General Questions

As far as we know, there are no contraindications.

I know of no medical literature addressing the effect of ambient temperature on peripheral nerve function in patients with CMT. If you want to use the hot tub, please first discuss it with your neurologist and consider trying brief exposures at lower temperatures to determine whether perceptible changes occur.

Dr. Scholl’s flat gel insoles might work. These are inexpensive; look for the ones that have very little absorbent cloth on the top. They dry quickly and you could even have two pair for not a lot of money. Pull them out of your water shoes after swimming-and hang dry the shoes and insoles separately so they can thoroughly dry. Excess moisture can easily grow fungus-not a friend to those of us with CMT.

Big box retailers (Target, Walmart, etc) typically have a good selection of these insoles. They can be easily trimmed to fit your water shoes.

There is remarkably very little information on this subject. Erectile dysfunction in men was reported in 1994 by Dr. Thomas Bird. We know that many neuropathies are associated with sexual dysfunction and diabetes is well described. I would suspect that any CMT patient with autonomic involvement may have sexual dysfunction. So CMT could directly impact sexual function, but there are lots of indirect issues as well.

We don’t really have any scientific evidence to support the fact that caffeine has any effect, positive or negative on CMT. If you have tremors, the caffeine may make the tremors worse. Overuse is certainly not recommended.

There is a big difference between Charcot-Marie-Tooth (CMT) disease and Charcot foot. These are two very different problems. The commonality is in name only, as it was the same physician, Dr. Charcot, who gave his name to the two diseases.

Charcot-Marie-Tooth is an inherited peripheral neuropathy, causing muscle weakness and sensory loss in the arms, hands, feet and legs.

Charcot foot is a condition causing weakening of the bones in the foot in people who have nerve damage. Oftentimes, people with diabetes get Charcot Foot. People with CMT are also known to develop Charcot Foot. You may want to see a good podiatrist for care and advice.

Although there is a possibility that the Agent Orange exposure played a role, I don’t know of any evidence to support this theory. Nonetheless, the Veterans Administration accepts that early onset neuropathy may have been caused by herbicides. We know that patients with CMT are probably more sensitive to neurotoxins such as chemotherapy meds and may have more severe neuropathy if they have diabetes. So there is some logic to this contention but no specific proof as far as we know.

Ulcerative colitis and some of the treatments have been associated with neuropathy but UC probably isn’t a direct cause.

Here are the names of some brands people with CMT wear:

• Drew
• Aetrex
• Nike
• Skechers
• New Balance
• Brooks
• Converse
• Keen
• Reebok
• Adidas
• Asics
• Proper
• Ecco
• Naot
• Hoka

No, I don’t think it would be more harmful than for someone who does not have CMT.

I am not aware of any reason why plasma donation should have any effects on CMT or vice versa.

The auditory nerves can be affected in many forms of CMT. Most of the literature mentions this in terms of hearing loss. The noises that are mentioned would be consistent with the term “tinnitus,” which can occur when the auditory nerves are disturbed. So it is certainly possible that these noises are related to CMT. I would suggest seeing an ENT physician and/or audiologist and determine if there are abnormalities of the auditory nerve or if the problem is caused by something else.

The main risk is for a patient with kidney insufficiency. I know of no relation to neuropathy unless you have mild kidney failure.

Yes, service dogs are available for people with CMT. Here is one site you can check out: https://canine.org/assistance-dogs/is-a-dog-right-for-you/

CMT, Multiple Sclerosis (MS) and Muscular Dystrophy (MD)are three completely separate and distinct diseases. Remember that our neuromuscular system really starts at the brain, which is the master computer, and sends signals to the motor (muscles) via the spinal cord (an intermediate connecting cable), which hooks up to the peripheral nerves (the connecting lines between brain and muscle).

CMT is primarily a disease of the peripheral nerves (the connecting lines between brain and muscle). CMT causes weakness and impaired sensory perception because the signal can’t get to and from the brain to muscle and skin, among other things. The muscles shrink because they aren’t getting the proper signals, but the muscles themselves are not directly diseased per se.

Muscular Dystrophy is a disease of the muscle itself, which causes weakness of varying degrees. There are many forms of MD. Sometimes the heart is involved because it is a muscle too. The lungs can also be affected because the breathing muscles are weak (similar to CMT, although in CMT it is because the phrenic nerves are affected, which in turn weakens the diaphragm, the main breathing muscle).

