title: Apolipoprotein E4 and brain white matter integrity in Alzheimer's disease: tract-based spatial statistics study under 3-Tesla MRI.
abstract: BACKGROUND
  Apolipoprotein E4 (ApoE ε4) polymorphism is a known genetic risk factor for Alzheimer's disease (AD).
  
  
  OBJECTIVE
  To evaluate the role of ApoE ε4 on white matter structural integrity in AD.
  
  
  METHODS
  Subjects were 32 patients with probable AD (ApoE ε4-positive: n = 15) and 18 matched controls (ApoE ε4-positive: n = 6). All subjects were right-handed, evaluated using standard scales and genotyped at the ApoE locus. Diffusion tensor imaging was performed with a 3-tesla MRI scanner and analyzed using the tract-based spatial statistics method.
  
  
  RESULTS
  AD patients had significantly lower fractional anisotropy (FA) in bilateral temporoparietal, limbic and parahippocampal regions in comparison to healthy comparison subjects. ApoE ε4 carriers among both AD and healthy comparison subjects showed lower FA in limbic and medial temporal regions.
  
  
  CONCLUSIONS
  There is a modest association between ApoE ε4 carrier status and reduction in white matter tract integrity at medial temporal and limbic regions in both healthy and AD subjects.
authors.affiliation: National Institute of Mental Health and Neurosciences, Bangalore, India. bshankara@gmail.com
authors.forename: Bhavani Shankara
authors.initials: BS
authors.lastname: Bagepally
authors.forename: Harsha N
authors.initials: HN
authors.lastname: Halahalli
authors.forename: John P
authors.initials: JP
authors.lastname: John
authors.forename: Lakshminarayan
authors.initials: L
authors.lastname: Kota
authors.forename: Meera
authors.initials: M
authors.lastname: Purushottam
authors.forename: Odity
authors.initials: O
authors.lastname: Mukherjee
authors.forename: Palanimuthu Thangaraju
authors.initials: PT
authors.lastname: Sivakumar
authors.forename: Srikala
authors.initials: S
authors.lastname: Bharath
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Jain
authors.forename: Mathew
authors.initials: M
authors.lastname: Varghese
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000235:genetics* / Q000473:pathology*; D016880:Anisotropy; D053327:Apolipoprotein E4 / Q000235:genetics*; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D056324:Diffusion Tensor Imaging; D005260:Female; D005838:Genotype; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D011569:Psychiatric Status Rating Scales
chemical_list: D053327:Apolipoprotein E4