Contributor: Dr. Staci-Marie Norman, PharmD, DCES

Peripheral neuropathy is a complication that doctors and diabetes educators may talk about, and the discussion might cause feelings of fear and doom for some. But I thought we could talk about what peripheral neuropathy is, ways to try to prevent it, and how it can be treated if it does present itself.

What is peripheral neuropathy?
Peripheral neuropathy is any type of damage to the peripheral nervous system, which includes all of the nerves outside the brain or spinal cord. So even though most of us might think that peripheral neuropathy just affects the toes and fingers, it can also affect nerves in the arms, legs, face, torso, and even internal organs and blood vessels. Peripheral neuropathy in the feet can cause pain, tingling, or numbness, while other peripheral neuropathies include gastroparesis, impotence, muscle weakness, bowel or bladder incontinence, or even sharp falls in blood pressure due to involvement of blood vessels.

What causes peripheral neuropathy?
Causes can include:

• damage from out-of-range blood glucose
• autoimmune diseases such as rheumatoid arthritis or lupus
• vitamin deficiencies, especially of B vitamins
• chemotherapy agents
• HIV medications
• alcoholism
• exposure to toxic substances
• some bacterial or viral infections

What do the various causes of peripheral neuropathy have in common?
They all damage the coating around the nerves. Think of the nerves as the electrical system of our body. Just like the electrical wires of our home are coated for safety and to ensure that the electrical current goes where it is being directed, our nerves have a coating that helps with correctly directing the impulses. When that coating is damaged, our nerves can misfire.

What happens when the nerves misfire?

• Misfiring can cause that tingling or pain in the extremities.
• It can slow stomach motility, causing digesting food to be dumped into the intestines.
• Blood vessels may not be stimulated correctly and can lose tone, causing your blood pressure to drop rapidly.
• Blood vessels may not react quickly enough to increase blood pressure when a person goes from seated to a standing position, causing dizziness.

What can you do to help prevent peripheral neuropathies from occurring?
The first place to focus is your diabetes management, including both blood glucose and blood pressure. At target blood glucose can decrease chances of damage to nerves and blood vessels. Decreasing high blood pressure can also protect the blood vessels and, in turn, the nerves. Our blood vessels need to "feed" our nerves in order to keep them healthy. If circulation is compromised, the nerves have a double whammy of damage from above range glucose and lack of the oxygenation needed to stay healthy. Following a healthy diet, exercising, smoking cessation, and taking medications can not only help your glucose management but can lower your risk of peripheral neuropathy.

What are the signs of peripheral neuropathy?
Since many things can cause peripheral neuropathy, a complete work-up is typically done, including labs, ultrasounds, and sometimes nerve conduction studies. Some symptoms that would prompt this work-up include:

• pain that could be sharp, jabbing, or electric-like in sensation
• numbness, burning, or tingling
• increased skin sensitivity
• low blood pressure
• nausea and vomiting
• constipation, diarrhea, or incontinence
• impotence

If you are experiencing any of these symptoms of peripheral neuropathy, speak up! The faster peripheral neuropathy is diagnosed and addressed, the more likely you can avoid damage.

What treatment options are there for peripheral neuropathy?
The goal of peripheral neuropathy therapy is to manage the underlying condition and provide relief from symptoms. Peripheral neuropathy in the feet or fingers often starts with pain or tingling.

• It has been found that improved management of blood glucose may cause the pain or tingling to subsides or even resolve. However, this may depend on how long the damage has been occurring and how much damage has been done.
• If appropriate, smoking cessation can also help decrease the damage to blood vessels and improve oxygenation to the nerves.
• Pain relievers such as acetaminophen, aspirin, ibuprofen, or naproxen can be used to relieve symptoms.
• For severe pain, opioids medications are an option.
• Topical analgesics, such as Capsaicin, BenGay, or Asprecream, can provide temporary localized relief.
• Over-the-counter lidocaine patches and creams may provide a numbing effect to specific areas.
• Anti-seizure medications such as gabapentin, pregabalin, carbamazepine, or phenytoin can help calm the nerves and prevent misfiring that can cause the symptoms.
• Some older tricyclic antidepressants, such as amitriptyline, nortriptyline, desipramine, or imipramine, can also help with the perception of pain from symptoms.
• And some newer serotonin or serotonin/norepinephrine reuptake inhibitors, such as fluoxetine, paroxetine, or duloxetine, have been found to provide better relief.
• Another potential symptom relief measure is TENS units, which issue a small electrical shock to the nerves in a localized area to provide temporary relief.
• Biofeedback, acupuncture, hypnosis, and relaxation techniques all have the potential to help with symptom relief.

Prevention is always the best method! So, keep your blood glucose and blood pressure at target, stop smoking if needed, practice healthy eating habits, get moving or keep up the exercise you are doing, and don't forget to see your doctor for your annual checkup. And when you are at that doctor's appointment, take off your shoes and socks and let your doctor see your feet. An annual foot exam with monofilament is a great way to keep track of your nerve health in those cute little toes!

Dr. Staci-Marie Norman, PharmD, DCES received her bachelors from Purdue University (’94) and her Doctor of Pharmacy from the University of Oklahoma (’96). In 2000 Dr. Norman added to her credentials by becoming a Certified Diabetes Care and Education Specialist. She is currently the Clinical Coordinator and staff pharmacist for Martin’s Pharmacy. Dr. Norman is a national faculty member for the American Pharmacist Association, teaching certificate programs in both diabetes and cardiovascular disease. She serves on the advisory board that oversees development and revision of these programs. Along with teaching and development responsibilities for APhA, Dr. Norman serves as a peer reviewer for research grants and publication submission. Dr. Norman has also spoken for Abbott, Bayer, Lilly, Mannkind, and Lifescan as a diabetes specialist.