Cerebral and systemic hemodynamic changes during cognitive and motor activation paradigms

Moody, Michelle; Panerai, Ronney B.; Eames, Penelope J.; Potter, John F.

doi:10.1152/ajpregu.00837.2004

Cited by 72 publications

(102 citation statements)

References 37 publications

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“…The method based on the analysis of TCD and ABP waveform was introduced to calculate CCP noninvasively in various clinical conditions Moody et al, 2005;Edouard et al, 2005). In our study, we confirmed a significant correlation between the values of CCP derived from TCD waveform (noninvasive) and that calculated from cardiac arrest (CCP LDF and CCP TCD ; invasive).…”

Section: Discussionsupporting

confidence: 81%

Critical Closing Pressure: Comparison of Three Methods

López-Magaña

Richards

Radolovich

et al. 2009

J Cereb Blood Flow Metab

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Critical closing pressure (CCP) is an arterial pressure threshold below which small arterial vessels collapse. Our aim was to compare different methods to estimate CCP in the cerebrovascular circulation using the relationships between transcranial Doppler flow velocity (FV), laser-Doppler flux (LDF), and arterial blood pressure (ABP). A total of 116 experiments in rabbits were analyzed retrospectively. At the end of each recording, cardiac arrest (CA) was induced. Arterial blood pressure in femoral artery, basilar artery FV, cortical blood LDF, intracranial pressure (ICP) was recorded. Critical closing pressure was estimated using linear regression between decreasing mean ABP values, FV, and LDF during CA. In addition, CCP was calculated from FV waveform just before CA. The correlation between CCP evaluated using LDF and FV during CA was 0.98 (P < 0.0001). The correlation between CCP measured during CA and CCP estimated from the transcranial Doppler ultrasonography (TCD) waveform was weaker (R = 0.39; P < 0.001), with CCP calculated from waveform being significantly greater than CCP from CA (median difference 9 mm Hg; P < 0.003). Critical closing pressures obtained from FV waveform and CA correlated with mean ICP before CA (R = 0.40; P = 0.001). In conclusion strong correlation exists between CCP values obtained by means of FV and LDF during cardiac arrest. However, predictions of CCP using TCD waveform analysis show substantial differences from values of CCP recorded during cardiac arrest.

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Section: Discussionsupporting

confidence: 81%

Critical Closing Pressure: Comparison of Three Methods

López-Magaña

Richards

Radolovich

et al. 2009

J Cereb Blood Flow Metab

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“…Scholkmann et al (2013) showed that PaCO 2 changes were evoked by speech and mathematical tasks, and strongly affected the fNIRI signals. Task execution may also lead to significant changes in BP during certain experimental tasks such as arm-rising (Minati et al, 2011), anagram task (Tachtsidis et al, 2008a(Tachtsidis et al, ,c, 2009), word generation and constructional puzzle task (Moody et al, 2005), semantic continuous performance task (Jelzow et al, 2011), or emotional picture presentation (Minati et al, 2009). These BP changes affect hemodynamics in the extracerebral compartment, measured as stimulus/task-related changes in SBF and/or volume (SBV) (Kirilina et al, 2012;Takahashi et al, 2011), or even in the cerebral compartment itself (Minati et al, 2011 Another source of systemic component is the influence of the autonomic nervous system (ANS) on the cerebral vasculature (Hamel, 2006;Wahl and Schilling, 1993).…”

Section: Classification Of Signal Componentsmentioning

confidence: 99%

A review on continuous wave functional near-infrared spectroscopy and imaging instrumentation and methodology

