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Ji W, Nightingale TE, Zhao F, Fritz NE, Phillips AA, Sisto SA, Nash MS, Badr MS, Wecht JM, Mateika JH, Panza GS. The Clinical Relevance of Autonomic Dysfunction, Cerebral Hemodynamics, and Sleep Interactions in Individuals Living With SCI. Arch Phys Med Rehabil 2024; 105:166-176. [PMID: 37625532 DOI: 10.1016/j.apmr.2023.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/25/2023] [Accepted: 08/06/2023] [Indexed: 08/27/2023]
Abstract
A myriad of physiological impairments is seen in individuals after a spinal cord injury (SCI). These include altered autonomic function, cerebral hemodynamics, and sleep. These physiological systems are interconnected and likely insidiously interact leading to secondary complications. These impairments negatively influence quality of life. A comprehensive review of these systems, and their interplay, may improve clinical treatment and the rehabilitation plan of individuals living with SCI. Thus, these physiological measures should receive more clinical consideration. This special communication introduces the under investigated autonomic dysfunction, cerebral hemodynamics, and sleep disorders in people with SCI to stakeholders involved in SCI rehabilitation. We also discuss the linkage between autonomic dysfunction, cerebral hemodynamics, and sleep disorders and some secondary outcomes are discussed. Recent evidence is synthesized to make clinical recommendations on the assessment and potential management of important autonomic, cerebral hemodynamics, and sleep-related dysfunction in people with SCI. Finally, a few recommendations for clinicians and researchers are provided.
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Affiliation(s)
- Wenjie Ji
- Department of Rehabilitation Science, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY
| | - Tom E Nightingale
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK; Centre for Trauma Science Research, University of Birmingham, Birmingham, UK; International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, Canada
| | - Fei Zhao
- Department of Health Care Sciences, Program of Occupational Therapy, Wayne State University, Detroit, MI; John D. Dingell VA Medical Center, Research and Development, Detroit, MI
| | - Nora E Fritz
- Department of Health Care Sciences, Program of Physical Therapy, Detroit, MI; Department of Neurology, Wayne State University, Detroit, MI
| | - Aaron A Phillips
- Department of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Biomedical Engineering, Libin Cardiovascular institute, Hotchkiss Brain Institute, Cumming School of Medicine, Calgary, AB, Canada; RESTORE.network, University of Calgary, Calgary, AB, Canad
| | - Sue Ann Sisto
- Department of Rehabilitation Science, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY
| | - Mark S Nash
- Department of Neurological Surgery, Physical Medicine & Rehabilitation Physical Therapy, Miami, FL; Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL
| | - M Safwan Badr
- John D. Dingell VA Medical Center, Research and Development, Detroit, MI; Departments of Physiology and Internal Medicine, Wayne State University, Detroit, MI
| | - Jill M Wecht
- James J Peters VA Medical Center, Department of Spinal Cord Injury Research, Bronx, NY; Icahn School of Medicine Mount Sinai, Departments of Rehabilitation and Human Performance, and Medicine Performance, and Medicine, New York, NY
| | - Jason H Mateika
- John D. Dingell VA Medical Center, Research and Development, Detroit, MI; Departments of Physiology and Internal Medicine, Wayne State University, Detroit, MI
| | - Gino S Panza
- Department of Health Care Sciences, Program of Occupational Therapy, Wayne State University, Detroit, MI; John D. Dingell VA Medical Center, Research and Development, Detroit, MI.
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Zhou R, Li J, Wang R, Chen Z, Zhou F. The neurovascular unit in healthy and injured spinal cord. J Cereb Blood Flow Metab 2023; 43:1437-1455. [PMID: 37190756 PMCID: PMC10414016 DOI: 10.1177/0271678x231172008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 02/09/2023] [Accepted: 03/24/2023] [Indexed: 05/17/2023]
Abstract
The neurovascular unit (NVU) reflects the close temporal and spatial link between neurons and blood vessels. However, the understanding of the NVU in the spinal cord is far from clear and largely based on generalized knowledge obtained from the brain. Herein, we review the present knowledge of the NVU and highlight candidate approaches to investigate the NVU, particularly focusing on the spinal cord. Several unique features maintain the highly regulated microenvironment in the NVU. Autoregulation and neurovascular coupling ensure regional blood flow meets the metabolic demand according to the blood supply or local neural activation. The blood-central nervous system barrier partitions the circulating blood from neural parenchyma and facilitates the selective exchange of substances. Furthermore, we discuss spinal cord injury (SCI) as a common injury from the perspective of NVU dysfunction. Hopefully, this review will help expand the understanding of the NVU in the spinal cord and inspire new insights into SCI.
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Affiliation(s)
- Rubing Zhou
- Department of Orthopedics, Peking University Third Hospital, Beijing, China
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Junzhao Li
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Ruideng Wang
- Department of Orthopedics, Peking University Third Hospital, Beijing, China
| | - Zhengyang Chen
- Department of Orthopedics, Peking University Third Hospital, Beijing, China
| | - Fang Zhou
- Department of Orthopedics, Peking University Third Hospital, Beijing, China
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Song SH, Sankary KM, Burns SP. Vital sign differences between septic patients with tetraplegia and paraplegia. Spinal Cord Ser Cases 2022; 8:87. [PMID: 36433952 PMCID: PMC9700738 DOI: 10.1038/s41394-022-00553-3] [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: 03/07/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/27/2022] Open
Abstract
STUDY DESIGN Retrospective chart review. OBJECTIVES Sepsis is a leading preventable cause of death in patients with chronic spinal cord injury (SCI). Individuals with tetraplegia may exhibit different signs and symptoms of infection compared to those with paraplegia. In this study, we examine differences in vital signs (VS) and mental status between septic patients with tetraplegia and paraplegia with the goal of improving early identification of sepsis in this population. SETTING Veterans hospital in Washington, USA. METHODS Participants consisted of 19 patients with tetraplegia and 16 with paraplegia who were transferred from an SCI Service to a higher level of care with sepsis between June 1, 2010 and June 1, 2018 (n = 35). We compared VS between patients with tetraplegia and paraplegia at baseline and during sepsis including temperature, heart rate (HR), and blood pressure as well as presence/absence of altered mental status (AMS). RESULTS While there were no significant VS differences between groups at baseline, septic patients with tetraplegia had lower maximum temperature (38.2 °C versus 39.2 °C, p = 0.003), lower maximum HR (106 versus 124 beats/minute, p = 0.004), and more frequent AMS compared to septic patients with paraplegia (79% versus 31%, p = 0.007). CONCLUSION Patients with tetraplegia may not be able to mount fever and tachycardia to the same degree as patients with paraplegia and may be more prone to developing AMS during sepsis. These findings suggest that changes to VS parameter cut-offs may improve sensitivity and be useful in identifying sepsis earlier in the tetraplegic population.
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Affiliation(s)
- Shawn H Song
- Spinal Cord Injury Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA.
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA.
| | - Kendl M Sankary
- Spinal Cord Injury Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
| | - Stephen P Burns
- Spinal Cord Injury Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, USA
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Sahota IS, Lucci VEM, McGrath MS, Ravensbergen HJC(R, Claydon VE. Cardiovascular and cerebrovascular responses to urodynamics testing after spinal cord injury: The influence of autonomic injury. Front Physiol 2022; 13:977772. [PMID: 36187786 PMCID: PMC9525190 DOI: 10.3389/fphys.2022.977772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/10/2022] [Indexed: 12/02/2022] Open
Abstract
Autonomic dysfunction is a prominent concern following spinal cord injury (SCI). In particular, autonomic dysreflexia (AD; paroxysmal hypertension and concurrent bradycardia in response to sensory stimuli below the level of injury) is common in autonomically-complete injuries at or above T6. AD is currently defined as a >20 mmHg increase in systolic arterial pressure (SAP) from baseline, without heart rate (HR) criteria. Urodynamics testing (UDS) is performed routinely after SCI to monitor urological sequelae, often provoking AD. We, therefore, aimed to assess the cardiovascular and cerebrovascular responses to UDS and their association with autonomic injury in individuals with chronic (>1 year) SCI. Following blood draw (plasma norepinephrine [NE]), continuous SAP, HR, and middle cerebral artery blood flow velocity (MCAv) were recorded at baseline (10-minute supine), during standard clinical UDS, and recovery (10-minute supine) (n = 22, age 41.1 ± 2 years, 15 male). Low frequency variability in systolic arterial pressure (LF SAP; a marker of sympathetic modulation of blood pressure) and cerebral resistance were determined. High-level injury (≥T6) with blunted/absent LF SAP (<1.0 mmHg2) and/or low plasma NE (<0.56 nmol•L−1) indicated autonomically-complete injury. Known electrocardiographic markers of atrial (p-wave duration variability) and ventricular arrhythmia (T-peak–T-end variability) were evaluated at baseline and during UDS. Nine participants were determined as autonomically-complete, yet 20 participants had increased SAP >20 mmHg during UDS. Qualitative autonomic assessment did not discriminate autonomic injury. Maximum SAP was higher in autonomically-complete injuries (207.1 ± 2.3 mmHg) than autonomically-incomplete injuries (165.9 ± 5.3 mmHg) during UDS (p < 0.001). HR during UDS was reduced compared to baseline (p = 0.056) and recovery (p = 0.048) only in autonomically-complete lesions. MCAv was not different between groups or phases (all p > 0.05). Cerebrovascular resistance index was increased during UDS in autonomically-complete injuries compared to baseline (p < 0.001) and recovery (p < 0.001) reflecting intact cerebral autoregulation. Risk for both atrial and ventricular arrhythmia increased during UDS compared to baseline (p < 0.05), particularly in autonomically-complete injuries (p < 0.05). UDS is recommended yearly in chronic SCI but is associated with profound AD and an increased risk of arrhythmia, highlighting the need for continued monitoring during UDS. Our data also highlight the need for HR criteria in the definition of AD and the need for quantitative consideration of autonomic function after SCI.
