Mohammadi Hanieh, Sirpal Parikshat, Bherer Louis, Lesage Frédéric, Joanette Yves
Montreal Heart Institute, Montreal, QC, Canada.
Faculty of Medicine, University of Montreal, Montreal, QC, Canada.
Front Aging Neurosci. 2025 May 20;17:1486775. doi: 10.3389/fnagi.2025.1486775. eCollection 2025.
Age-related increases in cerebral pulsatility are thought to stress cerebral microcirculation, with effects that may vary across different brain regions. The aging brain also undergoes neurofunctional changes to preserve and, in some cases, enhance cognitive abilities. This study investigated the association between cerebral pulsatility and neurofunctional changes in aging. Sixty healthy adults were divided into two groups of younger (aged 19-31 years) and older adults (aged 62-75 years). Participants underwent near-infrared spectroscopy (NIRS) imaging, including a resting-state recording to capture the baseline cortical cerebral pulsatility index, followed by a Stroop task to assess cortical hemodynamic-evoked activity. Phase-contrast magnetic resonance imaging (PC-MRI) was also performed to measure pulsatility in the large arteries supplying the brain. Results indicated that older adults exhibited a significant interhemispheric difference in cerebral pulsatility index, with a higher index in the left hemisphere compared to the right. In older adults, a greater interhemispheric difference in cerebral pulsatility index was associated with larger task-evoked oxyhemoglobin concentration changes in the right hemisphere and smaller changes in the left hemisphere for the Stroop task. Younger adults, in contrast, showed no significant interhemispheric difference in the cerebral pulsatility index nor a significant correlation with task-evoked activations. These findings suggest that age-related changes in cerebral pulsatility might contribute to or potentially drive functional reorganization in the aging brain. Further investigation is needed to provide more insight into this finding.
与年龄相关的脑搏动性增加被认为会给脑微循环带来压力，其影响可能因不同脑区而异。衰老的大脑也会发生神经功能变化，以维持并在某些情况下增强认知能力。本研究调查了衰老过程中脑搏动性与神经功能变化之间的关联。60名健康成年人被分为两组，即较年轻组（19 - 31岁）和较年长组（62 - 75岁）。参与者接受了近红外光谱（NIRS）成像，包括静息状态记录以获取基线皮质脑搏动指数，随后进行斯特鲁普任务以评估皮质血流动力学诱发活动。还进行了相位对比磁共振成像（PC - MRI）以测量供应大脑的大动脉中的搏动性。结果表明，较年长成年人在脑搏动指数上表现出显著的半球间差异，左半球的指数高于右半球。在较年长成年人中，脑搏动指数更大的半球间差异与斯特鲁普任务中右半球更大的任务诱发氧合血红蛋白浓度变化以及左半球更小的变化相关。相比之下，较年轻成年人在脑搏动指数上未表现出显著的半球间差异，也与任务诱发激活无显著相关性。这些发现表明，与年龄相关的脑搏动性变化可能促成或潜在驱动衰老大脑中的功能重组。需要进一步研究以更深入了解这一发现。
