Diabetic Neuropathy

Definition

Diabetic neuropathy is a nerve disorder and its many complications that are caused by diabetes.

Description

People who have had diabetes for years may experience numbness and sometimes pain in their hands, feet and legs. Nerve damage caused by diabetes can also lead to problems with indigestion, diarrhea or constipation, dizziness, bladder infections and impotence. In some cases, damaged nerves can strike suddenly, causing pain, weakness and weight loss. Depression may follow.

While some treatments are available, a great deal of research still needs to be done to understand how diabetes affects the nerves and to find better treatments for this complication. Nerve problems can affect anybody with diabetes, but they are most common in people who have had diabetes for more than 10 years. The majority of patients with neurological impairment due to diabetes do not have symptoms, such as pain or numbness. However, some studies have reported the following:

• 10 years after diagnosis, 30 percent of diabetes patients have symptoms or signs of diabetic neuropathy;

• 25 years after diagnosis, 40 percent of diabetes patients have symptoms or signs of neuropathy;

• 50 years of diagnosis, 50 percent of diabetes patients have symptoms or signs of neuropathy.

Causes and Risk Factors

Scientists do not know how diabetic neuropathy occurs, but it is likely that several factors come into play. High blood glucose causes chemical changes in nerves, impairing their ability to transmit nerve signals. High blood glucose also damages blood vessels that carry oxygen and nutrients to the nerves. Also, inherited factors probably unrelated to diabetes may make some people more susceptible to nerve disease than others.

Diabetic neuropathy appears to be more common in smokers, people over 40 years of age, and those who have had problems controlling the levels of glucose in their blood.

Symptoms

Types Of Diabetic Neuropathy

Doctors divide diabetic neuropathy into three main types:

Peripheral Neuropathy (also called "somatic neuropathy" or "distal sensory polyneuropathy"). The most common type of neuropathy, peripheral neuropathy can affect any of the nerves that transmit sensation throughout the body. However, the nerves of the limbs, and especially the feet, seem affected most often. Peripheral neuropathy usually involves nerves on both sides of the body. Some of the most common symptoms of this kind of neuropathy are:

• numbness or insensitivity to pain or temperature

• tingling, burning, or prickling

• sharp pains or cramps

• extreme sensitivity to touch, even very light touch

Mononeuropathy (including "multiplex neuropathy") is isolated peripheral neuropathy, involving the distribution of only one or a few nerves. Occasionally, diabetic neuropathy appears suddenly and affects specific nerves, most often in the torso, leg or head. When mononeuropathy occurs, it may cause:

• pain in the front of the thigh

• severe pain in the lower back or pelvis

• chest or abdominal pain sometimes mistaken for angina, heart attack, or appendicitis

• aching behind the eye

• inability to focus the eye

• double vision

• paralysis on one side of the face (Bell's palsy)

• problems with hearing

This kind of neuropathy is unpredictable and occurs most often in older people who have mild diabetes. Although mononeuropathy can be very painful, it tends to improve by itself after a period of weeks or months without causing long-term damage.

Autonomic Neuropathy (also called "visceral neuropathy"). Autonomic neuropathy is usually found in people who already have peripheral neuropathy. Autonomic neuropathy affects the nerves that supply the heart and internal organs and produces changes in urination, sexual response, digestion, and the cardiovascular system.

Autonomic neuropathy most often affects the organs that control urination and reproduction. Nerve damage prevents the bladder from emptying completely, so bacteria grow more easily in the urinary tract (bladder or kidneys). When the nerves of the bladder are damaged, it may be difficult to control the bladder or to know when it is full.

The nerve damage and circulatory problems of diabetes can also lead to frequent vaginal infections and a gradual loss of sexual sensation or response in both men and women, although sex drive is unchanged. Many men may be unable to have erections or may reach sexual climax without ejaculating normally.

Autonomic neuropathy also can affect how food is digested. Nerve damage can cause the stomach to empty too slowly, a disorder called gastroparesis. When the condition is severe (gastroparesis), a person can have persistent constipation, nausea and vomiting, bloating and loss of appetite. Blood glucose levels tend to fluctuate wildly.

Diagnosis

Diagnosis is often based on medical history, symptoms, and a thorough physical examination.

Treatment

Treatment aims at relieving discomfort and preventing further tissue damage.

The first step is to bring blood sugar under control by diet and oral drugs or insulin injections, if needed. Although symptoms can sometimes worsen as blood sugar is brought under control with intensive treatment, careful long-term monitoring of blood sugar may help reverse the pain or loss of sensation that neuropathy can cause. Good control of blood sugar with diet and if necessary, drug therapy, may also help prevent or delay the onset of further problems.

Another important part of treatment involves special care of the feet, which are especially prone to problems in people with diabetes. Since the nerves to the feet are the longest in the body, they are most often affected by neuropathy. At least 15 percent of all people with diabetes eventually have a foot ulcer, and at least 6 out of every 1,000 lose a limb to infection. However, doctors estimate that nearly three quarters of all amputations caused by neuropathy can be prevented with careful foot care.

If you have this condition, every day you should check your feet and toes for any cuts, sores, bruises, bumps or infections - using a mirror if necessary. Since diabetic neuropathy often causes numbness, you may be able to see injuries before you feel any discomfort. Also, poor circulation may cause infections to heal more slowly.

Your physician can discuss with you specific treatments for other complications of diabetic neuropathy, including options to treat gastroparesis (and digestive problems) and impotence.

Prevention

Maintaining optimal control of diabetes is the best way to prevent, or at least delay, the onset of diabetic neuropathy.

Questions to Ask Your Doctor

Does the numbness and pain occur slowly or is it a sudden onset?

What can be done to help prevent diabetic neuropathy?

How soon should a doctor be seen if neuropathy symptoms occur?

Are there any drugs that will help prevent neuropathy?

Are there any exercises that can be done to help reduce or prevent neuropathy?

Should a podiatrist be seen if there is evidence of peripheral neuropathy?

How should I care for my feet if I have diabetes? What should I do daily?

How do I treat corns and calluses?

How do I treat cold feet due to impaired circulation?