Functional magnetic resonance imaging responses in CADASIL.
OBJECTIVE
The magnitude of the blood oxygen dependent level (BOLD) functional MRI (fMRI) response to visual stimulation is reduced in the small vessel disease cerebral amyloid angiopathy (CAA), reflecting impaired vascular reactivity. We determined whether BOLD responses were reduced in another small vessel disease, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).


METHODS
BOLD fMRI data were collected using a visual stimulus (contrast-reversing checkerboard) and motor task (finger-tapping). The amplitude of BOLD responses in the visual cortex (visual stimulus) and motor cortex (motor task) were compared between 5 CADASIL, 18 CAA and 18 control subjects, controlling for age and hypertension.


RESULTS
BOLD response varied by group for the visual stimulus (p<0.001) but not the motor task (p=0.47). After adjusting for age and hypertension, the estimated mean visual cortex BOLD amplitude response was 3.95% in CADASIL (95% confidence interval, CI 3.15-4.75%), 1.73% in CAA (95% CI 1.19-2.27%), and 2.88% (95% CI 2.39-3.37%) in controls. In CADASIL, the visual BOLD response was greater than in CAA (p<0.001) and controls (p=0.04).


CONCLUSIONS
We observed increased and unchanged BOLD amplitude responses in the visual and motor cortices of CADASIL patients, respectively. This suggests that cortical blood flow regulation by neuronal activity may be relatively preserved in CADASIL, in contrast to CAA where occipital vascular reactivity is impaired. Cortical vascular reactivity in CADASIL may be preserved because the disease-related injury is primarily subcortical, whereas increased activation may reflect compensatory mechanisms for subcortical injury.
Department of Clinical Neurosciences, University of Calgary, Calgary, Canada.
Ikreet
I
Cheema
Department of Clinical Neurosciences, University of Calgary, Calgary, Canada.
Aaron R
AR
Switzer
Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada; Department of Clinical Neurosciences, University of Calgary, Calgary, Canada.
Cheryl R
CR
McCreary
Department of Clinical Neurosciences, University of Calgary, Calgary, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Canada; Calgary Stroke Program, Calgary, Canada.
Michael D
MD
Hill
Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada; Department of Clinical Neurosciences, University of Calgary, Calgary, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Canada.
Richard
R
Frayne
Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada; Department of Clinical Neurosciences, University of Calgary, Calgary, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Canada.
Bradley G
BG
Goodyear
Seaman Family MR Research Centre, Foothills Medical Centre, Alberta Health Services, Calgary, Canada; Department of Radiology, University of Calgary, Calgary, Canada; Department of Clinical Neurosciences, University of Calgary, Calgary, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, Canada; Calgary Stroke Program, Calgary, Canada. Electronic address: eesmith@ucalgary.ca.
Eric E
EE
Smith
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D046589:CADASIL / Q000000981:diagnostic imaging*; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000000981:diagnostic imaging; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood
D010100:Oxygen
CADASIL; Cerebral amyloid angiopathy; Functional MRI