White matter alterations in cerebral amyloid angiopathy measured by diffusion tensor imaging.
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.
Salat
David H
DH
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
Smith
Eric E
EE
Tuch
David S
DS
Benner
Thomas
T
Pappu
Vasanth
V
Schwab
Kristin M
KM
Gurol
M Edip
ME
Rosas
H Diana
HD
Rosand
Jonathan
J
Greenberg
Steven M
SM
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