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Affiliation(s)
- Inderjeet S. Sahota
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Vera-Ellen M. Lucci
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Maureen S. McGrath
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - H. J. C. (Rianne) Ravensbergen
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Victoria E. Claydon
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
- *Correspondence: Victoria E. Claydon,
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Leacy JK, Johnson EM, Lavoie LR, Macilwraith DN, Bambury M, Martin JA, Lucking EF, Linares AM, Saran G, Sheehan DP, Sharma N, Day TA, O'Halloran KD. Variation within the visually evoked neurovascular coupling response of the posterior cerebral artery is not influenced by age or sex. J Appl Physiol (1985) 2022; 133:335-348. [PMID: 35771218 PMCID: PMC9359642 DOI: 10.1152/japplphysiol.00292.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neurovascular coupling (NVC) is the temporal and spatial coordination between local neuronal activity and regional cerebral blood flow. The literature is unsettled on whether age and/or sex affect NVC, which may relate to differences in methodology and the quantification of NVC in small sample-sized studies. The aim of this study was to 1) determine the relative and combined contribution of age and sex to the variation observed across several distinct NVC metrics (n = 125, 21–66 yr; 41 males) and 2) present an approach for the comprehensive systematic assessment of the NVC response using transcranial Doppler ultrasound. NVC was measured as the relative change from baseline (absolute and percent change) assessing peak, mean, and total area under the curve (tAUC) of cerebral blood velocity through the posterior cerebral artery (PCAv) during intermittent photic stimulation. In addition, the NVC waveform was compartmentalized into distinct regions, acute (0–9 s), mid (10–19 s), and late (20–30 s), following the onset of photic stimulation. Hierarchical multiple regression modeling was used to determine the extent of variation within each NVC metric attributable to demographic differences in age and sex. After controlling for differences in baseline PCAv, the R2 data suggest that 1.6%, 6.1%, 1.1%, 3.4%, 2.5%, and 4.2% of the variance observed within mean, peak, tAUC, acute, mid, and late response magnitude is attributable to the combination of age and sex. Our study reveals that variability in NVC response magnitude is independent of age and sex in healthy human participants, aged 21–66 yr. NEW & NOTEWORTHY We assessed the variability within the neurovascular coupling response attributable to age and sex (n = 125, 21–66 yr; 41 male). Based on the assessment of posterior cerebral artery responses to visual stimulation, 0%–6% of the variance observed within several metrics of NVC response magnitude are attributable to the combination of age and sex. Therefore, observed differences between age groups and/or sexes are likely a result of other physiological factors.
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Affiliation(s)
- Jack K Leacy
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Emily M Johnson
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Lauren R Lavoie
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Diane N Macilwraith
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Megan Bambury
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Jason A Martin
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Eric F Lucking
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
| | - Andrea M Linares
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Gurkarn Saran
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Dwayne P Sheehan
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Nishan Sharma
- Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Trevor A Day
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland.,Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine and Health, University College Cork, Cork, Ireland
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Benedetti B, Weidenhammer A, Reisinger M, Couillard-Despres S. Spinal Cord Injury and Loss of Cortical Inhibition. Int J Mol Sci 2022; 23:5622. [PMID: 35628434 PMCID: PMC9144195 DOI: 10.3390/ijms23105622] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/09/2022] [Accepted: 05/13/2022] [Indexed: 02/04/2023] Open
Abstract
After spinal cord injury (SCI), the destruction of spinal parenchyma causes permanent deficits in motor functions, which correlates with the severity and location of the lesion. Despite being disconnected from their targets, most cortical motor neurons survive the acute phase of SCI, and these neurons can therefore be a resource for functional recovery, provided that they are properly reconnected and retuned to a physiological state. However, inappropriate re-integration of cortical neurons or aberrant activity of corticospinal networks may worsen the long-term outcomes of SCI. In this review, we revisit recent studies addressing the relation between cortical disinhibition and functional recovery after SCI. Evidence suggests that cortical disinhibition can be either beneficial or detrimental in a context-dependent manner. A careful examination of clinical data helps to resolve apparent paradoxes and explain the heterogeneity of treatment outcomes. Additionally, evidence gained from SCI animal models indicates probable mechanisms mediating cortical disinhibition. Understanding the mechanisms and dynamics of cortical disinhibition is a prerequisite to improve current interventions through targeted pharmacological and/or rehabilitative interventions following SCI.
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Affiliation(s)
- Bruno Benedetti
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (A.W.); (M.R.)
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), 5020 Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
| | - Annika Weidenhammer
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (A.W.); (M.R.)
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), 5020 Salzburg, Austria
| | - Maximilian Reisinger
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (A.W.); (M.R.)
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), 5020 Salzburg, Austria
| | - Sebastien Couillard-Despres
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (A.W.); (M.R.)
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), 5020 Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
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Hayes BD, Fossey MPM, Poormasjedi-Meibod MS, Erskine E, Soriano JE, Scott B, Rosentreter R, Granville DJ, Phillips AA, West CR. Experimental high thoracic spinal cord injury impairs the cardiac and cerebrovascular response to orthostatic challenge in rats. Am J Physiol Heart Circ Physiol 2021; 321:H716-H727. [PMID: 34448635 DOI: 10.1152/ajpheart.00239.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/24/2021] [Indexed: 11/22/2022]
Abstract
Spinal cord injury (SCI) impairs the cardiovascular responses to postural challenge, leading to the development of orthostatic hypotension (OH). Here, we apply lower body negative pressure (LBNP) to rodents with high-level SCI to demonstrate the usefulness of LBNP as a model for experimental OH studies, and to explore the effect of simulated OH on cardiovascular and cerebrovascular function following SCI. Male Wistar rats (n = 34) were subjected to a sham or T3-SCI surgery and survived into the chronic period postinjury (i.e., 8 wk). Cardiac function was tracked via ultrasound pre- to post-SCI to demonstrate the clinical utility of our model. At study termination, we conducted left-ventricular (LV) catheterization and insonated the middle cerebral artery to investigate the hemodynamic, cardiac, and cerebrovascular response to a mild dose of LBNP that is sufficient to mimic clinically defined OH in rats with T3-SCI but not sham animals. In response to mimicked OH, there was a greater decline in stroke volume, cardiac output, maximal LV pressure, and blood pressure in SCI compared with sham (P < 0.034), whereas heart rate was increased in sham but decreased in SCI (P < 0.029). SCI animals also had an exaggerated reduction in peak, minimum and mean middle cerebral artery flow, for a given change in blood pressure, in response to LBNP (P < 0.033), implying impaired dynamic cerebral autoregulation. Using a preclinical SCI model of OH, we demonstrate that complete high thoracic SCI impairs the cardiac response to OH and disrupts dynamic cerebral autoregulation.NEW & NOTEWORTHY This is the first use of LBNP to interrogate the cardiac and cerebrovascular responses to simulated OH in a preclinical study of SCI. Here, we demonstrate the utility of our simulated OH model and use it to demonstrate that SCI impairs the cardiac response to simulated OH and disrupts dynamic cerebrovascular autoregulation.
