Cerebral haemodynamics with head position changes post-ischemic stroke: A systematic review and meta-analysis

Lilian B. Carvalho, Sharon Kramer, Karen Borschmann, Brian Chambers, Vincent Thijs, Julie Bernhardt

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9 Citations (Scopus)

Abstract

The effects of upright postures on the cerebral circulation early post-ischemic stroke are not fully understood. We conducted a systematic review and meta-analysis to investigate the effects of head positioning on cerebral haemodynamics assessed by imaging methods post-ischemic stroke. Of the 21 studies included (n = 529), 15 used transcranial Doppler. Others used near-infrared, diffuse correlation spectroscopy and nuclear medicine modalities. Most tested head positions between 0° and 45°. Seventeen studies reported changes in CBF parameters (increase at lying-flat or decrease at more upright) in the ischaemic hemisphere with position change. However, great variability was found and risk of bias was high in many studies. Pooled data of two studies ≤24 h (n = 28) showed a mean increase in cerebral blood flow (CBF) velocity of 8.5 cm/s in the ischaemic middle cerebral artery (95%CI,−2.2–19.3) from 30° to 0°. The increase found ≤48 h (n = 50) was of 2.3 cm/s (95%CI,−4.6–9.2), while ≤7 days (n = 38) was of 8.4 cm/s (95%CI, 1.8–15). Few very early studies (≤2 days) tested head positions greater than 30° and were unable to provide information about the response of acute stroke patients to upright postures (sitting, standing). These postures are part of current clinical practice and knowledge on their effects on cerebral haemodynamics is required.

Original languageEnglish
Pages (from-to)1917-1933
Number of pages17
JournalJournal of Cerebral Blood Flow and Metabolism
Volume40
Issue number10
DOIs
Publication statusPublished - 1 Oct 2020
Externally publishedYes

Keywords

  • cerebral blood flow
  • cerebral haemodynamics
  • head position
  • Ischaemic stroke
  • upright position

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