scholarly journals Flat-head positioning increases cerebral blood flow in anterior circulation acute ischemic stroke. A cluster randomized phase IIb trial

2017 ◽  
Vol 13 (6) ◽  
pp. 600-611 ◽  
Author(s):  
Verónica V Olavarría ◽  
Pablo M Lavados ◽  
Paula Muñoz-Venturelli ◽  
Francisca González ◽  
Javier Gaete ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Odds Ratio ◽  
Anterior Circulation ◽  
Serious Adverse Events ◽  
Head Positioning ◽  
Blood Flow Velocities ◽  
Flow Velocities

Background Whether lying-flat improves blood flow in patients with acute ischemic stroke is unknown. Our aim was to investigate if lying-flat “changes” cerebral blood flow velocities assessed by transcranial Doppler in acute ischemic stroke patients. Methods In a multicenter cluster clinical trial, we randomly assigned patients within 12 h from onset of a neurological deficit due to cerebral ischemia of the anterior circulation to lying-flat or upright head positioning. The primary outcome was a change of 8 cm/s or more in mean cerebral blood flow velocities on transcranial Doppler to the middle cerebral artery at 1 and 24 h post-randomization, adjusted for imbalance in baseline variables. Secondary outcomes included serious adverse events and physical functioning at 90 days. Results Ninety-four of 304 patients screened were recruited. The primary outcome occurred in 11 (26%) of 43 patients in the lying-flat group and in 6 (12%) of 51 in the upright group at 1 h (adjusted odds ratio, 3.81; 95% CI, 1.07 to 13.54), and in 23 (53%) and 18 (36%) patients in these respective groups at 24 h (adjusted odds ratio, 3.04; 95% CI, 1.08 to 8.53). There were no between-group differences in serious adverse events, including pneumonia, heart failure or mortality, nor in functional outcome at 3 months (adjusted common odds ratio, 1.38; 95% CI 0.64 to 3.00). Conclusion The lying-flat head position was associated with a significant increase in cerebral blood flow velocities at one and 24 h within the ipsilateral hemisphere of anterior circulation acute ischemic stroke, without serious safety concerns. Clinical trial registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT01706094.

scholarly journals HOBOE (Head-of-Bed Optimization of Elevation) Study: Association of Higher Angle With Reduced Cerebral Blood Flow Velocity in Acute Ischemic Stroke

2011 ◽  
Vol 91 (10) ◽  
pp. 1503-1512 ◽  
Author(s):  
Abigail Jade Hunter ◽  
Suzanne J. Snodgrass ◽  
Debbie Quain ◽  
Mark W. Parsons ◽  
Christopher R. Levi
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Mean Flow ◽  
Study Association ◽  
Blood Flow Velocities ◽  
Flow Velocities

BackgroundCerebral autoregulation can be impaired after ischemic stroke, with potential adverse effects on cerebral blood flow during early rehabilitation.ObjectiveThe objective of this study was to assess changes in cerebral blood flow velocity with orthostatic variation at 24 hours after stroke.DesignThis investigation was an observational study comparing mean flow velocities (MFVs) at 30, 15, and 0 degrees of elevation of the head of the bed (HOB).MethodsEight participants underwent bilateral middle cerebral artery (MCA) transcranial Doppler monitoring during orthostatic variation at 24 hours after ischemic stroke. Computed tomography angiography separated participants into recanalized (artery completely reopened) and incompletely recanalized groups. Friedman tests were used to determine MFVs at the various HOB angles. Mann-Whitney U tests were used to compare the change in MFV (from 30° to 0°) between groups and between hemispheres within groups.ResultsFor stroke-affected MCAs in the incompletely recanalized group, MFVs differed at the various HOB angles (30°: median MFV=51.5 cm/s, interquartile range [IQR]=33.0 to 103.8; 15°: median MFV=55.5 cm/s, IQR=34.0 to 117.5; 0°: median MFV=85.0 cm/s, IQR=58.8 to 127.0); there were no significant differences for other MCAs. For stroke-affected MCAs in the incompletely recanalized group, MFVs increased with a change in the HOB angle from 30 degrees to 0 degrees by a median of 26.0 cm/s (IQR=21.3 to 35.3); there were no significant changes in the recanalized group (−3.5 cm/s, IQR=−12.3 to 0.8). The changes in MFV with a change in the HOB angle from 30 degrees to 0 degrees differed between hemispheres in the incompletely recanalized group but not in the recanalized group.LimitationsGeneralizability was limited by sample size.ConclusionsThe incompletely recanalized group showed changes in MFVs at various HOB angles, suggesting that cerebral blood flow in this group may be sensitive to orthostatic variation, whereas the recanalized group maintained stable blood flow velocities.

scholarly journals Intracranial blood flow velocities in acute ischemic stroke.