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Affiliation(s)
- Brian D Hayes
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mary Pauline Mona Fossey
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Experimental Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Erin Erskine
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jan Elaine Soriano
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Berkeley Scott
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ryan Rosentreter
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - David J Granville
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aaron A Phillips
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Christopher R West
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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8
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Craig A, Pozzato I, Arora M, Middleton J, Rodrigues D, McBain C, Tran Y, Davis GM, Gopinath B, Kifley A, Krassioukov A, Braithwaite J, Mitchell R, Gustin SM, Schoffl J, Cameron ID. A neuro-cardiac self-regulation therapy to improve autonomic and neural function after SCI: a randomized controlled trial protocol. BMC Neurol 2021; 21:329. [PMID: 34445983 PMCID: PMC8387669 DOI: 10.1186/s12883-021-02355-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 08/13/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Spinal cord injury (SCI) is associated with autonomic imbalance and significant secondary conditions, including cardiac and brain dysfunction that adversely impact health and wellbeing. This study will investigate the effectiveness (intention-to-treat) of a neuro-cardiac self-regulation therapy to improve autonomic and neural/brain activity in adults with SCI living in the community. METHODS A two-arm parallel, randomised controlled trial in which adults with SCI living in the community post-rehabilitation will be randomly assigned to a treatment or control group. The treatment group (N = 60) aged 18-70 years with a chronic traumatic or non-traumatic SCI, will receive intervention sessions once per week for 10 weeks, designed to regulate autonomic activity using computer-based feedback of heart rate variability and controlled breathing (called HRV-F). Comprehensive neurophysiological and psychological assessment will occur at baseline, immediate post-treatment, and 6 and 12-months post-treatment. Primary outcome measures include electrocardiography/heart rate variability (to assess autonomic nervous system function) and transcranial doppler sonography (to assess cerebral blood circulation in basal cerebral arteries). Secondary outcomes measures include continuous blood pressure, electroencephalography, functional near-infrared spectroscopy, respiration/breath rate, electrooculography, cognitive capacity, psychological status, pain, fatigue, sleep and quality of life. Controls (N = 60) will receive usual community care, reading material and a brief telephone call once per week for 10 weeks and be similarly assessed over the same time period as the HRV-F group. Linear mixed model analysis with repeated measures will determine effectiveness of HRV-F and latent class mixture modelling used to determine trajectories for primary and selected secondary outcomes of interest. DISCUSSION Treatments for improving autonomic function after SCI are limited. It is therefore important to establish whether a neuro-cardiac self-regulation therapy can result in improved autonomic functioning post-SCI, as well as whether HRV-F is associated with better outcomes for secondary conditions such as cardiovascular health, cognitive capacity and mental health. TRIAL REGISTRATION The study has been prospectively registered with the Australian and New Zealand Clinical Trial Registry ( ACTRN12621000870853 .aspx). Date of Registration: 6th July 2021. Trial Sponsor: The University of Sydney, NSW 2006. Protocol version: 22/07/2021.
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Affiliation(s)
- Ashley Craig
- John Walsh Centre Rehabilitation Research, Northern Sydney Local Health District, The Kolling Institute, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney, St Leonards, NSW, 2065, Australia.
| | - Ilaria Pozzato
- John Walsh Centre Rehabilitation Research, Northern Sydney Local Health District, The Kolling Institute, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney, St Leonards, NSW, 2065, Australia
| | - Mohit Arora
- John Walsh Centre Rehabilitation Research, Northern Sydney Local Health District, The Kolling Institute, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney, St Leonards, NSW, 2065, Australia
| | - James Middleton
- John Walsh Centre Rehabilitation Research, Northern Sydney Local Health District, The Kolling Institute, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney, St Leonards, NSW, 2065, Australia
| | - Dianah Rodrigues
- John Walsh Centre Rehabilitation Research, Northern Sydney Local Health District, The Kolling Institute, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney, St Leonards, NSW, 2065, Australia
| | - Candice McBain
- John Walsh Centre Rehabilitation Research, Northern Sydney Local Health District, The Kolling Institute, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney, St Leonards, NSW, 2065, Australia
| | - Yvonne Tran
- Macquarie University Hearing (MU Hearing), Macquarie University, North Ryde, NSW, 2113, Australia
| | - Glen M Davis
- Exercise and Sports Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Bamini Gopinath
- Macquarie University Hearing (MU Hearing), Macquarie University, North Ryde, NSW, 2113, Australia
| | - Annette Kifley
- John Walsh Centre Rehabilitation Research, Northern Sydney Local Health District, The Kolling Institute, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney, St Leonards, NSW, 2065, Australia
| | - Andrei Krassioukov
- ICORD, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, V5Z 1M9, Canada
| | - Jeffrey Braithwaite
- Centre for Healthcare Resilience and Implementation Science, Australian Institute of Health Innovation, Health Systems Research, Macquarie University, North Ryde, NSW, 2113, Australia
| | - Rebecca Mitchell
- Centre for Healthcare Resilience and Implementation Science, Australian Institute of Health Innovation, Health Systems Research, Macquarie University, North Ryde, NSW, 2113, Australia
| | - Sylvia M Gustin
- School of Psychology, Faculty of Science, University of New South Wales, Kensington, NSW, Australia
| | - Jacob Schoffl
- John Walsh Centre Rehabilitation Research, Northern Sydney Local Health District, The Kolling Institute, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney, St Leonards, NSW, 2065, Australia
| | - Ian D Cameron
- John Walsh Centre Rehabilitation Research, Northern Sydney Local Health District, The Kolling Institute, Northern Clinical School, Faculty of Medicine and Health, The University of Sydney, St Leonards, NSW, 2065, Australia
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9
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Cerebral Autoregulation during Postural Change in Patients with Cervical Spinal Cord Injury-A Carotid Duplex Ultrasonography Study. Diagnostics (Basel) 2021; 11:diagnostics11081321. [PMID: 34441256 PMCID: PMC8393722 DOI: 10.3390/diagnostics11081321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/13/2021] [Accepted: 07/21/2021] [Indexed: 11/17/2022] Open
Abstract
Patients with a spinal cord injury (SCI) frequently experience sudden falls in blood pressure during postural change. Few studies have investigated whether the measurement of blood flow velocity within vessels can reflect brain perfusion during postural change. By performing carotid duplex ultrasonography (CDU), we investigated changes in cerebral blood flow (CBF) during postural changes in patients with a cervical SCI, determined the correlation of CBF change with presyncopal symptoms, and investigated factors affecting cerebral autoregulation. We reviewed the medical records of 100 patients with a cervical SCI who underwent CDU. The differences between the systolic blood pressure, diastolic blood pressure, and CBF volume in the supine posture and after 5 min at 50° tilt were evaluated. Presyncopal symptoms occurred when the blood flow volume of the internal carotid artery decreased by ≥21% after tilt. In the group that had orthostatic hypotension and severe CBF decrease during tilt, the body mass index and physical and functional scores were lower than in other groups, and the proportion of patients with a severe SCI was high. The higher the SCI severity and the lower the functional score, the higher the possibility of cerebral autoregulation failure. CBF should be assessed by conducting CDU in patients with a high-level SCI.
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10
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van der Scheer JW, Goosey-Tolfrey VL, Valentino SE, Davis GM, Ho CH. Functional electrical stimulation cycling exercise after spinal cord injury: a systematic review of health and fitness-related outcomes. J Neuroeng Rehabil 2021; 18:99. [PMID: 34118958 PMCID: PMC8196442 DOI: 10.1186/s12984-021-00882-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 05/19/2021] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVES The objective of this review was to summarize and appraise evidence on functional electrical stimulation (FES) cycling exercise after spinal cord injury (SCI), in order to inform the development of evidence-based clinical practice guidelines. METHODS PubMed, the Cochrane Central Register of Controlled Trials, EMBASE, SPORTDiscus, and CINAHL were searched up to April 2021 to identify FES cycling exercise intervention studies including adults with SCI. In order to capture the widest array of evidence available, any outcome measure employed in such studies was considered eligible. Two independent reviewers conducted study eligibility screening, data extraction, and quality appraisal using Cochranes' Risk of Bias or Downs and Black tools. Each study was designated as a Level 1, 2, 3 or 4 study, dependent on study design and quality appraisal scores. The certainty of the evidence for each outcome was assessed using GRADE ratings ('High', 'Moderate', 'Low', or 'Very low'). RESULTS Ninety-two studies met the eligibility criteria, comprising 999 adults with SCI representing all age, sex, time since injury, lesion level and lesion completeness strata. For muscle health (e.g., muscle mass, fiber type composition), significant improvements were found in 3 out of 4 Level 1-2 studies, and 27 out of 32 Level 3-4 studies (GRADE rating: 'High'). Although lacking Level 1-2 studies, significant improvements were also found in nearly all of 35 Level 3-4 studies on power output and aerobic fitness (e.g., peak power and oxygen uptake during an FES cycling test) (GRADE ratings: 'Low'). CONCLUSION Current evidence indicates that FES cycling exercise improves lower-body muscle health of adults with SCI, and may increase power output and aerobic fitness. The evidence summarized and appraised in this review can inform the development of the first international, evidence-based clinical practice guidelines for the use of FES cycling exercise in clinical and community settings of adults with SCI. Registration review protocol: CRD42018108940 (PROSPERO).
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Affiliation(s)
- Jan W van der Scheer
- Peter Harrison Centre for Disability Sport, School for Sport, Exercise and Health Sciences, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK
- The Healthcare Improvement Studies (THIS) Institute, Department of Public Health and Primary Care, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Clifford Allbutt Building, Cambridge, CB2 OAH, UK
| | - Victoria L Goosey-Tolfrey
- Peter Harrison Centre for Disability Sport, School for Sport, Exercise and Health Sciences, Loughborough University, Epinal Way, Loughborough, LE11 3TU, UK
| | - Sydney E Valentino
- Department of Kinesiology, McMaster University, Room IWC EG115, 1280 Main St. W., Hamilton, ON, L8S 4K1, Canada
| | - Glen M Davis
- Discipline of Exercise and Sport Sciences, Faculty of Medicine and Health, Sydney School of Health Sciences, University of Sydney, Sydney, NSW, 2006, Australia
| | - Chester H Ho
- Division of Physical Medicine & Rehabilitation, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2R3, Canada.
