Carpal Tunnel and CMT
Dr. Stuart D. Patterson of the Hand and Upper Limb Centre at St. Joseph's Health Centre in London, Ontario, Canada answers a reader's question as to whether it is possible to differentiate between carpal tunnel syndrome and Charcot-Marie-Tooth disease.

"Clearly, people with Charcot-Marie-Tooth disease can have coexistent carpal tunnel syndrome or any other peripheral nerve compression neuropathy. Unfortunately, it would be very difficult for a lay person to be able to differentiate between the two. However, if the individual is aware that there has been a unilateral significant deterioration in function with regards to sensation in particular, the cause may be an isolated peripheral nerve compression neuropathy. Charcot-Marie-Tooth neuropathy tends to be symmetrical with regards to sensory loss, and asymmetrical loss would suggest an additional problem. A well trained physician, who is familiar with carpal tunnel syndrome, should be able to differentiate on the basis of the history, physical examination, and electro diagnostic studies as to whether one is dealing with the effects of Charcot-Marie-Tooth disease, or the effects of a superimposed compression neuropathy, such as carpal tunnel syndrome. This is not an uncommon scenario when dealing with patients who are affected with diabetes mellitus. These patients have a similar peripheral neuropathy, but it is very common to find an associated peripheral nerve compression neuropathy.

It is difficult to provide a definitive answer to your question as to whether carpal tunnel surgery would be successful or unsuccessful in a patient with Charcot-Marie-Tooth disease. Intuitively, one would anticipate that the sensory loss that has occurred as a result of the carpal tunnel syndrome would improve. However, if the compression of the nerve has been prolonged, it is less likely that recovery of the affected muscles will occur. Generally though, if recovery is expected, this should occur within six months of a carpal tunnel release."

Feels like an electrical shock
Q: I have found that when I am gripping something like a screwdriver it feels like an electrical shock going through my hand. Is this normal with the CMT?
A: Dr. Greg Carter, Medical Director, Providence Rehabilitation Hospital, Chehalis, WA, USA answers: Probably could be part of the expected symptoms of CMT but I'd also get checked for carpal tunnel syndrome (CTS) with nerve conduction studies across the wrist. People with peripheral neuropathies like CMT and diabetes are at higher risk to develop CTS, which is basically a pinched median nerve at the wrist.
By the way, vibration is very hard on nerves and can actually induce CTS (for example in chain saw or jackhammer operators or in motorcycle riders from gripping the vibrating handlebars).

Tremors
Q: Gary Schockley, who is deaf and blind and has CMT asks: What makes my hands have a tremor in them? My doctor said my hands do not shake enough to take any medicine to help.
A: Thomas Bird, M.D., Chief of Neurology, VA Medical Center, Seattle, WA, USA. answers: Some people with CMT have tremor in their hands. This is thought to be a result of the nerve disease causing a disruption of sensation in the fingers and arms. The particular loss of position sensation with loss of awareness of the limb and joints in space apparently causes the limb to move back and forth resulting in a tremor. Some persons have a tremor for other reasons. For example, it may be caused by medications, alcohol, caffeine, anxiety, or a separate hereditary condition. Medical treatment of tremor is non-specific and often unsatisfactory. There are a few medications that can partially alleviate tremor, but, of course, medications often have undesirable side effects.
Orest Hurko, Associate Professor, Neurology and Medicine, The Center for Medical Genetics, The Johns Hopkins Hospital, Baltimore, MD, USA answers: Tremor is often encountered in association with CMT. It used to be thought that tremor and CMT represented a separate syndrome called Roussy-Levy syndrome. Most of us now agree that Roussy-Levy is not a separate syndrome but represents either the concordance of another common heritable condition called essential tremor with CMT or is the direct result of the CMT itself in susceptible individuals. The cause of essential tremor is not known but is widely thought to be a minor abnormality of the extra pyramidal system in the brain. Essential tremor appears to be transmitted as an autosomal dominant trait, in the same manner as are the most common forms of CMT. However, there is no reason to believe that the putative essential tremor gene(s) are linked to any of those responsible for CMT.
Treatment for essential tremor is less than satisfactory. This type of tremor responds to benzodiazepine, minor tranquilizers, such as valium, and also to alcohol. Indeed, self-medication with alcohol has led to alcoholism in some individuals. The decision about wanting to treat with benzodiazepines has to be based on how badly the tremors affect an individuals patient. Is the trade-off for reduction of the tremors worth the potential side-effects? In some cases, the answer is yes. In other cases, it is better to live with a bit of tremor than take still another medication.
The final caution is to realize that there are other types of tremors other than essential tremor. The resting tremor associated with Parkinson's disease and related syndromes responds to anticholinergic drugs and dopamine agonists rather than benzodiazepines. The intention tremor of cerebellar disease doesn't respond well to medications at all. Neither of these two remors are associated with what most doctors refer to as CMT. However, blindness and deafness are not features of CMT either. Gary should check to see if there may be some other underlying condition responsible for his tremor.

