Effects of Normal Aging on Regional CBF and CMRO2 in Humans

Pantano, P.; Baron, J. C.; Lebrun-Grandié, Philippe; Duquesnoy, N.; Bousser, M. G.; Comar, D.

doi:10.1159/000409200

Cited by 3 publications

(3 citation statements)

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“…One interesting finding of the current study is that the GM to WM perfusion ratio decreases when the subject's age increases and such GM/WM ratios were especially lower among the MCI and AD patients. Although cerebral perfusion was previously reported to decrease with age at a rate of 0.45-0.7% per year, this pattern of age dependent CBF reduction may be nonlinear across stages of the lifespan (35)(36)(37). For example, by using ASL on 1.5 T MR system, a recent study found aging-related perfusion reductions in the frontal lobe (14) while another group reported a significant gap in CBF only between children and adult subjects, but much less CBF difference between adults and elderly subjects (38).…”

Section: Discussionmentioning

confidence: 89%

Reliability and precision of pseudo‐continuous arterial spin labeling perfusion MRI on 3.0 T and comparison with ¹⁵O‐water PET in elderly subjects at risk for Alzheimer's disease

et al. 2010

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Arterial spin labeling (ASL) offers MRI measurement of cerebral blood flow (CBF) in vivo, and may offer clinical diagnostic utility in populations such as those with early Alzheimer's disease (AD). In the current study, we investigated the reliability and precision of a pseudo-continuous ASL (pcASL) sequence that was performed two or three times within one hour on eight young normal control subjects, and 14 elderly subjects including 11 with normal cognition, one with AD and two with Mild Cognitive Impairment (MCI). Six of these elderly subjects including one AD, two MCIs and three controls also received 15 O-water positron emission tomography (PET) scans 2 h before their pcASL MR scan. The instrumental reliability of pcASL was evaluated with the intraclass correlation coefficient (ICC). The ICCs were greater than 0.90 in pcASL global perfusion measurements for both the young and the elderly groups. The cross-modality perfusion imaging comparison yielded very good global and regional agreement in global gray matter and the posterior cingulate cortex. Significant negative correlation was found between age and the gray/ white matter perfusion ratio (r ¼ -0.62, p < 0.002). The AD and MCI patients showed the lowest gray/white matter perfusion ratio among all the subjects. The data suggest that pcASL provides a reliable whole brain CBF measurement in young and elderly adults whose results converge with those obtained with the traditional 15 O-water PET perfusion imaging method. pcASL perfusion MRI offers an alternative method for non-invasive in vivo examination of early pathophysiological changes in AD.

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Section: Discussionmentioning

confidence: 89%

Reliability and precision of pseudo‐continuous arterial spin labeling perfusion MRI on 3.0 T and comparison with ¹⁵O‐water PET in elderly subjects at risk for Alzheimer's disease

et al. 2010

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“…Over the course of normal healthy human aging, physiological changes occur that result in the structural and functional alterations of the cerebrovascular system such as loss of white matter (18), hormonal changes in the brain (26), loss of brain mass (18), and a progressive loss of cortical neurons (34,35). As a result of these alterations, there is an observed reduction in resting cerebral blood flow and CBV (5).…”

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confidence: 99%

Relationship between blood pressure and cerebral blood flow during supine cycling: influence of aging

Smirl

Hoffman

Tzeng

et al. 2016

Journal of Applied Physiology

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The cerebral pressure-flow relationship can be quantified as a high-pass filter, where slow oscillations are buffered (<0.20 Hz) and faster oscillations are passed through relatively unimpeded. During moderate intensity exercise, previous studies have reported paradoxical transfer function analysis (TFA) findings (altered phase or intact gain). This study aimed to determine whether these previous findings accurately represent this relationship. Both younger (20-30 yr; n = 10) and older (62-72 yr; n = 9) adults were examined. To enhance the signal-to-noise ratio, large oscillations in blood pressure (via oscillatory lower body negative pressure; OLBNP) were induced during steady-state moderate intensity supine exercise (∼45-50% of heart rate reserve). Beat-to-beat blood pressure, cerebral blood velocity, and end-tidal Pco2 were monitored. Very low frequency (0.02-0.07 Hz) and low frequency (0.07-0.20 Hz) range spontaneous data were quantified. Driven OLBNP point estimates were sampled at 0.05 and 0.10 Hz. The OLBNP maneuvers augmented coherence to >0.97 at 0.05 Hz and >0.98 at 0.10 Hz in both age groups. The OLBNP protocol conclusively revealed the cerebrovascular system functions as a high-pass filter during exercise throughout aging. It was also discovered that the older adults had elevations (+71%) in normalized gain (+0.46 ± 0.36%/%: 0.05 Hz) and reductions (-34%) in phase (-0.24 ± 0.22 radian: 0.10 Hz). There were also age-related phase differences between resting and exercise conditions. It is speculated that these age-related changes in the TFA metrics are mediated by alterations in vasoactive factors, sympathetic tone, or the mechanical buffering of the compliance vessels.