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11
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Relationship Between Age and Cerebral Hemodynamic Response to Breath Holding: A Functional Near-Infrared Spectroscopy Study. Brain Topogr 2021; 34:154-166. [PMID: 33544290 DOI: 10.1007/s10548-021-00818-4] [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: 05/23/2020] [Accepted: 01/06/2021] [Indexed: 10/22/2022]
Abstract
Cerebrovascular reactivity (CVR) is routinely measured as a predictor of stroke in people with a high risk of ischemic attack. Neuroimaging techniques such as emission tomography, magnetic resonance imaging, and transcranial doppler are frequently used to measure CVR even though each technique has its limitations. Functional near-infrared spectroscopy (fNIRS), also based on the principle of neurovascular coupling, is relatively inexpensive, portable, and allows for the quantification of oxy- and deoxy-hemoglobin concentration changes at a high temporal resolution. This study examines the relationship between age and CVR using fNIRS in 45 young healthy adult participants aged 18-41 years (6 females, 26.64 ± 5.49 years) performing a simple breath holding task. Eighteen of the 45 participants were scanned again after a week to evaluate the feasibility of fNIRS in reliably measuring CVR. Results indicate (a) a negative relationship between age and hemodynamic measures of breath holding task in the sensorimotor cortex of 45 individuals and (b) widespread positive coactivation within medial sensorimotor regions and between medial sensorimotor regions with supplementary motor area and prefrontal cortex during breath holding with increasing age. The intraclass correlation coefficient (ICC) indicated only a low to fair/good reliability of the breath hold hemodynamic measures from sensorimotor and prefrontal cortices. However, the average hemodynamic response to breath holding from the two sessions were found to be temporally and spatially in correspondence. Future improvements in the sensitivity and reliability of fNIRS metrics could facilitate fNIRS-based assessment of cerebrovascular function as a potential clinical tool.
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12
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Cardiovascular Autonomic Dysfunction in Spinal Cord Injury: Epidemiology, Diagnosis, and Management. Semin Neurol 2020; 40:550-559. [PMID: 32906175 DOI: 10.1055/s-0040-1713885] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Spinal cord injury (SCI) disrupts autonomic circuits and impairs synchronistic functioning of the autonomic nervous system, leading to inadequate cardiovascular regulation. Individuals with SCI, particularly at or above the sixth thoracic vertebral level (T6), often have impaired regulation of sympathetic vasoconstriction of the peripheral vasculature and the splanchnic circulation, and diminished control of heart rate and cardiac output. In addition, impaired descending sympathetic control results in changes in circulating levels of plasma catecholamines, which can have a profound effect on cardiovascular function. Although individuals with lesions below T6 often have normal resting blood pressures, there is evidence of increases in resting heart rate and inadequate cardiovascular response to autonomic provocations such as the head-up tilt and cold face tests. This manuscript reviews the prevalence of cardiovascular disorders given the level, duration and severity of SCI, the clinical presentation, diagnostic workup, short- and long-term consequences, and empirical evidence supporting management strategies to treat cardiovascular dysfunction following a SCI.
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13
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Sachdeva R, Jia M, Wang S, Yung A, Zheng MMZ, Lee AHX, Monga A, Leong S, Kozlowski P, Fan F, Roman RJ, Phillips AA, Krassioukov AV. Vascular-Cognitive Impairment following High-Thoracic Spinal Cord Injury Is Associated with Structural and Functional Maladaptations in Cerebrovasculature. J Neurotrauma 2020; 37:1963-1970. [PMID: 32394805 DOI: 10.1089/neu.2019.6913] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Individuals living with chronic spinal cord injury (SCI) often exhibit impairments in cognitive function, which impede their rehabilitation and transition into the community. Although a number of clinical studies have demonstrated the impact of impaired cardiovascular control on cognitive impairment, the mechanistic understanding of this deleterious relationship is still lacking. The present study investigates whether chronic disruption of cardiovascular control following experimental SCI results in cerebrovascular decline and vascular cognitive impairment. Fourteen weeks following a high thoracic SCI (at the third thoracic segment), rats were subjected to a battery of in vivo and in vitro physiological assessments, cognitive-behavioral tests, and immunohistochemical approaches to investigate changes in cerebrovascular structure and function in the middle cerebral artery (MCA). We show that in the MCA of rats with SCI, there is a 55% (SCI vs. control: 13.4 ± 1.9% vs. 29.63 ± 2.8%, respectively) reduction in the maximal vasodilator response to carbachol, which is associated with reduced expression of endothelial marker cluster of differentiation 31 (CD31) and transient receptor potential cation channel 4 (TRPV 4) channels. Compared with controls, MCAs in rats with SCI were found to have 50% (SCI vs. control: 1.5 ± 0.2 vs. 1 ± 0.1 a.u., respectively) more collagen 1 in the media of vascular wall and 37% (SCI vs. control: 30.5 ± 2.9% vs. 42.0 ± 4.0%, respectively) less distensibility at physiological intraluminal pressure. Further, the cerebral blood flow (CBF) in the hippocampus was reduced by 32% in the SCI group (SCI vs. control: 44.3 ± 4.5 mL/100 g/min vs. 65.0 ± 7.2 mL/100 g/min, respectively) in association with impairment of short-term memory based on a novel object recognition test. There were no changes in the sympathetic innervation of the vasculature and passive structure in the SCI group. Chronic experimental SCI is associated with structural alterations and endothelial dysfunction in cerebral arteries that likely contribute to significantly reduced CBF and vascular cognitive impairment.
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Affiliation(s)
- Rahul Sachdeva
- International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada.,University of British Columbia, Vancouver, British Columbia, Canada
| | - Mengyao Jia
- International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada.,University of British Columbia, Vancouver, British Columbia, Canada
| | - Shaoxun Wang
- Department of Pharmacology and Toxicology, The University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Andrew Yung
- International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada.,University of British Columbia, Vancouver, British Columbia, Canada
| | - Mei Mu Zi Zheng
- International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada.,University of British Columbia, Vancouver, British Columbia, Canada
| | - Amanda H X Lee
- International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada.,University of British Columbia, Vancouver, British Columbia, Canada
| | - Aaron Monga
- International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada.,University of British Columbia, Vancouver, British Columbia, Canada
| | - Sarah Leong
- University of British Columbia, Vancouver, British Columbia, Canada
| | - Piotr Kozlowski
- International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada.,University of British Columbia, Vancouver, British Columbia, Canada
| | - Fan Fan
- Department of Pharmacology and Toxicology, The University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Richard J Roman
- Department of Pharmacology and Toxicology, The University of Mississippi Medical Center, Jackson, Mississippi, USA
| | - Aaron A Phillips
- Departments of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada.,University of British Columbia, Vancouver, British Columbia, Canada.,G.F. Strong Rehabilitation Center, Vancouver, British Columbia, Canada
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Nightingale TE, Zheng MMZ, Sachdeva R, Phillips AA, Krassioukov AV. Diverse cognitive impairment after spinal cord injury is associated with orthostatic hypotension symptom burden. Physiol Behav 2019; 213:112742. [PMID: 31738949 DOI: 10.1016/j.physbeh.2019.112742] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 12/11/2022]
Abstract
This study: 1) compared cognitive functioning between individuals with chronic (>1 year) spinal cord injury (SCI) and non-injured controls and, 2) assessed associations between symptoms of autonomic dysreflexia and orthostatic hypotension with cognitive functioning in SCI participants with a history of unstable blood pressure (BP). Thirty-two individuals with SCI (C4-L2, American Spinal Injury Association Impairment Scale A-D) and thirty age, sex-matched non-injured controls participated in this study. Participants completed a motor-free neuropsychological test battery assessing 1) memory, 2) attention/concentration/psychomotor speed and, 3) executive function. Nineteen participants with SCI who had injuries ≥T6 and a history of unstable BP also completed the Autonomic Dysfunction Following Spinal Cord Injury (ADFSCI) questionnaire. Cognitive function was significantly lower in people with SCI across measures of memory and executive function compared to non-injured controls. Significant, moderate-to-large associations were observed between cumulative (frequency x severity) orthostatic hypotension and total BP instability symptoms scores, with measures of attention/concentration/psychomotor speed and executive function. These data demonstrate a 10 - 65% reduced performance across specific realms of cognitive functioning in individuals with SCI relative to non-injured controls. Furthermore, cumulative subjective scores for symptoms of unstable BP were associated with diverse cognitive deficits. These findings, in individuals without co-occurring traumatic brain injury, imply cardiovascular dysregulation plays a role in cognitive deficits observed in this population.
