Peripheral neuropathy is a disorder characterized by damaged nerves that transmit sensations to the central nervous system, which includes the spinal cord and brain. The peripheral nerves that are affected first are usually in the hands and feet. Unfortunately, the problem can evolve and cause foot ulcers, amputations, and death.
Peripheral neuropathy can have a variety of causes. The Pharmacological Reference Guide ( The Physicians’ Desk Reference ―PDR―) includes a list of more than 60 drugs that can cause neuropathy. Alcoholics can also develop neuropathy as a result of alcohol’s toxic effect on the nerves. However, the most common cause of peripheral neuropathy is diabetes. When the cause is determined to be diabetes, the problem is called diabetic peripheral neuropathy (DPN), the main topic of this article.
Although DPN affects between 50 and 60 percent of people with diabetes, it is also one of the lesser-known complications of the disease. While there has been much speculation about the cause of this nerve damage, most experts agree to blame the repeated spike in blood sugar. The longer a person stays with high blood sugar, the more likely they are to develop DPN.
Types of DPN
The three types of DPN are motor, autonomic, and sensory.
Motor neuropathy affects the muscles, weakening, and deteriorating them. In turn, a muscular imbalance in the feet can lead to contractures and deformations, such as hammertoe. Unfortunately, foot deformities, such as hammertoe and bunions, are a major risk factor for added complications in people with diabetes. Therefore, these deformations require special care and it is vital to go to the podiatrist’s office.
Autonomic neuropathy in the feet reduces sweating, which dries and cracks the skin. These cracks can be portals for bacteria, which can cause infections and must be treated quickly and aggressively. People with autonomic DPN should hydrate their feet regularly, about twice a day. If over-the-counter preparations do not work, your podiatrist (everyone with diabetes should have a podiatrist) may suggest or prescribe an alternative product.
Sensory neuropathy causes the person to feel no pain at all or to feel too much pain in the affected area. If sensitivity is decreased due to peripheral neuropathy, second-order trauma to the skin may not be seen and therefore not treated. As a result, the skin could ulcerate and become infected. It is a common precursor to amputations.
Sometimes, especially in the early phase of DPN, pain occurs rather than decreased sensation. The pain may manifest as intense burning, a dull aching sensation, or as sharp, stabbing, and sudden jerks. Pain is a serious symptom that can affect all aspects of a person’s life. Many people claim that the pain is worse at night and that it can affect sleep.
Diagnosis and treatment
A doctor can confirm a diagnosis of DPN with a series of neurological exams. The doctor can check the person’s ability to feel the gentle touch of a monofilament fiber (similar to a fishing line) and the thermal sensation, evaluate the patient’s ability to feel vibrations with a tuning fork or an electric vibrating machine, or also You can perform nerve conduction studies that record the transmission time of an electrical stimulus through a nerve.
If you have diabetes and are concerned about these symptoms, your doctor will offer you several treatment options. First, most doctors agree that the first step in preventing or treating PDN is optimal blood glucose control. Let your doctor know that you want to closely monitor your diabetes and ask for their advice. Treatment may consist of diet, exercise, and medication. Checking your blood glucose levels several times a day can tell you if you are on the right track. For such control to be rigorous, it may also be necessary to consult an endocrinologist, a doctor who specializes in the treatment of diabetes.
Burning or tingling on the skin of the feet is caused by nerve damage that occurs in or under the skin. If the problem is mild, I usually suggest a very conservative treatment with a topical product, such as BenGay or Biofreeze.
In case the pain persists, the next step I recommend is to try a cream that contains capsaicin. Since capsaicin is made from chili, the first few applications may cause increased burning. However, for improvement to occur, the patient must continue to apply it despite discomfort. It should be applied three to four times a day and it usually takes two to four weeks to see if it has worked. Personally, I have seen amazing results with this topical preparation.
There is another topical medicine that contains lidocaine, a local anesthetic, and can be found in the form of patches (Lidoderm). Wearing these patches for 12 hours a day reduces pain in some patients.
If pain persists, I prescribe oral medications, such as gabapentin (Neurontin) or carbamazepine (Tegretol) – both were originally used for seizures – or pregabalin (Lyrica), a fairly new medication indicated to treat pain from DPN or pain caused by herpes. With pregabalin, results are usually seen in the first week of treatment. In case your kidneys are not working well, which is a common problem in people with diabetes, it is necessary to reduce the dose of this drug. Another recent drug that seems promising in the treatment of PDN is duloxetine (Cymbalta).
Shooting pain or tingling is usually treated with oral medications given as first-line therapy. In addition to the drugs mentioned above, antidepressants, such as amitriptyline (Elavil), have proven to be very helpful. However, caution should be exercised with these drugs as their side effects (headaches, dry mouth and dizziness when standing) can be bothersome, especially for older people.
Non-steroidal anti-inflammatory drugs (NSAIDs) do not appear to work well and, in the long term, may cause gastrointestinal (GI) problems, including GI bleeding.
Narcotic pain relievers, such as oxycodone (OxyContin), work well but also have side effects, such as nausea and constipation. Tramadol (Ultram) has also been shown to be effective in relieving the pain of PDN. Some professionals have also used dietary supplements, such as alpha-lipoic acid and primrose oil, to try to improve nerve function. Vitamins B6, B12, and folate can also help. Electrical stimulation devices, infrared therapy, and acupuncture have been studied and, in some cases, reported to be effective. However, magnetic insoles only appear to have a placebo effect.
More than mere physical pain
The psychological impact of chronic pain should not be ignored. Just having diabetes can be a very difficult situation to deal with, even without neuropathy. Pinching your fingers repeatedly, being consistent in exercise programs and special diets, and sticking to medication schedules all at the same time can affect your quality of life. Add to that the chronic pain, and a situation like that can be psychologically exhausting. Therefore, a consultation with a mental health professional can be a good idea for many of the people who are faced with these problems.
What works for one person may not work for another, and sometimes it is necessary to combine therapies to relieve symptoms. If your current doctor says there is no more she can do for you, see another doctor, perhaps one from another specialty. Doctors treating DPN may specialize in general medicine, internal medicine, rehabilitation medicine (rehabilitating physician), neurology, neurosurgery, plastic surgery, pain management, anesthesiology, endocrinology, psychiatry, or podiatry. Those of us who treat DPN know that each patient is different. Even if you have tried various treatments that have failed to alleviate symptoms, don’t be discouraged; The next medicine you try may be the one that works best for you.