Many people with CMT suffer from a chronic pain syndrome. The pain can be quite variable and may not only be different in every person but may vary within an individual from day to day, both in intensity and the type of pain. Sensations frequently described include numbness, tingling, aching, cramping, burning or a cold, bone-aching sensation.

There are, of course, a number of things which seem to make the pain come and go. Some of these might include the use of alcohol, exposure to cold, caffeine or even exposure to heat.

Some of the simplest things that seem to frequently alleviate the pain include exercise, soaking the hands in warm water, moving the hands around gently in the air, gently opening and closing the fists, meditation, etc.

The gist of this article is to describe one thing which has worked extremely well for me when nothing else seems to have a great deal of effect. The transcutaneous nerve stimulator has been around for quite a few years. Most characteristically it would be described as a small black box. It usually houses anywhere from two to four batteries, usually AAA size. Basically, the TNS unit includes a small dial which allows variable intensities of small electric impulses to travel from the main unit to small electrodes which are sometimes called pads. These pads come in a variety of sizes and shapes. There are quite a few different ones on the market. Each of them provides a different level of comfort for different types of skin but all of them serve the purpose of conducting electricity from the device across the skin.

Electrical impulses from the "black box" are extremely small, and when the electrical current is adjusted correctly it cannot be felt. There is absolutely no sensation to the wearer when things are working in the proper fashion.

The electrical impulses can, according to the manufacturer, be supplied in not only different intensities but different wave lengths and usually come as short bursts of unperceived current. The short bursts have different time levels that can often be set on the device itself, and the bursts of electricity can also be modulated, that is to say they can go up and down gently or come on and off suddenly. In either case, as mentioned above, the wearer does not perceive any sensation.

Some of the units come with two pads and others come with four pads.

Basically, the placement of the pads can be quite variable and only through personal experimentation can each person find the spot that is exactly right for him or her.
Most people find, however, that placement of the two pads along the top of the diseased or irritated nerve, someplace between the area of their pain and their neck, helps. For instance, if one had burning fingers or hands, they might choose to place the electrical pads anyplace on the wrists or forearms, or even arms, or at the base of the neck.

Those units with four pads are very useful for people who have burning pain in both limbs, that is to say, both arms or both legs and there would be two pads on each limb. Each pair of pads would have one positive and one negative electrode, of course, and basically the current flows between the two pads through the skin, muscles and nerve area.

The small "black box" is worn on a belt and is fairly unobtrusive. It usually isn't much bigger than a the size of a package of cigarettes. By the way, tobacco is a non-no for most people with neuropathic pain. It really tends to increase the degree of cramping and painful sensations.

No one really knows for sure why a TNS unit works, and it does not work for everyone. One of the theories is that is may help the body to secrete endorphins. These are natural morphine-like substances which help to deaden pain. The TNS unit theoretically increases the degree of endorphins found in cerebral spinal fluid, the fluid that bathes the spinal cord, which of course would be the transmitter of nerve pain from the hand to the brain, and endorphins at this level could act as a pain blocker.
There are other theories, one of which is that the electrical impulses, although not felt by the person wearing the unit, come at such a rate that they confuse the nerves and prohibit them from carrying pain messages back to the brain.

One thing should be mentioned, and that is the unit is very good at blocking pain but it does not have any function on strength. That is to say, it will not weaken nerve pathways to the motor nerves so there will be no change, either increase or decrease, in motor strength for a person wearing this unit.

As yet, side effects with this device are almost unheard of. There are, occasionally, people who become allergic to the skin pads. This is usually solved by changing pads or in some cases using a jell between the pad and the skin. There are a number of jells on the market, some of which are hypoallergenic, just as there are quite a few different pads on the market, and the selection of pads has no relationship to the selection of the electrical generating unit.

These units are expensive. They vary from a few hundred up to six hundred dollars each. However, for a person suffering chronic pain, that probably is minimal compared to the cost of medication over the years.

It is difficult to wear this unit in bed, but it can be done. On the other hand, it is easy to wear while you are walking around. The wires to the electrodes go underneath the shirt, and if you wear a long sleeve shirt they are totally invisible.

This type of device in the United States must be prescribed by a physician. Those types of physicians being most familiar with them would be an orthopedic surgeon, physiatrist or neurologist. Most physical therapists have had a great deal of experience in helping people get adjusted to the unit. It usually takes a day or two to find just the right spot to put the electrodes, and just the right level to set the dial. In addition, I might add that if a regular unit, which usually sells for about $200 does not seem to do the job, by all means see your physical therapist and get a modulated unit. Usually they will provide one for free. These are quite expensive and run about $500-$600. In my case, it was like night and day and I would strongly recommend the modulated unit.

(Editor's note: check with your family physician, chiropractor or a rehabilitation therapist in your area to find out how best to obtain a TNS Unit. Try before you buy by renting or borrowing from a professional therapist. It may not work for you.)