Division of Neurology, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada.
BC Children's Hospital Research Institute, Vancouver, BC, Canada.
Top Spinal Cord Inj Rehabil. 2024 Spring;30(2):78-95. doi: 10.46292/sci23-00068. Epub 2024 May 23.
Spinal cord injuries (SCI) often result in cardiovascular issues, increasing the risk of stroke and cognitive deficits.
This study assessed cerebrovascular reactivity (CVR) using functional magnetic resonance imaging (fMRI) during a hypercapnic challenge in SCI participants compared to noninjured controls.
Fourteen participants were analyzed ( = 8 with SCI [unless otherwise noted], median age = 44 years; = 6 controls, median age = 33 years). CVR was calculated through fMRI signal changes.
The results showed a longer CVR component (tau) in the grey matter of SCI participants ( = 7) compared to controls (median difference = 3.0 s; < .05). Time since injury (TSI) correlated negatively with steady-state CVR in the grey matter and brainstem of SCI participants ( = -0.81, = .014; = -0.84, = .009, respectively). Lower steady-state CVR in the brainstem of the SCI group ( = 7) correlated with lower diastolic blood pressure ( = 0.76, = .046). Higher frequency of hypotensive episodes ( = 7) was linked to lower CVR outcomes in the grey matter ( = -0.86, = .014) and brainstem ( = -0.89, = .007).
Preliminary findings suggest a difference in the dynamic CVR component, tau, between the SCI and noninjured control groups, potentially explaining the higher cerebrovascular health burden in SCI individuals. Exploratory associations indicate that longer TSI, lower diastolic blood pressure, and more hypotensive episodes may lead to poorer CVR outcomes. However, further research is necessary to establish causality and support these observations.
脊髓损伤（SCI）常导致心血管问题，增加中风和认知缺陷的风险。
本研究通过功能磁共振成像（fMRI）评估 SCI 参与者和非损伤对照者在高碳酸血症挑战期间的脑血管反应性（CVR）。
分析了 14 名参与者（=8 名 SCI 患者[除非另有说明]，中位年龄=44 岁；=6 名对照者，中位年龄=33 岁）。通过 fMRI 信号变化计算 CVR。
结果显示，SCI 参与者的灰质 CVR 成分（tau）较长（=7 名，中位数差异=3.0 s；<0.05）。损伤后时间（TSI）与 SCI 参与者的灰质和脑干的稳态 CVR 呈负相关（= -0.81，=0.014；= -0.84，=0.009）。SCI 组脑干的稳态 CVR 较低（=7）与舒张压较低相关（=0.76，=0.046）。SCI 组低血压发作次数较高（=7）与灰质（= -0.86，=0.014）和脑干（= -0.89，=0.007）的 CVR 结果较低有关。
初步研究结果表明，SCI 组和非损伤对照组之间的动态 CVR 成分 tau 存在差异，这可能解释了 SCI 个体更高的脑血管健康负担。探索性关联表明，TSI 较长、舒张压较低和低血压发作次数较多可能导致 CVR 结果较差。然而，需要进一步研究来确定因果关系并支持这些观察结果。
