Morgan W H, Khoo J, Vukmirovic A, Abdul-Rahman A, An D, Mehnert A, Obreschkow D, Chowdhury E, Yu D Y
Lions Eye Institute, Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, WA, Australia.
International Space Centre, 35 Stirling Hwy, Crawley, WA, 6009, Australia.
NPJ Microgravity. 2023 Mar 31;9(1):28. doi: 10.1038/s41526-023-00269-0.
Spaceflight associated neuro-ocular syndrome (SANS) is common amongst astronauts on long duration space missions and is associated with signs consistent with elevated cerebrospinal fluid (CSF) pressure. Additionally, CSF pressure has been found to be elevated in a significant proportion of astronauts in whom lumbar puncture was performed after successful mission completion. We have developed a retinal photoplethysmographic technique to measure retinal vein pulsation amplitudes. This technique has enabled the development of a non-invasive CSF pressure measurement apparatus. We tested the system on healthy volunteers in the sitting and supine posture to mimic the range of tilt table extremes and estimated the induced CSF pressure change using measurements from the CSF hydrostatic indifferent point. We found a significant relationship between pulsation amplitude change and estimated CSF pressure change (p < 0.0001) across a range from 2.7 to 7.1 mmHg. The increase in pulse amplitude was highest in the sitting posture with greater estimated CSF pressure increase (p < 0.0001), in keeping with physiologically predicted CSF pressure response. This technique may be useful for non-invasive measurement of CSF pressure fluctuations during long-term space voyages.
航天相关神经眼综合征(SANS)在执行长期太空任务的宇航员中很常见,且与符合脑脊液(CSF)压力升高的体征相关。此外,在成功完成任务后接受腰椎穿刺的相当一部分宇航员中,发现脑脊液压力升高。我们开发了一种视网膜光电容积描记技术来测量视网膜静脉搏动幅度。这项技术促成了一种非侵入性脑脊液压力测量装置的研发。我们在健康志愿者处于坐姿和仰卧姿势时对该系统进行了测试,以模拟倾斜台极端角度范围,并利用脑脊液流体静力平衡点的测量值估算诱导的脑脊液压力变化。我们发现,在2.7至7.1 mmHg的范围内,搏动幅度变化与估算的脑脊液压力变化之间存在显著关系(p < 0.0001)。在坐姿时脉搏幅度增加最高,估算的脑脊液压力升高幅度也更大(p < 0.0001),这与生理上预测的脑脊液压力反应一致。这项技术可能有助于在长期太空航行期间对脑脊液压力波动进行非侵入性测量。