Finger clawed almost overnight
Candie Mann, CA USA, writes: My hands/fingers are really getting bad. One finger on my right hand has clawed almost overnight. Boy, I thought I dropped things before! I also get tremors, but only in that finger. Weird, actually.
Dr. Stuart Patterson answers: It is quite unusual for a finger to "suddenly" claw. Invariably, this has been progressing quietly for some time, until clumsiness, weakness or some other symptom draws attention to the digit(s). Sudden deterioration could be due to a superimposed condition, such as diabetes mellitus, trauma, a peripheral compression neuropathy or alcohol abuse, to name but a few. In general, the clawing is most severe in the small finger and then the ring, initially. This is due to the nerve supply to the small muscles of the hand. As the disease progresses, the remaining fingers become involved, until the point is reached that all the fingers may be equally severely involved.

Surgery can correct the deformity and improve hand function; no guarantee though. As this is a progressive condition, the corrective surgery can be negatively affected by progressive muscle weakness in the forearm. However, in general, most people with CMT have only the small muscles of the hand involved. The more proximal (towards the elbow) muscles are preserved until late in the disease process, or not affected at all.
The finger tremor could be due to weakness or small spontaneous contractions in the muscles affected, which would be quite unusual. I do not know of any surgical treatment for that. Tremors can also be due to other conditions, such as age, Parkinson's disease, etc. However, these tremors are usually widespread.

Is it overuse?
Q: I'm having a problem with my left hand, the two middle fingers mostly. Sometimes they will start clinching shut at night. However, nearly every morning I have to pry them open, it hurts. I have to do that several times before the clinching stops. There is a click feeling in the middle joints. That seems to have started since I am in the wheelchair more, so I am wondering if it has anything to do with grasping the wheels. I have to grasp the cane hard too! Wouldn't it be wonderful if we had all the answers!
Geri Logan, MN, U.S.A.
A: Dr. Stuart Patterson, orthopedic surgeon (hands) answers: This sounds absolutely typical for "trigger finger" and is not directly related to the CMT. Geri may well be right, in that this is as a result of repetitive hand work. The problem is the tendons that bend the fingers to make a fist develop an area of thickening on them that catches on a pulley in the palm that the tendons run through. When the bump on the tendon is pulled up against the pulley it gets stuck. You then have to pull the finger straight and the bump gets pulled into the pulley with a pop, which is painful. The treatment consists of splinting the finger in extension at night initially. If this does not work, then I would recommend that the tendon sheath be injected with cortisone. If this and the splinting are not effective, the pulley needs to be divided surgically under local anesthetic. This is a 30 minute operation, which is done as an outpatient.

Tendon and ligament problems
Q: Now that my muscles are getting weaker, I am experiencing more tendon and ligament problems. I sprained my thumb ligament so badly they were talking surgery, although it is now healing. My sister is having significant problems with tendonitis in her thumbs that is causing her great pain. When I asked the doctor about it, his response was, "Now that your muscles are weaker, your joints are going to get damaged." Then he walked out of the room, and I decided to find a new hand doctor. I am very interested in what we can do to protect our ligaments and tendons.
Vicki Pollyea, FL, U.S.A.
A: Dr. Patterson answers: When someone injures themselves and they have an underlying medical condition, the question often asked is whether the underlying condition was a factor. We should always remember that we are ALL at risk of an injury. In general, if we are injuring ourselves repeatedly and this is something new, then there may well be a link.

