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Davies A, Gurung D, Ladthavorlaphatt K, Mankoo A, Panerai RB, Robinson TG, Minhas JS, Beishon LC. The effect of CO 2 on the age dependence of neurovascular coupling. J Appl Physiol (1985) 2024; 137:445-459. [PMID: 38961823 DOI: 10.1152/japplphysiol.00695.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 06/27/2024] [Accepted: 06/27/2024] [Indexed: 07/05/2024] Open
Abstract
Prior studies have identified variable effects of aging on neurovascular coupling (NVC). Carbon dioxide (CO2) affects both cerebral blood velocity (CBv) and NVC, but the effects of age on NVC under different CO2 conditions are unknown. Therefore, we investigated the effects of aging on NVC in different CO2 states during cognitive paradigms. Seventy-eight participants (18-78 yr), with well-controlled comorbidities, underwent continuous recordings of CBv by bilateral insonation of middle (MCA) and posterior (PCA) cerebral arteries (transcranial Doppler), blood pressure, end-tidal CO2, and heart rate during poikilocapnia, hypercapnia (5% CO2 inhalation), and hypocapnia (paced hyperventilation). Neuroactivation via visuospatial (VS) and attention tasks (AT) was used to stimulate NVC. Peak percentage and absolute change in MCAv/PCAv, were compared between CO2 conditions and age groups (≤30, 31-60, and >60 yr). For the VS task, in poikilocapnia, younger adults had a lower NVC response compared with older adults [mean difference (MD): -7.92% (standard deviation (SD): 2.37), P = 0.004], but comparable between younger and middle-aged groups. In hypercapnia, both younger [MD: -4.75% (SD: 1.56), P = 0.009] and middle [MD: -4.58% (SD: 1.69), P = 0.023] age groups had lower NVC responses compared with older adults. Finally, in hypocapnia, both older [MD: 5.92% (SD: 2.21), P = 0.025] and middle [MD: 5.44% (SD: 2.27), P = 0.049] age groups had greater NVC responses, compared with younger adults. In conclusion, the magnitude of NVC response suppression from baseline during hyper- and hypocapnia, did not differ significantly between age groups. However, the middle age group demonstrated a different NVC response while under hypercapnic conditions, compared with hypocapnia.NEW & NOTEWORTHY This study describes the effects of age on neurovascular coupling under altered CO2 conditions. We demonstrated that both hypercapnia and hypocapnia suppress neurovascular coupling (NVC) responses. Furthermore, that middle age exhibits an NVC response comparable with younger adults under hypercapnia, and older adults under hypocapnia.
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Affiliation(s)
- Aaron Davies
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Dewarkar Gurung
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Kannaphob Ladthavorlaphatt
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Alex Mankoo
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
| | - Ronney B Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Research Centre, British Heart Foundation Cardiovascular Centre, Leicester, United Kingdom
| | - Thompson G Robinson
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Research Centre, British Heart Foundation Cardiovascular Centre, Leicester, United Kingdom
| | - Jatinder S Minhas
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Research Centre, British Heart Foundation Cardiovascular Centre, Leicester, United Kingdom
| | - Lucy C Beishon
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM) Research Group, Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- NIHR Leicester Biomedical Research Centre, Glenfield Research Centre, British Heart Foundation Cardiovascular Centre, Leicester, United Kingdom
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Ladthavorlaphatt K, Surti FBS, Beishon LC, Panerai RB, Robinson TG. Challenging neurovascular coupling through complex and variable duration cognitive paradigms: A subcomponent analysis. Med Eng Phys 2022; 110:103921. [PMID: 36564144 DOI: 10.1016/j.medengphy.2022.103921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/04/2022] [Accepted: 11/09/2022] [Indexed: 11/13/2022]
Abstract
A similar pattern of cerebral blood velocity (CBv) response has been observed for neurovascular coupling (NVC) assessment with cognitive tasks of varying complexity and duration. This lack of specificity could result from parallel changes in arterial blood pressure (BP) and PaCO2, which could confound the estimates of NVC integrity. Healthy participants (n = 16) underwent recordings at rest (5 min sitting) and during randomized paradigms of different complexity (naming words (NW) beginning with P-, R-, V- words and serial subtractions (SS) of 100-2, 100-7, 1000-17, with durations of 5, 30 and 60 s). Bilateral CBv (middle cerebral arteries, transcranial Doppler), end-tidal CO2 (EtCO2, capnography), blood pressure (BP, Finapres) and heart rate (HR, ECG) were recorded continuously. The bilateral CBv response to all paradigms was classified under objective criteria to select only responders, then the repeated data were averaged between visits. Bilateral CBv change to tasks was decomposed into the relative contributions (subcomponents) of arterial BP (VBP; neurogenic), critical closing pressure (VCrCP; metabolic) and resistance area product (VRAP; myogenic). A temporal effect was demonstrated in bilateral VBP and VRAP during all tasks (p<0.002), increased VBP early (between 0 and 10 s) and followed by decreases of VRAP late (25-35 s) in the response. VCrCP varied by complexity and duration (p<0.046). The main contributions to CBv responses to cognitive tasks of different complexity and duration were VBP and VRAP, whilst a smaller contribution from VCrCP would suggest sensitivity to metabolic demands. Further studies are needed to assess the influence of different paradigms, ageing and cerebrovascular conditions.
