The effects of posture on cerebral blood flow velocity in acute stroke
Research type
Research Study
Full title
The effects of posture on cerebral blood flow velocity during the acute phase of stroke.
IRAS ID
295752
Contact name
Simon Nichols
Contact email
Sponsor organisation
Sheffield Hallam University
Duration of Study in the UK
0 years, 8 months, 30 days
Research summary
Clinical guidelines recommend that stroke survivors should engage in out-of-bed sitting, standing and walking activities early after stroke. Studies have found that compared to lying flat, sitting upright reduces brain blood flow early after stroke. To date, no research has been done to find out how standing affects brain blood flow early after stroke. The transition from sitting to standing causes blood to move away from the head toward the legs, which lowers blood pressure. In healthy individuals, the blood vessels in the brain respond to reduced blood flow and blood pressure by dilating (widening), diverting more blood to the brain. After a stroke, the blood vessels in the brain become damaged and their ability to control blood flow is reduced. This raises the concern that standing early after a stroke may cause brain blood flow to drop too low which could worsen the brain injury. A recent large-scale trial reported that starting rehabilitation activities (including standing) earlier (18.5 hours vs 22.4 hours after stroke) resulted in poorer recovery of physical function measured three months after stroke. This negative finding could be explained, in part, by reduced cerebral blood flow. We will investigate the effects of standing on cerebral blood flow velocity, measured using transcranial Doppler ultrasound, in people with acute stroke.
REC name
North West - Greater Manchester West Research Ethics Committee
REC reference
21/NW/0146
Date of REC Opinion
8 Jun 2021
REC opinion
Further Information Favourable Opinion