Preserved dynamic cerebral autoregulation in the middle cerebral artery among persons with migraine

2007 ◽  
Vol 180 (3) ◽  
pp. 517-523 ◽  
Author(s):  
M. Reinhard ◽  
E. Wehrle-Wieland ◽  
M. Roth ◽  
W. D. Niesen ◽  
J. Timmer ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cerebral Autoregulation ◽  
Dynamic Cerebral Autoregulation

scholarly journals Impaired Cerebrovascular Hemodynamics are Associated with Cerebral White Matter Damage

2013 ◽  
Vol 34 (2) ◽  
pp. 228-234 ◽  
Author(s):  
Sushmita Purkayastha ◽  
Otite Fadar ◽  
Aujan Mehregan ◽  
David H Salat ◽  
Nicola Moscufo ◽  
...  
Keyword(s):  
White Matter ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cerebral Autoregulation ◽  
Structural Integrity ◽  
Cerebral White Matter ◽  
Elderly Individuals ◽  
Transfer Function Analysis ◽  
Dynamic Cerebral Autoregulation ◽  
Cerebrovascular Hemodynamics

White matter hyperintensities (WMH) in elderly individuals with vascular diseases are presumed to be due to ischemic small vessel diseases; however, their etiology is unknown. We examined the cross-sectional relationship between cerebrovascular hemodynamics and white matter structural integrity in elderly individuals with vascular risk factors. White matter hyperintensity volumes, fractional anisotropy (FA), and mean diffusivity (MD) were obtained from MRI in 48 subjects (75±7years). Pulsatility index (PI) and dynamic cerebral autoregulation (dCA) was assessed using transcranial Doppler ultrasound of the middle cerebral artery. Dynamic cerebral autoregulation was calculated from transfer function analysis (phase and gain) of spontaneous blood pressure and flow velocity oscillations in the low (LF, 0.03 to 0.15 Hz) and high (HF, 0.16 to 0.5 Hz) frequency ranges. Higher PI was associated with greater WMH ( P<0.005). Higher phase across all frequency ranges was associated with greater FA and lower MD ( P<0.005). Lower gain was associated with higher FA in the LF range ( P=0.001). These relationships between phase and FA were significant in the territories limited to the middle cerebral artery as well as across the entire brain. Our results show a strong relationship between impaired cerebrovascular hemodynamics (PI and dCA) and loss of cerebral white matter structural integrity (WMH and DTI metrics) in elderly individuals.

scholarly journals Dynamic cerebral autoregulation during cognitive task: effect of hypoxia

2018 ◽  
Vol 124 (6) ◽  
pp. 1413-1419 ◽  
Author(s):  
Shigehiko Ogoh ◽  
Hiroki Nakata ◽  
Tadayoshi Miyamoto ◽  
Damian Miles Bailey ◽  
Manabu Shibasaki
Keyword(s):  
Reaction Time ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cerebral Autoregulation ◽  
Cognitive Task ◽  
Cognitive Activity ◽  
Blood Velocity ◽  
Dynamic Cerebral Autoregulation

