Definition Diabetic neuropathy is an injury to the peripheral nervous system caused by underlying diabetes mellitus.
What is going on in the body? The exact mechanism of injury is not known, but it is suspected that high blood glucose levels are neurotoxic, or have a poisonous effect on the nerves.
What are the signs and symptoms of the disease? Half of all individuals with diabetes have some evidence of neuropathy. Symptoms may include a number of different syndromes:
paralysis of the eye muscles, with double vision
acute damage to a nerve of the limbs or trunk, producing weakness or numbness
neuropathy of the nerves involved in body movements, producing pain and weakness
muscle wasting without pain
neuropathy in both legs or both arms, producing numbness and at times burning
neuropathy affecting bowel or bladder function and circulatory reflexes
neuropathy producing pain in the chest or abdomen
What are the causes and risks of the disease? Diabetic neuropathy is a complication of diabetes mellitus.
What can be done to prevent the disease? Keeping blood glucose levels as close to normal as possible helps limit the degree of peripheral nerve injury.
How is the disease diagnosed? Diabetic neuropathy can be diagnosed by electromyography (EMG) studies, which record electrical impulses in muscles, and nerve conduction velocity (NCV) studies, which measure the speed of nerve impulses.
What are the long-term effects of the disease? Motor involvement may produce progressive wasting and weakness. Sensory involvement may produce progressive numbness, which is sometimes painful. In extreme cases, sensory involvement can lead to amputation because of failure to detect injuries and poor healing caused by poor circulation.
What are the risks to others? Diabetic neuropathy is not associated with risk to others.
What are the treatments for the disease? Control of blood glucose levels helps limit nerve injury. Painful neuropathy may require treatment with analgesics, as well as various medications used to control painful neuropathies, such as valproate, carbamazepine, mexiletine, and amitriptyline. Physio and occupational therapies are helpful for treatment of motor involvement.
What are the side effects of the treatments? The medications used to treat painful neuropathies have various side effects.
What happens after treatment for the disease? Some neuropathies, such as diabetic ophthalmoplegia, or eye muscle paralysis, can improve and resolve, but many neuropathies progressively worsen at variable speeds.
How is the disease monitored? A doctor needs to monitor diabetic neuropathy. Repeat electromyography and nerve conduction velocity studies may be required.
Author: Michael Curiel, MD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 28/02/2005 Contributors Potential conflict of interest information for reviewers available on request