Stroke ◽  
1994 ◽  
Vol 25 (7) ◽  
pp. 1378-1383 ◽  
Author(s):  
A V Alexandrov ◽  
C F Bladin ◽  
J W Norris
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Blood Flow Velocities ◽  
Flow Velocities

Patterns of Cerebral Blood Flow and Systemic Hemodynamics During Arithmetic Processing

2008 ◽  
Vol 22 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Natalie Werner ◽  
Neval Kapan ◽  
Gustavo A. Reyes del Paso
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Time Course ◽  
Doppler Sonography ◽  
Transcranial Doppler Sonography ◽  
Systemic Hemodynamics ◽  
Heart Period ◽  
Blood Flow Velocities ◽  
Flow Velocities

The present study explored modulations in cerebral blood flow and systemic hemodynamics during the execution of a mental calculation task in 41 healthy subjects. Time course and lateralization of blood flow velocities in the medial cerebral arteries of both hemispheres were assessed using functional transcranial Doppler sonography. Indices of systemic hemodynamics were obtained using continuous blood pressure recordings. Doppler sonography revealed a biphasic left dominant rise in cerebral blood flow velocities during task execution. Systemic blood pressure increased, whereas heart period, heart period variability, and baroreflex sensitivity declined. Blood pressure and heart period proved predictive of the magnitude of the cerebral blood flow response, particularly of its initial component. Various physiological mechanisms may be assumed to be involved in cardiovascular adjustment to cognitive demands. While specific contributions of the sympathetic and parasympathetic systems may account for the observed pattern of systemic hemodynamics, flow metabolism coupling, fast neurogenic vasodilation, and cerebral autoregulation may be involved in mediating cerebral blood flow modulations. Furthermore, during conditions of high cardiovascular reactivity, systemic hemodynamic changes exert a marked influence on cerebral blood perfusion.

Longitudinal changes in cerebral blood flow velocities in different clinical courses of migraine

Cephalalgia ◽  
2016 ◽  
Vol 37 (10) ◽  
pp. 927-937 ◽  
Author(s):  
Mi Ji Lee ◽  
Min Kyung Chu ◽  
Hanna Choi ◽  
Hyun Ah Choi ◽  
Chungbin Lee ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Artery ◽  
Posterior Cerebral Artery ◽  
Clinical Course ◽  
Episodic Migraine ◽  
Longitudinal Changes ◽  
Blood Flow Velocities ◽  
Headache Clinic ◽  
Flow Velocities

Objective To assess longitudinal changes in cerebral blood flow velocities (ΔCBFVs) according to the clinical course of migraine. Methods We retrospectively included migraine patients with two or more attacks per month at baseline who were followed up within 2 years with transcranial Doppler in a tertiary headache clinic. ΔCBFVs were analyzed in relation to clinical courses, defined as remission (0–1 headache days/month), persistence (2–14/month), or progression (≥15/month) in episodic migraine (EM), and conversion to EM (<15/month) and persistence (≥15/month) in chronic migraine (CM). Results A total of 166 patients (90 EM and 76 CM) were included. In EM, the remission group ( n = 30) showed a decrease in CBFV in the middle cerebral artery (MCA) and the basilar artery (BA). The progression group ( n = 10) showed increasing CBFVs in the bilateral MCAs. Patients with the persistence course ( n = 50) showed generally unchanged CBFVs. In CM, ΔCBFVs decreased in the BA and increased in the posterior cerebral artery (PCA) after conversion to EM ( n = 61), whereas they remained unchanged in the persistence group ( n = 15). In all patients, % change in headache days was positively correlated with the %ΔCBFVs of the bilateral MCAs and the BA. Conclusions CBFV changes are associated with the different clinical courses of migraine. The association is more prominent in EM than CM.

scholarly journals Cerebral blood flow velocities and cerebrovascular resistance in normal-term neonates in the first 72 hours

2017 ◽  
Vol 54 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Danielle E Forster ◽  
Emmanuel Koumoundouros ◽  
Virginia Saxton ◽  
Gabrielle Fedai ◽  
James Holberton
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Term Neonates ◽  
Cerebrovascular Resistance ◽  
Normal Term ◽  
Blood Flow Velocities ◽  
Flow Velocities

scholarly journals Relationship Between Cerebral Blood Flow Velocities and Cerebral Electrical Activity in Sleep

SLEEP ◽  
1994 ◽  
Vol 17 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Göran Hajak ◽  
Jürgen Klingelhöfer ◽  
Maria Schulz-Varszegi ◽  
Gernot Matzander ◽  
Dirk Sander ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Electrical Activity ◽  
Blood Flow Velocities ◽  
Flow Velocities
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