Changes in cerebral blood flow (CBF) subsequent to alterations in the partial pressures of oxygen and carbon dioxide can modify dynamic cerebral autoregulation (CA). While cognitive activity increases CBF, the extent to which it impacts CA remains to be established. In the present study we determined whether dynamic CA would decrease during a cognitive task and whether hypoxia would further compound impairment. Fourteen young healthy subjects performed a simple Go/No-go task during normoxia and hypoxia (inspired O2 fraction = 12%), and the corresponding relationship between mean arterial pressure (MAP) and mean middle cerebral artery blood velocity (MCA Vmean) was examined. Dynamic CA and steady-state changes in MCA V in relation to changes in arterial pressure were evaluated with transfer function analysis. While MCA Vmean increased during the cognitive activity ( P < 0.001), hypoxia did not cause any additional changes ( P = 0.804 vs. normoxia). Cognitive performance was also unaffected by hypoxia (reaction time, P = 0.712; error, P = 0.653). A decrease in the very low- and low-frequency phase shift (VLF and LF; P = 0.021 and P = 0.01) and an increase in LF gain were observed ( P = 0.037) during cognitive activity, implying impaired dynamic CA. While hypoxia also increased VLF gain ( P < 0.001), it failed to cause any additional modifications in dynamic CA. Collectively, our findings suggest that dynamic CA is impaired during cognitive activity independent of altered systemic O2 availability, although we acknowledge the interpretive complications associated with additional competing, albeit undefined, inputs that could potentially distort the MAP-MCA Vmean relationship. NEW & NOTEWORTHY During normoxia, cognitive activity while increasing cerebral perfusion was shown to attenuate dynamic cerebral autoregulation (CA) yet failed to alter reaction time, thereby questioning its functional significance. No further changes were observed during hypoxia, suggesting that impaired dynamic CA occurs independently of altered systemic O2 availability. However, impaired dynamic CA may reflect a technical artifact, given the confounding influence of additional inputs that could potentially distort the mean arterial pressure-mean middle cerebral artery blood velocity relationship.

Effect of inhibition of nitric oxide synthase on dynamic cerebral autoregulation in humans

2000 ◽  
Vol 99 (6) ◽  
pp. 555-560 ◽  
Author(s):  
R. P. WHITE ◽  
P. VALLANCE ◽  
H. S. MARKUS
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Blood Flow ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cerebral Autoregulation ◽  
Arterial Blood ◽  
The Mean ◽  
Oxide Synthase ◽  
Dynamic Cerebral Autoregulation

Cerebral blood flow is maintained constant over a range of cerebral perfusion pressures by cerebral autoregulation. Impaired cerebral autoregulation may be important in the pathogenesis of cerebral ischaemia. The mechanisms mediating normal cerebral autoregulation in humans are poorly understood. We used a recently described transcranial Doppler technique, which allows non-invasive measurement of dynamic cerebral autoregulation, to test the hypothesis that nitric oxide mediates cerebral autoregulation. The rate of rise of middle cerebral artery blood flow velocity, compared with that of arterial blood pressure, was determined following a stepwise fall in arterial blood pressure, in order to calculate an autoregulatory index. The effect of the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (L-NMMA) on dynamic autoregulation was compared with that of noradrenaline titrated to result in a similar rise in blood pressure. Six healthy subjects were studied in each group. The mean (S.D.) change in autoregulatory index following noradrenaline at a similar pressor dose was significantly greater than the change following the L-NMMA bolus: 1.1 (1.2) compared with -0.8 (0.8) for the left middle cerebral artery (P = 0.002), and 1.1 (0.8) compared with -0.8 (0.8) for the right middle cerebral artery (P = 0.002). There was no difference in the mean (S.D.) blood pressure increase resulting from the two agents: L-NMMA, 19.7 (7.4) mmHg; noradrenaline, 15.5 (4.8) mmHg (P = 0.281). These results suggest that nitric oxide mediates at least part of the dynamic phase of cerebral autoregulation in humans. Reduced nitric oxide release may play a role in the impaired cerebral autoregulation seen in patients with, or at risk of, cerebral ischaemia.

scholarly journals Dynamic Cerebral Autoregulation in Acute Lacunar and Middle Cerebral Artery Territory Ischemic Stroke

Stroke ◽  
2005 ◽  
Vol 36 (12) ◽  
pp. 2595-2600 ◽  
Author(s):  
Rogier V. Immink ◽  
Gert A. van Montfrans ◽  
Jan Stam ◽  
John M. Karemaker ◽  
Michaela Diamant ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Cerebral Autoregulation ◽  
Middle Cerebral Artery Territory ◽  
Dynamic Cerebral Autoregulation

scholarly journals Impaired cerebral autoregulation and neurovascular coupling in middle cerebral artery stroke: Influence of severity?

