Diabetic Neuropathy

Diabetes mellitus, often called diabetes, is a condition that affects the body's ability to regulate the level of glucose in the blood. Glucose is the main form of sugar in the body.

It is suspected that a high concentration of glucose is neurotoxic, that is, that it damages the nerve cells. If blood sugar levels are elevated significantly for a period of time, the damage can be permanent.

Some evidence of neuropathy is present in 60% of all individuals with diabetes. Thirty to 40 percent of those individuals have not yet developed symptoms.

When symptoms do occur, they may include any or all of the following:

• abdominal distress
• back pain
• chest pain
• constipation or diarrhea
• diminished sexual response and erectile dysfunction
• dizziness
• extreme sensitivity to touch
• gastroparesis, a condition in which the stomach empties too slowly
• hearing impairment
• heart attack
• loss of balance and coordination
• nausea and vomiting
• numbness or burning in the hands, feet, and legs
• orthostatic hypotension, or a drop in blood pressure when standing up
• problems with urination that lead to urinary tract infections
• visual impairment, including double vision
• weakness

Diabetic neuropathy is a complication of high blood glucose in people who have diabetes.

A 10-year study by the National Institute of Diabetes and Digestive and Kidney Diseases showed that blood sugar control is key in preventing diabetic neuropathy. People who kept their blood sugar levels as close to the normal range as possible were able to delay the onset and progression of neuropathy.

Diabetic neuropathy is also more common in people who are more than 40 years old, and in those who smoke. Because some people are more susceptible to nerve damage than others, a genetic predisposition to the condition is suspected.

The diagnosis of diabetic neuropathy begins with a medical history and physical exam. The healthcare provider may order tests such as the following:

• blood glucose tests
• electromyography (EMG) studies, which record electrical impulses in muscles
• nerve biopsies to look for nerve damage
• nerve conduction velocity (NCV) studies, which measure the speed of nerve impulses
• screening tests to measure sensation in the feet
• ultrasounds to look for damage to internal organs

If diabetic neuropathy is not treated effectively, it can have devastating effects. Muscles may waste and become weak. Sensory involvement may produce progressive numbness and pain. In extreme cases, lack of sensation can result in lead to diabetic ulcers and amputation because the person fails to protect him- or herself from an injury that would normally be painful.

Diabetic neuropathy is not contagious, and poses no risk to others.

Good control of blood sugar levels prevents further nerve damage and can reverse the pain or numbness. Treatment for pain caused by diabetic neuropathy includes the following therapies:

• acupuncture
• biofeedback
• hypnosis
• massage
• physical and occupational therapies for treatment of motor involvement
• regular moderate walking
• relaxation training
• transcutaneous electronic nerve stimulation (TENS), which uses small bursts of electricity to block pain signals
• warm baths
• wrapping the legs in elastic stockings

The following medications may be used for treatment of pain caused by diabetic neuropathy:

• antidepressant medications, such as amitriptyline (i.e., Elavil) and an antipsychotick medication, fluphenazine (i.e., Prolixin), to relieve pain
• capsaicin (i.e., Zostrix), a topical cream that helps relieve pain
• codeine, a powerful narcotic, for short term relief of severe pain
• medications commonly used for seizures, which may relieve nerve pain. These include carbamazepine (i.e., Carbatrol, Equetro, Tegretol) and phenytoin sodium (i.e., Dilantin, Phenytek).
• over-the-counter analgesic ointment
• pain medications for burning, tingling, or numbness. These include aspirin, acetaminophen (i.e., Tylenol), and ibuprofen (i.e., Advil, Motrin).
• newer medications designed to decrease the perception of pain

Gastroparesis may be treated by taking the following steps:

• Avoid excess fat in the diet.
• Eat less fiber.
• Eat small, frequent meals.

Medications that can be used in the treatment of gastroparesis are as follows:

• erythromycin, an antibiotic
• medications that reduce excess stomach acid
• metoclopramide, a medication that speeds digestion

Diarrhea and other intestinal problems may be treated with the following:

• antibiotics, such as tetracycline
• clonidine, a medication normally used to treat high blood pressure
• a wheat-free diet, since diarrhea can be caused by gluten in wheat flour

Antibiotics are used to treat urinary tract infections. The affected person may be taught to empty the bladder frequently. He or she may be advised to increase fluid intake. Men who have erectile dysfunction may be treated with medication, or sometimes with a penile implant. Counseling may be helpful to reduce stress

Antibiotics and other medications may cause stomach upset or allergic reactions.

Good control of blood sugar levels is important. It can help prevent the onset and progression of neuropathy. Once sensation is impaired to an area, the person will need to be careful to avoid injury. Good diabetic foot care, for example, is especially important if the feet are numb.

The individual and his or her healthcare provider can monitor diabetic neuropathy. Repeat electromyography and nerve conduction velocity studies may be helpful. Any new or worsening symptoms should be reported to the healthcare provider.