We investigate whether common circle of Willis (CoW) variants relate to cerebral blood flow (CBF) characteristics among aging adults. Vanderbilt Memory and Aging Project participants free of clinical stroke (n = 390, 71 ± 8 years, 55% male) completed magnetic resonance angiography to assess cerebral artery variants and pseudocontinuous arterial spin labeling to quantify resting CBF and spatial coefficient of variation (sCoV), a marker of perfusion heterogeneity or stability. Linear regression models related categorical variants to regional CBF and sCoV, adjusting for age, sex, race/ethnicity, education, cognitive status, Framingham Stroke Risk Profile, and APOE-ε4 status. Absence of at least one posterior communicating artery (PcoA) related to lower occipital lobe CBF (p = 0.001) and higher global (p = 0.003), temporal (p = 0.001), and occipital lobe sCoV (p = 0.01). Bilateral PcoA absence related to lower global (p = 0.01), parietal (p = 0.01), and occipital lobe CBF (p = 0.0001) and higher global (p p p = 0.0003). Hypoplastic and fetal-type variants did not relate to outcomes (p > 0.22). Findings demonstrate that missing PcoAs influence both perfusion magnitude and efficiency, suggesting that common CoW variants may produce regionally coherent hemodynamic effects in heart-healthy aging adults and represent markers of early cerebrovascular vulnerability.
Cambronero et al. (Thu,) studied this question.