Cerebral Blood Flow Changes Indicative of Dementia
Blood flow changes in specific regions suggests pathological progression to Alzheimer's disease
08 mar 2009 -- Continuous arterial spin-labeling (CASL) MRI is a non-invasive technique that can reveal changes in cerebral blood flow within specific brain regions, which may help to identify progression to Alzheimer's disease, according to research published in the March issue of Radiology.
Weiying Dai, Ph.D., of Harvard Medical School in Boston, and colleagues performed CASL MRI on 104 control individuals and patients with mild cognitive impairment or Alzheimer's disease. Contiguous axial section images were generated to compare the regional cerebral blood flow.
Compared with control individuals, decreased blood flow in the posterior cingulate gyrus with extension to the medial precuneus was noted among patients with either mild cognitive impairment or Alzheimer's disease, the researchers report. Alzheimer's disease patients also displayed decreased blood flow in the left inferior parietal, left lateral frontal, left superior temporal and left orbitofrontal cortices, the investigators found. Increases in right anterior cingulate gyrus blood flow was observed in Alzheimer's disease patients, while mild cognitive impairment patients showed increases in the left hippocampus and right amygdala.
"Decreases in blood flow (and by implication, decreases in brain function) were observed both subcortically and cortically in patients with early Alzheimer's disease," the authors write. "We found increases in regional cerebral blood flow in portions of the limbic system, which suggests some form of compensatory mechanism during the early expression of the clinical syndrome, especially during the mild cognitive impairment stage."