title: Converging PET and fMRI evidence for a common area involved in human focal epilepsies.
abstract: OBJECTIVE
  Experiments in animal models have identified specific subcortical anatomic circuits, which are critically involved in the pathogenesis and control of seizure activity. However, whether such anatomic substrates also exist in human epilepsy is not known.
  
  
  METHODS
  We studied 2 separate groups of patients with focal epilepsies arising from any cortical location using either simultaneous EEG-fMRI (n = 19 patients) or [¹¹C]flumazenil PET (n = 18).
  
  
  RESULTS
  Time-locked with the interictal epileptiform discharges, we found significant hemodynamic increases common to all patients near the frontal piriform cortex ipsilateral to the presumed cortical focus. GABA(A) receptor binding in the same area was reduced in patients with more frequent seizures.
  
  
  CONCLUSIONS
  Our findings of cerebral blood flow and GABAergic changes, irrespective of where interictal or ictal activity occurs in the cortex, suggest that this area of the human primary olfactory cortex may be an attractive new target for epilepsy therapy, including neurosurgery, electrical stimulation, and focal drug delivery.
authors.affiliation: Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College, London, UK. mkoepp@ion.ucl.ac.uk
authors.forename: H
authors.initials: H
authors.lastname: Laufs
authors.forename: M P
authors.initials: MP
authors.lastname: Richardson
authors.forename: A
authors.initials: A
authors.lastname: Salek-Haddadi
authors.forename: C
authors.initials: C
authors.lastname: Vollmar
authors.forename: J S
authors.initials: JS
authors.lastname: Duncan
authors.forename: K
authors.initials: K
authors.lastname: Gale
authors.forename: L
authors.initials: L
authors.lastname: Lemieux
authors.forename: W
authors.initials: W
authors.lastname: Löscher
authors.forename: M J
authors.initials: MJ
authors.lastname: Koepp
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004569:Electroencephalography / Q000379:methods; D004828:Epilepsies, Partial / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009833:Olfactory Pathways / Q000000981:diagnostic imaging* / Q000473:pathology*; D049268:Positron-Emission Tomography / Q000379:methods*; D055815:Young Adult