[Autonomic dysreflexia in spinal cord injury patients: recognition is vital].

Depending on the level and severity of spinal cord injury (SCI), SCI patients may suffer from loss of autonomic nervous system function besides the well-known motor and sensory function loss. Changes in the autonomic control of the cardiovascular system can lead to the life-threatening phenomenon of autonomic dysreflexia (AD), especially in patients with cervical or high thoracic SCI. AD is defined as a sudden increase in systolic blood pressure of at least 20 mmHg above baseline. It results from an uncontrolled reaction of the sympathetic nervous system to a stimulus below the neurological SCI level. The characteristic symptoms above the neurological level are caused by vasodilation (headache, flushing, sweating, nasal congestion) whereas the symptoms below the neurological level are caused by vasoconstriction (piloerection). Recognition and appropriate management of AD are essential in preventing life-threatening complications of hypertensive crisis as well as identifying underlying disease requiring further treatment.