Metabolic neuropathies

Definition

A metabolic neuropathy is a disease of the nerves that is caused by a disruption of the chemical processes in the body. In some cases, nerve damage is caused by the inability to properly use energy in the body. In other cases, dangerous substances (toxins) build up in the body and damage nerves. Some metabolic disorders are pass down through families (inherited), while others are develop due to various diseases.

Causes

Diabetes is one of the most common causes of metabolic neuropathies. Those who have poorly controlled blood sugar are at the highest risk. People who have damage to the kidneys or eyes from diabetes are also more likely to have nerve damage from diabetes.

Other common metabolic causes of neuropathies include:

• Thyroid disease
• Hypoglycemia (low blood sugar)
• Nutritional deficiencies, including vitamin B12, vitamin B6, vitamin E, and vitamin B1 deficiency
• Alcoholism
• Sepsis (severe systemic infection)
• Kidney failure
• Porphyria

Symptoms

The symptoms are due to the inability of nerves to send proper signals to and from your brain:

• Numbness (inability to feel things properly)
• Pain -- burning, pins and needles, or shooting pains
• Loss of coordination
• Clumsy gait
• Weakness

Usually, these symptoms start in the toes and feet and progress up the legs, eventually affecting the hands and arms.

Exams and Tests

Your doctor will test your strength, coordination, and sensation. Abnormal reflexes, weakness, or sensation can indicate that you have a neuropathy.

Blood tests are often used to detect most metabolic neuropathies. In some cases, an electrical test of the nerves called EMG can show how severely the nerves are affected and can indicate if a metabolic disorder is suspected.

Treatment

For most metabolic neuropathies, the best treatment is to correct the underlying metabolic problem. Vitamin deficiencies are treated with an appropriate diet. Abnormal blood sugar or thyroid function may require specific medications to correct the problem.

In some cases, pain is treated with medications that reduce abnormal pain signals from the nerves. Specific lotions, creams, or medicated patches can provide relief in some cases.

Weakness is often treated with physical therapy. Affected patients may need to learn how to use a cane of walker if balance is affected. Special braces on the ankles may be needed to walk better.

Support Groups

For additional information and support, see www.neuropathy.org.

Outlook (Prognosis)

The outlook mainly depends on the underlying metabolic cause. In some cases, the problem can easily be fixed. In other cases, the underlying metabolic problem cannot be adequately controlled and nerves may continue to deteriorate.

Possible Complications

• Pain
• Weakness
• Trouble walking
• Numbness
• Injury to feet

Prevention

Maintaining a healthy lifestyle can reduce the risk of neuropathy. Avoid excess use of alcohol and eat a balanced diet. Regular doctor visits can detect many metabolic disorders before neuropathy develops.

If you already have a metabolic problem, regular doctor visits can help control the problem and reduce the chance of further nerve damage.

Patients who already have metabolic neuropathy can reduce the risk of some complications. A podiatrist can teach patients about inspecting their feet for signs of injury and infection. Proper fitting shoes can lessen the chance of skin breakdown in sensitive areas of the feet