In Charcot-Marie-Tooth disease, the peripheral nerve damage results in permanent muscle atrophy (wasting). Why is this important for joints? The muscles, through their tendons, are attached to the bone. Muscles not only move joints, but they also have a role in stabilizing them. By this, I mean that the muscles are partly responsible for enduring that we do not dislocate our joints. The main or primary stabilizer of a joint is the fibrous joint capsule and its thickenings, called ligaments. However, without healthy muscles and tendons, joints can dislocate. Therefore, when the small muscles of the hand become weak, the joints that are intrinsically unstable are most at risk. These are joints that are not constrained or well captured by their bony architecture. For example, the ball and socket joint of the hip is very stable and not prone to dislocation, because the ball is well contained by the socket. As a result, it is very difficult to dislocate this joint. The joints of the thumb (interphalangeal, metacarpophalangeal and trapeziometacarpal joints) are not inherently stable, and if there is a loss of the joint stabilizers (muscles), instability can occur.

The simplest remedy to this problem, and probably the most effective, is the use of custom fabricated thermoplastic hand splints. These are removable splints made by hand therapists or occupational therapists out of plastics that are lightweight and can be moulded to fit your hand. If splints are not useful, then another alternative is surgery.
The operations generally fall into two categories: fusions and tendon transfers. In the right patient, surgery is extremely effective in not only correcting deformities but also improving dexterity and strength.

Tendonitis is a different issue. Unfortunately, the term "tendonitis" is often used loosely and is often used to include a wide variety of problems, all with different causes, findings and treatment. The word itself is technically incorrect, as tendons do not become inflamed. Their lining, or tenosynovium, may become inflamed, in which case the correct term is tenosynovitis. This is a condition seen commonly in individuals who have rheumatoid arthritis or related conditions, such as psoriasis. It is also seen in manual workers who do repetitive activities with their hands and upper extremities. In addition, there is another group of conditions called enthesopathies, where the attachment of the tendon to the bone degenerates, tears and becomes painful. A good example of this is tennis elbow.

In general, most of these conditions are treated by activity modification, bracing, splinting, physical therapy and corticosteroid injections. Surgery is only resorted to when all other options have failed and the individual is severely incapacitated. As a rule, the results of surgery are unpredictable, with a 60% chance of success.

Pain in the hand is often referred to as being cause by "tendonitis." However, this is often a diagnosis provided to the patient, merely to give them a "label" or "hook to hang their hat on." By that, I mean the physician gives the patient a diagnosis so that, when they leave the office, the patient can now say, "I know what is wrong with me, I have tendonitis." However, that is not particularly helpful. I always try to be as specific as possible in defining the cause of the pain. This allows one to be more specific with treatment and hopefully obtain a more predictable outcome. It is not unusual for the pain to be a result of joint instability, arthritis or nerve compression. I may also have no idea as to the origin of the pain, and if that is the case, I will tell the patient that despite the frustration that arouses.

Nevertheless, by excluding a significant cause for the pain, I can tell the patient that there is no serious problem that is being missed.

Can't wear rings
Q: I can't bear to wear rings on my fingers. They continually bother me and I never get used to them as people say I will. Is there some reason for this?
A: You may find rings difficult to wear if you have an increased sensation or hyperesthesia in your fingers. CMT nerves lose their myelin covering in a spotty more segmental fashion. Some CMT patients have increased pain or other sensations possibly when this process is happening.
Linda here: I'm asked often by women with CMT what to do about earrings. Because we sometimes have very little thumb action we can't get them on, especially earrings for pierced ears. My answer (and I've worn them for 10 years) is earrings by Nina Ricci with French backs. These earrings have a post that goes through the hole in your ear lobe and a clip that goes over the post. You can't lose them and they are very easy to put on. There is no tiny back to try to position, sight unseen, using weak thumbs. They are available at better jewelry stores.

