Nervous System

What Is Nerve Pain?

[Used with permission from Pain Free 1-2-3 (McGraw Hill 2006) by Jacob Teitelbaum, M.D.]

One of the more difficult and uncomfortable types of pain comes from nerve pain (called neuropathic pain or neuropathies). Whether the pain comes from diabetes, shingles, fibromyalgia, chemotherapy, or a host of other causes, this searing, burning, electric shock kind of pain can leave you miserable. Unfortunately, most physicians are still not trained in addressing nerve pain, and give anti-inflammatory medications like Motrin (which are not effective) or narcotics, which are modestly effective.

Many studies have shown that using nutritional support with alpha lipoic acid 300 mg 2x day, acetyl L-carnitine 500-1,500 mg 2x day, inositol (500-1,000 mg a day), and vitamins B6 (50-100 mg a day) and B12 (500-5,000 mcg a day—both B vitamins and inositol are in a good multivitamin powder) can help support healthy nerves.

The term "neuropathic pain," or nerve pain, refers to a wide range of problems that cause diseases of, or injury to, the nervous system. It is a category of pain syndromes and not a single problem. Neuropathic pain can come from malfunction of nerves or the brain associated with illness (e.g., diabetes, low thyroid, etc.), infections (e.g., shingles), pinched nerves, nutritional deficiencies (e.g., vitamin B6 and B12), injury (e.g., stroke, tumors, spinal cord injury, and multiple sclerosis), and medication/therapy side effects (e.g., radiation and chemotherapy, AIDS drugs, Flagyl®). It is estimated that 50 to 80 percent of diabetics will develop some nerve injury with 30 to 40 percent of these having painful diabetic neuropathy unless preventive measures are taken such as nutritional support. Neuropathic pain affects approximately 0.6 to 1.5 percent of the US population and 25 to 40 percent of cancer patients.This represents over two million Americans.

Neuropathies are characterized by pain that is burning, shooting (often to distant areas), or stabbing. It also has an "electric" quality about it. "Tingling or numbness" (paresthesias) and increased sensitivity with normal touch being painful (allodynia) are also commonly seen. Ongoing pain is often continually present regardless of what the patient does or does not do. In some cases, pain comes in sudden attacks without any apparent trigger. Diagnosis is made predominantly by history and physical examination, as testing often offers little benefit clinically unless the testing is looking for an addressable cause.

As with other pain problems, neuropathies are both expensive and poorly addressed.

In one study of 55,686 patients with neuropathic pain, health care charges were three-fold higher than they were in the overall population. Use of relatively ineffective therapies such as NSAIDs (e.g. Motrin®) and opioids was widespread, while relatively few received anti-epileptic drugs, tricyclic anti-depressants, or any of the many other medications that are often much more effective in relieving neuropathic pain.

In the presence of nerve pain, it is especially important to look for addressable causes. Lab testing should include:

1. A blood count (CBC) and an inflammation/sedimentation rate (ESR).
2. Thyroid testing with a Free T4 and TSH.
3. Vitamin B12 level.
4. Screening for diabetes with a morning fasting blood sugar and a glycosylated hemoglobin (HgBA1C).

The medical history should be assessed for excess alcohol use, vitamin deficiencies, hereditary factors, or therapy with medications that can cause nerve injury. A neurological examination may also give an indication of the cause.

Nerve pain is often associated with a process called pain Central Sensitization. The nerves and brain are like wires that carry information. When they become over-stimulated with chronic pain, it may make the whole system over-excitable. In these situations normal touch and other usually comfortable contact can be painful. This is called allodynia. Medications that stimulate the "calming (GABA) receptors" in the brain, such as a number of anti-seizure medications (see below), can help settle the system and decrease pain.

