What is Charcot-Marie-Tooth Disease (CMT)? Let's talk about it simply!

Do you sometimes feel like your limbs are a little numb, or your muscles are a little weak? Maybe your legs get tangled when you walk, or do you feel like there is a slight change in the shape of your legs? One of the reasons for these things is Charcot-Marie-Tooth Disease (CMT) , which we are going to talk about today. This name may sound a little strange, but it is very important to know about it.

So, what is this Shako-Marie-Tooth (CMT)?

Simply put, CMT is a condition that affects the nerves that control our body's muscles. It is mainly caused by a genetic mutation. This means that you can inherit this gene from either your mother, your father, or both.

CMT is one of the most common genetic peripheral neuropathy . "Peripheral nerves" refers to all the nerves that branch out from our brain and spinal cord (that is, the central nervous system). These nerves are like the roads that lead from the main cities of our country to remote areas. These nerves are what carry sensations to our limbs, fingers, and muscles.

Who is most affected by this disease?

This condition called CMT can affect people of any race or ethnicity. It affects both men and women equally. However, it is considered a relatively rare disease worldwide. Research suggests that nearly one million people worldwide suffer from this condition.

How does CMT affect our bodies?

To understand this, we first need to know a little about our nerve cells, or neurons . Neurons are like little messengers that carry information around our bodies.

A little more about neurons

Each neuron has several main parts:

• Cell body: This is like the main control center of the neuron.
• Axon: This is the long, arm-like part that extends out from the cell body. Think of it like an electrical wire. This is where electrical signals travel. At the end of the axon are little finger-like structures called synapses . These synapses convert electrical signals into chemical signals and pass information to other nearby neurons.
• Dendrites: These are small, branch-like structures that extend from the cell body. They are named so because they look like the branches of a tree. These dendrites receive chemical signals from other neurons.
• Myelin: This is the protective fatty sheath that surrounds the axons of most neurons. It's like the plastic covering around an electrical wire. This myelin sheath allows signals to travel along the axon quickly.

Now, in CMT disease, these neurons are damaged in two main ways.

1. Myelin loss: CMT can sometimes damage this myelin sheath. Or myelin may not form properly in the first place. However, this slows down the speed at which nerve signals travel. It's like a wire with a broken plastic sheath leaking current.

2. Axon problems: When axons begin to shrink or weaken due to CMT, the strength of the signals passing through that neuron decreases.

In some types of CMT, the speed of nerve signals is only slightly reduced, but that's enough to cause symptoms. But it's hard to say for sure whether the problem is with the myelin or the axon. Experts call these "intermediate" types.

Not all neurons in our bodies are the same length or size. The longest neurons that run along our spinal cord to our legs and feet are the ones that are affected first in CMT . The hands and arms can also be affected, but this usually doesn't happen early in the disease.

What are the symptoms of CMT disease?

Symptoms of CMT usually begin in adolescence, around the age of ten or twelve . However, they can begin earlier, in childhood, or in middle age. The symptoms appear gradually, gradually increasing over time.

There are two main types of symptoms in CMT, depending on which nerve signals are affected. These signals are called motor and sensory .

• Motor signals: These are the signals that go from our brain to our muscles. These signals tell our muscles to "move here and there." So, when there is a problem with the transmission of these motor signals, we cannot control our muscles properly. Especially in our limbs.
• Muscle weakness.
• Maybe conditions like paralysis .
• Muscle atrophy is the shrinkage of muscle tissue .
• Decreased or lost reflexes.
• Toe deformities, for example, a condition called hammertoes .
• Foot drop , which means the inability to lift the sole of the foot and causing it to fall downward, or the arch of the foot going too high.
• Frequent trips and falls due to changes in walking patterns ( gait disorders ).
• Frequent ankle sprains .
• Difficulty breathing (this is usually only seen in severe cases).

• Sensory signals: These are the signals that go to the brain from different parts of our body. These signals tell the brain, "This feels like this." So, when there is a problem with these sensory signals, we experience changes in the sensations in our lower legs, feet, and hands.
• Numbness or tingling .
• Loss of feeling of warmth or pain in the lower legs, feet, or palms.
• A feeling like something is crawling along my legs.
• Chronic pain .
• Decreased or loss of sensation in other senses, especially vision and hearing (these are not very common, only seen in certain subtypes of CMT).