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Affiliation(s)
- Tom E Nightingale
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada
| | - Mei Mu Zi Zheng
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, Canada; MD Undergraduate Program, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Rahul Sachdeva
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada
| | - Aaron A Phillips
- Departments of Physiology and Pharmacology, Cardiac Sciences, and Clinical Neurosciences, Libin Cardiovascular Institute of Alberta, Hotchkiss Brain Institute, University of Calgary, Alberta, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada; GF Strong Rehabilitation Centre, Vancouver Coastal Health, Vancouver, Canada.
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15
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Yue JK, Hemmerle DD, Winkler EA, Thomas LH, Fernandez XD, Kyritsis N, Pan JZ, Pascual LU, Singh V, Weinstein PR, Talbott JF, Huie JR, Ferguson AR, Whetstone WD, Manley GT, Beattie MS, Bresnahan JC, Mummaneni PV, Dhall SS. Clinical Implementation of Novel Spinal Cord Perfusion Pressure Protocol in Acute Traumatic Spinal Cord Injury at U.S. Level I Trauma Center: TRACK-SCI Study. World Neurosurg 2019; 133:e391-e396. [PMID: 31526882 DOI: 10.1016/j.wneu.2019.09.044] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/05/2019] [Accepted: 09/06/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We sought to report the safety of implementation of a novel standard of care protocol using spinal cord perfusion pressure (SCPP) maintenance for managing traumatic spinal cord injury (SCI) in lieu of mean arterial pressure goals at a U.S. Level I trauma center. METHODS Starting in December 2017, blunt SCI patients presenting <24 hours after injury with admission American Spinal Injury Association Impairment Scale (AIS) A-C (or AIS D at neurosurgeon discretion) received lumbar subarachnoid drain (LSAD) placement for SCPP monitoring in the intensive care unit and were included in the TRACK-SCI (Transforming Research and Clinical Knowledge in Spinal Cord Injury) data registry. This SCPP protocol comprises standard care at our institution. SCPPs were monitored for 5 days (goal ≥65 mm Hg) achieved through intravenous fluids and vasopressor support. AISs were assessed at admission and day 7. RESULTS Fifteen patients enrolled to date were aged 60.5 ± 17 years. Injury levels were 93.3% (cervical) and 6.7% (thoracic). Admission AIS was 20.0%/20.0%/26.7%/33.3% for A/B/C/D. All patients maintained mean SCPP ≥65 mm Hg during monitoring. Fourteen of 15 cases required surgical decompression and stabilization with time to surgery 8.8 ± 7.1 hours (71.4% <12 hours). At day 7, 33.3% overall and 50% of initial AIS A-C had an improved AIS. Length of stay was 14.7 ± 8.3 days. None had LSAD-related complications. There were 7 respiratory complications. One patient expired after transfer to comfort care. CONCLUSIONS In our initial experience of 15 patients with acute SCI, standardized SCPP goal-directed care based on LSAD monitoring for 5 days was feasible. There were no SCPP-related complications. This is the first report of SCPP implementation as clinical standard of care in acute SCI.
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Affiliation(s)
- John K Yue
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Debra D Hemmerle
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Ethan A Winkler
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Leigh H Thomas
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Xuan Duong Fernandez
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Nikolaos Kyritsis
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Jonathan Z Pan
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Lisa U Pascual
- Department of Rehabilitation Medicine, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Vineeta Singh
- Department of Neurology, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Philip R Weinstein
- Department of Neurological Surgery, University of California, San Francisco, California, USA
| | - Jason F Talbott
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - J Russell Huie
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Adam R Ferguson
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - William D Whetstone
- Department of Emergency Medicine, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Geoffrey T Manley
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Michael S Beattie
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Jacqueline C Bresnahan
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA
| | - Praveen V Mummaneni
- Department of Neurological Surgery, University of California, San Francisco, California, USA
| | - Sanjay S Dhall
- Department of Neurological Surgery, University of California, San Francisco, California, USA; Brain and Spinal Injury Center, Zuckerberg San Francisco General Hospital, San Francisco, California, USA.
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16
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Solstrand Dahlberg L, Becerra L, Borsook D, Linnman C. Brain changes after spinal cord injury, a quantitative meta-analysis and review. Neurosci Biobehav Rev 2018; 90:272-293. [DOI: 10.1016/j.neubiorev.2018.04.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 02/21/2018] [Accepted: 04/23/2018] [Indexed: 12/11/2022]
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17
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A comparison of static and dynamic cerebral autoregulation during mild whole-body cold stress in individuals with and without cervical spinal cord injury: a pilot study. Spinal Cord 2018; 56:469-477. [PMID: 29330514 DOI: 10.1038/s41393-017-0021-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/14/2017] [Accepted: 09/14/2017] [Indexed: 11/09/2022]
Abstract
STUDY DESIGN Experimental study. OBJECTIVES To characterize static and dynamic cerebral autoregulation (CA) of individuals with cervical spinal cord injury (SCI) compared to able-bodied controls in response to moderate increases in mean arterial pressure (MAP) caused by mild whole-body cold stress. SETTING Japan METHODS: Five men with complete autonomic cervical SCI (sustained > 5 y) and six age-matched able-bodied men participated in hemodynamic, temperature, catecholamine and respiratory measurements for 60 min during three consecutive stages: baseline (10 min; 33 °C water through a thin-tubed whole-body suit), mild cold stress (20 min; 25 °C water), and post-cold recovery (30 min; 33 °C water). Static CA was determined as the ratio between mean changes in middle cerebral artery blood velocity and MAP, dynamic CA as transfer function coherence, gain, and phase between spontaneous changes in MAP to middle cerebral artery blood velocity. RESULTS MAP increased in both groups during cold and post-cold recovery (mean differences: 5-10 mm Hg; main effect of time: p = 0.001). Static CA was not different between the able-bodied vs. the cervical SCI group (mean (95% confidence interval (CI)) of between-group difference: -4 (-11 to 3) and -2 (-5 to 1) cm/s/mm Hg for cold (p = 0.22) and post-cold (p = 0.24), respectively). At baseline, transfer function phase was shorter in the cervical SCI group (mean (95% CI) of between-group difference: 0.6 (0.2 to 1.0) rad; p = 0.006), while between-group differences in changes in phase were not different in response to the cold stress (interaction term: p = 0.06). CONCLUSIONS This pilot study suggests that static CA is similar between individuals with cervical SCI and able-bodied controls in response to moderate increases in MAP, while dynamic CA may be impaired in cervical SCI because of disturbed sympathetic control.
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Phillips AA, Matin N, Jia M, Squair JW, Monga A, Zheng MMZ, Sachdeva R, Yung A, Hocaloski S, Elliott S, Kozlowski P, Dorrance AM, Laher I, Ainslie PN, Krassioukov AV. Transient Hypertension after Spinal Cord Injury Leads to Cerebrovascular Endothelial Dysfunction and Fibrosis. J Neurotrauma 2018; 35:573-581. [PMID: 29141501 DOI: 10.1089/neu.2017.5188] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We aimed to create a clinically relevant pre-clinical model of transient hypertension, and then evaluate the pathophysiological cerebrovascular processes resulting from this novel stimulus, which has recently been epidemiologically linked to cerebrovascular disease. We first developed a clinically relevant model of transient hypertension, secondary to induced autonomic dysreflexia after spinal cord injury and demonstrated that in both patients and rats, this stimulus leads to drastic acute cerebral hyperperfusion. For this, iatrogenic urodynamic filling/penile vibrostimulation was completed while measuring beat-by-beat blood pressure and cerebral blood flow (CBF) in patients. We then developed a rodent model mimicking the clinical reality by performing colorectal distention (to induce autonomic dysreflexia) using pre-clinical beat-by-beat blood pressure and CBF assessments. We then performed colorectal distension in rats for four weeks (6x/day) to evaluate the long-term cerebrovascular consequences of transient hypertension. Outcome measures included middle cerebral artery endothelial function, remodeling, profibrosis and perivascular innervation; measured via pressure myography, immunohistochemistry, molecular biology, and magnetic resonance imaging. Our model demonstrates that chronic repetitive cerebral hyperperfusion secondary to transient hypertension because of autonomic dysreflexia: (1) impairs cerebrovascular endothelial function; (2) leads to profibrotic cerebrovascular stiffening characterized by reduced distensibility and increased collagen deposition; and (3) reduces perivascular sympathetic cerebrovascular innervation. These changes did not occur concurrent to hallmark cerebrovascular changes from chronic steady-state hypertension, such as hypertrophic inward remodeling, or reduced CBF. Chronic exposure to repetitive transient hypertension after spinal cord injury leads to diverse cerebrovascular impairment that appears to be unique pathophysiology compared with steady-state hypertension in non-spinal cord injured models.
