Abstract
ABSTRACTThe prevalence of Alzheimer’s disease is projected to reach 13 million in the U.S. by 2050. Although major efforts have been made to avoid this outcome, so far there are no treatments that can stop or reverse the progressive cognitive decline that defines Alzheimer’s disease. The utilization of preventative treatment before significant cognitive decline has occurred may ultimately be the solution, necessitating a reliable biomarker of preclinical/prodromal disease stages to determine which older adults are most at risk. Quantitative cerebral blood flow is a promising potential early biomarker for Alzheimer’s disease, but the spatiotemporal patterns of altered cerebral blood flow in Alzheimer’s disease are not fully understood. The current systematic review compiles the findings of 29 original studies that compared quantitative cerebral blood flow in older adults with mild cognitive impairment or Alzheimer’s disease to that of cognitively normal older adults and/or assessed the relationship between cerebral blood flow and objective cognitive function. Individuals with Alzheimer’s disease had relatively decreased cerebral blood flow in all brain regions investigated, especially the temporoparietal and posterior cingulate, while individuals with mild cognitive impairment had less consistent results, with relatively increased cerebral blood flow reported in the temporal lobe and thalamus. Most papers reported a positive correlation between cerebral blood flow and cognitive function. This review highlights the need for more studies comparing cerebral blood flow between cognitively normal individuals and those with mild cognitive impairment, as well as the importance of including potential confounding factors in these analyses.
Publisher
Cold Spring Harbor Laboratory