autonomic dysreflexia, a syndrome affecting persons with a spinal cord lesion above the midthoracic level (tetraplegics and some paraplegics) that is characterized by hypertension, bradycardia, severe headaches, pallor below and flushing above the cord lesions, and convulsions. It is the result of impaired function of the autonomic nervous system caused by simultaneous sympathetic and parasympathetic activity, such as may occur with bowel or bladder distension pain or a pressure ulcer. It is usually a medical emergency requiring care in an intensive care unit. A cerebrovascular accident and death may occur during an attack. Also called autonomic hyperreflexia.
