title: Metabolic networks in epilepsy by MR spectroscopic imaging.
abstract: OBJECTIVE
  The concept of an epileptic network has long been suggested from both animal and human studies of epilepsy. Based on the common observation that the MR spectroscopic imaging measure of NAA/Cr is sensitive to neuronal function and injury, we use this parameter to assess for the presence of a metabolic network in mesial temporal lobe epilepsy (MTLE) patients.
  
  
  METHODS
  A multivariate factor analysis is performed with controls and MTLE patients, using NAA/Cr measures from 12 loci: the bilateral hippocampi, thalami, basal ganglia, and insula. The factor analysis determines which and to what extent these loci are metabolically covarying.
  
  
  RESULTS
  We extract two independent factors that explain the data's variability in control and MTLE patients. In controls, these factors characterize a 'thalamic' and 'dominant subcortical' function. The MTLE patients also exhibit a 'thalamic' factor, in addition to a second factor involving the ipsilateral insula and bilateral basal ganglia.
  
  
  CONCLUSIONS
  These data suggest that MTLE patients demonstrate a metabolic network that involves the thalami, also seen in controls. The MTLE patients also display a second set of metabolically covarying regions that may be a manifestation of the epileptic network that characterizes limbic seizure propagation.
authors.affiliation: Department of Neurosurgery, Yale School of Medicine, New Haven, CT 06525, USA. Julie.Pan@yale.edu
authors.forename: J W
authors.initials: JW
authors.lastname: Pan
authors.forename: D D
authors.initials: DD
authors.lastname: Spencer
authors.forename: R
authors.initials: R
authors.lastname: Kuzniecky
authors.forename: R B
authors.initials: RB
authors.lastname: Duckrow
authors.forename: H
authors.initials: H
authors.lastname: Hetherington
authors.forename: S S
authors.initials: SS
authors.lastname: Spencer
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D053858:Metabolic Networks and Pathways / Q000502:physiology*; D055815:Young Adult