charcot

Charcot-Marie-Tooth disease (CMT) is a group of genetic nerve disorders. It is named after the three doctors who first identified it. In the United States, CMT affects about 1 in 2,500 people.

CMT affects your peripheral nerves. Peripheral nerves carry movement and sensation signals between the brain and spinal cord and the rest of the body. Symptoms usually start around the teen years. Foot problems such as high arches or hammertoes can be early symptoms. As CMT progresses, your lower legs may weaken. Later, your hands may also become weak.

Doctors diagnose CMT by doing a neurologic exam, nerve tests, genetic tests, or a nerve biopsy. There is no cure. The disease can be so mild you don't realize you have it or severe enough to make you weak. Physical therapy, occupational therapy, braces and other devices and sometimes surgery can help.

NIH: National Institute of Neurological Disorders and Stroke

Diabetes is a disease in which your blood glucose, or blood sugar, levels are too high. Glucose comes from foods you eat. The cells of your body need glucose for energy. A hormone called insulin helps the glucose get into your cells.

With type 1 diabetes, your body doesn't make insulin. With type 2 diabetes, your body doesn't make or use insulin well. Without enough insulin, glucose can't get into your cells as quickly as usual. The glucose builds up in your blood and causes high blood sugar levels.

Foot problems are common in people with diabetes. They can happen over time when high blood sugar damages the nerves and blood vessels in the feet. The nerve damage, called diabetic neuropathy, can cause numbness, tingling, pain, or a loss of feeling in your feet.

If you can't feel pain, you may not know when you have a cut, blister, or ulcer (open sore) on your foot. A wound like that could get infected. The infection may not heal well because the damaged blood vessels can cause poor blood flow in your feet.

Having an infection and poor blood flow can lead to gangrene. That means the muscle, skin, and other tissues start to die. If you have gangrene or a foot ulcer that does not get better with treatment, you may need an amputation. This is a surgery to cut off your damaged toe, foot, or part of your leg. It may prevent a bad infection from spreading and could save your life.

But there's a lot you can do to prevent a foot wound from becoming a major health problem.

The best way to protect your feet is by controlling your blood sugar levels every day. This will help keep nerve and blood vessel damage from getting worse. The next step is to keep the skin of your feet healthy.

Good foot care for people with diabetes includes:

• Checking your feet every day. Look for cuts, redness, and other changes in the skin and toenails, including warts or other spots that your shoes could rub. Make sure to check the bottoms of your feet too.
• Washing your feet every day. Use warm water and soap. Don't soak your feet because that can dry out your skin. After you dry your feet, you can use talcum powder or cornstarch between your toes. They soak up moisture that can cause infection. If you use lotion, don't apply it between your toes.
• Asking your doctor how to remove corns and calluses safely. Thick skin on your feet can rub and lead to sores. But removing it the wrong way could damage your skin. So you don't want to cut the skin or use medicated pads or liquid removers.
• Trimming your toenails straight across with a clipper. If it's hard for you to trim your own toenails, or if they're thick or curve into the skin, have a podiatrist (foot doctor) do it for you.
• Always wearing well-fitting shoes and socks or slippers to protect your feet when walking. You don't want to walk barefoot, even indoors. And be sure your shoes are smooth inside. A seam or pebble could rub your skin raw.
• Protecting your feet from heat and cold. Use sunscreen on exposed skin and don't walk barefoot at the beach. In cold weather, wear warm socks instead of warming your feet near a heater or fireplace.
• Keeping the blood flowing in your feet. Put your feet up when you're sitting. Wiggle your toes and circle your feet throughout the day. Don't wear tight socks. And get plenty of activity that's not too hard on the feet, such as walking.
• Getting your feet checked at your health care visits. Even if you haven't noticed a problem, it's good to have your health care provider look at your feet.

Serious foot problems can develop quickly. See your health care provider right away if you notice:

• A cut, blister, or bruise on your feet that doesn't start to heal in a few days
• Red, warm, or painful skin on your feet
• A callus with dried blood inside
• A foot infection that becomes black and smells bad that could be gangrene

Remember, controlling your blood sugar and caring for your feet every day are the best steps you can take to prevent serious diabetic foot problems.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

Each of your feet has 26 bones, 33 joints, and more than 100 tendons, muscles, and ligaments. No wonder a lot of things can go wrong. Here are a few common problems:

• Bunions - hard, painful bumps on the big toe joint
• Corns and calluses - thickened skin from friction or pressure
• Plantar warts - warts on the soles of your feet
• Fallen arches - also called flat feet

Ill-fitting shoes often cause these problems. Aging and being overweight also increase your chances of having foot problems.

Genetic disorders are health conditions caused by changes (also called mutations or variants) in your genes. Genes are parts of DNA found in your cells that carry instructions for how your body grows, develops, and functions. Many genes tell your body how to make proteins, which are needed for your body to work properly.