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Affiliation(s)
- Aaron A Phillips
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Nusrat Matin
- 2 Michigan State University East Lansing , Michigan
| | - Mengyao Jia
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Jordan W Squair
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Aaron Monga
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Mei Mu Zi Zheng
- 3 Faculty of Graduate Studies, University of British Columbia , Vancouver, British Columbia, Canada
| | - Rahul Sachdeva
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Andrew Yung
- 4 MRI Research Centre, Life Sciences Centre, University of British Columbia , Vancouver, British Columbia, Canada
| | - Shea Hocaloski
- 5 Sexual Health Rehabilitation Service; Vancouver Coastal Health Authority , Vancouver, British Columbia, Canada
| | - Stacy Elliott
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,6 Department of Psychiatry and Urologic Sciences, Vancouver Coastal Health Authority , Vancouver, British Columbia, Canada
| | - Piotr Kozlowski
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | | | - Ismail Laher
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Philip N Ainslie
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Andrei V Krassioukov
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
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Wecht JM, Weir JP, Bauman WA. Inter-day reliability of blood pressure and cerebral blood flow velocities in persons with spinal cord injury and intact controls. J Spinal Cord Med 2017; 40:159-169. [PMID: 26860937 PMCID: PMC5430472 DOI: 10.1080/10790268.2015.1135556] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
BACKGROUND Due to interruption of cardiovascular autonomic control unstable blood pressure (BP) is common in individuals with spinal cord injury (SCI) above the sixth thoracic vertebral level. The impact of unstable BP on cerebral blood flow (CBF) is not well appreciated, but symptoms associated with altered cerebral perfusion are reported, which can negatively impact daily life activities. METHODS We measured seated BP and CBF in participants with SCI and able-bodied (AB) controls on three laboratory visits to determine the inter-day reliability (intraclass correlation coefficient: ICC). BP was assessed at the finger using photoplethysmography and at the brachial artery with manual sphygmomanometry. CBF velocities (CBFv) were assessed at the middle cerebral artery using transcranial Doppler (TCD) ultrasound. RESULTS Data were collected in 15 participants with chronic SCI (C3-T4) and 10 AB controls, the groups did not differ for age, height, weight or BMI; however, brachial BP (P < 0.001), finger BP (P < 0.01) and CBFv (P < 0.05) were significantly lower in the SCI group compared to the controls. The inter-day ICC for brachial BP ranged from 0.51 to 0.79, whereas the ICC for finger BP was not as high (0.17 to 0.47). The inter-day ICC for CBFv ranged from 0.45 to 0.96, indicating fair to substantial reliability. CONCLUSIONS These data indicate good inter-day reliability of brachial BP and TCD recording of CBFv; however, the assessment of finger BP appears to be somewhat less reliable. In addition, these data confirm reduced resting CBFv in association with hypotension in individuals with SCI compared to matched controls with low BP.
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Affiliation(s)
- Jill M. Wecht
- VA RR&D Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VAMC, Bronx, NY, USA,Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Rehabilitation Medicine, The Icahn School of Medicine at Mount Sinai, New York, NY, USA,Correspondence to: Jill M. Wecht, Center of Excellence: Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center; Room 1E-02, 130 West Kingsbridge Rd., Bronx, NY 10468, USA. E-mail:
| | - Joseph P. Weir
- Department of Health, Sport and Exercise Sciences, The University of Kansas, Lawrence, KS, USA
| | - William A. Bauman
- VA RR&D Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VAMC, Bronx, NY, USA,The Medical Service, James J. Peters VAMC, Bronx, NY, USA,Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Rehabilitation Medicine, The Icahn School of Medicine at Mount Sinai, New York, NY, USA
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20
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Davidson R, Phillips A. Cardiovascular Physiology and Responses to Sexual Activity in Individuals Living with Spinal Cord Injury. Top Spinal Cord Inj Rehabil 2017; 23:11-19. [PMID: 29339873 PMCID: PMC5340505 DOI: 10.1310/sci2301-11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Background: Spinal cord injury (SCI) may profoundly impact autonomic function producing a variable degree of dysfunction in cardiovascular, bronchopulmonary, sweating, bladder, bowel, and sexual function. The cardiovascular system is crucially important for sexual function, as it is responsible for blood flow shifts to cavernous and musculoskeletal tissue during sexual activity. This system is prone to 3 main abnormalities after SCI including low resting blood pressure (LRBP), orthostatic hypotension (OH), and autonomic dysreflexia (AD), all of which have important effects on sexual function. Methods: We review the current etiological mechanisms and manifestations of cardiovascular dysfunction after SCI and discuss how this is documented to impact sexual function in individuals living with SCI. Conclusions: All individuals with SCI at or above the T6 neurologic level have an increased risk of AD during sexual stimulation, with increasing risk associated with higher levels of injury and greater completeness of injury. AD can be silent, and individuals living with SCI should be aware of blood pressure values at baseline and during sexual activity. Clinicians performing vibrostimulation fertility procedures need to be aware of the risk of AD and consider pretreatment if needed. Researchers studying the cardiovascular response to sexual stimulation should consider continuous monitoring of blood pressure, as intermittent monitoring may underestimate true blood pressure values.
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Affiliation(s)
- Ross Davidson
- International Collaboration On Repair Discoveries, Vancouver, BC, Canada
- Faculty of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, British Columbia, Canada
| | - Aaron Phillips
- International Collaboration On Repair Discoveries, Vancouver, BC, Canada
- Faculty of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, British Columbia, Canada
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21
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Caldas JR, Panerai RB, Haunton VJ, Almeida JP, Ferreira GSR, Camara L, Nogueira RC, Bor-Seng-Shu E, Oliveira ML, Groehs RRV, Ferreira-Santos L, Teixeira MJ, Galas FRBG, Robinson TG, Jatene FB, Hajjar LA. Cerebral blood flow autoregulation in ischemic heart failure. Am J Physiol Regul Integr Comp Physiol 2016; 312:R108-R113. [PMID: 27927624 DOI: 10.1152/ajpregu.00361.2016] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 12/01/2016] [Accepted: 12/01/2016] [Indexed: 12/24/2022]
Abstract
Patients with ischemic heart failure (iHF) have a high risk of neurological complications such as cognitive impairment and stroke. We hypothesized that iHF patients have a higher incidence of impaired dynamic cerebral autoregulation (dCA). Adult patients with iHF and healthy volunteers were included. Cerebral blood flow velocity (CBFV, transcranial Doppler, middle cerebral artery), end-tidal CO2 (capnography), and arterial blood pressure (Finometer) were continuously recorded supine for 5 min at rest. Autoregulation index (ARI) was estimated from the CBFV step response derived by transfer function analysis using standard template curves. Fifty-two iHF patients and 54 age-, gender-, and BP-matched healthy volunteers were studied. Echocardiogram ejection fraction was 40 (20-45) % in iHF group. iHF patients compared with control subjects had reduced end-tidal CO2 (34.1 ± 3.7 vs. 38.3 ± 4.0 mmHg, P < 0.001) and lower ARI values (5.1 ± 1.6 vs. 5.9 ± 1.0, P = 0.012). ARI <4, suggestive of impaired CA, was more common in iHF patients (28.8 vs. 7.4%, P = 0.004). These results confirm that iHF patients are more likely to have impaired dCA compared with age-matched controls. The relationship between impaired dCA and neurological complications in iHF patients deserves further investigation.