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Affiliation(s)
- Kannaphob Ladthavorlaphatt
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom; Medical Diagnostics Unit, Thammasat University Hospital, Thammasat University, Pathumthani, Thailand.
| | - Farhaana B S Surti
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom
| | - Lucy C Beishon
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom; NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom; NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, College of Life Sciences, Leicester Royal Infirmary, University of Leicester, Level 4, Robert Kilpatrick Clinical Sciences Building, Leicester LE2 7LX, United Kingdom; NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
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Beishon L, Panerai RB, Robinson TG, Haunton VJ. Cerebral blood flow response rate to task-activation using a novel method can discriminate cognitive impairment from healthy aging. Physiol Meas 2021; 42. [PMID: 34229305 DOI: 10.1088/1361-6579/ac1185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 07/06/2021] [Indexed: 12/20/2022]
Abstract
Objective.A new method to classify individuals as 'responders' to task-activated cerebral blood flow velocity (CBFv) has recently been developed. This study investigated whether CBFv response rate to task-activation is affected by Alzheimer's disease (AD) and mild cognitive impairment (MCI).Approach.The 95th thresholds for cross correlation function peak and variance ratio were derived from 270 unstimulated, healthy hemispheres, and were used to classify the presence of a response to task-activation. Thresholds were applied to five cognitive tasks (attention, verbal fluency, language, visuospatial, memory) in CBFv data from 30 healthy older adults (HC), 35 AD and 22 MCI participants. Cumulative response rate (CRR) was calculated from the sum of responses across five tasks, for both hemispheres. Area under the curve (AUC) was derived from receiver operating characteristic (ROC) curve analysis.Main results. The number of responders differed significantly between tasks (p < 0.005) and diagnostic groups (p = 0.011). On post hoc tests there were more responders in the visuospatial (79%-90%) compared to fluency (45%-80%), language (50%-77%), and memory (44%-70%) tasks bilaterally, and responders were greater in the HC (70%) compared to AD (41%) and MCI (23%) groups to at least eight out of ten tasks. At an optimal threshold of 7.5 out of 10 responses, the AUC-ROC distinguished HC from AD and MCI with a; sensitivity 66% and specificity 70% (AUC = 0.72).Significance. Using a novel method to classify responders to cognitive task-activation, HC demonstrated a higher CRR than those with MCI or AD, and a threshold of <8 responses distinguished healthy ageing from dementia.
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Affiliation(s)
- Lucy Beishon
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom
| | - Ronney B Panerai
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Thompson G Robinson
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Victoria J Haunton
- University of Leicester, Department of Cardiovascular Sciences, Leicester, United Kingdom.,NIHR Leicester Biomedical Research Centre, British Heart Foundation Cardiovascular Research Centre, Glenfield Hospital, Leicester, United Kingdom
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An objective method to identify non-responders in neurovascular coupling testing. J Neurosci Methods 2020; 341:108779. [DOI: 10.1016/j.jneumeth.2020.108779] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/10/2020] [Accepted: 05/11/2020] [Indexed: 01/04/2023]
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Iyer PC, Rosenberg A, Baynard T, Madhavan S. Influence of neurovascular mechanisms on response to tDCS: an exploratory study. Exp Brain Res 2019; 237:2829-2840. [PMID: 31455998 DOI: 10.1007/s00221-019-05626-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/08/2019] [Indexed: 10/26/2022]
Abstract
The beneficial effects of transcranial direct current stimulation (tDCS) for stroke rehabilitation are limited by the variability in changes in corticomotor excitability (CME) after tDCS. Neuronal activity is closely related to cerebral blood flow; however, the cerebral hemodynamics of neuromodulation in relation to neural effects have been less explored. In this study, we examined the effects of tDCS on cerebral blood velocity (CBv) in chronic stroke survivors using transcranial Doppler (TCD) ultrasound in relation to changes in CME and described the neurovascular characteristics of tDCS responders. Middle cerebral artery (MCA) CBv, cerebrovascular resistance (CVRi) and other cerebral hemodynamics-related variables were continuously measured before and after 15 min of 1 mA anodal tDCS to the lesioned lower limb M1. tDCS did not modulate CBv in the whole group and upon TMS-based stratification of responders and non-responders. However, at baseline, responders demonstrated lower CME levels, lower CBv and higher CVRi as compared to non-responders. These results indicate a possible difference in baseline CME and CBv in tDCS responders that may influence their response to neuromodulation. Future trials with a large sample size and repeated baseline measurements may help validate these findings and establish a relationship between neuromodulation and neurovascular mechanisms in stroke.
