In a patient with a spinal cord injury (SCI), autonomic hyperreflexia (autonomic dysreflexia) is initiated by noxious stimuli below the level of cord injury. The noxious stimuli elicits a hypertensive response, which is followed immediately by a profound vagal response. In response to the increase in afterload, patient may vasodilate and appear flushed above the level of cord injury.
Thus, during an episode of autonomic hyperreflexia, patients are typically hypertensive and bradycardic.
Paraplegia: Autonomic hyperreflexia