Multiple sclerosis is a disease of the brain and spinal cord. It can affect both movement and sensory perception and sometimes thinking processes.

No, there are no growth charts for CMT. Children at neuromuscular or pediatric clinics routinely get standardized growth charts to determine whether head growth as a sign of brain growth is appropriate. These are not disease-specific.

Yes. CMT is not contagious. As long as a person meets the basic eligibility requirements set by the American Red Cross (http://www.redcrossblood.org/donating-blood/eligibility-requirements), (s)he can donate blood.

Dr. Scherer writes, “I think that these are quite unrelated. Neuropathic pain probably results from the spontaneous activity of injured pain fibers in the nerves; most foot deformities result from imbalances in weakened muscles.”

Yes, fatigue is very common in people who have CMT, who expend far more energy to walk, stand, balance and do normal, everyday things than those who don’t.

Anyone with any type of CMT who visits a CMTA Center of Excellence can have his or her information submitted to the Rare Disease Clinical Research Network Patient Registry. Registrants will be sent alerts about current and future CMT studies and clinical trials. Opportunities to participate are also listed on the CMTA’s Patients as Partners in Research webpage, and people who complete a PAP profile may also choose to receive research updates.

Generally speaking, the answer is “no” because CMT affects the peripheral nerves and not the central nerves.

Most cases of CMT do not affect the internal organs. While some rarer forms may include organ involvement, this is very uncommon. Breathing can be affected from muscle weakness but the lung tissue is not involved. Bowel function can be affected by weakness of sphincters, but that’s very uncommon.

Peripheral nerves going to the diaphragm are affected in various types of CMT as these are large myelinated nerves. Abnormalities can be detected by nerve conduction studies, but they are not typically performed because many CMTers are not used to the technique and it is uncomfortable.

In most people, nerve abnormalities do not result in weak or paralyzed diaphragms. Typically this occurs only in more severely affected patients. A few types of CMT, typically those that are axonal forms and severe, are more likely to result in paralyzed diaphragms. Remember that clinical abnormalities in CMT are usually length-dependent, causing problems at the far ends of the longest nerves, which are usually the hands and feet. In more severe forms, shorter nerves have problems at their far ends. This includes the phrenic nerve, which goes to the diaphragm.

No, CMT is not a type of muscular dystrophy. CMT is primarily a disease of the peripheral nerves, whereas muscular dystrophy is a group of diseases of the muscle itself.

CMT causes weakness and impaired sensory perception because signals can’t get to and from the brain to muscle and skin, among other things. In the case of CMT, muscles atrophy because they aren’t getting the proper signals. When CMT affects breathing, it’s because CMT is affecting the phrenic nerves, which in turn weakens the diaphragm (the main breathing muscle).

With muscular dystrophy, disease in the muscle itself causes weakness of varying degrees. Sometimes the heart is involved because the heart is a muscle. The lungs can also be affected by muscular dystrophy, causing breathing muscles to be weak.

Not typically, but there are two exceptions:

(1) In the case of Hereditary Sensory Neuropathies (HSN) also known as Hereditary Sensory and Autonomic Neuropathies (HSAN), which fall under the CMT umbrella.

(2) In the case of genetic neuropathies that have known autonomic abnormalities, such as Familial Amyloid Polyneuropathies (FAP). Patients with genetic neuropathies also typically have liver, kidney, and eye problems. We include these neuropathies loosely under the CMT umbrella because they are genetic. Note that FAP, a fatal disorder, is now being successfully treated by ASOs (from IONIS) and RNAi (from Alnylam).

There can be some effects of CMT1A on hearing loss. To quote an abstract by Dr. Shy and his colleagues from 2015, “Audiologic results were consistent with hearing loss that is partly cochlear and partly neural in nature, particularly those with CMT1A.” An audiologist can test to determine the nature of the hearing loss, but there will be some overlap of age-related changes and effects of CMT. (See also, Hearing Loss and CMT.)

We know there are rare forms of CMT that are fatal. However, the cause of death would most likely not be CMT, because people die from breathing-related issues and cardiac arrest. The latter would most likely be listed as the cause of death.