Cerebrovascular control following spinal cord injury

Spinal cord injury (SCI) leads to drastic loss of motor and sensory function. The autonomic consequences of SCI are less well known and include diminished cardiovascular control, with large decreases and increases in blood pressure; conditions known as orthostatic hypotension (OH) and autonomic dysreflexia (AD), respectively. These disorders have important quality of life implications for individuals with SCI, due not only to blood pressure fluctuations, but also due to proposed alterations in cerebral perfusion secondary to impaired cerebral autoregulation. However, comprehensive studies examining autoregulation during OH and AD after SCI are scarce. We, therefore, determined cardiovascular and cerebrovascular responses to these conditions in individuals with SCI; accounting for level and severity of injury to sympathetic cardiovascular pathways, arterial gas concentrations and symptoms. Our results indicate, for the first time, that cerebral autoregulation is diminished after SCI and that this dysfunction is related to the level and severity of autonomic injury.