by Jenny L. F. Andrus, MD
As an Interventional Pain Management Specialist at the Orthopaedic & Spine Center, I treat many patients who are suffering with chronic pain caused by peripheral neuropathy. Often, a patient will come to me frustrated by the symptoms and functional limitations caused by peripheral neuropathy. Peripheral neuropathy isn\’t a single disease, but rather has many potential causes. For that reason, it can be difficult to diagnose and more difficult to treat. Early diagnosis and treatment is key – it offers a better chance to control symptoms and prevent further damage. The best outcome is achieved by working together with your Interventional Pain Management specialist to determine where the nerve damage is, what is causing it and how the pain can be relieved.
Our nervous system
To better understand peripheral neuropathy, let’s start with an anatomy lesson about our nervous system. The nervous system is very complex – it has several parts, and is the “command center” for the body. It sends and receives messages using electrical impulses. It has two primary functions. Orders are sent from the brain to body organs and muscles that cause each movement in our bodies. Its other function is to send information about the body’s condition or environment to the brain along sensory nerves. The nervous system clearly carries a heavy load; therefore, when something goes wrong with our nerves, the result can be very debilitating.
The nervous system is divided into the central nervous system and the peripheral nervous system. The central nervous system is comprised of the spinal cord and brain. The peripheral nervous system consists of the nerves outside of the spinal cord and brain. Unlike the central nervous system, the peripheral nervous system is not protected by the bones of the spine and skull, leaving it exposed to toxins and mechanical injuries. This exposure can allow damage to the peripheral nerves.
What is peripheral neuropathy?
Peripheral neuropathy results from some type of damage to the nerves. It often causes numbness and pain. People typically describe the pain of peripheral neuropathy as tingling or burning. You may also lose feeling in your hands, feet, arms and legs.
What causes peripheral neuropathy?
We know that damage to the peripheral nerves causes peripheral neuropathy. However, it is not always easy to pinpoint the exact cause of peripheral neuropathy, because a number of factors can cause neuropathies. These include:
• Diabetes
o The most common cause of peripheral neuropathy. Prolonged exposure to high blood glucose, long duration of diabetes, abnormal blood fat levels, and possibly low levels of insulin all cause nerve damage. At least half of all people with diabetes develop some type of neuropathy.
• Autoimmune disorders
o such as rheumatoid arthritis or lupus
• Chronic kidney disease
• Infections
o such as HIV
• Low levels of vitamin B12 or other vitamin deficiencies
• Underactive thyroid gland
• Heavy exposure to toxins
o such as lead, mercury and solvents
• Alcoholism – prolonged heavy use of alcohol can cause nerve damage
• Some medications that treat infections, cancer, seizures, and high blood pressure may cause nerve damage
• Exposure to cold temperatures for an extended period of time
• Pressure from bad-fitting casts, splints, a brace, or crutches can damage a nerve
What are the symptoms of peripheral neuropathy?
Symptoms of peripheral neuropathy include:
• Numbness, tingling
• Burning, pins and needles sensation
• Loss of sensation to touch
• Loss of positional sense (knowing where a body part is without looking)
• Weakness
These symptoms can increase risk of injury to the affected limb. You may lose feeling in your legs and arms, so you may not notice when you touch something that is too hot or cold, making you more susceptible to burns. The reduced feeling may also cause you to not know when you have a small blister or sore on your feet or when you step on something sharp. These can raise your risk of serious infection.
Damage to the nerves can make it harder to control your muscles and can cause weakness. You may fall, because your legs buckle or you may trip over your own toes. A fall can cause much larger problems, including broken bones or a concussion.
How is peripheral neuropathy diagnosed?
When I see a patient in the office for pain from peripheral neuropathy, I usually complete the following:
• A Patient history, including your symptoms, work environment, social habits, exposure to any toxins, potential infections, and family history of neurological disease
• A neurological examination to check your tendon reflexes, muscle strength and tone, ability to feel certain sensations, posture, and coordination.
• Related tests may reveal the presence of a systemic disease causing nerve damage. Blood tests can detect diabetes, vitamin deficiencies, liver or kidney dysfunction, other metabolic disorders, and signs of abnormal immune system activity.
Based on the results of the neurological exam, physical exam, patient history, and any previous screening or testing, additional testing may be ordered to help determine the nature and extent of the neuropathy. Additional tests may include:
• Nerve Function Tests – This test gives your doctor information about the cause and severity of your peripheral neuropathy. Electromyography (EMG) involves inserting a fine needle into a muscle to evaluate for certain types of nerve damage. Nerve conduction velocity (NCV) tests assess how our nerves and muscles respond to small electrical stimuli, generated by a probe and measured by an electrode along the nerve’s pathway.
• Imaging Tests – CT scans and MRIs may be ordered if there is concern that a nerve may be pinched causing the neuropathy symptoms. These tests are not always necessary but can help rule out other causes of your symptoms.
• Nerve or skin biopsy – These tests involve removing and examining a sample of tissue for abnormalities. These are not typically necessary.
How is peripheral neuropathy treated?
The goal of treatment for peripheral neuropathy is to treat the condition or disease that is causing the neuropathy. Once the underlying cause is improved, the neuropathy may improve. Many types of neuropathy cannot be cured and in those cases the main goal is to reduce pain and improve function. In general, adopting healthy habits can reduce the physical and emotional effects of peripheral neuropathy. I recommend that you maintain optimal body weight, avoid exposure to toxins, follow a physician-supervised exercise program, eat a balanced diet, correct vitamin deficiencies, limit or avoid alcohol consumption, and control diabetes (if applicable).
Neuropathic pain is often difficult to control. Mild pain may sometimes be alleviated by analgesics or pain relievers sold over the counter. Several types of medications have recently proven helpful to many patients suffering from severe chronic peripheral neuropathy pain. These include several anti-epileptic drugs such as gabapentin and some classes of antidepressants. There are medications in both the antidepressant and anti-epileptic classes which have an FDA indication for painful diabetic peripheral neuropathy. Drugs containing opiates have many potential side effects and risks. They may be helpful in some cases but are not used as first line treatment for neuropathy pain.
In addition to medication, we can also utilize physical therapy as well as physical modalities such as Transcutaneous Electrical Nerve Stimulation (TENS) to help to relieve symptoms. For some patients with refractory pain spinal cord stimulation may be effective for pain control. In spinal cord stimulation the spinal cord is stimulated to produce a pleasant sensation to override the pain sensation.
As with any other health concern, it is important to consult with a qualified physician who can treat the condition properly. If you are experiencing symptoms that you think might be neuropathy, please make an appointment with an Interventional Pain Management Specialist at the Orthopaedic & Spine Center. We will work with you to determine the best treatment to help you feel better again.
Jenny L.F. Andrus, MD, is a Fellowship-trained, Board-certified, Interventional Pain Management Specialist who practices at Orthopaedic & Spine Center in Newport News, VA. For an appointment, call 757-596-1900.