title: Alteration of functional connectivity within visuospatial working memory-related brain network in patients with right temporal lobe epilepsy: a resting-state fMRI study.
abstract: OBJECTIVE
  This study aimed to investigate the resting-state brain network related to visuospatial working memory (VSWM) in patients with right temporal lobe epilepsy (rTLE). The functional mechanism underlying the cognitive impairment in VSWM was also determined.
  
  
  METHODS
  Fifteen patients with rTLE and 16 healthy controls matched for age, gender, and handedness underwent a 6-min resting-state functional MRI session and a neuropsychological test using VSWM_Nback. The VSWM-related brain network at rest was extracted using multiple independent component analysis; the spatial distribution and the functional connectivity (FC) parameters of the cerebral network were compared between groups. Behavioral data were subsequently correlated with the mean Z-value in voxels showing significant FC difference during intergroup comparison.
  
  
  RESULTS
  The distribution of the VSWM-related resting-state network (RSN) in the group with rTLE was virtually consistent with that in the healthy controls. The distribution involved the dorsolateral prefrontal lobe and parietal lobe in the right hemisphere and the partial inferior parietal lobe and posterior lobe of the cerebellum in the left hemisphere (p<0.05, AlphaSim corrected). Between-group differences suggest that the group with rTLE had a decreased FC within the right superior frontal lobe (BA8), right middle frontal lobe, and right ventromedial prefrontal lobe compared with the controls (p<0.05, AlphaSim corrected). The regions of increased FC in rTLE were localized within the right superior frontal lobe (BA11), right superior parietal lobe, and left posterior lobe of the cerebellum (p<0.05, AlphaSim corrected). Moreover, patients with rTLE performed worse than controls in the VSWM_Nback test, and there were negative correlations between ACCmeanRT (2-back) and the mean Z-value in the voxels showing decreased or increased FC in rTLE (p<0.05).
  
  
  CONCLUSIONS
  The results suggest that the alteration of the VSWM-related RSN might underpin the VSWM impairment in patients with rTLE and possibly implies a functional compensation by enlarging the FC within the ipsilateral cerebral network.
authors.affiliation: Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China.
authors.forename: Zong-xia
authors.initials: ZX
authors.lastname: Lv
authors.affiliation: Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China.
authors.forename: Dong-Hong
authors.initials: DH
authors.lastname: Huang
authors.affiliation: Department of Radiology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ye
authors.affiliation: Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China.
authors.forename: Zi-rong
authors.initials: ZR
authors.lastname: Chen
authors.affiliation: Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China.
authors.forename: Wen-li
authors.initials: WL
authors.lastname: Huang
authors.affiliation: Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China. Electronic address: jinouzheng@163.com.
authors.forename: Jin-ou
authors.initials: JO
authors.lastname: Zheng
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000503:physiopathology; D004833:Epilepsy, Temporal Lobe / Q000150:complications* / Q000473:pathology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology* / Q000473:pathology*; D008570:Memory, Short-Term / Q000502:physiology*; D009415:Nerve Net / Q000098:blood supply / Q000473:pathology; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D012146:Rest / Q000502:physiology; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: Independent component analysis; Resting-state functional magnetic resonance imaging; Right temporal lobe epilepsy; Visuospatial working memory