What causes CMT?

Every nerve cell in our body has something called DNA . This DNA is like an instruction book. It is this DNA that gives the cells instructions to do their job properly. A genetic mutation is like a mistake in a letter in this DNA instruction book. Our cells follow the instructions in this DNA exactly. So, because of such mutations, the cells start to function incorrectly. That is how CMT develops.

CMT can be caused by mutations in a single gene or by mutations in multiple genes. Researchers have now identified dozens of genetic mutations that cause different types of CMT.

There are two main ways you can get a DNA mutation:

• Inherited: You get these DNA mutations from your mother, your father, or both.
• Spontaneous: These mutations occur while you are developing as a fetus in your mother's womb. These are sometimes called "de novo" mutations, which means "new."

Are there different types of CMT?

Yes, there are seven main types of CMT. However, CMT type 1 (CMT1) and CMT type 2 (CMT2) are the most common. The other types are much rarer.

• CMT type 1 (CMT1): This type affects myelin, so signals travel slowly. Symptoms usually appear between the ages of 10 and 40. However, some people may remain symptom-free for decades. This is the most common type of CMT. It is about twice as common as CMT2.
• CMT2: This type affects the axons. Nerve signals are weak and may travel a little slower. About a third of CMT patients fall into this type.

Apart from this, there are other types of CMT:

• CMT3 (also called Dejerine-Sottas disease ).
• CMT X-linked (CMTX).
• Dominant Intermediate CMT (CMTDI).
• Recessive intermediate CMT (CMTRI).

Is this a contagious disease?

No, CMT is not a contagious disease. It cannot be spread from one person to another.

How is CMT disease accurately diagnosed?

A doctor will usually use several methods to determine exactly what type of CMT you have and how severe it is. These include a physical and neurological exam , laboratory tests, imaging tests, and other diagnostic tests. The doctor will also ask about your family medical history, your symptoms, and lifestyle information.

What kind of tests are done for this?

If you suspect you have CMT, you are more likely to have these tests:

• Electromyogram (EMG) , specifically nerve conduction tests , measure how quickly and strongly your nerves conduct signals.
• Genetic testing: This can detect whether there are genetic mutations that cause CMT.
• Spinal tap / lumbar puncture: This is used to examine the cerebrospinal fluid. This is not done for everyone.
• Magnetic Resonance Imaging (MRI) .
• Ultrasound examination.
• Evoked potential tests: This helps to see if there are subtypes of CMT, especially those that affect hearing and vision.
• Nerve biopsy: This is not done very often. It involves taking a small piece of tissue from a nerve and examining it.

What are the treatments for CMT? Can it be completely cured?

To be honest, there is currently no way to completely cure CMT or directly treat the disease . However, the symptoms and effects caused by this disease can usually be treated.

What kind of medication/treatment is used?

The most commonly used treatments for CMT are:

• Physical therapy and occupational therapy: These can help you strengthen your muscles, improve your balance, and make everyday tasks easier.
• Mobility aids such as leg braces, walkers , and wheelchairs .
• Special shoes that adapt to changes in the shape of the feet.
• Surgery to correct changes in the shape of the arms, legs, hips, or back.
• Medications for some symptoms, especially chronic pain.

There are other treatments available for CMT, but they vary depending on the specific subtype of the disease. Your doctor is best able to advise you on which treatments will be most helpful for you, as they can tailor the information to your specific condition and needs.

Your doctor will also tell you more about the side effects and complications that may occur with different treatments, and how long it will take for you to recover and return to normal life.

What can you expect when living with CMT? What does the future hold?

Generally speaking, CMT is not a serious condition . However, some of the more severe subtypes of the disease can be serious. Many people with CMT have problems walking, moving, or experiencing some sensations. However, these problems rarely shorten their lifespan. With special assistive devices, especially foot and ankle braces or shoes, many people with CMT can live a normal life and lead happy, fulfilling lives.

Remember, you can live a good life even with CMT. All you need is proper medical advice and support.

