Abnormal regional cerebral blood flow in cognitively normal elderly subjects with hypertension.
OBJECTIVE
The purpose of this study was to examine regional cerebral blood flow (rCBF) in normal cognitive-performing subjects with hypertension (HTN) using continuous arterial spin-labeled MRI. The most common explanation for the effect of blood pressure on cognition is that HTN increases the risk of cerebrovascular disease, and it may increase the risk for Alzheimer disease possibly through small vessel disease, ischemia, oxidative stress, and inflammation. However, few studies to date have examined the rCBF of cognitively normal subjects with HTN in population-based cohorts, and none have used continuous arterial spin-labeled MRI. This is a noninvasive technique that does not require either injections or ionizing radiation and can measure absolute rCBF rates over the entire brain.


METHODS
rCBF was measured at 1.5 T using continuous arterial spin-labeled MRI in 41 cognitively normal subjects who were participating in the Cardiovascular Health Study Cognition Study. A deformable atrophy-corrected registration method was used to warp the rCBF maps to the standard colin27 brain space. Image and cluster-based statistical analyses were performed between subject groups.


RESULTS
Cognitively normal subjects with HTN (n=19) had decreased rCBF in the putamen, globus pallidus, bilaterally, and in the left hippocampus compared with normotensives (n=22). In addition, decreased rCBF was observed in the right and left anterior cingulate gyrus with extension to the subcallosal region, left posterior cingulate gyrus and medial precuneus, left lateral inferior and superior frontal, and inferior parietal, left orbitofrontal, and left superior temporal cortices.


CONCLUSIONS
rCBF is affected in normal subjects with HTN, not only in the subcortical regions, but also in limbic and paralimbic structures. We hypothesize that the HTN creates a vulnerability state for the development of neurodegenerative disorders, especially Alzheimer disease.
Dai
Weiying
W
Department of Computer Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Lopez
Oscar L
OL
Carmichael
Owen T
OT
Becker
James T
JT
Kuller
Lewis H
LH
Gach
H Michael
HM
D000368:Aged; D000369:Aged, 80 and over; D002540:Cerebral Cortex / Q000098:blood supply; D002560:Cerebrovascular Circulation; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D005917:Globus Pallidus / Q000098:blood supply; D006179:Gyrus Cinguli / Q000098:blood supply; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D011699:Putamen / Q000098:blood supply; D013113:Spin Labels
D013113:Spin Labels