Postherpetic Neuralgia (PHN)

Postherpetic Neuralgia follows a rash called herpes zoster. Often called shingles, it is caused by the same virus that causes chickenpox. The first time you get chickenpox, the virus remains in your nerve endings even after the chickenpox is gone. This usually causes no problems. If the virus re-activates in one of the nerve endings, however, it causes a rash all along the distribution of the nerve. The rash of herpes zoster is characterized by being painful and being in a line totally on one side of the body. If it extends past the midline of your body, the rash is probably coming from something else. If the pain persists after the rash is gone, continuing for weeks to years (over one year in half of elderly patients), it is called Postherpetic Neuralgia (PHN). The pain tends to be burning, electric, or deep and aching. PHN affects between 500,000 and 1 million Americans—most of which are elderly. It can severely disrupt one's life, but fortunately can now be effectively addressed in most cases.

Painful Diabetic Neuropathy (PDN)

This is the most common cause of neuropathy in U. S. Alterations in sensation are common, and the feet, which are most often affected, may feel both numb and painful at the same time. There are many factors contributing to nerve injury in diabetes, including decreased circulation, accumulation of toxic byproducts, damage from elevated sugars, and nutritional deficiencies. There are also changes in NMDA and opiate receptors.

Nutritional Deficiencies

Neuropathic pain can also be caused by deficiencies of vitamins B12, B1, B6, D, E and zinc (all are present in a good multivitamin powder). A number of studies have shown that different kinds of nerve pain can improve by supplementation with high dose B vitamins. Excess vitamin B6 (over 500 mg a day for years), however, can also cause neuropathy. Vitamin D 2,000 units a day was also shown to decrease diabetic neuropathy pain by 47% after 3 months.

In patients with long-standing shingles pain, one study showed that taking 1,600 units of vitamin E (use the natural form) daily before a meal for 6 months was markedly helpful in eliminating the pain. Another study showed that taking lower doses for less than 6 months was not effective.

Hormonal Deficiencies

Hormonal deficiencies, especially an under-active thyroid, can also cause neuropathic as well as muscular pain. A therapeutic trial of thyroid hormone is reasonable for anybody who has the symptoms of low thyroid including fatigue, cold intolerance, achiness, having low body temperatures, or unexplained inappropriate weight gain.

Nerve Entrapments

A pinched nerve can cause nerve pain in many places in the body. Two of the more common ones are low back pain from sciatica and pains in the hand and sometimes wrist from carpal tunnel syndrome. Sciatica usually goes away without surgery by using intravenous colchicine, and carpal tunnel syndrome usually resolves after 6 to 12 weeks with vitamin B6 (250 mg a day), thyroid hormone, and wrist splints.

Reflex Sympathetic Dystrophy (CRPS)

This usually manifests as horribly severe pain in one hand or foot but can certainly spread elsewhere.

How Can I Make the Neuropathic Pain Go Away?

Neuropathic pain occurs biochemically, making it a very fluid system that can often be quickly modified, resulting in pain relief. Many different chemicals (neurotransmitters) in your body may be involved in your pain, and therefore it is worth trying different types of medications to see which ones work best in your case. For many, addressing the nutritional and thyroid deficiencies and eliminating the muscle spasms, which are compressing your nerves, may be enough to eliminate your pain. Others may need to take medications to suppress the pain while we look for ways to eliminate the underlying cause. The best way to tell which chemicals are involved in your nerve pain is to simply try different medications (individually and, if needed, in combination) to see what eases your pain. Basically, it is like trying on different shoes to see what fits best. The good news is that we have a large assortment of "shoes" that you can try on and that are likely to help you.

It is, of course, critical to begin by eliminating the underlying causes of neuropathy and giving the nerves what they need to heal. This includes the nutritional support we've discussed. In addition, the involvement of free radicals in nerve excitation was found in 1995, supporting the use of antioxidants in nerve pain. Since that time, the antioxidant lipoic acid (300 mg 2 times a day) has been shown to be helpful in diabetic neuropathy and should be tried in other neuropathies as well. You will be amazed at how much benefit you may get over time simply from optimizing nutritional support.

