Orthostatic systemic and cerebral hemodynamics in newly injured patients with spinal cord injury*

Background: Low blood pressure (BP) may lead to reduced cerebral blood flow velocity (CBFv) during an orthostatic challenge in newly injured patients with traumatic spinal cord injury (SCI), which, may relate to the neurological level of injury (NLI) as documented on the International Standards for the Neurologic Classification of SCI (ISNCSCI), or to evidence of cardiovascular autonomic impairment as determined by the International Standards to document remaining Autonomic Function after SCI (ISAFSCI). Objective: To examine the influence of patient demographics, ISNCSCI and ISAFSCI scores on hemodynamic responses to a bedside sit-up test in newly injured patients with SCI. Design: Cross-sectional, prospective analysis. Methods: A modified sit-up test was conducted at the bedside with the hips at an angle between 45 degrees and 90 degrees and the legs horizontal, level with the hips. Heart rate, BP, and CBFv were recorded for 10 min in the supine and seated positions. Results: Fifty-three newly injured patients (median 39.5 days post-injury) with traumatic SCI were enrolled. Overall, 28 (53%) patients met ISAFSCI criteria, and the number of criteria met (total score) was significantly related to orthostatic changes in CBFv. Change in SBP and change in CBFv were not significantly related, but NLI and total sensory score from the ISNCSCI were significant predictors of the change in CBFv. Conclusions: Total ISAFSCI score, NLI and sensory scores were positively associated with orthostatic changes in CBFv. Long term follow-up should be considered to determine the consequences of diminished CBFv on cognitive function and quality of life following SCI.