title: fMRI "deactivation" of the posterior cingulate during generalized spike and wave.
abstract: Using spike-triggered fMRI, we sought to document regional changes in blood oxygen level-dependent (BOLD) activity associated with spontaneous generalised spike and slow-wave discharges (S&W). Five adult patients were studied who had idiopathic generalised epilepsy (IGE) and frequent S&W. EEG was recorded inside a 3T MRI, allowing acquisition of single, whole-brain fMRI images following S&W, as well as baseline images. Between 4 and 25 spike and wave complexes were captured in individuals. Four of the five individuals showed significant S&W-related BOLD signal reductions ("deactivation") in the posterior cingulate (P<0.001 uncorrected). Significant changes were absent only in the individual with fewest spikes. Group analysis including all five subjects confirmed fMRI deactivation in the posterior cingulate. Some S&W-related BOLD signal increases were seen in the depths of the precentral sulci in individuals and on group analysis. No significant S&W-related changes in thalamic BOLD activity were observed. The posterior cingulate may have a role in the electroclinical phenomenon of S&W and "absence." Possibilities include a causative role, with reduced activity in the cingulate facilitating the onset of S&W, a secondary role, explaining the cognitive changes observed during prolonged S&W, or an epiphenomenon.
authors.affiliation: Brain Research Institute, Neurosciences Building, Austin & Repatriation Medical Centre, Banksia Street, Heidelberg West, 3081, Victoria, Australia.
authors.forename: John S
authors.initials: JS
authors.lastname: Archer
authors.forename: David F
authors.initials: DF
authors.lastname: Abbott
authors.forename: Anthony B
authors.initials: AB
authors.lastname: Waites
authors.forename: Graeme D
authors.initials: GD
authors.lastname: Jackson
mesh_terms: D000293:Adolescent; D000328:Adult; D001923:Brain Chemistry / Q000502:physiology; D004569:Electroencephalography; D004832:Epilepsy, Absence / Q000503:physiopathology; D004829:Epilepsy, Generalized / Q000378:metabolism / Q000503:physiopathology*; D005260:Female; D006179:Gyrus Cinguli / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood
chemical_list: D010100:Oxygen