Longitudinal decrease in blood oxygenation level dependent response in cerebral amyloid angiopathy

• Published in: NeuroImage clinical 2016-01, Vol.11 (C), p.461-467
• Main Authors: Switzer, Aaron R, McCreary, Cheryl, Batool, Saima, Stafford, Randall B, Frayne, Richard, Goodyear, Bradley G, Smith, Eric E
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Cerebral amyloid angiopathy; Cerebral Amyloid Angiopathy - diagnostic imaging; Cerebral Amyloid Angiopathy - pathology; Cross-Sectional Studies; Disease Progression; Female; Functional magnetic resonance imaging; Humans; Image Processing, Computer-Assisted; Linear Models; Longitudinal Studies; Magnetic Resonance Imaging; Male; Middle Aged; Oxygen - blood; Regular; Visual Cortex - blood supply
• ISSN: 2213-1582; 2213-1582
• DOI: 10.1016/j.nicl.2016.02.020

Lower blood oxygenation level dependent (BOLD) signal changes in response to a visual stimulus in functional magnetic resonance imaging (fMRI) have been observed in cross-sectional studies of cerebral amyloid angiopathy (CAA), and are presumed to reflect impaired vascular reactivity. We used fMRI to detect a longitudinal change in BOLD responses to a visual stimulus in CAA, and to determine any correlations between these changes and other established biomarkers of CAA progression. Data were acquired from 22 patients diagnosed with probable CAA (using the Boston Criteria) and 16 healthy controls at baseline and one year. BOLD data were generated from the 200 most active voxels of the primary visual cortex during the fMRI visual stimulus (passively viewing an alternating checkerboard pattern). In general, BOLD amplitudes were lower at one year compared to baseline in patients with CAA (p = 0.01) but were unchanged in controls (p = 0.18). The longitudinal difference in BOLD amplitudes was significantly lower in CAA compared to controls (p < 0.001). White matter hyperintensity (WMH) volumes and number of cerebral microbleeds, both presumed to reflect CAA-mediated vascular injury, increased over time in CAA (p = 0.007 and p = 0.001, respectively). Longitudinal increases in WMH (rs = 0.04, p = 0.86) or cerebral microbleeds (rs = -0.18, p = 0.45) were not associated with the longitudinal decrease in BOLD amplitudes.