It is pretty common for people, doctors and patients alike, to call many symptoms you may be having in your arms or legs “neuropathy.” To understand neuropathy, think of the nerves in your arms and legs as electric cords connecting your extremities to your spinal cord. Not only do they carry sensation from the arms and legs to the spinal cord, but they also carry directions on how to move from brain and spinal cord to your muscles. Just like electric cords, the nerves have a wire in the center and insulation around the wire, both of which are needed to transmit the signals. Neuropathy is when damage occurs to these electric cords, whether to the wire, the insulation, or both.
So many different things can cause neuropathy that it is more helpful to think of them in terms of groups. Abnormal levels of hormones or other substances in the blood, vitamin or nutrient deficiencies, inflammatory diseases, certain medications, and primary neurologic conditions can all be the cause of neuropathy.
The most common cause of neuropathy overall is diabetes. Having high blood sugars can injure the nerves and to the blood vessels that supply them, damaging the wire as well as the insulation of the nerve. Liver disease and kidney disease can cause abnormalities in the blood that damage the nerves as well. Thyroid disease can also cause neuropathy.
Vitamin B12 deficiency is the most common nutritional cause of neuropathy. Vitamin B1 deficiency, vitamin E deficiency, copper deficiency, and too much vitamin B6 can also cause damage to the nerves. Alcohol can deplete a lot of these nutrients and is another common cause of neuropathy.
Additionally inflammatory diseases can cause neuropathy. Autoimmune conditions such as lupus, rheumatoid arthritis, Sjogren disease, celiac disease, and abnormal blood proteins such as in multiple myeloma can all cause neuropathy.
Chemotherapy medications, medications that can treat gout, medications that can treat abnormal heart rhythms, and medications that treat seizures can all cause neuropathy. Many other medications can also damage the nerves. Please check with your prescribing doctor if you think any of these medications may be worsening your neuropathy.
Some people are born with neuropathy due to their genes, such as patients with Charcot-Marie-Tooth disease. Other patients develop neurologic conditions that can damage the nerves, such as Guillain-Barre syndrome or chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).
Neuropathy is common, affecting about 25 – 30% of Americans and nearly 2 in 3 people with diabetes. Symptoms depend on the types of nerve fibers that are injured and include:
A neurologist may suspect neuropathy based on your history and examination. The doctor may refer you for an EMG, a test that checks the health of your nerves and muscles. The EMG can be helpful in determining what nerves are damaged, how severe the damage is, whether the damage is to the wire or the insulation, whether the damage is to the nerves that carry sensation or signals to muscles, and how long the damage has been occurring. Different causes of neuropathy look different on EMG, and the results of this test can help your doctor diagnose the cause of your neuropathy.
How do we classify neuropathy?
The treatment of neuropathy depends on the cause. Neuropathy is often a sign of another condition rather than a disease on its own, and treating the condition that is causing it is usually the best way to treat neuropathy.
Possible treatment options for neuropathy:
The nerves do have an ability to regenerate. However, to help with that regeneration, we have to take away what is damaging them. In a patient with vitamin B12 deficiency, this treatment is as simple as having the patient take a B12 supplement, which may be enough to make the symptoms better. In a patient with kidney disease or diabetes, we can limit the damage by keeping the kidneys healthy or the sugars well controlled to the best of our abilities. In a patient with an inflammatory condition causing neuropathy, we can try to treat the disease by reducing inflammation, which may help the nerves regenerate.
Physical therapy can be helpful in training our body to make the most of the nerve function that remains. Physical therapy can also be very helpful for balance difficulties that may come with neuropathy.
Certain medications can help ease the burning pain that may come with neuropathy. If you are experiencing significant pain in your hands and feet, please ask your doctor if there are any treatment options.
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Reviewed by: Dr. Christopher Good, MD, FACS.