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Cerebral autoregulatory performance and the cerebrovascular response to head‐of‐bed positioning in acute ischaemic stroke
Author(s) -
Truijen J.,
Rasmussen L. S.,
Kim Y. S.,
Stam J.,
Stok W. J.,
Pott F. C.,
Lieshout J. J.
Publication year - 2018
Publication title -
european journal of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 124
eISSN - 1468-1331
pISSN - 1351-5101
DOI - 10.1111/ene.13737
Subject(s) - medicine , cerebral autoregulation , transcranial doppler , cerebral blood flow , cardiology , cerebral blood volume , autoregulation , acute stroke , stroke (engine) , anesthesia , cerebral perfusion pressure , blood pressure , mechanical engineering , tissue plasminogen activator , engineering
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.