Autonomic Neuropathy

What is Autonomic Neuropathy?

Autonomic neuropathy occurs when the nerves that control involuntary bodily functions are damaged. The nerve damage interferes with the messages sent between the brain and other organs and areas of the autonomic nervous system, such as the heart, blood vessels and sweat glands. This may affect blood pressure, temperature control, digestion, bladder function and even sexual function. 

While diabetes is generally the most common cause of autonomic neuropathy, other health conditions — even an infection — may be to blame. Some medications also may cause nerve damage. Symptoms and treatment will vary based on which nerves are damaged.

 

Signs and symptoms of autonomic neuropathy vary based on the nerves affected. They may include:

  • Dizziness and fainting when standing caused by a sudden drop in blood pressure.

  • Urinary problems, such as difficulty starting urination, incontinence, difficulty sensing a full bladder and inability to completely empty the bladder, which can lead to urinary tract infections.

  • Sexual difficulties, including problems achieving or maintaining an erection (erectile dysfunction) or ejaculation problems in men and vaginal dryness, low libido and difficulty reaching orgasm in women.

  • Difficulty digesting food, such as feeling full after a few bites of food, loss of appetite, diarrhea, constipation, abdominal bloating, nausea, vomiting, difficulty swallowing and heartburn, all due to changes in digestive function.

  • Sweating abnormalities, such as sweating too much or too little, which affects the ability to regulate body temperature.

  • Sluggish pupil reaction, making it difficult to adjust from light to dark and seeing well when driving at night.

  • Exercise intolerance, which may occur if your heart rate stays the same instead of adjusting in response to your activity level.

Many health conditions can cause autonomic neuropathy. It may also be a side effect of treatments for other diseases, such as cancer. Some common causes of autonomic neuropathy include:

 

  • Abnormal protein buildup in organs (amyloidosis), which affects the organs and the nervous system.

  • Autoimmune diseases, in which your immune system attacks and damages parts of your body, including your nerves. Examples include Sjogren's syndrome, systemic lupus erythematosus, rheumatoid arthritis and celiac disease. Guillain-Barre syndrome is an autoimmune disease that happens rapidly and can affect autonomic nerves.

    Autonomic neuropathy may also be caused by an abnormal attack by the immune system that occurs as a result of some cancers (paraneoplastic syndrome).

  • Diabetes, which is the most common cause of autonomic neuropathy, can gradually cause nerve damage throughout the body.

  • Injury to nerves caused by surgery or radiation to the neck.

  • Treatment with certain medications, including some drugs used in cancer chemotherapy.

  • Other chronic illnesses, such as Parkinson's disease, multiple sclerosis and some types of dementia.

  • Certain infectious diseases. Some viruses and bacteria, such as botulism, Lyme disease and HIV, can cause autonomic neuropathy.

  • Inherited disorders. Certain hereditary disorders can cause autonomic neuropathy

 

Factors that may increase your risk of autonomic neuropathy include:

 

  • Diabetes. Diabetes, especially when poorly controlled, increases your risk of autonomic neuropathy and other nerve damage. You’re at greatest risk if you have had the disease for more than 25 years and have difficulty controlling your blood sugar, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

    Additionally, people with diabetes who are overweight or have high blood pressure or high cholesterol have a higher risk of autonomic neuropathy.

  • Other diseases. Amyloidosis, porphyria, hypothyroidism and cancer (usually due to side effects from treatment) may also increase the risk of autonomic neuropathy.

Sources:

http://www.ncbi.nlm.nih.gov/pubmed/12530507

https://www.mayoclinic.org/diseases-conditions/autonomic-neuropathy/symptoms-causes/syc-20369829

Image Source: Blausen.com staff. "Blausen gallery 2014". Wikiversity Journal of Medicine. DOI:10.15347/wjm/2014.010. ISSN 20018762. (Own work) [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons