What is Charcot-Marie-Tooth disease?

Charcot-Marie-Tooth disease is an inherited nerve defect that causes abnormalities in the nerves that supply your feet, legs, hands, and arms. It affects both your motor and sensory nerves. Motor nerves carry signals from your brain to your muscles, telling them to move. Sensory nerves carry sensations, such as heat, cold, and pain back to your brain. Charcot-Marie-Tooth is considered a peripheral neuropathy because it affects nerves outside of your brain and spinal cord.

This disease is named after the 3 doctors who first described the disease in 1886. It is one of the most common types of inherited nerve diseases.

What causes Charcot-Marie-Tooth disease?

Charcot-Marie-Tooth is almost always caused by a gene defect inherited from one or both parents. The genetic information that one or both of your parents passes on to you determines the type of gene mutation you have. This gene mutation determines what symptoms you have and how old you are when they start.

Some genetic defects affect the axon, the part of the nerve that sends signals to other nerves. Other genetic defects affect the protective lining around the axon, called the myelin sheath. Either type of defect can lead to long-term damage of the nerve and affect its ability to send signals.

What are the symptoms of Charcot-Marie-Tooth disease?

Charcot-Marie-Tooth symptoms may vary from person to person, though they usually start in your feet and legs. Over time, the disease may also affect your hands and arms. Symptoms usually first appear in teens and young adults.

Common symptoms include:

• Weakness of your foot and lower leg muscles

• Foot deformities, including a high arch and bent toes (hammer toes)

• Difficulty lifting your foot while walking (foot drop)

• Loss of muscle around your hands and feet

• Numbness, tingling, burning, or loss of temperature sensation in your hands and feet

• Discomfort or pain in your hands and feet

How is Charcot-Marie-Tooth disease diagnosed?

A specialist called a neurologist may diagnose Charcot-Marie-Tooth after doing a complete neurological exam and asking about your family history. Tests that help make the diagnosis include:

• A blood test to look for genetic defects

• Nerve conduction studies to measure the strength and speed of electrical signals passing through your nerves

• Electromyography to measure how well your muscles respond to electrical stimulation

• Nerve biopsy, which involves taking a small piece of a nerve and examining it under a microscope

If you have no family history of this disease, your healthcare provider may consider looking for other causes of your symptoms.

How is Charcot-Marie-Tooth disease treated?

There is no cure for Charcot-Marie-Tooth, but these treatment options can help:

• Physical therapy to strengthen and stretch your muscles. This may help prevent or delay disability caused by weakness and deformity.

• Occupational therapy to help with your daily activities. This includes using special devices like rubber grips, or changing from buttons and zippers to Velcro.

• Orthopedic devices like ankle braces, high-top boots, and thumb splints.

• Pain medicines if needed.

What are the complications of Charcot-Marie-Tooth disease?

Charcot-Marie-Tooth is not a fatal disease, and most people live to a normal age and remain active. In rare cases, it may affect the muscles you need to breathe. Because this can be especially dangerous at night, you may need a nighttime breathing assistive device.

More common complications include:

• Injuries from falls

• Worsening of the disease that certain prescription drugs can cause

• Injuries or infections of the feet that go unnoticed because of lack of pain and temperature sensation

Living with Charcot-Marie-Tooth disease

It is very important to learn as much as you can about your disease, and work closely with your neurologist. Genetic counseling may be important for family planning. Other ways to manage your disease include:

• Getting regular low-impact aerobic exercise

• Avoiding alcohol except in moderation

• Eating a healthy diet and maintaining a healthy weight

• Checking your feet regularly for any injury or infection

• Certain prescription drugs can worsen symptoms, so when taking a new prescription drug for the first time, check with your healthcare professional about any possible effects on your condition.

When should I call my healthcare provider?

• If you have been diagnosed with Charcot-Marie-Tooth disease, talk with your healthcare provider about when you might need to call them. They will likely advise you to call if you have: Any new or worsening symptoms

• Signs of foot injury or infection

• Trouble breathing

Key points

• Charcot-Marie-Tooth disease is an inherited disorder that affects the nerves supplying the feet, legs, hands, and arms. It is caused by gene defects that are nearly always inherited from a person's parents.

• Symptoms often begin in the teen or early adult years and can include weakness in the feet and legs and foot deformities. Over time, the hands and arms might be affected as well.

• Charcot-Marie-Tooth can't be cured at this time, but treatments such as physical and occupational therapy can often be very helpful. Most people with this condition live to a normal age and remain active.