If you have had diabetes for more than 10 years and you have not kept your blood glucose levels close to near-normal levels, you probably have some symptoms of peripheral neuropathy. It is a condition that affects to 75% of all people with diabetes.
What is peripheral neuropathy?
“Peripheral” means at the edges or away from the center. “Neuro” means nerves and “pathy” means “a disorder of”. Thus, peripheral neuropathy is the name for damage to motor and sensory nerves, the ones that help you move and touch the world around you.
You can think of the nervous system as the electrical system in your house. The fuse box and the main cable would be the central nervous system (the brain and spinal cord). The wires to the lights and appliances would be the peripheral nerves.
Because the longest nerves are usually affected first, symptoms such as tingling, burning, or numbness appear first in the feet and hands.
Diabetes can cause more than one kind of neuropathy
Diabetic nerve damage can affect three kinds of nerves in your body:
Nerves you feel with (sensory neuropathy). With sensory nerve damage you may not be able to feel heat and cold and may have tingling, pain, or numbness. You may not be able to sense where your feet and be more likely to fall.
Nerves that go to the muscles (motor neuropathy). With motor nerve damage, muscles are weakened and you are more likely to develop foot deformities such as hammertoes.
Nerves that control automatic body activities such as blood flow and digestion (autonomic neuropathy). Damage to autonomic nerves can affect major systems in your body, such as the heart, stomach, or sexual organs. It can affect heart rate and blood pressure. This type of nerve damage can also interfere with the functioning of your bladder, eyes, sweat glands, and cause hypoglycemia.
How do you know if you have peripheral neuropathy?
Look for these symptoms:
Do you have muscle weakness, cramps?
Do you have feelings in your feet and legs such as numbness, tingling, pins and needles, and burning sensations?
Do your feet bother you more at night?
Have you had any episodes of fainting or vomiting?
Have you had a change in bowel habits?
Have you noticed a change in bladder control or sexual functioning?
All these systems can be affected by diabetic nerve damage.
What kind of tests detects peripheral neuropathy?
If you have feelings of numbness, tingling, pain, or if these symptoms are worse at night, you probably know or suspect you have neuropathy. However, you could have neuropathy from a cause other than diabetes, such as:
Poisons (alcohol, lead, mercury, or arsenic)
Your doctor needs to make sure that you do not have any of these other problems.
One of the most common tests for neuropathy is for your doctor to touch your feet with a plastic wire called a monofilament. If you cannot feel the wire, you are considered to have nerve damage. Similar tests check if you can feel a pin prick, or the vibration of a tuning fork.
If there is confusion about the nerve damage, some people may need a nerve conduction study (NCS). An NCS measures the speed of an impulse traveling along a nerve. Two small surface electrodes are placed over a particular nerve. A series of mild electrical impulses will then be given in this area. When stimulated, the patient feels a slight tingling sensation.
The time it takes for the impulse to travel from one spot to another will be recorded. A neurologist specializing in neuro-diagnostic medicine evaluates the data collected. (Description of process by North Shore Medical Center, Neuro-diagnostic Laboratories).
On rare occasions, a nerve biopsy in which a small piece of nerve tissue is examined under a microscope is done. If you are asked to have tests for neuropathy, ask your doctor to explain the tests to you.
How does diabetes cause nerve damage?
It seems almost certain that levels of blood glucose higher than normal are part of the cause. We do know the following:
Keeping your blood sugar near normal levels can lower your chances of getting neuropathy.
People with high blood sugar are more likely to have neuropathy.
The longer a person has diabetes, the more likely he or she is to have neuropathy.
There are several theories about how blood sugar affects nerves:
It is possible that sugar coats the proteins in the nerves and that the proteins sugar-coated no longer function normally.
It could be that high blood sugar levels interfere with chemical events in the nerves.
Maybe high blood sugar levels damage the insulation layer of cells around the nerves.
It might be that high blood sugar levels damage the tiny blood vessels that supply the nerves. Then the nerves would not get enough oxygen and nutrients, and this could cause problems.
Are there any treatments for peripheral neuropathy?
The best treatment is to get your blood sugar under control. Studies show that good blood sugar control can also help prevent the nerve damage that you already have from getting worse.
Different treatments have been used to treat neuropathy symptoms. Among them we find the following medications:
Evening primrose oil
Physical therapy treatments include:
Electrical nerve stimulation
Although studies of these treatments report some improvement in painful symptoms for some patients, there is no single treatment that works for everyone. It may be difficult to get complete relief.
Although researchers are working to understand the causes of neuropathy and to find treatments to avoid the damage it does, remember that a way to prevent nerve damage or stop its progression is by having good control of your blood sugar. Having blood glucose levels near normal can spare you from a lot of suffering.