Hand exercise?
Q: Is there some kind of hand exercises I can do to prevent my hands from getting weaker? Could you tell me why my hands get weak and what muscles usually deteriorate first and why?
A: Dr. Richard E. Brown, a hand surgeon from SIU School of Medicine in Springfield IL answers: As noted in our study that we presented at the American Association of Hand Surgery in Boston, MA, patients with CMT frequently will develop weakness of their hands secondary to involvement of the nerves of the upper extremity. The hand involvement tends to begin somewhat after the onset of the lower extremity problems and are often overshadowed by the concerns with the lower legs. Because of the involvement of the nerves to the hand, the patients eventually develop marked wasting of the small muscles of the hand which are used for fine control of the fingers and positioning of the thumb. As with the lower extremity, the nerve involvement of the upper extremity is of a progressive nature and little can be done to prevent its onset or its progression. Once atrophy has occurred to a point that hand function is limited, reconstructive procedures can be done to improve the hand function at least temporarily.

Because the neuropathy itself is of a progressive nature, exercises cannot prevent the development of muscle atrophy. However, it is vitally important to maintain the range of motion of the joints of the hand through active use and passive range of motion exercises. Everyday use of the hand in normal day-to-day fashion is also beneficial in maintaining the tone of the muscles and maintaining the range of motion of the joints. Overuse of the hands in repetitive type occupations or leisure activities may actually cause a further deterioration of the nerves by a secondary compression problem such as carpal tunnel syndrome. An underlying peripheral neuropathy such as occurs in Charcot-Marie-Tooth disease can predispose to a secondary nerve compression syndrome which can then worsen the underlying neuropathy. Consequently, it is important not to overuse the hands in occupations that require repetitive type motions such as constant computer data input, repetitive factory or assembly line type work, meat cutting, etc. These repetitive type motions may be quite detrimental to the long term function of the hand.

In summary, the main nerves of the upper extremity do tend to be involved with Charcot-Marie-Tooth to a variable degree. The involvement may lead to weakness of the hand secondary to loss of innervation to the small muscles in the hand itself. The extrinsic muscles of the hands (i.e. the muscles in the forearm) tend to be involved less often. Normal day-to-day use and range of motion of the joints is important to maintain good mobility.

Strength deteriorates in inward pattern
Q: The strength in my hands seems to be deteriorating in an inward pattern. My hand strength is now concentrated in my thumb and the next two fingers. As the hand and finger strength deteriorates, those knuckles sink into my hand. Is this the usual way CMT progresses? Why?
A: Dr. Lowell Williams answers: You describe a greater loss of muscles in the outside half of your hand than the inner half. Usually in CMT, strength is lost equally in the fingers but, depending on your activity, may be more noticeable in certain fingers. Check with a hand surgeon to see if you may also have nerve entrapment in your hand.

Peeling

Q: There is something I would like to ask. I am getting sore, peeling patches between my fingers. The doctor says it is a form of athletes foot and has given me some cream for it. Unfortunately it doesn't seem to be working. Perhaps your other readers may have suffered this and have found something that helps. The doctor thinks it is because I can't open my fingers.
A: Dr. Williams answers: The fungal infections that commonly occur between fingers and toes do resist treatment as you described, particularly when there are poor nerves to those areas as in CMT and diabetes. I suggest you ask your doctor to try another treatment salve (there are several available) and be patient. This is a common CMT problem and does take time to heal.

Muscle spasms

Q: I would like to know if any CMT patients have had difficulties unclenching their hands, and if so, what did they do about it? Do you know anything that might help?
A: Dr. Williams: Muscle spasms are common in CMT and may be quite painful. Some of these may be due to poor circulation secondary to the nerve problems of the blood vessels in your hands. It sounds as if this might be your problem. Heat (warm water) or massage may help when it happens. If it occurs regularly, consult your doctor.
(Editor's note: If you wake up with fists clenched hard, try forcing one hand open with the other and lying with them under your head for a few minutes or even under your buttocks. There are also night splints that can be prescribed and worn that will keep your fingers and hands from curling in and clenching throughout the night.) Please see article Night Splints and Quality of Life.