title: White matter alterations in cerebral amyloid angiopathy measured by diffusion tensor imaging.
abstract: OBJECTIVE
  Cerebral amyloid angiopathy (CAA) represents beta-amyloid deposition in the small- and medium-sized vessels of the brain and meninges. CAA contributes to altered vessel function and is associated with white matter damage, cognitive impairment, and most salient, hemorrhagic stroke. We used diffusion tensor imaging to evaluate the anatomic distribution of white matter degeneration in participants diagnosed with advanced CAA.
  
  
  METHODS
  Diffusion tensor imaging was obtained from 11 participants diagnosed with CAA-related intracerebral hemorrhage and 13 matched healthy control participants. Fractional anisotropy (FA) and diffusivity maps were compared using voxel based t test and region-of-interest analyses.
  
  
  RESULTS
  FA was reduced in CAA in temporal white matter and in the splenium of the corpus callosum (P<0.001 with approximately 17% reduction in temporal white matter and 15% reduction in the splenium). FA was marginally increased in CAA in the posterior limb of the internal capsule and subthalamic gray matter regions (approximately 7% increase in subthalamic gray). FA changes were bilateral, remained significant in cluster analysis controlling for multiple comparisons, and did not depend on the hemisphere of the cerebral hemorrhage. Diffusivity was not substantially altered.
  
  
  CONCLUSIONS
  These findings suggest that a pattern of regional brain tissue degeneration is a characteristic feature of advanced CAA.
authors.affiliation: Massachusetts General Hospital/Massachusetts Institute of Technology/Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Mass 02129-2060, USA. salat@nmr.mgh.harvard.edu
authors.forename: David H
authors.initials: DH
authors.lastname: Salat
authors.forename: Eric E
authors.initials: EE
authors.lastname: Smith
authors.forename: David S
authors.initials: DS
authors.lastname: Tuch
authors.forename: Thomas
authors.initials: T
authors.lastname: Benner
authors.forename: Vasanth
authors.initials: V
authors.lastname: Pappu
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Schwab
authors.forename: M Edip
authors.initials: ME
authors.lastname: Gurol
authors.forename: H Diana
authors.initials: HD
authors.lastname: Rosas
authors.forename: Jonathan
authors.initials: J
authors.lastname: Rosand
authors.forename: Steven M
authors.initials: SM
authors.lastname: Greenberg
mesh_terms: D000368:Aged; D016880:Anisotropy; D001921:Brain / Q000473:pathology*; D016657:Cerebral Amyloid Angiopathy / Q000150:complications / Q000473:pathology*; D002543:Cerebral Hemorrhage / Q000209:etiology / Q000473:pathology; D003337:Corpus Callosum / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male