title: Differential interictal activity of the precuneus/posterior cingulate cortex revealed by resting state functional MRI at 3T in generalized vs. partial seizure.
abstract: OBJECTIVE
  To characterize, using functional MRI (fMRI), the pattern of active brain regions in the resting state in patients with epilepsy.
  
  
  METHODS
  We studied 28 patients with epilepsy, divided into a partial seizure (PS; N = 9) and a generalized seizure group (GS; N = 19), and 34 control subjects. Resting state fMRI was performed using a GE 3T scanner by collecting 200 volumes of echo-planar imaging (EPI) images with subjects relaxed, eyes closed. Data were processed using a modification of the method of Fransson (Hum Brain Mapp 2005;26:15-29), which reveals information on regional low-frequency Blood Oxygenation Level Dependent (BOLD) signal oscillations in the resting state without any a priori hypothesis. The significant active areas in brain were identified with both individual and group analysis.
  
  
  RESULTS
  Controls showed active regions in the precuneus/posterior cingulate cortex (PCC) and medial prefrontal cortex (MPFC)/ventral anterior cingulate cortex (vACC), theregions associated with the brain "default mode." Similar active regions were observed in PS, whereas GS showed no significant activation of precuneus/PCC.
  
  
  CONCLUSIONS
  In GS, the lack of activation in precuneus/PCC may partly account for their more severe interictal deficits, compared to PS, in cognitive functions such as concentration and memory.
authors.affiliation: Huaxi MR Research Center, Department of Radiology, West China Hospital of Sichuan University, West China School of Medicine, Chengdu, China.
authors.forename: Su
authors.initials: S
authors.lastname: Lui
authors.forename: Luo
authors.initials: L
authors.lastname: Ouyang
authors.forename: Qin
authors.initials: Q
authors.lastname: Chen
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Huang
authors.forename: Hehan
authors.initials: H
authors.lastname: Tang
authors.forename: Huafu
authors.initials: H
authors.lastname: Chen
authors.forename: Dong
authors.initials: D
authors.lastname: Zhou
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Kemp
authors.forename: Qiyong
authors.initials: Q
authors.lastname: Gong
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D003937:Diagnosis, Differential; D017352:Echo-Planar Imaging / Q000295:instrumentation / Q000379:methods*; D004569:Electroencephalography / Q000379:methods; D004828:Epilepsies, Partial / Q000175:diagnosis* / Q000503:physiopathology*; D004829:Epilepsy, Generalized / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D012146:Rest