clinical variables, post-operative pathology, magnetic resonance imaging and PET results were analyzed for possible differences between the patients with or without insular hypometabolism.
  
  
  RESULTS
  7 patients showed insular hypometabolism, while 6 patients were clear of insular lesion on PET exam. 8 patients received anterior temporal lobectomy with amygdalohippocampectomy (AH), 2 patients received radical temporal lobectomy with AH, and 3 patients received insular cortisectomy. Post-operative results were favorable in 8 patients and unfavorable in 5, with unfavorable outcomes in all recipients of insular cortisectomy. Presence of insular hypometabolism did not have any significant relationship with the post-surgical outcome (p=0.266), but its trend showed a tendency towards favorable outcome if insular hypometabolism was not present.
  
  
  CONCLUSIONS
  Presence of insular hypometabolism in [(18)F]FDG-PET analysis was not significantly correlated with the post-operative outcome, and recipients of insular cortisectomy among our patients with insular hypometabolism resulted in poor surgical outcome. However, the outcome trend showed a tendency towards better surgical outcome with absence of hypometabolic lesion in the ipsilateral insular cortex. Further studies employing a larger patient group is needed.
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, Pediatric Epilepsy Clinic, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul;
authors.forename: Ji Ae
authors.initials: JA
authors.lastname: Hur
authors.affiliation: Department of Pediatrics, Chungnam National University Hospital, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Joon Won
authors.initials: JW
authors.lastname: Kang
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, Pediatric Epilepsy Clinic, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul;
authors.forename: Hoon-Chul
authors.initials: HC
authors.lastname: Kang
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, Pediatric Epilepsy Clinic, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul;
authors.forename: Heung Dong
authors.initials: HD
authors.lastname: Kim
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, Pediatric Epilepsy Clinic, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul;
authors.forename: Jeong Tae
authors.initials: JT
authors.lastname: Kim
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, Pediatric Epilepsy Clinic, Severance Children's Hospital, Epilepsy Research Institute, Yonsei University College of Medicine, Seoul;
authors.forename: Joon Soo
authors.initials: JS
authors.lastname: Lee
keywords: Epilepsy; Insular; PET; Pediatric; Post-operative outcome; Surgery