scholarly journals 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

2014 ◽  
Vol 34 (5) ◽  
pp. 794-801 ◽  
Author(s):  
Aaron A Phillips ◽  
Darren ER Warburton ◽  
Philip N Ainslie ◽  
Andrei V Krassioukov
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Cognitive Function ◽  
Neurovascular Coupling ◽  
Control Group ◽  
Cord Injury ◽  
Low Blood Pressure ◽  
High Level

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 ( r2 = 0.52; P<0.05). Impaired NVC, secondary to low BP, may partially mediate reduced cognitive function in individuals with high-level SCI.

scholarly journals Cerebral Autoregulation during Postural Change in Patients with Cervical Spinal Cord Injury—A Carotid Duplex Ultrasonography Study

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1321
Author(s):  
Joo-Hyun Kee ◽  
Jun-Hyeong Han ◽  
Chang-Won Moon ◽  
Kang Hee Cho
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Cerebral Autoregulation ◽  
Duplex Ultrasonography ◽  
Postural Change ◽  
Carotid Duplex ◽  
Cord Injury ◽  
Carotid Duplex Ultrasonography

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.

Increased vascular resistance in paralyzed legs after spinal cord injury is reversible by training

2002 ◽  
Vol 93 (6) ◽  
pp. 1966-1972 ◽  
Author(s):  
Maria T. E. Hopman ◽  
Jan T. Groothuis ◽  
Marcel Flendrie ◽  
Karin H. L. Gerrits ◽  
Sibrand Houtman
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Vascular Resistance ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Cord Injury

The purpose of the present study was to determine the effect of a spinal cord injury (SCI) on resting vascular resistance in paralyzed legs in humans. To accomplish this goal, we measured blood pressure and resting flow above and below the lesion (by using venous occlusion plethysmography) in 11 patients with SCI and in 10 healthy controls (C). Relative vascular resistance was calculated as mean arterial pressure in millimeters of mercury divided by the arterial blood flow in milliliters per minute per 100 milliliters of tissue. Arterial blood flow in the sympathetically deprived and paralyzed legs of SCI was significantly lower than leg blood flow in C. Because mean arterial pressure showed no differences between both groups, leg vascular resistance in SCI was significantly higher than in C. Within the SCI group, arterial blood flow was significantly higher and vascular resistance significantly lower in the arms than in the legs. To distinguish between the effect of loss of central neural control vs. deconditioning, a group of nine SCI patients was trained for 6 wk and showed a 30% increase in leg blood flow with unchanged blood pressure levels, indicating a marked reduction in vascular resistance. In conclusion, vascular resistance is increased in the paralyzed legs of individuals with SCI and is reversible by training.

scholarly journals Cognitive function after spinal cord injury

Neurology ◽  
2018 ◽  
Vol 91 (13) ◽  
pp. 611-621 ◽  
Author(s):  
Rahul Sachdeva ◽  
Feng Gao ◽  
Chetwyn C.H. Chan ◽  
Andrei V. Krassioukov
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cognitive Impairment ◽  
Brain Injury ◽  
Sleep Apnea ◽  
Cognitive Function ◽  
Cardiovascular Control ◽  
Current Evidence ◽  
Control Group ◽  
Cord Injury

ObjectiveTo systematically examine the incidence of cognitive impairment in individuals with spinal cord injury (SCI), as well as identify potential contributing and confounding factors.MethodsStudies quantitatively reporting cognitive ability after spinal cord injury were searched electronically via Medline, CINAHL, Embase, and PsycINFO. Manual screening for references within articles was also performed. A total of 2,481 studies were screened and a total of 70 were included in this review, 21 reporting cognitive function after SCI compared to an able-bodied control group and 49 with no able-bodied controls. Studies were analyzed for the incidence of impairment and the interactions with concomitant traumatic brain injury, psychological or somatic complaints, decentralized cardiovascular control, sleep apnea, neurologic level of injury, and age.ResultsThere is a high volume of evidence reporting substantial cognitive impairment in individuals with SCI. Potential co-contributors include concomitant brain injury, psychological or somatic comorbidities, decentralized cardiovascular control, and sleep apnea. Cognitive functioning was negatively correlated with age. No clear agreement was found for the incidence of cognitive impairment or its association with level of injury.ConclusionCurrent evidence suggests that individuals with SCI should be examined and addressed for cognitive impairment. Future studies aimed at identifying potential secondary causative factors should employ stringent controls for co-occurring brain trauma since it appears to be a major contributor and confounder to impaired cognition.

