Autonomic Dysreflexia


Autonomic dysreflexia is a response to painful stimuli below your spinal cord lesion that you cannot feel, but your body recognizes as painful. Autonomic dysreflexia can occur if you have a spinal cord lesion above T6. The intact portions of your nervous system respond by constricting your blood vessels and increasing your blood pressure. Other parts of your body sense the increase in blood pressure and try to counteract the change by slowing your heart rate and sending signals to tell your blood vessels to relax. Unfortunately, these signals can't pass through your spinal cord lesion. So your body keeps slowing your heart and sends a flood of signals to your blood vessels, while your blood pressure continues to rise.


What can Trigger Autonomic Dysreflexia?


Some of the stimuli that may trigger autonomic dysreflexia are as follows:

  • Distended bladder or rectum (too full)
  • Pelvic, rectal, or urologic exam
  • Uterine contractions, especially during labor and delivery
  • Urinary tract infection
  • Pelvic infection
  • Pressure ulcer
  • Clots in your leg veins

What are symptoms of autonomic dysreflexia?


During autonomic dysreflexia, you may experience some or all of the following symptoms, depending on the level of spinal cord injury and the severity of the trigger:

  • very high blood pressure - the systolic (top number) may be greater than 300
  • slow heart rate
  • blurred vision
  • throbbing headache
  • sweating
  • flushing
  • erection of body hair
  • nasal congestion
  • increased spasticity
  • nausea

The full-blown syndrome can be avoided if early warning signs such as flushing, sweating, and increased spasticity are heeded and the cause removed.


What Kind of Intervention is Necessary?


These symptoms can become life threatening, so intervention is critical.

If you are being examined by a health care provider when these symptoms begin, let her know what you are feeling and demand that the examination stop. The stimulus may be causing the problem. You may be able to alleviate some of the symptoms by having the head of your bed elevated by 45 degrees, your clothing loosened, and your shoes removed. If your bladder is distended, you may need immediate catheterization. Your health care provider may give you drugs to control the symptoms.

If you have had dysreflexia in the past, let the health care provider know in advance. You should not be left alone at any time. Once symptoms start, you may not have enough breath to tell anyone. Medication can then be prepared in advance to administer if needed. A nurse should check your blood pressure every few minutes during the exam. If your blood pressure rises, the exam should stop immediately.

Be sure to alert your obstetrician that you are susceptible to autonomic dysreflexia if you become pregnant. These episodes may increase during pregnancy. Pregnant women with spinal cord injury have died during labor and delivery because the physician misdiagnosed their dysreflexia as preeclampsia, which also presents with rising blood pressure. The treatment for these two conditions is very different.


Fact Sheet with Wallet Card


The Model Systems Knowledge Translation Center recently released a fact sheet on autonomic dysreflexia that includes a wallet card you can carry with you at all times. In case of an emergency, this card can alert medical providers you are at risk of this condition and what to do if they recognize symptoms. We've posted the English version for you to the right to download and a Spanish version is also available.