Centre for Heart, Lung and Vascular Health, Faculty of Health and Social Development, University of British Columbia Okanagan, 1147 Research Rd, Kelowna, BC, Canada.
Department of Neurology, Clinical Hospital Center Split, Spinciceva 1, Split, Croatia.
Spinal Cord. 2019 Nov;57(11):979-984. doi: 10.1038/s41393-019-0321-1. Epub 2019 Jul 9.
Experimental study.
Compromised cerebrovascular function likely contributes to elevated neurological risk in spinal cord injury (SCI). Passive heating offers many cardiovascular and neurological health benefits; therefore, we aimed to determine the effects of an acute bout of heating on cerebrovascular function in chronic SCI.
Persons with cervical SCI (n = 15) and uninjured controls (CON; n = 15) completed 60 min of lower limb hot water immersion (40 °C). Assessments of middle cerebral (MCA) and posterior cerebral artery (PCA) velocities, pulsatilities, and neurovascular coupling (NVC) were performed using transcranial Doppler ultrasound. Duplex ultrasonography was used to index cerebral blood flow via the internal carotid artery (ICA), and carotid-femoral pulse-wave velocity (PWV) was measured using tonometry. The NVC response was quantified as the peak hyperemic value during 30-s cycles of visual stimulation.
Mean arterial pressure changed differentially with heating [mean (standard deviation); SCI: +6(14) mmHg, CON: -8(12) mmHg; P = 0.01]. There were no differences in any intracranial artery measures (all P > 0.05), except for small (~10%) increases in MCA conductance in CON after heating vs. SCI (interaction P = 0.006). Resting ICA flow was greater in SCI vs. CON (P = 0.03) but did not change with heating in either group (interaction P = 0.34). There were also no between-group differences in the NVC response (ΔPCA conductance) pre- [SCI: 29(19)% vs. CON: 30(9)%] or post-heating [SCI 30(9)% vs. 25(9)%; interaction P = 0.22].
Mild acute heating does not impair or improve cerebrovascular function in SCI or CON. Thus, further study of the effects of chronic heating interventions are warranted.
实验研究。
脑血管功能受损可能导致脊髓损伤（SCI）患者的神经风险增加。被动加热对心血管和神经系统健康有诸多益处；因此，我们旨在确定急性热疗对慢性 SCI 患者脑血管功能的影响。
15 名颈段 SCI 患者（SCI 组）和 15 名未受伤对照者（CON 组）完成了 60 分钟的下肢热水浸泡（40°C）。使用经颅多普勒超声评估大脑中动脉（MCA）和大脑后动脉（PCA）速度、搏动性和神经血管耦合（NVC）。使用双功能超声评估颈内动脉（ICA）的脑血流，并使用张力测量法测量颈动脉-股动脉脉搏波速度（PWV）。NVC 反应通过 30 秒的视觉刺激循环中的峰值充血值来量化。
平均动脉压随加热而不同变化[平均值（标准差）；SCI：+6（14）mmHg，CON：-8（12）mmHg；P=0.01]。除了 CON 组加热后 MCA 传导性略有增加（与 SCI 相比，差异具有统计学意义，P=0.006）外，所有颅内动脉指标均无差异（所有 P>0.05）。SCI 组的静息 ICA 流量大于 CON 组（P=0.03），但两组的 ICA 流量均无变化（交互作用 P=0.34）。加热前后，NVC 反应（ΔPCA 传导性）在 SCI 组和 CON 组之间也没有差异[SCI：29（19）%比 CON：30（9）%；交互作用 P=0.22]。
轻度急性加热不会损害或改善 SCI 或 CON 的脑血管功能。因此，有必要进一步研究慢性加热干预的效果。