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Affiliation(s)
- J R Caldas
- Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil.,Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil
| | - R B Panerai
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom; .,Leicester National Institute for Health Research Biomedical Research Unit in Cardiovascular Disease, Glenfield Hospital, Leicester, United Kingdom
| | - V J Haunton
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.,Leicester National Institute for Health Research Biomedical Research Unit in Cardiovascular Disease, Glenfield Hospital, Leicester, United Kingdom
| | - J P Almeida
- Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil
| | - G S R Ferreira
- Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil
| | - L Camara
- Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil
| | - R C Nogueira
- Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil.,Department of Neurology, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil; and
| | - E Bor-Seng-Shu
- Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil
| | - M L Oliveira
- Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil
| | - R R V Groehs
- Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil
| | - L Ferreira-Santos
- Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil
| | - M J Teixeira
- Department of Neurosurgery, Hospital das Clinicas, University of São Paulo, São Paulo, Brazil
| | - F R B G Galas
- Department of Anesthesia, Heart Institute, University of São Paulo, São Paulo, Brazil
| | - T G Robinson
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom.,Leicester National Institute for Health Research Biomedical Research Unit in Cardiovascular Disease, Glenfield Hospital, Leicester, United Kingdom
| | - F B Jatene
- Department of Cardiopneumology, Heart Institute, University of São Paulo, São Paulo, Brazil
| | - L A Hajjar
- Department of Cardiopneumology, Heart Institute, University of São Paulo, São Paulo, Brazil
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22
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Phillips AA, Hansen A, Krassioukov AV. In with the new and out with the old: enter multivariate wavelet decomposition, exit transfer function. Am J Physiol Heart Circ Physiol 2016; 311:H735-7. [PMID: 27473940 DOI: 10.1152/ajpheart.00512.2016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Aaron A Phillips
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada; International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada; and
| | - Alex Hansen
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
| | - Andrei V Krassioukov
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia-Okanagan, Kelowna, British Columbia, Canada; International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada; Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada; and GF Strong Rehabilitation Centre, Vancouver Health Authority, Vancouver, Canada
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23
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Phillips AA, Chan FH, Zheng MMZ, Krassioukov AV, Ainslie PN. Neurovascular coupling in humans: Physiology, methodological advances and clinical implications. J Cereb Blood Flow Metab 2016; 36:647-64. [PMID: 26661243 PMCID: PMC4821024 DOI: 10.1177/0271678x15617954] [Citation(s) in RCA: 260] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 10/22/2015] [Accepted: 10/23/2015] [Indexed: 12/16/2022]
Abstract
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 non-physiologicalex vivopreparations 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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Affiliation(s)
- Aaron A Phillips
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada International Collaboration on Repair Discoveries (ICORD), UBC, Vancouver, Canada Experimental Medicine Program, Faculty of Medicine, UBC, Vancouver, Canada
| | - Franco Hn Chan
- International Collaboration on Repair Discoveries (ICORD), UBC, Vancouver, Canada
| | - Mei Mu Zi Zheng
- International Collaboration on Repair Discoveries (ICORD), UBC, Vancouver, Canada Experimental Medicine Program, Faculty of Medicine, UBC, Vancouver, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries (ICORD), UBC, Vancouver, Canada Experimental Medicine Program, Faculty of Medicine, UBC, Vancouver, Canada Department of Physical Therapy, UBC, Vancouver, Canada GF Strong Rehabilitation Center, Vancouver, Canada Department of Medicine, Division of Physical Medicine and Rehabilitation, UBC, Vancouver, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan, Kelowna, British Columbia, Canada
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24
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Phillips AA, Matin N, Frias B, Zheng MMZ, Jia M, West C, Dorrance AM, Laher I, Krassioukov AV. Rigid and remodelled: cerebrovascular structure and function after experimental high-thoracic spinal cord transection. J Physiol 2016; 594:1677-88. [PMID: 26634420 DOI: 10.1113/jp270925] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 11/18/2015] [Indexed: 12/25/2022] Open
Abstract
High-thoracic or cervical spinal cord injury (SCI) is associated with several critical clinical conditions related to impaired cerebrovascular health, including: 300-400% increased risk of stroke, cognitive decline and diminished cerebral blood flow regulation. The purpose of this study was to examine the influence of high-thoracic (T3 spinal segment) SCI on cerebrovascular structure and function, as well as molecular markers of profibrosis. Seven weeks after complete T3 spinal cord transection (T3-SCI, n = 15) or sham injury (Sham, n = 10), rats were sacrificed for either middle cerebral artery (MCA) structure and function assessments via ex vivo pressure myography, or immunohistochemical analyses. Myogenic tone was unchanged, but over a range of transmural pressures, inward remodelling occurred after T3-SCI with a 40% reduction in distensibility (both P < 0.05), and a 33% reduction in vasoconstrictive reactivity to 5-HT trending toward significance (P = 0.09). After T3-SCI, the MCA had more collagen I (42%), collagen III (24%), transforming growth factor β (47%) and angiotensin II receptor type 2 (132%), 27% less elastin as well as concurrent increased wall thickness and reduced lumen diameter (all P < 0.05). Sympathetic innervation (tyrosine hydroxylase-positive axon density) and endothelium-dependent dilatation (carbachol) of the MCA were not different between groups. This study demonstrates profibrosis and hypertrophic inward remodelling within the largest cerebral artery after high-thoracic SCI, leading to increased stiffness and possibly impaired reactivity. These deleterious adaptations would substantially undermine the capacity for regulation of cerebral blood flow and probably underlie several cerebrovascular clinical conditions in the SCI population.
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Affiliation(s)
- A A Phillips
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Experimental Medicine Program, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Centre for Heart, Lung, and Vascular Health, Faculty of Health and Social Development, University of British Columbia, Vancouver, Canada
| | - N Matin
- Pharmacology, Michigan State University, East Lansing, MI, USA
| | - B Frias
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - M M Z Zheng
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Experimental Medicine Program, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - M Jia
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - C West
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - A M Dorrance
- Pharmacology, Michigan State University, East Lansing, MI, USA
| | - I Laher
- Deptartment of Pharmacology and Therapeutic, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - A V Krassioukov
- International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,GF Strong Rehabilitation Center, Vancouver Coastal Health, Vancouver, Canada.,Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, Canada
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25
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Gatouillat A, Bleton H, VanSwearingen J, Perera S, Thompson S, Smith T, Sejdić E. Cognitive tasks during walking affect cerebral blood flow signal features in middle cerebral arteries and their correlation to gait characteristics. Behav Brain Funct 2015; 11:29. [PMID: 26409878 PMCID: PMC4583750 DOI: 10.1186/s12993-015-0073-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 09/09/2015] [Indexed: 11/23/2022] Open
Abstract
Gait is a complex process involving both cognitive and sensory ability and is strongly impacted by the environment. In this paper, we propose to study of the impact of a cognitive task during gait on the cerebral blood flow velocity, the blood flow signal features and the correlation of gait and blood flow features through a dual task methodology. Both cerebral blood flow velocity and gait characteristics of eleven participants with no history of brain or gait conditions were recorded using transcranial Doppler on mid-cerebral artery while on a treadmill. The cognitive task was induced by a backward counting starting from 10,000 with decrement of 7. Central blood flow velocity raw and envelope features were extracted in both time, frequency and time-scale domain; information-theoretic metrics were also extracted and statistical significances were inspected. A similar feature extraction was performed on the stride interval signal. Statistical differences between the cognitive and baseline trials, between the left and right mid-cerebral arteries signals and the impact of the antropometric variables where studied using linear mixed models. No statistical differences were found between the left and right mid-cerebral arteries flows or the baseline and cognitive state gait features, while statistical differences for specific features were measured between cognitive and baseline states. These statistical differences found between the baseline and cognitive states show that cognitive process has an impact on the cerebral activity during walking. The state was found to have an impact on the correlation between the gait and blood flow features.
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Affiliation(s)
- Arthur Gatouillat
- Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Héloïse Bleton
- Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Jessie VanSwearingen
- Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Subashan Perera
- Division of Geriatric Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Scott Thompson
- Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Traci Smith
- Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Ervin Sejdić
- Department of Electrical and Computer Engineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA, USA.
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26
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27
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Bleton H, Sejdić E. A cerebral blood flow evaluation during cognitive tasks following a cervical spinal cord injury: a case study using transcranial Doppler recordings. Cogn Neurodyn 2015; 9:615-26. [PMID: 26557931 DOI: 10.1007/s11571-015-9355-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 06/15/2015] [Accepted: 08/27/2015] [Indexed: 10/23/2022] Open
Abstract
A spinal cord injury (SCI) is one of the most common neurological disorders. In this paper, we examined the consequences of upper SCI in a male participant on the cerebral blood flow velocity. In particular, transcranial Doppler was used to study these effects through middle cerebral arteries (MCA) during resting-state periods and during cognitive challenges (non-verbal word-generation tasks and geometric-rotation tasks). Signal characteristics were analyzed from raw signals and envelope signals (maximum velocity) in the time domain, the frequency domain and the time-frequency domain. The frequency features highlighted an increase of the peak frequency in L-MCA and R-MCA raw signals, which revealed stronger cerebral blood flow during geometric/verbal processes respectively. This underlined a slight dominance of the right hemisphere during word-generation periods and a slight dominance of the left hemisphere during geometric processes. This finding was confirmed by cross-correlation in the time domain and by the entropy rate in information-theoretic domain. A comparison of our results to other neurological disorders (Alzheimer's disease, Parkinson's disease, autism, epilepsy, traumatic brain injury) showed that the SCI had similar effects such as general decreased cerebral blood flow and similar regular hemispheric dominance in a few cases.
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Affiliation(s)
- Héloïse Bleton
- Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, PA 15261 USA
| | - Ervin Sejdić
- Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, PA 15261 USA
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28
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Phillips AA, Krassioukov AV. Contemporary Cardiovascular Concerns after Spinal Cord Injury: Mechanisms, Maladaptations, and Management. J Neurotrauma 2015; 32:1927-42. [PMID: 25962761 DOI: 10.1089/neu.2015.3903] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cardiovascular (CV) issues after spinal cord injury (SCI) are of paramount importance considering they are the leading cause of death in this population. Disruption of autonomic pathways leads to a highly unstable CV system, with impaired blood pressure (BP) and heart rate regulation. In addition to low resting BP, on a daily basis the majority of those with SCI suffer from transient episodes of aberrantly low and high BP (termed orthostatic hypotension and autonomic dysreflexia, respectively). In fact, autonomic issues, including resolution of autonomic dysreflexia, are frequently ranked by individuals with high-level SCI to be of greater priority than walking again. Owing to a combination of these autonomic disturbances and a myriad of lifestyle factors, the pernicious process of CV disease is accelerated post-SCI. Unfortunately, these secondary consequences of SCI are only beginning to receive appropriate clinical attention. Immediately after high-level SCI, major CV abnormalities present in the form of neurogenic shock. After subsiding, new issues related to BP instability arise, including orthostatic hypotension and autonomic dysreflexia. This review describes autonomic control over the CV system before injury and the mechanisms underlying CV abnormalities post-SCI, while also detailing the end-organ consequences, including those of the heart, as well as the systemic and cerebral vasculature. The tertiary impact of CV dysfunction will also be discussed, such as the potential impediment of rehabilitation, and impaired cognitive function. In the recent past, our understanding of autonomic dysfunctions post-SCI has been greatly enhanced; however, it is vital to further develop our understanding of the long-term consequences of these conditions, which will equip us to better manage CV disease morbidity and mortality in this population.