In addition, if you are tired, cold intolerant, experience achiness, have low body temperatures, or have weight gain I think it is reasonable to consider a therapeutic trial of natural thyroid hormone regardless of your blood levels. It may take 3 to 6 months for the thyroid and/or nutritional therapies to begin working, but regardless of the cause of your neuropathy, this therapy may result in nerve healing. It is reasonable to begin medications along with the nutritional support so that you can get pain relief as quickly as possible. If only a small area is involved, it makes sense to begin with a Lidocaine® patch (called Lidoderm). Otherwise, I prefer to begin with Neurontin® and/or tricyclic anti-depressants.

Below are just some of the different categories of therapies that can be helpful for nerve pain. Help promote healthy nerves using the nutritional and thyroid support noted above. You can then add the medications below as needed in the order that they're listed.

1. Lidocaine® patch, 5 percent. This Novocain®-like patch is applied directly over the area of maximum pain. It can be cut to fit the area, and up to four patches can be used at a time (although the package insert says only three). It is left on for 12 hours and then removed for 12 hours each day, although recent reports have suggested that the patch can be left on up to 18 hours and still be safe and effective. Results will usually be seen within two weeks. Because the effect is local, side effects are minimal. The most common side effect is a mild skin rash from the patch. It should not be used if you have an allergy to Novocain/lidocaine.

   The patches are most likely to be helpful if the pain is localized to a moderately-sized area. Even in a large area, however, patches can be used on the most uncomfortable spots. The main downside of the patches is that they are expensive. If you have prescription insurance, however, they will usually be covered.

2. Neurontin® and other seizure medications. Newer anti-seizure medications, and some of the older ones, can also be very helpful for neuropathic pain. Neurontin has been shown to be helpful for both shingles and diabetes pain. Common side effects include sedation, dizziness, and sometimes mild swelling in the ankles when first starting therapy. These side effects can often be avoided by starting with a low dose and raising the dose slowly. A common total dose for Neurotonin is 600 mg, 3 to 4 times a day.
3. Tricyclic anti-depressants. These include medications such as Elavil®, Tofranil®, nortriptyline or doxepin.
4. Topical Gels. A wonderful new addition to the therapy of pain in general, and especially nerve pain, is the use of prescription topical gels. New gels have been developed that markedly increase the absorption of medications through the skin. By using a low dose of many different medications in the cream, one can get a powerful effect locally with minimal side effects. It is best to have a knowledgeable compounding pharmacist guide you and your physician in the prescribing of these creams and gels.

   To explore an example of how to address with these creams combined with nutritional support, let's use the example of diabetic neuropathy. One must, of course, begin with proper control of the elevated blood sugars. Nutritional support with high levels of vitamin B12, B6, and inositol are also important in diabetic nerve pain as are many other nutrients, such as vitamins C and E, magnesium, antioxidants, and bioflavonoids (all in a good multivitamin powder). In addition, lipoic acid 300 mg 2 times a day has been shown to be helpful for diabetic neuropathy. A compounded gel containing (as one of many possible mixes) Ketamine 10 percent, Neurontin® 6 percent, clonidine 0.2 percent, and nifedipine should be added to painful areas (apply 1g 3 times a day as needed). The nutritional support can actually make the pain go away over time, while the cream/gel can add symptomatic relief. Other medications discussed in this chapter can then be added as needed to assist in the neuropathic pain.

5. Anti-depressants such as Effexor or Cymbalta.
6. Ultram (Tramadol®). This is an interesting medication that works on many areas of pain and in many different types of pain. It has been shown to be effective for nerve pain in a placebo-controlled study after four weeks.
7. Topamax (Topiramate®)
8. Lamictal (Lamotrigine®)
9. Lyrica (Pregabalin) or Gabitril (Tiagabine®)
10. Keppra®
11. Trileptal® (oxcarbazepine)
12. Dilantin®
13. Capsaicin®
14. Narcotics. Narcotics are only modestly helpful but are considered an accepted therapy for neuropathic pain.
15. Benadryl® (diphenhydramine). Sometimes we get help from unexpected places. Studies have shown in both humans and animals that antihistamines can help pain—in spite of our not knowing why this works. It has even been found to be helpful in patients who failed therapy with heavy narcotics. It is recommended that you start with 25 mg every 6 to 8 hours and adjust the dose to the optimum effect.