Associations between cerebral blood flow and structural and functional brain imaging measures in individuals with neuropsychologically defined mild cognitive impairment

Neurobiol Aging. 2020 Feb;86:64-74. doi: 10.1016/j.neurobiolaging.2019.10.023. Epub 2019 Nov 6.

Abstract

Reduced cerebral blood flow (CBF), an indicator of neurovascular processes and metabolic demands, is a common finding in Alzheimer's disease. However, little is known about what contributes to CBF deficits in individuals with mild cognitive impairment (MCI). We examine regional CBF differences in 17 MCI compared with 21 age-matched cognitively healthy older adults. Next, we examined associations between CBF, white matter lesion (WML) volume, amplitude of low-frequency fluctuations, and cortical thickness to better understand whether altered CBF was detectable before other markers and the potential mechanistic underpinnings of CBF deficits in MCI. MCI had significantly reduced CBF, whereas cortical thickness and amplitude of low-frequency fluctuation were not affected. Reduced CBF was associated with the WML volume but not associated with other measures. Given the presumed vascular etiology of WML and relative worsening of vascular health in MCI, it may suggest CBF deficits result from early vascular as opposed to metabolic deficits in MCI. These findings may support vascular mechanisms as an underlying component of cognitive impairment.

Keywords: ALFF; Alzheimer's disease; Cerebral blood flow; Mild cognitive impairments; Vascular; White matter lesions.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Alzheimer Disease
  • Cerebrovascular Circulation*
  • Cognitive Dysfunction / diagnostic imaging*
  • Cognitive Dysfunction / pathology
  • Cognitive Dysfunction / physiopathology*
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Organ Size
  • White Matter / diagnostic imaging*
  • White Matter / pathology*