scholarly journals Perturbed and spontaneous regional cerebral blood flow responses to changes in blood pressure after high-level spinal cord injury: the effect of midodrine

2014 ◽  
Vol 116 (6) ◽  
pp. 645-653 ◽  
Author(s):  
Aaron A. Phillips ◽  
Andrei V. Krassioukov ◽  
Philip N. Ainslie ◽  
Darren E. R. Warburton
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Orthostatic Intolerance ◽  
Function Analysis ◽  
Orthostatic Tolerance ◽  
Transfer Function Analysis ◽  
Cord Injury

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.

scholarly journals Serum CCL21 as a Potential Biomarker for Cognitive Impairment in Spinal Cord Injury

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Yuanzhen Chen ◽  
Liangke Liang ◽  
Shengnan Cao ◽  
Guangjian Hou ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cognitive Impairment ◽  
Cognitive Function ◽  
Clinical Characteristics ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Potential Biomarker ◽  
Cord Injury ◽  
Moca Score

Objective. Cognitive impairment is considered to be an important complication of spinal cord injury (SCI), but its underlying mechanism remains unclear. The purpose of this study is to explore whether serum CCL21 can be used as a potential biomarker of cognitive impairment in SCI. Methods. In Neck-Shoulder and Lumbocrural Pain Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, hospitalized or treated acute SCI patients were included in the study as the SCI group (SCI). At the same time, a normal control group (NC) matching the age and sex of the SCI group was recruited in the outpatient clinic. Once the two groups were enrolled, their demographics and clinical characteristics were collected immediately. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum CCL21 levels within 24 hours of admission. Three months later, the Montreal Cognitive Assessment (MoCA) was used to test the cognitive function of the population. Results. A total of 84 SCI patients and 49 NC populations were eligible for inclusion in the study. There was no significant statistical difference in the demographics and clinical characteristics (age, gender, BMI, TG, LDL-C, FBG, SBP, and DBP) between the two groups ( p > 0.05 ). Compared with the NC group, the SCI group had a higher serum CCL21 level ( p < 0.001 ) and a lower MoCA score ( p < 0.001 ). Serum CCL21 level in SCI was negatively correlated with MoCA score ( p = 0.023 ). Multivariable analyses showed that serum CCL21 level is an independent prognostic factor of cognitive impairment in SCI. Conclusions. MoCA score has a linear relationship with serum CCL21 quartile, and SCI cognitive function has a negative correlation with serum CCL21. Serum CCL21 is an independent risk factor for cognitive impairment after SCI.

Cardiovascular responses to vaginocervical stimulation in the spinal cord-transected rat

1997 ◽  
Vol 273 (4) ◽  
pp. R1361-R1366 ◽  
Author(s):  
Giorgio R. Sansone ◽  
Ralph Bianca ◽  
Rafael Cueva-Rolón ◽  
Lisbeth E. Gómez ◽  
Barry R. Komisaruk
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Heart Rate ◽  
Spinal Cord Injury ◽  
Cardiovascular Responses ◽  
Spinal Cord Transection ◽  
Autonomic Dysreflexia ◽  
Control Group ◽  
Cord Injury ◽  
Sh Group

The present study ascertained whether increases in heart rate (HR) and systolic blood pressure (SBP) produced by vaginocervical stimulation (VS; 500 g force) persist in the unanesthetized rat after chronic spinal cord transection at selected levels. Three groups were used: spinal cord transection at T7 ( n = 10) or L5 ( n = 10) or a sham-operated control group (Sh, n = 10). In the Sh group, VS increased significantly both HR, by 95 ± 14.3 beats/min (bpm) (22 ± 3.7% above baseline), and BP, by 37 ± 5.7 mmHg (37 ± 7.7% above baseline), confirming earlier findings. In the T7 group, VS significantly decreased HR by 107 ± 21.4 bpm (27 ± 4.1% below baseline) and increased BP by 41.3 ± 12.9 mmHg (32 ± 8.3% above baseline). In response to VS, HR increased in every rat in the Sh group and decreased in every rat in the T7 group. In the L5 group, VS failed to significantly affect HR or BP. In the present study, specific levels of spinal cord transection produced differential HR and BP responses to VS in the rat. A model is presented addressing the component responses of autonomic dysreflexia that can occur, contingent on the level of spinal cord injury, in women during parturition or sexual intercourse.

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