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Affiliation(s)
- Pooja C Iyer
- Graduate Program in Rehabilitation Science, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Alexander Rosenberg
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA.,Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Tracy Baynard
- Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Sangeetha Madhavan
- Brain Plasticity Laboratory, Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, 1919 West Taylor Street, Chicago, IL, 60612, USA.
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Marra A, Naro A, Chillura A, Bramanti A, Maresca G, De Luca R, Manuli A, Bramanti P, Calabrò RS. Evaluating Peripersonal Space through the Functional Transcranial Doppler: Are We Paving the Way for Early Detecting Mild Cognitive Impairment to Dementia Conversion? J Alzheimers Dis 2019; 62:133-143. [PMID: 29439353 DOI: 10.3233/jad-170973] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Identifying the patients with mild cognitive impairment (MCI) who may develop dementia (MDC) is challenging. The study of peripersonal space (PPS) by using functional transcranial Doppler (fTCD) could be used for this purpose. OBJECTIVE To identify changes in cerebral blood flow (CBF) during motor tasks targeting PPS, which can predict MDC. METHODS We evaluated the changes in CBF in 22 patients with MCI and 23 with dementia [Alzheimer's disease (AD) and vascular dementia (VaD)] during a motor task (passive mobilization, motor imagery, and movement observation) in which the hand of the subject moved forward and backward the face. RESULTS CBF increased when the hand approached the face and decreased when the hand moved from the face in the healthy controls (HCs). CBF changed were detectable only in patients with MCI but not in those with the AD and those who were MDC after 8-month follow-up. On the other hand, the patients with VaD presented a paradoxical response to the motor task (i.e., a decrease of CBF rather than an increase, as observed in HCs and MCI). Therefore, we found a modulation of PPS-related CBF only in HCs and patients with stable MCI (at the 8-month follow-up). CONCLUSIONS fTCD may allow preliminarily differentiating and following-up the patients with MCI and MDC, thus allowing the physician to plan beforehand more individualized cognitive rehabilitative training.
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Affiliation(s)
- Angela Marra
- IRCCS centro Neurolesi "Bonino-Pulejo", Messina, Italy
| | - Antonino Naro
- IRCCS centro Neurolesi "Bonino-Pulejo", Messina, Italy
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Chillura A, Naro A, Ciappina F, Bramanti A, Lauria P, Bramanti P, Calabrò RS. Detecting peripersonal space: The promising role of ultrasonics. Brain Behav 2018; 8:e01085. [PMID: 30094963 PMCID: PMC6160641 DOI: 10.1002/brb3.1085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 04/18/2018] [Accepted: 06/20/2018] [Indexed: 12/04/2022] Open
Abstract
INTRODUCTION The approach of an external stimulus to the peripersonal space (PPS) modifies some physiological measures, including the cerebral blood flow (CBF) in the supplementary motor area and premotor cortex. CBF measurement may be useful to assess brain activations when producing specific motor responses, likely mediated by cortical and subcortical neural circuits. METHODS This study investigated PPS in 15 healthy humans by characterizing the hemodynamic responses (pulsatility index, PI; and heart rate, HR) related to different directions of movements of individual's hand toward and backward his/her own face, so to perturb PPS). RESULTS We observed that the CBF and HR were enhanced more when the stimulated hand was inside the PPS of the face in the passive and active condition than when the hand was outside the PPS and during motor imagery task. CONCLUSIONS These results suggest that the modulation of PPS-related brain responses depends on specific sensory-motor integration processes related to the location and the final position of a target in the PPS. We may thus propose TCD as a rapid and easy approach to get information concerning brain responses related to stimuli approaching the PPS. Understanding the modulations of brain activations during tasks targeting PPS can help to understand the results of psychophysical and behavioral trials and to plan patient-tailored cognitive rehabilitative training.
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Affiliation(s)
| | - Antonino Naro
- IRCCS centro Neurolesi "Bonino-Pulejo", Messina, Italy
| | | | | | - Paola Lauria
- IRCCS centro Neurolesi "Bonino-Pulejo", Messina, Italy
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Beishon L, Williams CAL, Robinson TG, Haunton VJ, Panerai RB. Neurovascular coupling response to cognitive examination in healthy controls: a multivariate analysis. Physiol Rep 2018; 6:e13803. [PMID: 30033685 PMCID: PMC6055030 DOI: 10.14814/phy2.13803] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 06/24/2018] [Indexed: 12/21/2022] Open
Abstract
Cognitive testing with transcranial Doppler ultrasonography (TCD) has been used to assess neurovascular coupling (NVC), but few studies address its multiple contributions. Subcomponent analysis considers the relative myogenic (resistance area product, RAP) and metabolic (critical closing pressure (CrCP)) contributors. The aim of this study was to investigate the changes in subcomponents that occur with cognitive stimulation with the Addenbrooke's Cognitive Examination (ACE-III) in healthy controls. Healthy volunteers underwent continuous recording of bilateral TCD, heart rate (HR, three-lead ECG), end-tidal CO2 (ETCO2 , capnography), and mean arterial pressure (MAP, Finometer). The study comprised a 5-min baseline recording, followed by all 20 paradigms from the ACE-III. The cerebral blood flow velocity (CBFv) response was decomposed into the relative contributions (subcomponents); VBP (MAP), VCrCP (CrCP), and VRAP (RAP). Data are presented as peak population normalized mean changes from baseline, and median area under the curve (AUC). Forty bilateral datasets were obtained (27 female, 37 right hand dominant). VBP increased at task initiation in all paradigms but differed between tasks (range (SD): 4.06 (8.92)-16.04 (12.23) %, P < 0.05). HR, but not ETCO2 , also differed significantly (P < 0.05). Changes in VRAP reflected changes in MAP, but in some paradigms atypical responses were seen. VCrCP AUC varied significantly within paradigm sections (range [SD]: 18.4 [24.17] to 244.21 [243.21] %*s, P < 0.05). All paradigms demonstrated changes in subcomponents with cognitive stimulation, and can be ranked based on their relative presumed metabolic demand. The integrity of NVC requires further investigation in patient populations.
