Mapping cerebral pulse pressure and arterial compliance over the adult lifespan with optical imaging

• Published in: PloS one 2017-02, Vol.12 (2), p.e0171305-e0171305
• Main Authors: Tan, Chin Hong, Low, Kathy A, Kong, Tania, Fletcher, Mark A, Zimmerman, Benjamin, Maclin, Edward L, Chiarelli, Antonio M, Gratton, Gabriele, Fabiani, Monica
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Adults; Age; Aged; Aged, 80 and over; Aging; Aging - pathology; Aging - physiology; Anatomy; Atrophy; Biology and Life Sciences; Blood pressure; Blood Pressure - physiology; Brain; Brain architecture; Cardiorespiratory fitness; Central Nervous System - blood supply; Central Nervous System - diagnostic imaging; Central Nervous System - physiopathology; Cerebrovascular Circulation - physiology; Cerebrovascular system; Cognition; Cognition - physiology; Cognitive ability; Cognitive Dysfunction - diagnostic imaging; Cognitive Dysfunction - physiopathology; Cognitive tasks; Correlation; Degeneration; Dementia; Female; Fitness; Health; Hemodynamics; Humans; Hypertension; Intracranial Pressure - physiology; Ischemia; Life span; Magnetic Resonance Imaging; Male; Medicine and Health Sciences; Memory, Short-Term - physiology; Mental task performance; Middle age; Middle Aged; Mortality; Neurodegeneration; Neuroimaging; Older people; Optical tomography; People and Places; Pulse amplitude; Recording; Regional analysis; Research and Analysis Methods; Short term memory; Substantia grisea; Vascular Stiffness - physiology; Veins & arteries; Visual cortex; Young adults
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0171305

Cerebrovascular health is important for maintaining a high level of cognitive performance, not only in old age, but also throughout the lifespan. Recently, it was first demonstrated that diffuse optical imaging measures of pulse amplitude and arterial compliance can provide estimates of cerebral arterial health throughout the cortex, and were associated with age, estimated cardiorespiratory fitness (eCRF), neuroanatomy and cognitive function in older adults (aged 55-87). The current study replicates and extends the original findings using a broader age range (a new adult sample aged 18-75), longer recording periods (360 s), and a more extensive optical montage (1536 channels). These methodological improvements represent a 5-fold increase in recording time and a 4-fold increase in coverage compared to the initial study. Results show that reliability for both pulse amplitude and compliance measures across recording blocks was very high (r(45) = .99 and .75, respectively). Pulse amplitude and pulse pressure were shown to correlate with age across the broader age range. We also found correlations between arterial health and both cortical and subcortical gray matter volumes. Additionally, we replicated the correlations between arterial compliance and age, eCRF, global brain atrophy, and cognitive flexibility. New regional analyses revealed that higher performance on the operation span (OSPAN) working memory task was associated with greater localized arterial compliance in frontoparietal cortex, but not with global arterial compliance. Further, greater arterial compliance in frontoparietal regions was associated with younger age and higher eCRF. These associations were not present in the visual cortex. The current study not only replicates the initial one in a sample including a much wider age range, but also provides new evidence showing that frontoparietal regions may be especially vulnerable to vascular degeneration during brain aging, with potential functional consequences in cognition.