Autonomic dysreflexia is a pathologic response to pain or other noxious stimuli, and is characterized by hypertension, bradycardia and vasodilation above the level of the cord injury. Can develop any time after the period of spinal shock ends. The release of catecholamines causes vasoconstriction and hypertension.
Hypertension stimulates baroreceptors in the carotid sinus, aorta and cerebral vessels.
This causes the parasympathetic nervous system to be stimulated, which attempts to restore the BP back to normal. Vasoconstriction below the level of the cord injury causes the hypertension to persist. SIgns and Symptoms Vasoconstriction causes hypertension and decreased peripheral circulation below the level of the cord injury. Vasodilation above the level of the cord injury causes facial flushing, headache, nasal congestion, blurred vision, nausea and diaphoresis. Inhibition causes bradycardia.