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Affiliation(s)
- Lucy Beishon
- Department of Cardiovascular SciencesUniversity of LeicesterLeicesterUnited Kingdom
| | | | - Thompson G. Robinson
- Department of Cardiovascular SciencesUniversity of LeicesterLeicesterUnited Kingdom
- NIHR Leicester Biomedical Research CentreUniversity of LeicesterLeicesterUnited Kingdom
| | - Victoria J. Haunton
- Department of Cardiovascular SciencesUniversity of LeicesterLeicesterUnited Kingdom
- NIHR Leicester Biomedical Research CentreUniversity of LeicesterLeicesterUnited Kingdom
| | - Ronney B. Panerai
- Department of Cardiovascular SciencesUniversity of LeicesterLeicesterUnited Kingdom
- NIHR Leicester Biomedical Research CentreUniversity of LeicesterLeicesterUnited Kingdom
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Naro A, Chillura A, Portaro S, Bramanti A, De Luca R, Bramanti P, Calabrò RS. Novel Approaches to the Diagnosis of Chronic Disorders of Consciousness: Detecting Peripersonal Space by Using Ultrasonics. Front Neurol 2018; 9:47. [PMID: 29459847 PMCID: PMC5807342 DOI: 10.3389/fneur.2018.00047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 01/18/2018] [Indexed: 01/17/2023] Open
Abstract
The assessment of behavioral responsiveness in patients suffering from chronic disorders of consciousness (DoC), including Unresponsive Wakefulness Syndrome (UWS) and Minimally Conscious State (MCS), is challenging. Even if a patient is unresponsive, he/she may be covertly aware in reason of a cognitive-motor dissociation, i.e., a preservation of cognitive functions despite a solely reflexive behavioral responsiveness. The approach of an external stimulus to the peripersonal space (PPS) modifies some biological measures (e.g., hand-blink reflex amplitude) to the purpose of defensive responses from threats. Such modulation depends on a top-down control of subcortical neural circuits, which can be explored through changes in cerebral blood flow velocity (CBFV), using functional transcranial Doppler (fTCD) and, thus, gaining useful, indirect information on brain connectivity. These data may be used for the DoC differential diagnosis. We evaluated the changes in CBFV by measuring the pulsatility index (PI) in 21 patients with DoC (10 patients with MCS and 11 with UWS) and 25 healthy controls (HC) during a passive movement and motor imagery (MI) task in which the hand of the subject approached and, then, moved away from the subject’s face. In the passive movement task, the PI increased progressively in the HCs when the hand was moved toward the face and, then, it decreased when the hand was removed from the face. The PI increased when the hand was moved toward the face in patients with DoC, but then, it remained high when the hand was removed from the face and up to 30 s after the end of the movement in the patients with MCS (both MCS+ and MCS−) and 1 min in those with UWS, thus differentiating between patients with MCS and UWS. In the MI task, all the HCs, three out of four patients with MCS+, and one out of six patients with MCS− showed an increase–decrease PI change, whereas the remaining patients with MCS and all the patients with UWS showed no PI changes. Even though there is the possibility that our findings will not be replicated in all patients with DoC, we propose fTCD as a rapid and very easy tool to differentiate between patients with MCS and UWS, by identifying residual top-down modulation processes from higher-order cortical areas to sensory-motor integration networks related to the PPS, when using passive movement tasks.
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Affiliation(s)
- Antonino Naro
- IRCCS centro Neurolesi Bonino-Pulejo, Messina, Italy
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Kim SS, Lee BH. Measuring cerebral hemodynamic changes during action observation with functional transcranial doppler. J Phys Ther Sci 2015; 27:1379-81. [PMID: 26157224 PMCID: PMC4483402 DOI: 10.1589/jpts.27.1379] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 01/11/2015] [Indexed: 12/31/2022] Open
Abstract
[Purpose] The purpose of this study was to investigate the effects of action observation
training (AOT) on cerebral hemodynamic changes including cerebral blood flow velocity
(CBFV) and cerebral blood flow volume (CBFvol) in healthy subjects. [Subjects] Fifteen
healthy subjects participated in this study. [Methods] All subjects were educated
regarding AOT, and systolic peak velocity (Vs) as well as mean flow velocity (Vm) in the
middle cerebral artery (MCA), anterior cerebral artery (ACA), and posterior cerebral
artery (PCA) were evaluated using functional transcranial doppler with a 2-MHz probe,
before and after performing AOT. [Results] Healthy subjects showed significant differences
in Vs and Vm in the MCA, ACA, and PCA after AOT compared with those before AOT.