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“…Cerebral blood flow (CBF) has a negative correlation with age. Most studies report that CBF declines in the frontal lobes bilaterally with increasing age [14][15][16][17]. The frontal lobes are likely to be influenced disproportionately compared with other regions of the cortex.…”

Section: Change Of Cerebral Blood Flowmentioning

confidence: 99%

Novel Quantitative Approach in Functional and Structural Imaging of Brain in Normal Ageing and Neurodegenerative Disorders: Part II. Clinical Applications of Positron Emission Tomography

Promteangtrong

Kolber

Ramchandra

et al. 2019

j exp clin neurosci

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Normal Aging Brain Normal aging is associated with a progressive decline in cognitive performance, including perception, attention, language and memory [1-3]. Age-related functional and biochemical changes in the brain include alterations in cerebral metabolism, cerebral blood flow and neurotransmitter function. With the advent of functional neuroimaging techniques, these biochemical changes can be measured in vivo throughout the life span of person. Because functional disturbances herald structural changes, imaging with positron emission tomography (PET) may yield abnormal results whereas the brain anatomy appears to be normal. Several positronlabeled tracers have been presented to discern the distribution and activity of age-related biochemical changes in the brain. Change of Cerebral Metabolism There is an inconsistency in 18-fluorodeoxyglucose (FDG)-PET findings for aging brain. A number of studies in normal aging subjects have shown significant decrease in whole brain glucose metabolism with advancing age, while others have noted no noticeable change. Although some decline in local glucose metabolism in the temporal, parietal, and frontal areas has been reported by some studies, others have revealed that the prefrontal cortex is the most important region affected by aging. The divergence in results may be due to different methodologies, screening criteria, range of subject ages, and especially sample size, which is one of the key factors for obtaining consistent statistical results. In addition, most early studies on age-related glucose metabolism used region of interest (ROI) analysis. However, recently voxel-based analysis such as Statistical Parametric Mapping (SPM) package, have been widely used to help detect the area missed in ROI analysis and avoid subjective variation. Several studies have now characterized the effect of aging on the distribution of glucose metabolism using FDG-PET. Kuhl et al. [4] reported the use of FDG-PET for determining patterns of local cerebral glucose utilization in 40 normal

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Effects of Normal Aging on Regional CBF and CMRO2 in Humans

Cited by 3 publications

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Reliability and precision of pseudo‐continuous arterial spin labeling perfusion MRI on 3.0 T and comparison with ¹⁵O‐water PET in elderly subjects at risk for Alzheimer's disease

Reliability and precision of pseudo‐continuous arterial spin labeling perfusion MRI on 3.0 T and comparison with ¹⁵O‐water PET in elderly subjects at risk for Alzheimer's disease

Relationship between blood pressure and cerebral blood flow during supine cycling: influence of aging

Novel Quantitative Approach in Functional and Structural Imaging of Brain in Normal Ageing and Neurodegenerative Disorders: Part II. Clinical Applications of Positron Emission Tomography

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Effects of Normal Aging on Regional CBF and CMRO2 in Humans

Cited by 3 publications

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Reliability and precision of pseudo‐continuous arterial spin labeling perfusion MRI on 3.0 T and comparison with 15O‐water PET in elderly subjects at risk for Alzheimer's disease

Reliability and precision of pseudo‐continuous arterial spin labeling perfusion MRI on 3.0 T and comparison with 15O‐water PET in elderly subjects at risk for Alzheimer's disease

Relationship between blood pressure and cerebral blood flow during supine cycling: influence of aging

Novel Quantitative Approach in Functional and Structural Imaging of Brain in Normal Ageing and Neurodegenerative Disorders: Part II. Clinical Applications of Positron Emission Tomography

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Reliability and precision of pseudo‐continuous arterial spin labeling perfusion MRI on 3.0 T and comparison with ¹⁵O‐water PET in elderly subjects at risk for Alzheimer's disease

Reliability and precision of pseudo‐continuous arterial spin labeling perfusion MRI on 3.0 T and comparison with ¹⁵O‐water PET in elderly subjects at risk for Alzheimer's disease