In severe forms of the disease, the most dangerous thing is the weakening of the muscles that control breathing and swallowing. This can lead to respiratory failure , pneumonia, and even life-threatening conditions. These serious conditions are more likely to occur if CMT symptoms begin early in life, especially in childhood.

How long does CMT last?

CMT is a permanent, lifelong condition . You are born with it, but most people don't develop symptoms until they are adults. There is currently no cure for it, and it doesn't get better on its own.

Is there a way to prevent CMT from developing?

Shaklo-Marie-Tooth disease is either something you inherit or something that occurs unexpectedly. Therefore, there is no way to prevent it or reduce the risk of developing it .

Although CMT cannot be prevented, genetic testing and counseling can help you find out if your children are at risk of developing it. Your doctor or a genetic counselor can tell you more about this.

What happens if someone with CMT gets pregnant?

Most people with CMT can have children. However, some complications may occur or be more likely to occur. Many pregnant women with CMT may need extra care during pregnancy or childbirth. They also have a slightly higher risk of bleeding after giving birth.

Your doctor will tell you more about whether this applies to you and what you can do. They may refer you to specialists, especially maternal-fetal medicine physicians who specialize in complex pregnancies.

How can I take care of myself and manage my symptoms?

If you have CMT, your doctor is the best source of information about what you can and should do to take care of yourself and manage this condition. They can monitor the progress of your condition and recommend treatments or strategies to help you.

Typically, you should do these things:

• See your doctor as recommended. This is very important because your doctor can see how your condition is progressing and how it is affecting you. They may be able to change your treatment plan or make suggestions about things that might help you.
• Follow your treatment plan exactly. This means taking your medications and using your medical equipment as prescribed by your doctor. These are very important, as they can help you get relief from your symptoms or slow down the rate at which some symptoms get worse.
• Avoid drugs or substances that are harmful to the nervous system (neurotoxic substances). These are things that have a high risk of damaging your nervous system. Your doctor will probably tell you to limit or stop drinking alcohol completely. Because drinking too much alcohol can also damage the nervous system.

When should you see a doctor? When is emergency treatment needed?

Your doctor will schedule regular follow-up visits to monitor your condition and symptoms. Also, if you notice any changes in your symptoms, especially if they interfere with your normal activities, you should see your doctor.

When should you go to the hospital (ETU) for emergency treatment?

Most people with CMT do not need emergency treatment, unless they have difficulty controlling their leg muscles and fall. If you fall, you should seek medical attention if there is any risk of injury to your head , neck, or back . This is because CMT can cause serious complications if any part of your central nervous system is damaged.

A few more small questions...

Is Shaklo-Marie-Tooth disease the same type of disease as Multiple Sclerosis (MS)?

No. Multiple sclerosis (MS) is a condition in which the myelin sheath around neurons in the brain and spinal cord becomes inflamed. Some types of CMT have similar symptoms, but apart from that, the two are very different conditions.

Is CMT an autoimmune disease?

No, CMT is not an autoimmune disease. However, certain mutations in the PMP22 gene, which often causes CMT, may increase the risk of developing certain autoimmune diseases.

Does CMT disease affect the brain?

In general, CMT does not directly affect the brain . CMT mostly affects long neurons and nerve fibers. These are found in the spinal cord and peripheral nerves, not in the brain. Some subtypes of CMT can cause small changes in the structure of the brain, but experts have not yet found that this has a significant, worrying effect on brain function.

The most important things to remember from what we have discussed (Take-Home Message)

Chaucer-Marie-Tooth disease (CMT) is a group of conditions that affect your peripheral nervous system, the network of nerves that connects your brain and spinal cord. The condition mainly affects your ability to control muscle movement and the way you feel and perceive the world around you. Many people with this condition need assistive devices or appliances. Some need surgery or things like physical therapy or occupational therapy.

However, CMT is not usually a dangerous or life-threatening condition. Most people with it live a normal lifespan, and lead happy, fulfilling lives. The important thing is to remember that you are not alone and that you can get help to live successfully with this condition. If you have any questions or concerns about this, be sure to talk to a doctor.

` Shako-Marie-Tooth, CMT, Neurological diseases, Genetic diseases, Muscle weakness, Peripheral neuropathy, Neurons