[Conclusion] Our findings indicate that AOT has a positive effect in terms of an increase
in CBFV and CBFvol in healthy subjects, since the brain requires more blood to meet the
metabolic demand during AOT.
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Affiliation(s)
- Seong-Sik Kim
- Department of Physical Therapy, Sahmyook University: 815 Hwarang-ro, Nowon-gu, Seoul 139-742, Republic of Korea
| | - Byoung-Hee Lee
- Department of Physical Therapy, Sahmyook University: 815 Hwarang-ro, Nowon-gu, Seoul 139-742, Republic of Korea
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de Lima Oliveira M, de Azevedo DS, de Azevedo MK, de Carvalho Nogueira R, Teixeira MJ, Bor-Seng-Shu E. Encephalic hemodynamic phases in subarachnoid hemorrhage: how to improve the protective effect in patient prognoses. Neural Regen Res 2015; 10:748-52. [PMID: 26109948 PMCID: PMC4468765 DOI: 10.4103/1673-5374.156969] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2015] [Indexed: 11/23/2022] Open
Abstract
Subarachnoid hemorrhage is frequently associated with poor prognoses. Three different hemodynamic phases were identified during subarachnoid hemorrhage: oligemia, hyperemia, and vasospasm. Each phase is associated with brain metabolic changes. In this review, we correlated the hemodynamic phases with brain metabolism and potential treatment options in the hopes of improving patient prognoses.
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Affiliation(s)
- Marcelo de Lima Oliveira
- Division of Neurological Surgery, Hospital das Clinicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Daniel Silva de Azevedo
- Division of Neurological Surgery, Hospital das Clinicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Milena Krajnyk de Azevedo
- Division of Neurological Surgery, Hospital das Clinicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Ricardo de Carvalho Nogueira
- Division of Neurological Surgery, Hospital das Clinicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Manoel Jacobsen Teixeira
- Division of Neurological Surgery, Hospital das Clinicas, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Edson Bor-Seng-Shu
- Division of Neurological Surgery, Hospital das Clinicas, School of Medicine, University of São Paulo, São Paulo, Brazil
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Salinet ASM, Robinson TG, Panerai RB. Effects of cerebral ischemia on human neurovascular coupling, CO2 reactivity, and dynamic cerebral autoregulation. J Appl Physiol (1985) 2014; 118:170-7. [PMID: 25593216 DOI: 10.1152/japplphysiol.00620.2014] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Cerebral blood flow (CBF) regulation can be impaired in acute ischemic stroke but the combined effects of dynamic cerebral autoregulation (CA), CO2 cerebrovascular reactivity (CVR), and neurovascular coupling (NVC), obtained from simultaneous measurements, have not been described. CBF velocity in the middle cerebral artery (MCA) (CBFv, transcranial Doppler), blood pressure (BP, Finometer), and end-tidal Pco2 (PetCO2 , infrared capnography) were recorded during a 1-min passive movement of the arm in 27 healthy controls [mean age (SD) 61.4 (6.0) yr] and 27 acute stroke patients [age 63 (11.7) yr]. A multivariate autoregressive-moving average model was used to separate the contributions of BP, arterial Pco2 (PaCO2 ), and the neural activation to the CBFv responses. CBFv step responses for the BP, CO2, and stimulus inputs were also obtained. The contribution of the stimulus to the CBFv response was highly significant for the difference between the affected side [area under the curve (AUC) 104.5 (4.5)%] and controls [AUC 106.9 (4.3)%; P = 0.008]. CBFv step responses to CO2 [affected hemisphere 0.39 (0.7), unaffected 0.55 (0.8), controls 1.39 (0.9)%/mmHg; P = 0.01, affected vs. controls; P = 0.025, unaffected vs. controls] and motor stimulus inputs [affected hemisphere 0.20 (0.1), unaffected 0.22 (0.2), controls 0.37 (0.2) arbitrary units; P = 0.009, affected vs. controls; P = 0.02, unaffected vs. controls] were reduced in the stroke group compared with controls. The CBFv step responses to the BP input at baseline and during the paradigm were not different between groups (P = 0.07), but PetCO2 was lower in the stroke group (P < 0.05). These results provide new insights into the interaction of CA, CVR, and NVC in both health and disease states.
