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Eur J Neurol. 2018 Nov;25(11):1365-e117. doi: 10.1111/ene.13737. Epub 2018 Jul 31.

Cerebral autoregulatory performance and the cerebrovascular response to head-of-bed positioning in acute ischaemic stroke.

Author information

1
Department of Internal Medicine, Waterlandziekenhuis, Purmerend.
2
Medical Biology, Laboratory for Cardiovascular Physiology, AMC Center for Heart Failure Research, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
3
Bispebjerg Hospital Research Unit for Anesthesia and Intensive Care, University of Copenhagen, Copenhagen, Denmark.
4
Department of Nephrology, VU University Medical Center, Amsterdam.
5
Stroke Unit, Department of Neurology, Academic Medical Center, University of Amsterdam, Amsterdam.
6
Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
7
MRC/ARUK Centre for Musculoskeletal Ageing Research, School of Life Sciences, The Medical School, Queen's Medical Centre, University of Nottingham Medical School, Nottingham, UK.

Abstract

BACKGROUND AND PURPOSE:

Cerebrovascular responses to head-of-bed positioning in patients with acute ischaemic stroke are heterogeneous, questioning the applicability of general recommendations on head positioning. Cerebral autoregulation is impaired to various extents after acute stroke, although it is unknown whether this affects cerebral perfusion during posture change. We aimed to elucidate whether the cerebrovascular response to head position manipulation depends on autoregulatory performance in patients with ischaemic stroke.

METHODS:

The responses of bilateral transcranial Doppler ultrasound-determined cerebral blood flow velocity (CBFV) and local cerebral blood volume (CBV), assessed by near-infrared spectroscopy of total hemoglobin tissue concentration ([total Hb]), to head-of-bed lowering from 30° to 0° were determined in 39 patients with acute ischaemic stroke and 17 reference subjects from two centers. Cerebrovascular autoregulatory performance was expressed as the phase difference of the arterial pressure-to-CBFV transfer function.

RESULTS:

Following head-of-bed lowering, CBV increased in the reference subjects only ([total Hb]: + 2.1 ± 2.0 vs. + 0.4 ± 2.6 μM; P < 0.05), whereas CBFV did not change in either group. CBV increased upon head-of-bed lowering in the hemispheres of patients with autoregulatory performance <50th percentile compared with a decrease in the hemispheres of patients with better autoregulatory performance ([total Hb]: +1.0 ± 1.3 vs. -0.5 ± 1.0 μM; P < 0.05). The CBV response was inversely related to autoregulatory performance (r = -0.68; P < 0.001) in the patients, whereas no such relation was observed for CBFV.

CONCLUSION:

This study is the first to provide evidence that cerebral autoregulatory performance in patients with acute ischaemic stroke affects the cerebrovascular response to changes in the position of the head.

KEYWORDS:

cerebral infarction; hemodynamics; near-infrared spectroscopy; patient positioning; transcranial Doppler ultrasonography

PMID:
29935041
PMCID:
PMC6220945
DOI:
10.1111/ene.13737
[Indexed for MEDLINE]
Free PMC Article

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