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

Immink, Rogier V.; Montfrans, Gert A. van; Stam, Jan; Karemaker, John M.; Diamant, Michaëla; Lieshout, Johannes J. van

doi:10.1161/01.str.0000189624.06836.03

Cited by 174 publications

(195 citation statements)

References 29 publications

Supporting

Mentioning

178

Contrasting

Unclassified

Order By: Relevance

“…This limit correlates well with several studies reporting values of VLF phase in cerebrovascular conditions (Panerai 2008, Chen et al 2014, Immink et al 2005, Reinhard et al 2003. In particular, Reinhard et al (Reinhard et al 2008) proposed a threshold of normality of 20.6 degrees (0.36 radians), based on analysis of 79 older subjects.…”

Section: Normative Valuessupporting

confidence: 86%

The Leicester cerebral haemodynamics database: normative values and the influence of age and sex

et al. 2016

View full text Add to dashboard Cite

Normative values of physiological parameters hold significance in modern day clinical decision-making. Lack of such normative values has been a major hurdle in the translation of research into clinical practice. A large database containing uniform recordings was constructed to allow more robust estimates of normative ranges and also assess the influence of age and sex.Doppler recordings were performed on healthy volunteers in the same laboratory, using similar protocols and equipment. Beat-to-beat blood pressure, heart-rate, electrocardiogram, and end-tidal CO2 were measured continuously. Bilateral insonation of the middle cerebral arteries (MCAs) was performed using TCD following a 15-minute stabilisation, and a 5-minute baseline recording.Good quality Doppler recordings for both MCAs were obtained in 129 participants (57 female) with a median age of 57 years (range 20-82). Age was found to influence baseline haemodynamic and transfer function analysis parameters. Cerebral blood flow velocity and critical closing pressure were the only sex-related differences found, which was significantly higher in females than males.Normative values for cerebral haemodynamic parameters have been defined in a large, healthy population. Such age/sex-defined normal values can be used to reduce the burden of collecting additional control data in future studies, as well as to identify disease-associated changes. Key wordsCerebral haemodynamics, cerebral autoregulation, ageing, sex differences, cerebral blood

show abstract

Section: Normative Valuessupporting

confidence: 86%

The Leicester cerebral haemodynamics database: normative values and the influence of age and sex

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Magnetic resonance imaging is ideally placed to assess CBF in disease states such as acute stroke, in which interhemispheral and regional changes may be expected, and indeed MRI is increasingly becoming the preferred modality for informing acute management in stroke and TIA. Cerebral autoregulation is a homeostatic mechanism that protects the brain against fluctuations in ABP, and impairment of dynamic CA has previously reported following acute stroke (Dawson et al, 2000;Immink et al, 2005). Importantly, the effects of stroke on dynamic CA may be further influenced by stroke subtype.…”

Section: Discussionmentioning

confidence: 96%

Measurement of Cerebral Blood Flow Responses to the Thigh Cuff Maneuver: A Comparison of TCD with a Novel MRI Method

Saeed

Horsfield

Panerai

et al. 2010

J Cereb Blood Flow Metab

View full text Add to dashboard Cite

Cerebral autoregulation (CA) describes the mechanism responsible for maintaining cerebral blood flow (CBF) relatively constant, despite changes in mean arterial blood pressure (ABP). This paper introduces a novel method for assessing CA using magnetic resonance imaging (MRI). Images are rapidly and repeatedly acquired using a gradient-echo echo-planar imaging pulse sequence for a period of 4 minutes, during which a transient decrease in ABP is induced by rapid release of bilateral thigh cuffs. The method was validated by comparing the observed MRI signal intensity change with the CBF velocity change in the middle cerebral arteries, as measured by transcranial Doppler (TCD) ultrasound, using a standardized thigh cuff maneuver in both cases. Cross-correlation analysis of the response profiles from the left and right hemispheres showed a greater consistency for MRI measures than for TCD, both for interhemisphere comparisons and for repeated measures. The new MRI method may provide opportunities for assessing regional autoregulatory changes following acute stroke, and in other conditions in which poor autoregulation is implicated.