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Affiliation(s)
- Angela S M Salinet
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom; and
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom; and National Institutes for Health Research (NIHR), Biomedical Research Unit in Cardiovascular Sciences, Glenfield Hospital, Leicester, United Kingdom
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom; and National Institutes for Health Research (NIHR), Biomedical Research Unit in Cardiovascular Sciences, Glenfield Hospital, Leicester, United Kingdom
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Salinet ASM, Panerai RB, Robinson TG. The longitudinal evolution of cerebral blood flow regulation after acute ischaemic stroke. Cerebrovasc Dis Extra 2014; 4:186-97. [PMID: 25298773 PMCID: PMC4176407 DOI: 10.1159/000366017] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/20/2014] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Acute stroke is known to impair cerebral blood flow (CBF) regulation, but the longitudinal changes of these effects have been poorly reported. The main CBF regulatory mechanisms [cerebral autoregulation (CA) and neurovascular coupling (NVC)] were assessed over 3 months after acute ischaemic stroke. METHODS Recordings of CBF velocity (CBFv), blood pressure (BP), and end-tidal CO2 were performed during 5 min baseline and 1 min passive movement of the elbow. Stroke patients were assessed <72 h of stroke onset, and at 2 weeks, 1 and 3 months after stroke. RESULTS Fifteen acute stroke subjects underwent all 4 sessions and were compared to 22 control subjects. Baseline recordings revealed a significantly lower CBFv in the affected hemisphere within 72 h after stroke compared to controls (p = 0.02) and a reduction in CA index most marked at 2 weeks (p = 0.009). CBFv rise in response to passive arm movement was decreased bilaterally after stroke, particularly in the affected hemisphere (p < 0.01). Both alterations in CA and NVC returned to control levels during recovery. CONCLUSION The major novel finding of this study was that both CA and NVC regulatory mechanisms deteriorated initially following stroke onset, but returned to control levels during the recovery period. These findings are relevant to guide the timing of interventions to manipulate BP and potentially for the impact of intensive rehabilitation strategies that may precipitate acute physiological perturbations but require further exploration in a larger population that better reflects the heterogeneity of stroke. Further, they will also enable the potential influence of stroke subtype to be investigated.
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Affiliation(s)
- Angela S M Salinet
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Ronney B Panerai
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK ; National Institutes for Health Research, Biomedical Research Unit in Cardiovascular Sciences, Clinical Sciences Wing, Glenfield Hospital, Leicester, UK
| | - Thompson G Robinson
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK ; National Institutes for Health Research, Biomedical Research Unit in Cardiovascular Sciences, Clinical Sciences Wing, Glenfield Hospital, Leicester, UK
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Maggio P, Salinet ASM, Robinson TG, Panerai RB. Influence of CO2 on neurovascular coupling: interaction with dynamic cerebral autoregulation and cerebrovascular reactivity. Physiol Rep 2014; 2:e00280. [PMID: 24760531 PMCID: PMC4002257 DOI: 10.1002/phy2.280] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PaCO2 affects cerebral blood flow (CBF) and its regulatory mechanisms, but the interaction between neurovascular coupling (NVC), cerebral autoregulation (CA), and cerebrovascular reactivity to CO2 (CVR), in response to hypercapnia, is not known. Recordings of cerebral blood flow velocity (CBFv), blood pressure (BP), heart rate, and end‐tidal CO2 (EtCO2) were performed in 18 subjects during normocapnia and 5% CO2 inhalation while performing a passive motor paradigm. Together with BP and EtCO2, a gate signal to represent the effect of stimulation was used as input to a multivariate autoregressive‐moving average model to calculate their separate effects on CBFv. Hypercapnia led to a depression of dynamic CA at rest and during stimulation in both hemispheres (P <0.02) as well as impairment of the NVC response, particularly in the ipsilateral hemisphere (P <0.01). Neither hypercapnia nor the passive motor stimulation influenced CVR. Dynamic CA was not influenced by the motor paradigm during normocapnia. The CBFv step responses to each individual input (BP, EtCO2, stimulation) allowed identification of the influences of hypercapnia and neuromotor stimulation on CA, CVR, and NVC, which have not been previously described, and also confirmed the depressing effects of hypercapnia on CA and NVC. The stability of CVR during these maneuvers and the lack of influence of stimulation on dynamic CA are novel findings which deserve further investigation. Dynamic multivariate modeling can identify the complex interplay between different CBF regulatory mechanisms and should be recommended for studies involving similar interactions, such as the effects of exercise or posture on cerebral hemodynamics. The influence of hypercapnia on dynamic cerebral autoregulation (CA), CO2 vasoreactivity (CVR), and neurovascular coupling (NVC) was described based on a single recording during motor stimulation coupled to a new multivariate modeling approach. Hypercapnia led to a depression of CA at rest and during stimulation in both hemispheres as well as impairment of the NVC response. Neither hypercapnia nor the passive motor stimulation influenced CVR. Dynamic CA was not influenced by the motor paradigm during normocapnia. The stability of CVR during these maneuvers and the lack of influence of stimulation on dynamic CA are novel findings which deserve further investigation.
