Autonomic Dysreflexia, also known as Hyperreflexia, is a state that is unique to patients after spinal cord injury at a T-5 level and above. Patients with spinal cord injuries at Thoracic 5 (T-5) level and above are very susceptible. Patients with spinal cord injuries at Thoracic 6 – Thoracic 10 (T6-T10) may be susceptible. Patients with Thoracic 10 (T-10) and below are usually not susceptible. Also, the older the injury the less likely the person will experience autonomic dysreflexia.

Autonomic dysreflexia can develop suddenly, and is a possible emergency situation. If not treated promptly and correctly, it may lead to seizures, stroke, and even death.

Autonomic dysreflexia means an over-activity of the Autonomic Nervous System. It can occur when an irritating stimulus is introduced to the body below the level of spinal cord injury, such as an overfull bladder. The stimulus sends nerve impulses to the spinal cord, where they travel upward until they are blocked by the Lesion at the level of injury. Since the impulses cannot reach the brain, a Reflex is activated that increases activity of the sympathetic portion of autonomic nervous system. This results in spasms and a narrowing of the blood vessels, which causes a rise in the blood pressure. Nerve receptors in the heart and blood vessels detect this rise in blood pressure and send a message to the brain. The brain sends a message to the heart, causing the heartbeat to slow down and the blood vessels above the level of injury to dilate. However, the brain cannot send messages below the level of injury, due to the spinal cord lesion, and therefore the blood pressure cannot be regulated.

Symptoms and Causes

* Pounding headache (caused by the elevation in blood pressure)
* Goose Pimples
* Sweating above the level of injury
* Nasal Congestion
* Slow Pulse
* Blotching of the Skin
* Restlessness

There can be many stimuli that cause Autonomic Dysreflexia. Anything that would have been painful, uncomfortable, or physically irritating before the injury may cause autonomic dysreflexia after the injury.

The most common cause seems to be overfilling of the bladder. This could be due to a blockage in the urinary drainage device, bladder infection (cystitis), inadequate bladder emptying, bladder spasms, or possibly stones in the bladder. The second most common cause is a bowel that is full of stool or gas. Any stimulus to the rectum, such as digital stimulation, can trigger a reaction, leading to autonomic dysreflexia.

Other causes include skin irritations, wounds, pressure sores, burns, broken bones, pregnancy, ingrown toenails, appendicitis, and other medical complications.


Treatment of Autonomic Dysreflexia must be initiated quickly to prevent complications.

* Remain in a sitting position, but do a Pressure Release immediately. You may transfer yourself to bed, but always keep your head elevated.
* Since a full bladder is the most common cause, check the urinary drainage system. If you have a Foley or suprapubic Catheter, check the following:
o Is your drainage full?
o Is there a kink in the tubing?
o Is the drainage bag at a higher level than your bladder?
o Is the catheter plugged?

After correcting an obvious problem, and if your catheter is not draining within 2-3 minutes, your catheter must be changed immediately. If you do not have a Foley or Suprapubic Catheter, perform a catheterization and empty your bladder.

If your bladder has not triggered the episode of autonomic dysreflexia, the cause may be your Bowel. Perform a digital stimulation and empty your bowel. If you are performing a digital stimulation when the symptoms first appear, stop the procedure and resume after the symptoms subside.

If your bladder or bowel are not the cause, check to see if:

* You have a Pressure Sore
* You have an ingrown toenail
* You have a fractured bone.

If you are unable to find the stimulus causing autonomic dysreflexia, or your attempts to receive the stimulus fail, you need to obtain emergency medical treatment. Since not all physicians are familiar with autonomic dysreflexia (Hyperreflexia) and its treatment, you should carry a card in your billfold that describes the condition and the treatment required.


Prevention of Autonomic Dysreflexia is very important. Following are precautions you can take which may prevent episodes:

If you have an indwelling Catheter:

* Keep the tubing free of kinks
* Keep the drainage bags empty
* Check daily for grits (deposits) inside of the catheter.
* If you are on an Intermittent Catheterization program, catheterize yourself as often as necessary to prevent overfilling.
* If you have spontaneous voiding, make sure you have an adequate output.
* Carry spare clothes and an intermittent catheter kit when you are away from home.
* Maintain a regular Bowel program.
* Perform routine skin assessments.
* Have a yearly re-evaluation.


PoinTIS Copyright © 1998 the Louis Calder Memorial Library of the University of Miami/Jackson Memorial Medical Center, all rights reserved.

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