Background: Spinal cord injuries (SCI) often result in cardiovascular issues, increasing the risk of stroke and cognitive deficits.
Objectives: This study assessed cerebrovascular reactivity (CVR) using functional magnetic resonance imaging (fMRI) during a hypercapnic challenge in SCI participants compared to noninjured controls.
Methods: Fourteen participants were analyzed (n = 8 with SCI [unless otherwise noted], median age = 44 years; n = 6 controls, median age = 33 years). CVR was calculated through fMRI signal changes.
Results: The results showed a longer CVR component (tau) in the grey matter of SCI participants (n = 7) compared to controls (median difference = 3.0 s; p < .05). Time since injury (TSI) correlated negatively with steady-state CVR in the grey matter and brainstem of SCI participants (RS = -0.81, p = .014; RS = -0.84, p = .009, respectively). Lower steady-state CVR in the brainstem of the SCI group (n = 7) correlated with lower diastolic blood pressure (RS = 0.76, p = .046). Higher frequency of hypotensive episodes (n = 7) was linked to lower CVR outcomes in the grey matter (RS = -0.86, p = .014) and brainstem (RS = -0.89, p = .007).
Conclusion: Preliminary findings suggest a difference in the dynamic CVR component, tau, between the SCI and noninjured control groups, potentially explaining the higher cerebrovascular health burden in SCI individuals. Exploratory associations indicate that longer TSI, lower diastolic blood pressure, and more hypotensive episodes may lead to poorer CVR outcomes. However, further research is necessary to establish causality and support these observations.
Background: The proportion of patients with American Spinal Injury Association Impairment Scale (AIS) grade D traumatic spinal cord injuries (tSCI) is increasing. Although initial motor deficits can be relatively mild, some individuals fail to recover functional independence.
Objectives: This study aims to identify factors associated with failure to reach complete functional independence after AIS grade D tSCI.
Methods: An observational prospective cohort study was conducted at a level 1 trauma center specialized in SCI care. A prospective cohort of 121 individuals with an AIS-D tSCI was considered. The baseline characteristics, length of acute stay, need for inpatient rehabilitation, and 12-month functional status were assessed. Univariate and classification and regression tree (CART) analyses were performed to identify factors associated with reaching complete versus incomplete functional independence (defined as perfect total SCIM III score at 12-month follow-up).
Results: There were 69.3%, 83.3%, and 61.4% individuals reaching complete independence in self-care, respiration/sphincter management, and mobility, respectively. A total of 64 individuals (52%) reached complete functional independence in all three domains. In the CART analysis, we found that patients are more likely to achieve complete functional independence when they have a baseline motor score ≥83 (65% individuals) and if they present fewer medical comorbidities (70% individuals if Charlson Comorbidity Index [CCI] ≤4).
Conclusion: About half of individuals with AIS grade D tSCI can expect complete long-term functional independence. It is important to recognize early during acute care individuals with baseline motor score <83 or a high burden of comorbidities (CCI ≥5) to optimize their rehabilitation plan.