show abstract

“…Multimodal pressure-flow method) were used. ARi was calculated using a second order model proposed by Tiecks et al (Immink et al 2005).…”

Section: Autoregulation Indexmentioning

confidence: 99%

“…Hypertension and diabetes, that are the leading causes of stroke and dementia of elderly people, are associated with microvascular disease that compromises capacity to regulate perfusion in cerebrovascular bed (Lipsitz et al 2000;Novak et al 2003). Cerebral autoregulation compensating fluctuations of systemic BP is lost post-stroke (Eames et al 2002;Novak et al 2004;Immink et al 2005) and after traumatic brain injury (TBI) (Czosnyka et al 1997;Schmidt et al 2003), rendering blood flow dependent on perfusion pressure. Furthermore, autoregulation failure has been associated with increased morbidity and mortality in these conditions.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Assessment of Cerebral Autoregulation from Spontaneous Blood Pressure and Cerebral Blood Flow Fluctuations

Peng

Czosnyka

et al. 2007

Cardiovasc Eng

View full text Add to dashboard Cite

Cerebral autoregulation (CA) is an most important mechanism responsible for the relatively constant blood flow supply to brain when cerebral perfusion pressure varies. Its assessment in nonacute cases has been relied on the quantification of the relationship between noninvasive beat-to-beat blood pressure (BP) and blood flow velocity (BFV). To overcome the nonstationary nature of physiological signals such as BP and BFV, a computational method called multimodal pressure-flow (MMPF) analysis was recently developed to study the nonlinear BP-BFV relationship during the Valsalva maneuver (VM). The present study aimed to determine (i) whether this method can estimate autoregulation from spontaneous BP and BFV fluctuations during baseline rest conditions; (ii) whether there is any difference between the MMPF measures of autoregulation based on intra-arterial BP (ABP) and based on cerebral perfusion pressure (CPP); and (iii) whether the MMPF method provides reproducible and reliable measure for noninvasive assessment of autoregulation. To achieve these aims, we analyzed data from existing databases including: (i) ABP and BFV of 12 healthy control, 10 hypertensive, and 10 stroke subjects during baseline resting conditions and during the Valsalva maneuver, and (ii) ABP, CPP, and BFV of 30 patients with traumatic brain injury (TBI) who were being paralyzed, sedated, and ventilated. We showed that autoregulation in healthy control subjects can be characterized by specific phase shifts between BP and BFV oscillations during the Valsalva maneuver, and the BP-BFV phase shifts were reduced in hypertensive and stroke subjects (P < 0.01), indicating impaired autoregulation. Similar results were found during baseline condition from spontaneous BP and BFV oscillations. The BP-BFV phase shifts obtained during baseline and during VM were highly correlated (R > 0.8, P < 0.0001), showing no statistical difference (pairedt test P > 0.47). In TBI patients there were strong correlations between phases of ABP and CPP oscillations (R = 0.99, P < 0.0001) and, thus, between ABP-BFV and CPP-BFV phase shifts (P < 0.0001, R = 0.76). By repeating the MMPF 4 times on data of TBI subjects, each time on a selected cycle of spontaneous BP and BFV oscillations, we showed that MMPF had better reproducibility than traditional autoregulation index. These results indicate that the MMPF method, based on instantaneous phase relationships between cerebral blood flow velocity and peripheral blood pressure, has better performance than the traditional standard method, and can reliably assess cerebral autoregulation dynamics from ambulatory blood pressure and cerebral blood flow during supine rest conditions.

show abstract

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

Cited by 174 publications

References 29 publications

The Leicester cerebral haemodynamics database: normative values and the influence of age and sex

The Leicester cerebral haemodynamics database: normative values and the influence of age and sex

Measurement of Cerebral Blood Flow Responses to the Thigh Cuff Maneuver: A Comparison of TCD with a Novel MRI Method

Nonlinear Assessment of Cerebral Autoregulation from Spontaneous Blood Pressure and Cerebral Blood Flow Fluctuations

Contact Info

Product

Resources

About