Platform Presentation The Joint Annual Meeting of the Stroke Society of Australasia (SSA) and Smartstrokes 2023

Cerebral haemodynamics and orthostatic response to upright position in acute ischaemic stroke: the CHORUS study (#72)

Lilian B Carvalho 1 , Tina Kaffenberger 1 , Brian Chambers 2 , Karen Borschmann 1 , Christopher Levi 3 , Leonid Churilov 4 , Vincent Thijs 1 2 , Julie Bernhardt 1
  1. The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Heidelberg, VIC, Australia
  2. Neurology Department, Austin Health, Melbourne, VIC, Australia
  3. John Hunter Hospital, University of Newcastle, Newcastle, NSW, Australia
  4. Department of Medicine (Austin Health) and Melbourne Brain Centre at Royal Melbourne Hospital, Melbourne Medical School, University of Melbourne, Melbourne, VIC, Australia

Background

The effects of upright positions on cerebral haemodynamics in acute ischaemic stroke are not well understood. A potential mechanism for harm is that upright activity (sitting, standing, walking) could worsen cerebral perfusion early post ischaemic stroke.

Aims

To estimate the effects of early upright positions (sitting, standing) on cerebral haemodynamics in people with acute ischaemic stroke, with and without occlusive disease.

Methods

We recruited ischaemic stroke (<48h onset) participants with and without occlusive disease, and controls. We investigated MCA mean velocity using transcranial Doppler in 0° head position then 30°, 70°, 90° sitting, and 90° standing, at both <48h and 3-7days post-stroke. A blinded assessor determined mean velocities. We used mixed effect linear regression to analyse orthostatic changes in mean velocity from 0° to other head positions. Logistic regression was used to explore associations between mean velocity and 30-day mRS.

Results

Forty-two stroke participants (13 with occlusive disease, 29 without) and 22 controls were recruited. Stroke participants’ median age was 67.5 years (IQR 59-77), controls 61 years (IQR 44-69). Affected hemisphere mean velocity decreased in stroke with occlusive disease (<48h): from 0° to sitting (-9.9cm/s, 95% CI [-16.4,-3.4]) and standing (-7.1cm/s, 95% CI [-14.3,-0.01]); and in stroke without occlusive disease from 0° to sitting (-3.3cm/s, 95% CI [-5.6,-1.1]) and standing (-3.6cm/s, 95% CI [-5.9,-1.3]) (p-value  interaction=0.07). Similar changes were observed in controls (0° to sitting -3.8cm/s, 95%CI [-6.0,-1.63] and standing -3cm/s, 95% CI [-5.2,-0.81]) (no significant interaction stroke vs controls). Orthostatic changes in mean velocity in stroke <48h were similar to 3-7 days. No association between orthostatic changes in velocity <48h and 30-day mRS was found.

Conclusion

Moving to more upright positions in the first 2 days post-stroke does reduce mean velocity, but these changes were not significantly different for people with stroke with and without occlusive disease.