title: [11 C]Flumazenil binding in the medial temporal lobe in patients with temporal lobe epilepsy: correlation with hippocampal MR volumetry, T2 relaxometry, and neuropathology.
abstract: OBJECTIVE
  To detect reduced [11C]flumazenil in patients with temporal lobe epilepsy (TLE) and to relate binding to histopathology.
  
  
  METHODS
  The authors studied 16 patients who underwent epilepsy surgery because of drug-resistant TLE using [11C]flumazenil PET and quantitative MRI. In 12 patients, resected hippocampus was available for histologic analysis. [11C]Flumazenil binding potential (fitted BP) was assessed with the simplified reference tissue model.
  
  
  RESULTS
  [11C]Flumazenil fitted BP in the medial temporal lobe was reduced in all patients with abnormal hippocampal volumetry or T2 relaxometry on MRI. Fitted BP was also reduced in 46% of the patients with hippocampal volume within the normal range and in 38% of patients with less than 2 SD T2 prolongation. In all MRI-negative/PET-positive patients, the histologic analysis verified hippocampal damage. Also, [11C]flumazenil fitted BP correlated with the severity of reduced hippocampal volume, T2 prolongation, and histologically assessed neuronal loss and astrogliosis.
  
  
  CONCLUSIONS
  [11C]Flumazenil PET provides a useful tool for investigating the hippocampal damage in vivo even in patients with no remarkable hippocampal abnormalities on quantitative MRI.
authors.affiliation: Department of Neurology, University of Turku, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Lamusuo
authors.forename: A
authors.initials: A
authors.lastname: Pitkänen
authors.forename: L
authors.initials: L
authors.lastname: Jutila
authors.forename: A
authors.initials: A
authors.lastname: Ylinen
authors.forename: K
authors.initials: K
authors.lastname: Partanen
authors.forename: R
authors.initials: R
authors.lastname: Kälviäinen
authors.forename: H M
authors.initials: HM
authors.lastname: Ruottinen
authors.forename: V
authors.initials: V
authors.lastname: Oikonen
authors.forename: K
authors.initials: K
authors.lastname: Någren
authors.forename: P
authors.initials: P
authors.lastname: Lehikoinen
authors.forename: M
authors.initials: M
authors.lastname: Vapalahti
authors.forename: P
authors.initials: P
authors.lastname: Vainio
authors.forename: J O
authors.initials: JO
authors.lastname: Rinne
mesh_terms: D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D001569:Benzodiazepines / Q000627:therapeutic use; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000628:therapy; D005260:Female; D005442:Flumazenil / Q000493:pharmacokinetics*; D018757:GABA Modulators / Q000493:pharmacokinetics; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D014055:Tomography, Emission-Computed; D016896:Treatment Outcome; D014635:Valproic Acid / Q000627:therapeutic use; D020888:Vigabatrin / Q000627:therapeutic use
chemical_list: D000927:Anticonvulsants; D018757:GABA Modulators; D001569:Benzodiazepines; D005442:Flumazenil; D014635:Valproic Acid; D020888:Vigabatrin