Scholkmann¹,

Kleiser²,

Metz³

et al. 2014

NeuroImage

1,523

1,394

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This year marks the 20th anniversary of functional near-infrared spectroscopy and imaging (fNIRS/fNIRI). As the vast majority of commercial instruments developed until now are based on continuous wave technology, the aim of this publication is to review the current state of instrumentation and methodology of continuous wave fNIRI. For this purpose we provide an overview of the commercially available instruments and address instrumental aspects such as light sources, detectors and sensor arrangements. Methodological aspects, algorithms to calculate the concentrations of oxy-and deoxyhemoglobin and approaches for data analysis are also reviewed. From the single-location measurements of the early years, instrumentation has progressed to imaging initially in two dimensions (topography) and then three (tomography). The methods of analysis have also changed tremendously, from the simple modified Beer-Lambert law to sophisticated image reconstruction and data analysis methods used today. Due to these advances, fNIRI has become a modality that is widely used in neuroscience research and several manufacturers provide commercial instrumentation. It seems likely that fNIRI will become a clinical tool in the foreseeable future, which will enable diagnosis in single subjects. This year marks the 20th anniversary of functional near-infrared spectroscopy and imaging (fNIRS/fNIRI). As the vast majority of commercial instruments developed until now are based on continuous wave technology, the aim of this publication is to review the current state of instrumentation and methodology of continuous wave fNIRI. For this purpose we provide an overview of the commercially available instruments and address instrumental aspects such as light sources, detectors and sensor arrangements. Methodological aspects, algorithms to calculate the concentrations of oxy-and deoxyhemoglobin and approaches for data analysis are also reviewed. From the single-location measurements of the early years, instrumentation has progressed to imaging initially in two dimensions (topography) and then three (tomography). The methods of analysis have also changed tremendously, from the simple modified Beer-Lambert law to sophisticated image reconstruction and data analysis methods used today. Due to these advances, fNIRI has become a modality that is widely used in neuroscience research and several manufacturers provide commercial instrumentation. It seems likely that fNIRI will become a clinical tool in the foreseeable future, which will enable diagnosis in single subjects. Contents

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“…[65][66][67] Using this approach, a number of interesting studies have been completed with the following conclusions: (1) hypercapnia impairs the metabolic regulation of neurovascular coupling, (2) breath-bybreath changes in ETCO 2 during cognition can impact the neurovascular coupling response, and (3) the blood pressure response to cognitive activation plays a large role in the neurovascular coupling response, particularly the initial spike. 53,66,68 These interesting studies have yet to confirm a direct mechanistic link between the physiological regulatory pathways of interest (i.e., metabolic versus myogenic influences) and the subcomponent models/metrics being utilized (i.e. critical closing pressure versus resistance area product).…”

Section: Human Neurovascular Couplingmentioning

confidence: 99%

Neurovascular coupling in humans: Physiology, methodological advances and clinical implications

Phillips

Chan

Zheng

et al. 2015

J Cereb Blood Flow Metab

363

364

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Neurovascular coupling reflects the close temporal and regional linkage between neural activity and cerebral blood flow. Although providing mechanistic insight, our understanding of neurovascular coupling is largely limited to nonphysiological ex vivo preparations and non-human models using sedatives/anesthetics with confounding cerebrovascular implications. Herein, with particular focus on humans, we review the present mechanistic understanding of neurovascular coupling and highlight current approaches to assess these responses and the application in health and disease. Moreover, we present new guidelines for standardizing the assessment of neurovascular coupling in humans. To improve the reliability of measurement and related interpretation, the utility of new automated software for neurovascular coupling is demonstrated, which provides the capacity for coalescing repetitive trials and time intervals into single contours and extracting numerous metrics (e.g., conductance and pulsatility, critical closing pressure, etc.) according to patterns of interest (e.g., peak/minimum response, time of response, etc.). This versatile software also permits the normalization of neurovascular coupling metrics to dynamic changes in arterial blood gases, potentially influencing the hyperemic response. It is hoped that these guidelines, combined with the newly developed and openly available software, will help to propel the understanding of neurovascular coupling in humans and also lead to improved clinical management of this critical physiological function.

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Cerebral and systemic hemodynamic changes during cognitive and motor activation paradigms

Cited by 72 publications

References 37 publications

Critical Closing Pressure: Comparison of Three Methods

Critical Closing Pressure: Comparison of Three Methods

A review on continuous wave functional near-infrared spectroscopy and imaging instrumentation and methodology

Neurovascular coupling in humans: Physiology, methodological advances and clinical implications

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