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Affiliation(s)
- Paola Maggio
- Neurologia Clinica, Università Campus Bio-Medico, Rome, Italy
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Kim SS, Kim TH, Lee BH. Effects of Action Observational Training on Cerebral Hemodynamic Changes of Stroke Survivors: A fTCD Study. J Phys Ther Sci 2014; 26:331-4. [PMID: 24707078 PMCID: PMC3975997 DOI: 10.1589/jpts.26.331] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 09/22/2013] [Indexed: 11/24/2022] Open
Abstract
[Purpose] The purpose of this study was to investigate the effect of Action
Observational Training (AOT) on cerebral hemodynamic changes, including
cerebral blood flow velocity (CBFV) and cerebral blood flow volume (CBFvol) in healthy
subjects and stroke survivors. [Subjects] This study had a cross-sectional design. Seven
healthy subjects and six patients with a first-time stroke participated in this study.
[Methods] All subjects were educated about AOT, and we measured their systolic peak
velocity (Vs), mean flow velocity (Vm), pulsatility index (PI), and resistance index (RI)
in the middle cerebral artery (MCA), the anterior cerebral artery (ACA), and the posterior
cerebral artery (PCA), before and after performance of AOT, using Functional Transcranial
Doppler (fTCD) with a 2-MHz probe. [Results] Both healthy subjects and stroke survivors
showed significant improvements of Vs and Vm in MCA, ACA and PCA after AOT. [Conclusion]
Our findings indicate that AOT increases CBFV in healthy subjects and stroke survivors,
because the brain requires more blood in order to meet the metabolic demand of the brain
during AOT.
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Affiliation(s)
- Seong-Sik Kim
- Graduate School of Physical Therapy, Sahmyook University, Republic of Korea
| | - Tae-Hoon Kim
- Graduate School of Physical Therapy, Sahmyook University, Republic of Korea
| | - Byoung-Hee Lee
- Graduate School of Physical Therapy, Sahmyook University, Republic of Korea
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Vernieri F, Altamura C, Palazzo P, Altavilla R, Fabrizio E, Fini R, Melgari JM, Paolucci M, Pasqualetti P, Maggio P. 1-Hz Repetitive Transcranial Magnetic Stimulation Increases Cerebral Vasomotor Reactivity: A Possible Autonomic Nervous System Modulation. Brain Stimul 2014; 7:281-6. [DOI: 10.1016/j.brs.2013.12.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 12/11/2013] [Accepted: 12/27/2013] [Indexed: 11/30/2022] Open
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Salinet ASM, Robinson TG, Panerai RB. Cerebral blood flow response to neural activation after acute ischemic stroke: a failure of myogenic regulation? J Neurol 2013; 260:2588-95. [PMID: 23824356 DOI: 10.1007/s00415-013-7022-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/17/2013] [Accepted: 06/23/2013] [Indexed: 12/19/2022]
Abstract
We tested two hypotheses: (1) neurovascular coupling is impaired after acute ischemic stroke, (2) subcomponent analysis of cerebral blood flow velocity can reveal significant differences between acute ischemic stroke and healthy controls. This was explored through the comparison of nineteen acute ischemic stroke patients with healthy controls. Recordings of cerebral blood flow velocity, blood pressure and end-tidal CO2 were obtained during 60s of passive elbow flexion. Cerebral blood flow velocity changes were decomposed into standardized subcomponents describing the contributions of blood pressure (V BP), resistance area product (V RAP) and critical closing pressure (V CrCP). The passive paradigm led to a bilateral cerebral blood flow velocity increase in both groups, but in acute ischemic stroke the magnitude of change was significantly lower. Blood pressure increases were shown to be an important contributor to cerebral blood flow velocity response throughout the paradigm in both groups, with no significant difference between groups. The V CrCP contribution was not different between groups or hemispheres; its continuous rise during activation indicating a vasodilatory effect. On the other hand, the V RAP contribution showed significant differences (p = 0.03), thus suggesting myogenic impairment in acute ischemic stroke. Cerebral blood flow velocity responses to passive elbow flexion suggest an impairment of neurovascular coupling in acute ischemic stroke. Subcomponent analysis suggests an impairment of the myogenic pathways, giving a greater insight into the different mechanisms contributing to neurovascular coupling. Further research is needed to assess the clinical value of subcomponent analysis of neurovascular coupling and the natural history of such changes following acute ischemic stroke.
