Influence of the neurological level of spinal cord injury on cardiovascular outcomes in humans: a meta-analysis

Abstract

Background: Although motor and sensory deficits following spinal cord injury (SCI) are well known, there are still contrasting reports on how SCI affects baseline cardiovascular (CV) parameters and other autonomic functions. Study design: Meta-analysis is performed. Objectives: To examine the effect of injury level on supine and seated CV function in individuals with SCI. Methods: A total of 98 studies representing 1968 individuals were retrieved for analysis. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were abstracted from the studies and compared between four groups according to the neurological lesion level, cervical (C) SCI (C4-C8), high-thoracic (HT) SCI (T1-T6), low-thoracic lumbar (LTL) SCI (below T6) and able-bodied (AB) controls. Results: In the supine position, SBP, DBP and HR were lower in C compared with HT, LTL and AB (all Po0.04). In the seated position, SBP and DBP were significantly lower in C compared with LTL and AB (all Po0.003) and HR was significantly lower in C compared with LTL only (P¼0.01). A final finding was that C exhibited a lower resting SBP in the seated compared with the supine position (Po0.001). Conclusion: Individuals with SCI exhibit a lesion-dependent impairment in resting CV function, whereby those with the highest injury had the greatest degree of CV dysfunction. A further finding was that individuals with a C injury exhibited a lower resting SBP in the seated vs supine position. Thus, clinicians and researchers should consider lesion level and body position when measuring and interpreting CV parameters in individuals with SCI.

Peripheral vascular function in spinal cord injury: a systematic review

“…20,21 Of particular importance in the development of hypotension is the loss of sympathetic tonic activity to a significant portion of the peripheral blood vessels below the lesion; hence, those with the highest (cervical) injuries exhibit the most severe hypotension. 8 In addition to resting hypotension, most individuals with high SCI experience orthostatic hypotension when transferring from a supine to a seated position. [22][23][24][25][26] In the AB population, it is well known that on assumption of the upright posture, there is a baroreflex-mediated peripheral vasoconstriction via an increased sympathetic outflow to maintain blood pressure and cerebral perfusion.…”

“…6 These 'traditional' risk factors, however, do not fully explain the increased CVD risk in individuals with SCI. 7 For instance, people with high-thoracic/cervical SCI exhibit autonomic disturbances that result in a low resting arterial blood pressure 8 -something that is usually considered cardioprotective-yet they exhibit a greater prevalence of CVD than the AB population. Thus, other factors must at least partly be responsible for the elevated CVD risk in the SCI population, and recent evidence suggests that there is a need for more specific recommendations for the management of CVD in the SCI population.…”

Spinal Cord Injury Causes Chronic Liver Pathology in Rats

“…16,[32][33][34][35] To determine if post-injury changes in the liver were dependent on the level of SCI, we examined liver inflammation and lipid accumulation after midline cervical (C5 level) contusion injury in rats. Similar to thoracic SCI, hepatic CD68 mRNA significantly increased by 1 dpi, reaching levels *1000-fold higher than in naïve/uninjured livers (Fig.…”

Cardiovascular Function in Individuals with Incomplete Spinal Cord Injury: A Systematic Review

“…It is now well recognized that the extent of impairment in cardiovascular function is related to the neurological level of injury, 4 whereby persons with cervical/high-thoracic injuries exhibit a greater impairment in cardiovascular function and an earlier onset of CVD than those with lowthoracic/lumbar injuries. Injury to the cervical/ upper thoracic cord disrupts descending input relationship between the severity (ie, completeness) of SCI and cardiovascular control is less clear.…”