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Affiliation(s)
- Aaron A Phillips
- 1 Center for Heart, Lung, and Vascular Health, Faculty of Health and Social Development, University of British Columbia , Kelowna, British Columbia, Canada .,2 Experimental Medicine Program, Faculty of Medicine, University of British Columbia , Vancouver, British Columbia, Canada .,3 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Andrei V Krassioukov
- 2 Experimental Medicine Program, Faculty of Medicine, University of British Columbia , Vancouver, British Columbia, Canada .,3 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,4 Department of Physical Medicine and Rehabilitation, University of British Columbia , Vancouver, British Columbia, Canada
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29
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Toledo-Perdomo K, Viña-Cabrera Y, Martín-Urcuyo B, Morales-Umpiérrez A. Hypertensive crisis in a patient with a medullary lesion. Nefrologia 2015; 35:329-31. [PMID: 26299176 DOI: 10.1016/j.nefro.2015.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Accepted: 03/05/2015] [Indexed: 10/23/2022] Open
Affiliation(s)
- Katia Toledo-Perdomo
- Servicio de Nefrología, Hospital José Molina Orosa, Arrecife, Las Palmas, España.
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30
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James MFM. Volume therapy in trauma and neurotrauma. Best Pract Res Clin Anaesthesiol 2014; 28:285-96. [PMID: 25208963 DOI: 10.1016/j.bpa.2014.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 06/25/2014] [Accepted: 06/27/2014] [Indexed: 11/30/2022]
Abstract
Volume therapy in trauma should be directed at the restitution of disordered physiology including volume replacement to re-establishment of tissue perfusion, correction of coagulation deficits and avoidance of fluid overload. Recent literature has emphasised the importance of damage control resuscitation, focussing on the restoration of normal coagulation through increased use of blood products including fresh frozen plasma, platelets and cryoprecipitate. However, once these targets have been met, and in patients not in need of damage control resuscitation, clear fluid volume replacement remains essential. Such volume therapy should include a balance of crystalloids and colloids. Pre-hospital resuscitation should be limited to that required to sustain a palpable radial artery and adequate mentation. Neurotrauma patients require special consideration in both pre-hospital and in-hospital management.
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Affiliation(s)
- M F M James
- Department of Anaesthesia, University of Cape Town, Anzio Road, Observatory, Cape Town, Western Cape 7925, South Africa.
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31
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Phillips AA, Krassioukov AV, Ainslie PN, Cote AT, Warburton DER. Increased central arterial stiffness explains baroreflex dysfunction in spinal cord injury. J Neurotrauma 2014; 31:1122-8. [PMID: 24634993 DOI: 10.1089/neu.2013.3280] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
After cervical spinal cord injury (SCI), orthostatic hypotension and intolerance commonly ensue. The cardiovagal baroreflex plays an important role in the acute regulation of blood pressure (BP) and is associated with the onset of presyncope. The cardiovagal baroreflex is dysfunctional after SCI; however, this may be influenced by either increased stiffening of the arteries containing the stretch-receptors (which has been shown in SCI) or a more downstream neural mechanism (i.e., solitary nucleus, sinoatrial node). Identifying where along this pathway baroreflex dysfunction occurs may highlight a potential therapeutic target. This study examined the relationship between spontaneous cardiovagal baroreflex sensitivity (BRS) and common carotid artery (CCA) stiffness in those with high level SCI before and after midodrine (alpha1-agonist) administration, as well as in able-bodied controls, to evaluate: (1) the role arterial stiffening plays mediating baroreflex function after SCI and (2) the effect of normalizing BP on these parameters. Three to five min recordings of beat-by-beat BP and heart rate, as well as 30 sec duration recordings of CCA diameter were used for analysis. All participants were tested supine and during upright-tilt. Arterial stiffness (β-stiffness index) was elevated in those with SCI when upright (+12%; p<0.05). Further, β-stiffness index was negatively related to reduced BRS in those with SCI when upright (R2=0.55; p<0.05), but not in able-bodied persons. Normalizing BP did not improve BRS or CCA stiffness. This study clearly shows that reduced BRS is closely related to increased arterial stiffness in the population with SCI.
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Affiliation(s)
- Aaron A Phillips
- 1 Cardiovascular Physiology and Rehabilitation Laboratory , Physical Activity Promotion and Chronic Disease Prevention Unit, University of British Columbia , Vancouver, Canada
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32
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Regional neurovascular coupling and cognitive performance in those with low blood pressure secondary to high-level spinal cord injury: improved by alpha-1 agonist midodrine hydrochloride. J Cereb Blood Flow Metab 2014; 34:794-801. [PMID: 24473484 PMCID: PMC4013775 DOI: 10.1038/jcbfm.2014.3] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 12/10/2013] [Accepted: 12/30/2013] [Indexed: 12/30/2022]
Abstract
Individuals with high-level spinal cord injury (SCI) experience low blood pressure (BP) and cognitive impairments. Such dysfunction may be mediated in part by impaired neurovascular coupling (NVC) (i.e., cerebral blood flow responses to neurologic demand). Ten individuals with SCI >T6 spinal segment, and 10 age- and sex-matched controls were assessed for beat-by-beat BP, as well as middle and posterior cerebral artery blood flow velocity (MCAv, PCAv) in response to a NVC test. Tests were repeated in SCI after 10 mg midodrine (alpha1-agonist). Verbal fluency was measured before and after midodrine in SCI, and in the control group as an index of cognitive function. At rest, mean BP was lower in SCI (70 ± 10 versus 92 ± 14 mm Hg; P<0.05); however, PCAv conductance was higher (0.56 ± 0.13 versus 0.39 ± 0.15 cm/second/mm Hg; P<0.05). Controls exhibited a 20% increase in PCAv during cognition; however, the response in SCI was completely absent (P<0.01). When BP was increased with midodrine, NVC was improved 70% in SCI, which was reflected by a 13% improved cognitive function (P<0.05). Improvements in BP were related to improved cognitive function in those with SCI (r(2)=0.52; P<0.05). Impaired NVC, secondary to low BP, may partially mediate reduced cognitive function in individuals with high-level SCI.
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Phillips AA, Krassioukov AV, Ainslie PN, Warburton DER. Perturbed and spontaneous regional cerebral blood flow responses to changes in blood pressure after high-level spinal cord injury: the effect of midodrine. J Appl Physiol (1985) 2014; 116:645-53. [PMID: 24436297 DOI: 10.1152/japplphysiol.01090.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Individuals with spinal cord injury (SCI) above the T6 spinal segment suffer from orthostatic intolerance. How cerebral blood flow (CBF) responds to orthostatic challenges in SCI is poorly understood. Furthermore, it is unclear how interventions meant to improve orthostatic tolerance in SCI influence CBF. This study aimed to examine 1) the acute regional CBF responses to rapid changes in blood pressure (BP) during orthostatic stress in individuals with SCI and able-bodied (AB) individuals; and 2) the effect of midodrine (alpha1-agonist) on orthostatic tolerance and CBF regulation in SCI. Ten individuals with SCI >T6, and 10 age- and sex-matched AB controls had beat-by-beat BP and middle and posterior cerebral artery blood velocity (MCAv, PCAv, respectively) recorded during a progressive tilt-test to quantify the acute CBF response and orthostatic tolerance. Dynamic MCAv and PCAv to BP relationships were evaluated continuously in the time domain and frequency domain (via transfer function analysis). The SCI group was tested again after administration of 10 mg midodrine to elevate BP. Coherence (i.e., linearity) was elevated in SCI between BP-MCAv and BP-PCAv by 35% and 22%, respectively, compared with AB, whereas SCI BP-PCAv gain (i.e., magnitudinal relationship) was reduced 30% compared with AB (all P < 0.05). The acute (i.e., 0-30 s after tilt) MCAv and PCAv responses were similar between groups. In individuals with SCI, midodrine led to improved PCAv responses 30-60 s following tilt (10 ± 3% vs. 4 ± 2% decline; P < 0.05), and a 59% improvement in orthostatic tolerance (P < 0.01). The vertebrobasilar region may be particularly susceptible to hypoperfusion in SCI, leading to increased orthostatic intolerance.
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Affiliation(s)
- Aaron A Phillips
- Cardiovascular Physiology and Rehabilitation Laboratory, Physical Activity Promotion and Chronic Disease Prevention Unit, University of British Columbia, Vancouver, British Columbia, Canada
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