Evaluation and management of autonomic functions in patients with spinal cord injury: A scoping review.

Abstract

Context: Individuals with high-level spinal cord injury (SCI) face serious cardiovascular (CV) autonomic complications, contributing to increased mortality and morbidity. The assessment of CV autonomic function in SCI is challenging and varies widely across studies, with no clear or definitive interventions to restore hemodynamic stability or prevent complications.

Objectives: This review outlines available clinical data on measuring and managing CV autonomic dysfunction after SCI and identifies gaps in these domains.

Methods: A scoping review was conducted, using a search strategy targeting broad keywords related to SCI, autonomic function parameters, and management from six relevant databases, as well as reference lists and gray literatures.

Results: Of 2,749 articles identified, 92 were included. Studies categorized CV autonomic complications by acute and chronic stages. High-level SCI was commonly associated with bradycardia, low BP, orthostatic hypotension, and autonomic dysreflexia, compared to lower thoracic SCI. However, the correlation between these complications and SCI completeness was unclear. Various measurement methods were used, including 24-hour ambulatory BP monitoring (ABPM), ECG derivatives, heart rate variability, sympathetic skin response, cold pressor test, head-up tilt, the International Standards to document Autonomic Function following SCI (ISAFSCI) and the Autonomic Dysfunction Following SCI (ADFSCI) tools. Of these, 24-hour ABPM demonstrated superiority in identifying diurnal variation and activity effects on CV conditions. Studies reported mixed outcomes for both pharmacological and non-pharmacological management of CV complications.

Conclusion: Research gaps persist, especially in sub-acute stages and in standardized tools for assessing CV autonomic dysfunction. Chronic complications have a long-term impact on health and CV disease risk. While promising methodologies exist, such as 24-hour ABPM and questionnaire-based assessments, further refinement is needed. Comprehensive management strategies should also be developed. This includes emerging techniques like spinal neuromodulation, which require extensive research and clinical trials.