Monitoring cerebrovascular pressure reactivity with rheoencephalography

Brady, Kenneth Martin; Mytar, Jennifer; Kibler, Kathleen K.; Easley, R. Blaine; Koehler, Raymond C.; Czosnyka, Marek; Smielewski, Peter; Zweifel, Christian; Bodó, Michael; Pearce, Frederick J.; Armonda, Rocco A.

doi:10.1088/1742-6596/224/1/012089

Cited by 17 publications

(24 citation statements)

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“…Some discrepancies among REG, NIRS, TCD and LDF methodologies were observed during these tests. Our future validation studies will include enhanced computational methods [4,17], further animal studies and clinical monitoring studies of humans. A human study using REGx calculation is currently being prepared.…”

Section: Resultsmentioning

confidence: 99%

“…In previous studies, we reported results of correlative studies indicating that REG has potential for use in neuro-monitoring [25]. A previous study documented that REG (REGx) and ICP (PRx) has high correlation in order to detect the lower limit of CBF autoregulation [4]. The fundamental relationships between arterial blood pressure (ABP), vessel tone, cerebral blood volume and intracranial pressure (ICP) form the basis for the pressure reactivity index (PRx) [17,24].…”

Section: Reg: Cbf Autoregulation Monitoringmentioning

confidence: 97%

“…Currently, available computerized data processing techniques make REG a potential method for neuromonitoring by mitigating artifacts and extracting characteristics and information not visible in the raw REG signal [4].…”

Section: Rheoencephalographymentioning

confidence: 99%

“…A positive index (positive correlation) implies impaired cerebral autoregulation, while a negative index (inverse correlation) implies intact autoregulation. Rheoencephalography as a monitoring modality has been discussed since the name 'REG' was initially used [3,26], and the promise of REG has been demonstrated [4,27].…”

Section: Reg: Cbf Autoregulation Monitoringmentioning

confidence: 99%

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Comparison of cerebrovascular reactivity tests: a pilot human study

Bodó

Mahon

Razumovsky³

et al. 2017

Journal of Electrical Bioimpedance

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In neurosurgery intensive care units, cerebrovascular reactivity tests for neuromonitoring are used to evaluate the status of cerebral blood flow autoregulation; lack of autoregulation indicates a poor patient outcome. The goal of neuromonitoring is to prevent secondary injuries following a primary central nervous system injury, when the brain is vulnerable to further compromise due to hypoxia, ischemia and disturbances in cerebral blood flow and intracranial pressure. Ideally, neuromonitoring would be noninvasive and continuous. This study compares cerebrovascular reactivity monitored by rheoencephalography, a noninvasive continuous monitoring modality, to cerebrovascular reactivity measured by currently used neuromonitoring modalities: transcranial Doppler, near infrared spectroscopy and laser Doppler flowmetry. Fourteen healthy volunteer subjects were measured. The tests used for comparison of cerebrovascular reactivity were breath-holding, hyperventilation, CO2 inhalation, the Valsalva maneuver, and the Trendelenburg and reverse Trendelenburg positions. Data for all modalities measured were recorded by computers and processed off line. All measured modalities reflected cerebrovascular reactivity with variabilities. Breath-holding, CO2 inhalation, and the Valsalva maneuver caused CO2 increase and consequent brain vasodilatation; hyperventilation caused CO2 decrease and brain vasoconstriction. The Trendelenburg and reverse Trendelenburg positions caused extracranial blood volume changes, which masked intracranial cerebrovascular reactivity. The hyperventilation test proved ineffective for measuring cerebrovascular reactivity with rheoencephalography due to respiratory artifacts. Some discrepancies among the various modalities tested were observed. Further validation studies are under preparation to test the applicability of rheoencephalography for noninvasive continuous brain monitoring, including enhanced computational methods, animal studies and clinical monitoring studies of humans.

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Section: Resultsmentioning

confidence: 99%

Section: Reg: Cbf Autoregulation Monitoringmentioning

confidence: 97%

Section: Rheoencephalographymentioning

confidence: 99%

Section: Reg: Cbf Autoregulation Monitoringmentioning

confidence: 99%

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Comparison of cerebrovascular reactivity tests: a pilot human study

Bodó

Mahon

Razumovsky³

et al. 2017

Journal of Electrical Bioimpedance

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“…Rheoencephalography is one of the most commonly used methods for investigating the reactivity of the vessels of the brain, which is, in fact, an integral indicator of the adaptive capacity of the cerebral circulation system (the ability of brain vessels to respond in response to changing conditions and to optimize blood flow in accordance with these conditions) [2,5,7].…”

mentioning

confidence: 99%

Regression Models of Rheoencephalographic Indices, Depending on the Anthropo-Somatometric Parameters of the Body in Practically Healthy Women With Endo-Mesomorphic Somatotype

Serebrennikova¹,

Semenchenko²,

Моskovko³

et al. 2017

WOMAB

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The article describes and analyzes regression models of individual indicators of cerebral circulation in practically healthy women of the endo-mesomorphic somatotype, depending on the features of anthropo-somatotypological indicators. Constructed all 5 possible time indices of rheoencephalogram with determination coefficient (R2) from 0.593 to 0.904; of the 5 possible amplitude indices of the rheoencephalogram, 3 of R2 from 0.540 to 720 were constructed; of the 8 possible derivatives of the rheoencephalogram, 7 with R2 from 0.528 to 0.865 were constructed. Constructed models with R2 more than 0.5 most often include: for amplitude rheoencephalogram indicators -body diameters (29,4%), cephalometric indices and thickness of skin and fat folds (by 23,5%); for the time indices of the rheoencephalogram -the thickness of skin and fat folds (35.7%), cephalometric indices (21.4%), longitudinal, circumferential dimensions and diameters of the body (by 10.7%); for derivative indices of the rheoencephalogram -the thickness of skin and fat folds (29.3%), the circumferential size of the body and the width of distal epiphyses of long limb bones (by 17.1%) and body diameters (14.6%).Key words: practically healthy women, endo-mesomorphic somatotype, cerebral hemodynamics, anthropometric indices, regression models.Problems of timely diagnosis of cerebrovascular disorder in young people attach great importance to health care institutions concerned about the "rejuvenation" of cerebrovascular pathology and institutions involved in the problem of age and pathological physiology [18,19]. Rheoencephalography is one of the most commonly used methods for investigating the reactivity of the vessels of the brain, which is, in fact, an integral indicator of the adaptive capacity of the cerebral circulation system (the ability of brain vessels to respond in response to changing conditions and to optimize blood flow in accordance with these conditions) [2,5,7].Changes in cerebral hemodynamics should be considered as regional manifestations of general circulatory disorders and the state of support for the homeostasis of the body as a whole [6,22]. Therefore, it is definitely important to study the integrative mechanisms of the interaction of elements of the system of regulation of vascular activity and the general human constitution, the definition of which becomes possible in mathematical modeling of rheoencephalographic indices, depending on the anthropo-somatometric parameters of the body in persons of a certain somatotype [4,9,10,13,20]. It is possible to use the results of mathematical modeling to develop criteria for assessing the functional state of the macrocirculation of the cerebral circulation and in determining the strategy of corrective measures in patients with minimal or asymptomatic brain dysfunctions [13,15].Research purpose -to construct and analyze the regression models of individual indicators of cerebral circulation, depending on the anthropo-somatometric parameters of the body of practically healthy women of Podillia endo...

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