Definition

Charcot-Marie-Tooth, also known as Hereditary Motor and Sensory Neuropathy (HMSN), is a group of inherited disorders that cause nerve damage. Symptoms can appear from birth and are genetically inherited, affecting the peripheral nerves such as those in the arms and legs. The disease is named after the three scientists who first discovered it in 1886: Jean-Martin Charcot, Pierre Marie, and Howard Henry Tooth.

Charcot-Marie-Tooth disease causes muscles to become smaller and weaker. It can also result in the loss of sensation to pain and temperature stimuli, loss of muscle contraction ability, and difficulty walking. Symptoms typically first appear in the feet and soles, then progress to the arms and hands.

In the United States, this disease is quite common and is one of the most prevalent genetic diseases affecting the nervous system. It is estimated that about 126,000 people in the United States and 2.6 million people worldwide are affected by this disease.

Causes

Charcot-Marie-Tooth disease is caused by genetic mutations in genes that form and maintain nerve tubes and axons responsible for transmitting signals to other nerves. Genetic mutations are changes in the abnormal arrangement of genes in human DNA. Charcot-Marie-Tooth occurs when there is a change in the genes that form and maintain nerve tubes and axons. These genetic mutations can be inherited from one or both parents and are not contagious through contact or air.

Risk factor

Since this disease is hereditary, the risk of developing Charcot-Marie-Tooth increases if there is a family member with the same condition. Additionally, other causes of nerve disorders like diabetes can produce symptoms similar to Charcot-Marie-Tooth. If Charcot-Marie-Tooth and diabetes occur simultaneously, the symptoms can worsen. Treatments like chemotherapy can also worsen symptoms, so it's important to report all treatments to the doctor.

Symptoms

The signs and symptoms of this disease usually appear in adolescence or early adulthood but can develop and worsen in middle age. As this disease is progressive, symptoms become noticeable as the disease worsens. Symptoms include:

• Weakness in the legs, heels, and soles
• Reduced muscle mass and size in the legs and soles
• High arches in the feet
• Deformities in the big toe muscles (hammertoes)
• Decreased ability to run
• Difficulty lifting the heel
• Abnormal gait (walking problems)
• Frequent falls or tripping
• Reduced sensation or numbness in the soles and legs

Diagnosis

Doctors will follow a structured approach to diagnosis, starting with an interview session with the patient, conducting a physical examination, and performing supporting tests.

During the interview, the doctor will ask about the patient's complaints, associated complaints, how long these complaints have been present, job and daily activity history, history of injuries, treatment history, past medical history, and family medical history, especially if any family members have Charcot-Marie-Tooth disease.

Next is the physical examination. The doctor will conduct a thorough physical examination and then perform more specific tests to check muscle strength and nerve function. Muscle strength is assessed by observing changes in the shape of the arms, legs, and soles, then examining the ability to move the legs and arms. Nerve function is tested by stimulating pain, temperature, and position changes.

Diagnostic tests to confirm the diagnosis include:

• Genetic testing with a blood sample
• Electromyography (EMG) to assess electrical activity in nerves and muscles
• Nerve conduction studies to measure the strength and speed of electrical signals
• Nerve biopsy, which involves taking a small nerve tissue sample and examining it under a microscope

Management

There is currently no cure for Charcot-Marie-Tooth disease, and it rarely threatens life. However, it can reduce the quality of life for patients. Therefore, the management aims to provide supportive therapy and improve patients' quality of life. These management strategies include:

• Physical Therapy

Physical therapy is useful for strengthening and stretching muscles to prevent stiffness and loss of muscle function. The therapy carried out includes stretching exercises taught by therapists or physiotherapists who have been appointed by doctors. By doing this therapy muscle disability can be prevented. 

• Occupational Therapy

Occupational therapy helps patients perform daily activities more easily. Charcot-Marie-Tooth disease can cause difficulty moving the hands and fingers, so occupational therapy focuses on gripping and finger flexibility movements, such as writing or buttoning clothes.

• Orthopedic Devices

Certain orthopedic devices, like boots or shoes with additional heel support, can improve walking. Orthopedic devices can also maintain mobility and prevent injuries to the legs and feet.

• Surgery

Surgery is an option for severe deformities. Foot surgery can help reduce pain and improve walking ability. However, if there is numbness or reduced sensory sensation, surgery may not help.

• Joining Support Groups

Joining a support group with other Charcot-Marie-Tooth patients allows individuals to share experiences and provide psychological support to improve their quality of life.

Complications

Complications of Charcot-Marie-Tooth disease depend on the severity in each individual. Foot deformities and walking difficulties are the main serious problems. Muscles can become weaker, and patients may suffer injuries more frequently because of axon disorders in the nerves, causing "pain" signals not to be sent, so they are unaware of injuries. Patients may also have difficulty breathing, swallowing, or speaking if the muscles responsible for these activities are affected by the disease.

Prevention

There is no specific way to prevent Charcot-Marie-Tooth disease since it is genetically inherited. However, screening by visiting a neurologist during adolescence or early adulthood can be a preventive step if there is a family history of the disease.

Additionally, if planning to marry or have children, screening before marriage to detect any family history of Charcot-Marie-Tooth disease is advisable.

It is also recommended to maintain a healthy lifestyle, including meeting nutritional and fluid needs with a balanced diet, drinking 1.5 to 2 liters of water per day, avoiding smoking and alcohol, and staying active with moderate exercise for at least 150 minutes per week.

When to see a doctor?

It is recommended to see a doctor immediately if there is a decline in movement function and numbness in the legs and soles, especially if there is a family history of Charcot-Marie-Tooth disease. Consult a neurologist for appropriate treatment.