2018 ◽  
Vol 39 (11) ◽  
pp. 2277-2285 ◽  
Author(s):  
Angela SM Salinet ◽  
Nathália CC Silva ◽  
Juliana Caldas ◽  
Daniel S de Azevedo ◽  
Marcelo de-Lima-Oliveira ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Functional Outcome ◽  
Cerebral Artery ◽  
Cerebral Autoregulation ◽  
Cerebral Blood Flow Velocity ◽  
Neurovascular Coupling ◽  
Stroke Severity ◽  
Healthy Controls ◽  
Stroke Patients ◽  
Severe Stroke

We aimed to assess cerebral autoregulation (CA) and neurovascular coupling (NVC) in stroke patients of differing severity comparing responses to healthy controls and explore the association between CA and NVC with functional outcome. Patients admitted with middle cerebral artery (MCA) stroke and healthy controls were recruited. Stroke severity was defined by the National Institutes of Health Stroke Scale (NIHSS) scores: ≤4 mild, 5–15 moderate and ≥16 severe. Transcranial Doppler ultrasound and Finometer recorded MCA cerebral blood flow velocity (CBFv) and blood pressure, respectively, over 5 min baseline and 1 min passive movement of the elbow to calculate the autoregulation index (ARI) and CBFv amplitude responses to movement. All participants were followed up for three months. A total of 87 participants enrolled in the study, including 15 mild, 27 moderate and 13 severe stroke patients, and 32 control subjects. ARI was lower in the affected hemisphere (AH) of moderate and severe stroke groups. Decreased NVC was seen bilaterally in all stroke groups. CA and NVC correlated with stroke severity and functional outcome. CBFv regulation is significantly impaired in acute stroke, and further compromised with increasing stroke severity. Preserved CA and NVC in the acute period were associated with improved three-month functional outcome.

scholarly journals Dynamic Cerebral Autoregulation Post Endovascular Thrombectomy in Acute Ischemic Stroke

2020 ◽  
Vol 10 (9) ◽  
pp. 641
Author(s):  
Faheem Sheriff ◽  
Pedro Castro ◽  
Mariel Kozberg ◽  
Sarah LaRose ◽  
Andrew Monk ◽  
...  
Keyword(s):  
Cerebral Artery ◽  
Cerebral Autoregulation ◽  
Function Analysis ◽  
Blood Pressure Monitoring ◽  
Multiple Time ◽  
Monitoring And Control ◽  
Endovascular Thrombectomy ◽  
Transfer Function Analysis ◽  
The Impact ◽  
Dynamic Cerebral Autoregulation

The development of the endovascular thrombectomy (EVT) technique has revolutionized acute stroke management for patients with large vessel occlusions (LVOs). The impact of successful recanalization using an EVT on autoregulatory profiles is unknown. A more complete understanding of cerebral autoregulation in the context of EVT may assist with post-procedure hemodynamic optimization to prevent complications. We examined cerebral autoregulation in 107 patients with an LVO in the anterior circulation (proximal middle cerebral artery (M1/2) and internal cerebral artery (ICA) terminus) who had been treated using an EVT. Dynamic cerebral autoregulation was assessed at multiple time points, ranging from less than 24 hours to 5 days following last seen well (LSW) time, using transcranial Doppler ultrasound recordings and transfer function analysis. Complete (Thrombolysis in Cerebral Infarction (TICI) 3) recanalization was associated with a more favorable autoregulation profile compared with TICI 2b or poorer recanalization (p < 0.05), which is an effect that was present after accounting for differences in the infarct volumes. Less effective autoregulation in the first 24 h following the LSW time was associated with increased rates of parenchymal hematoma types 1 and 2 hemorrhagic transformations (PH1–PH2). These data suggest that patients with incomplete recanalization and poor autoregulation (especially within the first 24 h post-LSW time) may warrant closer blood pressure monitoring and control in the first few days post ictus.

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