Standing middle cerebral artery velocity predicts cognitive function and gait speed in older adults with cognitive impairment, and is impacted by sex differences

Figures

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  Fig. 1. Correlations between resistance index (RI), pulsatility index (PI) and middle cerebral artery velocity pulse amplitude (MCApv) with Montreal Cognitive Assessment (MoCA) scores and gait speed (GS). The p-values and r values are representative of the partial Pearson correlations controlling for age and the regression lines are simple linear regressions for females (solid line) and males (dashed line) to allow for visual comparison between sexes and among clinical cohorts of participants with dementia (DEM), mild cogntivie impairment (MCI), and intact cognition (CNT). A. Supine and standing RI and PI are negatively associated with MoCA scores, and simple linear regression analysis reveals that males are predominantly driving this relationship. B. standing RI, PI and MCApv are associated with GS in females and males.

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  Fig. 2. Middle cerebral artery velocity at diastole (MCAdv) and Montreal Cognitive Assessment (MoCA) scores within each clinical cohort (A) and in two age-matched males (B). A. Supine and standing MCAdv at supine rest and during standing in controls (CNT, circles), mild cognitive impairment (MCI, triangles), and cognitive impairment (DEM, squares) for females (filled symbols and solid regression line) and males (open symbols and dashed regression line). B. Beat-to-beat- changes in MCAdv in two age- and sex-matched individuals during a supine to stand.

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  Fig. 3. Performance on the Montreal Cognitive Assessment (MoCA), gait speed (GS) and postural stability (total path length, TPL) are associated with one another in both sexes. The p-values and corresponding r values from the partial Pearson correlations (controlling for age) reflect relationships between MoCA, GS, and TPL across varying levels of cognitive function; controls (CNT), mild cognitive impairment (MCI), and dementia (DEM). The regression lines for females (solid line) and males (dashed lines) demonstrate how the relationships between outcome variables differ among the sexes.

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  Fig. 4. Group differences and the effects of posture on hemodynamic variables.CNT control group, MCI mild cognitive impairment group, DEM group with dementia, Interaction group effect by effect of position, SVi stroke volume, MAP mean arterial pressure, CVRi cerebrovascular resistance index, MCAv middle cerebral artery velocity (subscripts: d diastolic, m mean), ETCO2 end-tidal carbon dioxide, tSO2 cerebral tissue saturation, OxHb oxygenated hemoglobin, DexHb deoxygenated hemoglobin. Group effect post-hoc ** p<0.05, * p<0.085 (trend). Pairwise comparisons marked by §.