Autonomic neuropathy is a group of diseases and syndromes that cause damage to the nerves. It often affects the nerves of the heart, gastrointestinal (GI) tract, circulatory system, and bladder. This results in problems with digestion, heart rate, and blood pressure. It can also lead to incontinence and abnormal body temperature.
The condition can be caused by prolonged alcohol abuse and certain infections, such as HIV and AIDS. It can also occur in patients who were born with nerve disorders. Another common cause is diabetes. This is a chronic disease marked by high levels of blood glucose (blood sugar). It damages the blood vessels that feed the nerves. Without enough supply of oxygen and nutrients, the nerves will start to malfunction. This causes them to lose their ability to send signals to and from the brain. This prevents certain organs and muscles from carrying out their normal functions.
There is no cure for the condition. This is because damage to the nerves caused by diabetes is often permanent. However, there are available treatments to manage its symptoms.
Causes of Condition
Diabetic autonomic neuropathy (DAN) is one of the most common complications of diabetes. Patients who are at most risk are those who have had the disease for at least 25 years. Those who are unable to keep their blood sugar levels under control are also prone to the condition. Other factors that can increase the risk of DAN are high blood pressure, high cholesterol levels, and obesity.
Symptoms of DAN depend on which nerves are affected. These include:
Digestive problems - Damage to the nerves along the GI tract results in digestive problems. The condition can slow down the flow of food and faecal matter in the GI tract. As such, patients often feel full after eating only a small meal. They are also prone to constipation and abdominal pain. DAN is also one of the causes of gastroparesis. This disorder is marked by the stomach’s inability to empty its contents completely.
Heart-related symptoms - DAN can cause damage to the nerves of the heart and circulatory system. This can result in a sudden drop of blood pressure. The patient’s heart may also beat either too fast or too slow. DAN can cause a silent heart attack, or when a person has a heart attack without showing any signs of it. Due to the lack of symptoms, most patients do not seek treatment. This is a cause for concern because it can cause permanent damage to the heart. It can also lead to death.
Sweating abnormalities - A patient with DAN can sweat either too much or too little. This can affect the body’s ability to regulate temperature. It also increases the risk of heatstroke and hypothermia.
Urinary and sexual problems - DAN can also damage the nerves of the bladder and sex organs. This can cause incontinence and urinary tract infections (UTIs). Male patients may also suffer from erectile dysfunction. Female patients, on the other hand, may experience vaginal dryness.
Who to See and Types of Treatments Available
Nerve damage caused by DAN is often permanent. As such, there is no cure for it. For this reason, patients with diabetes are strongly advised to prevent it from occurring. The key is keeping their blood sugar levels under control all the time. This can be achieved with insulin therapy and making healthy lifestyle changes. It is very important for patients to exercise regularly and eat a balanced diet. They must also commit to annual DAN screening. This can help diagnose the condition in the early stages. This is key to preventing it from progressing.
Diabetic patients showing signs of DAN often do not need to undergo several tests to get a diagnosis. Diabetes specialists (endocrinologists) may only perform a physical exam and ask about their symptoms.
Treatment of DAN focuses mainly on providing symptom relief. This is often done using medications. The goals of medical treatment are to:
Ensure patients are able to empty their stomach completely - Signs of nerve damage to the GI tract can be treated with medications that make the abdominal muscles contract. This allows food in the GI tract to flow smoothly. Such medications can also treat constipation and vomiting.
Treat infections - When food and faecal materials stay in the GI tract longer than they should, patients become more prone to infections. In such cases, they are given antibiotics.
Help patients empty their bladder - Medications used to empty the bladder can also be prescribed. This helps patients avoid urine leakage. The bladder can also be emptied by inserting a tube through the urethra.
Improve sexual function - Medications, such as Viagra, can help men with DAN enable and sustain erections. Vaginal lubricants, on the other hand, can address vaginal dryness among female patients.
Regulate blood pressure - If needed, patients are prescribed with medications that they can take if their blood pressure suddenly increases or drops. Beta-blockers can also be prescribed to regulate heart rate.
Patients undergoing treatment for DAN must work closely with their doctors. Their body’s response to treatment should be monitored regularly in relation to side effects and symptoms. Doctors may need to make adjustments from time to time to improve treatment outcomes.
The prognosis for patients with DAN depends on how well their diabetes is managed. Improvement in blood glucose levels can slow down the progression of the disease. However, recovery is often very slow. The condition is associated with increased mortality, especially when the nerves of the heart are affected. Many patients with this condition can die from a silent heart attack.
Benarroch E, Freeman R, Kaufman H. Autonomic nervous system. In: Goetz CG, eds. Textbook of Clinical Neurology. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 21.
Ohto T, Iwasaki N, Fujiwara J, et al. The evaluation of autonomic nervous function in a patient with hereditary sensory and autonomic neuropathy type IV with novel mutations of the TRKA gene. Neuropediatrics. 2004 Oct. 35(5):274-8.