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Affiliation(s)
- Angela S M Salinet
- Department of Cardiovascular Sciences, University of Leicester, Trent Stroke Research Network Office, Victoria Building, Leicester Royal Infirmary, LE1 5WW, Leicester, UK,
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Maggio P, Salinet ASM, Panerai RB, Robinson TG. Does hypercapnia-induced impairment of cerebral autoregulation affect neurovascular coupling? A functional TCD study. J Appl Physiol (1985) 2013; 115:491-7. [PMID: 23743398 DOI: 10.1152/japplphysiol.00327.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Neurovascular coupling (NVC) and dynamic cerebral autoregulation (dCA) are both impaired in the acute phase of ischemic stroke, but their reciprocal interactions are difficult to predict. To clarify these aspects, the present study explored NVC in a healthy volunteer population during a surrogate state of impaired dCA induced by hypercapnia. This study aimed to test whether hypercapnia leads to a depression of NVC through an impairment of dCA. Continuous recordings of middle cerebral arteries cerebral blood flow velocity (CBFv), blood pressure (BP), heart rate, and end-tidal CO2 were performed in 19 right-handed subjects (aged >45 yr) before, during, and after 60 s of a passive paradigm during normocapnia and hypercapnia. The CBFv response was broken down into subcomponents describing the relative contributions of BP (VBP), critical closing pressure (VCrCP), and resistance area product (VRAP). VRAP reflects myogenic activity in response to BP changes, whereas VCrCP is more indicative of metabolic control. The results revealed that hypercapnia significantly affected NVC, with significant reductions in the relative contribution of VCrCP to the paradigm-induced increase in CBFv. The present study suggests that hypercapnia impairs both dCA and NVC, probably acting through an impairment of the metabolic component of CBF control.
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Affiliation(s)
- Paola Maggio
- Neurologia Clinica, Università Campus Bio-Medico, Rome, Italy
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Salinet ASM, Robinson TG, Panerai RB. Active, passive, and motor imagery paradigms: component analysis to assess neurovascular coupling. J Appl Physiol (1985) 2013; 114:1406-12. [PMID: 23449939 DOI: 10.1152/japplphysiol.01448.2012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The association between neural activity and cerebral blood flow (CBF) has been used to assess neurovascular coupling (NVC) in health and diseases states, but little attention has been given to the contribution of simultaneous changes in peripheral covariates. We used an innovative approach to assess the contributions of arterial blood pressure (BP), PaCO2, and the stimulus itself to changes in CBF velocities (CBFv) during active (MA), passive (MP), and motor imagery (MI) paradigms. Continuous recordings of CBFv, beat-to-beat BP, heart rate, and breath-by-breath end-tidal CO2 (EtCO2) were performed in 17 right-handed subjects before, during, and after motor-cognitive paradigms performed with the right arm. A multivariate autoregressive-moving average model was used to calculate the separate contributions of BP, EtCO2, and the neural activation stimulus (represented by a metronome on-off signal) to the CBFv response during paradigms. Differences were found in the bilateral CBFv responses to MI compared with MA and MP, due to the contributions of stimulation (P < 0.05). BP was the dominant contributor to the initial peaked CBFv response in all paradigms with no significant differences between paradigms, while the contribution of the stimulus explained the plateau phase and extended duration of the CBFv responses. Separating the neural activation contribution from the influences of other covariates, it was possible to detect differences between three paradigms often used to assess disease-related NVC. Apparently similar CBFv responses to different motor-cognitive paradigms can be misleading due to the contributions from peripheral covariates and could lead to inaccurate assessment of NVC, particularly during MI.
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Affiliation(s)
- Angela S M Salinet
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.
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Sejdić E, Kalika D, Czarnek N. An analysis of resting-state functional transcranial Doppler recordings from middle cerebral arteries. PLoS One 2013; 8:e55405. [PMID: 23405146 PMCID: PMC3566175 DOI: 10.1371/journal.pone.0055405] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 12/22/2012] [Indexed: 11/18/2022] Open
Abstract
Functional transcrannial Doppler (fTCD) is used for monitoring the hemodynamics characteristics of major cerebral arteries. Its resting-state characteristics are known only when considering the maximal velocity corresponding to the highest Doppler shift (so called the envelope signals). Significantly more information about the resting-state fTCD can be gained when considering the raw cerebral blood flow velocity (CBFV) recordings. In this paper, we considered simultaneously acquired envelope and raw CBFV signals. Specifically, we collected bilateral CBFV recordings from left and right middle cerebral arteries using 20 healthy subjects (10 females). The data collection lasted for 15 minutes. The subjects were asked to remain awake, stay silent, and try to remain thought-free during the data collection. Time, frequency and time-frequency features were extracted from both the raw and the envelope CBFV signals. The effects of age, sex and body-mass index were examined on the extracted features. The results showed that the raw CBFV signals had a higher frequency content, and its temporal structures were almost uncorrelated. The information-theoretic features showed that the raw recordings from left and right middle cerebral arteries had higher content of mutual information than the envelope signals. Age and body-mass index did not have statistically significant effects on the extracted features. Sex-based differences were observed in all three domains and for both, the envelope signals and the raw CBFV signals. These findings indicate that the raw CBFV signals provide valuable information about the cerebral blood flow which can be utilized in further validation of fTCD as a clinical tool.
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Affiliation(s)
- Ervin Sejdić
- Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
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Salinet ASM, Haunton VJ, Panerai RB, Robinson TG. A systematic review of cerebral hemodynamic responses to neural activation following stroke. J Neurol 2013; 260:2715-21. [DOI: 10.1007/s00415-013-6836-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 01/04/2013] [Indexed: 10/27/2022]
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