Autonomic assessment of animals with spinal cord injury: tools, techniques and translation

Study design: Literature review. Objectives: To present a comprehensive overview of autonomic assessment in experimental spinal cord injury (SCI). Methods: A systematic literature review was conducted using PubMed to extract studies that incorporated functional motor, sensory or autonomic assessment after experimental SCI. Results: While the total number of studies assessing functional outcomes of experimental SCI increased dramatically over the past 27 years, studies with motor outcomes dramatically outnumber those with autonomic outcomes. Within the areas of autonomic dysfunction (cardiovascular, respiratory, gastrointestinal, lower urinary tract, sexual function and thermoregulation), not all aspects have been characterized to the same extent. Studies focusing on bladder and cardiovascular function greatly outnumber those on sexual function, gastrointestinal function and thermoregulation. This review addresses the disparity between well-established motor-sensory testing presently used in experimental animals and the lack of standardized autonomic testing following experimental SCI. Throughout the review, we provide information on the correlation between existing experimental and clinically used autonomic tests. Finally, the review contains a comprehensive set of tables and illustrations to guide the reader through the complexity of autonomic assessment and dysfunctions observed following SCI. Conclusions: A wide variety of techniques exist to evaluate autonomic function in experimental animals with SCI. The incorporation of autonomic assessment as outcome measures in experiments testing treatments or interventions for SCI should be considered a high, clinically relevant priority.