A genetic disorder happens when a gene variant changes how a protein is made. The variant may cause the protein to work poorly or not be made at all. If genes don't make the right proteins, or don't make them correctly, it can lead to a genetic disorder.

Not all gene changes cause disease. Often, these changes have no effect. But sometimes, even a small change in DNA can affect how proteins are made.

Gene variants can be grouped into two main types:

• Inherited variants (also called germline variants) are passed down from your parents. They come from egg or sperm cells.
• Non-inherited (also called somatic variants) are not passed down from your parents. They happen during your lifetime. They may be caused by things like harmful chemicals or ultraviolet (UV) rays from the sun.

Genetic disorders may be caused by:

• Single gene disorders are caused by changes in one gene. Examples can include sickle cell anemia, where a change in a single gene can cause the condition, and Charcot-Marie-Tooth disease, where a variant in one of many different genes can cause the condition.
• Chromosomal disorders are caused by missing, extra, or altered chromosomes. Chromosomes are structures that carry genes. These disorders involve changes in the number of chromosomes people have or changes in the structure of one or more chromosomes. An example is Down syndrome, which is caused by an extra copy of chromosome 21.
• Complex (multifactorial) disorders are caused by changes in many genes. Each change alone may not cause the disease, but together they increase the risk. Lifestyle and environmental factors, such as exercise, diet, or exposure to pollutants, also play a role. Colon cancer is an example.

Some genetic conditions are passed down through families (inherited) in one of several patterns, depending on the specific gene involved.

Patterns of inheritance can include:

• Dominant means you only need one changed gene to cause the condition.
• Recessive means you need two changed copies of the gene (one from each parent) for the condition to occur.
• X-linked conditions involve genes located on the X chromosome. These conditions often affect males more frequently.
• Mitochondrial conditions are passed down by the mother.

Your health care provider may check for a genetic condition based on:

• A physical examination.
• Your personal medical history.
• Your family health history.
• Laboratory tests, including genetic testing.

NIH: National Library of Medicine

Nerves are like wires that carry messages back and forth between your brain and your body. Your peripheral nerves branch off from your brain and spinal cord and connect to all parts of your body, including your muscles and organs. Peripheral nerves carry messages from your brain that control your movement, breathing, heartbeat, digestion, and more. They also carry messages from your body to your brain, so you can feel things, such as pain, heat, and cold.

Peripheral nerve disorders happen when one or more peripheral nerves are damaged. Damaged nerves may not carry messages correctly, or they may not work at all. As a result, you may have pain, trouble walking, or a variety of other problems, depending on which nerves are involved.

Peripheral nerve disorders are very common. There are more than 100 different types.

Many things can damage nerves and lead to peripheral nerve disorders:

• Diabetes is the most common cause of peripheral nerve disorders. Most people with diabetes will develop diabetic nerve problems.
• Physical injury (trauma) that stretches, crushes, squeezes, cuts, or puts pressure on one or more nerves. Some examples of peripheral nerve disorders from physical injury include complex regional pain syndrome and brachial plexus injuries.
• Health conditions, including:
  • Certain cancers and their treatment (chemotherapy and radiation therapy).
  • Infections, such as HIV and Lyme disease.
  • Problems with blood or blood vessels.
  • Autoimmune diseases, such as rheumatoid arthritis and lupus.
  • Kidney or liver disease.
• Certain medicines.
• Contact with certain toxic substances, such as lead or mercury.
• Alcohol use disorder (AUD) and smoking.
• Vitamin imbalances, especially a lack of vitamin B12.
• Your genes, including changes in your genes or conditions that you inherit from your parents, such as Charcot-Marie-Tooth disease.

In certain cases, the cause of peripheral nerve disorder is not known.

The symptoms of peripheral nerve disorders depend on which nerves are affected, what is causing the damage, and how serious it is:

• Weak or aching muscles
• Problems with balance, walking, or using your arms and hands
• Cramps or twitching muscles
• Muscle shrinking

• Tingling, numbness, or pain often in the hands and feet
• Not being able to feel heat, cold, or pain, such as a cut on your foot
• Pain from even light touch

• A heartbeat that's too fast or too slow
• Trouble swallowing
• Sweating too much or too little
• Vomiting, diarrhea, or constipation
• Problems with urination or sexual function

Symptoms may range from mild to very strong. They may develop quickly over days or slowly over months and years. But they are rarely life-threatening.

To find out if you have a peripheral nerve disorder, your provider will:

• Ask about your medical history
• Ask about your family health history
• Do a physical exam
• Order tests, which may include:
  • Blood tests
  • Genetic tests
  • Nerve tests that measure:
    • Electrical activity in your nerves and muscles
    • How well your autonomic nerves are working
  • A biopsy of nerve or skin tissue
  • CT or MRI scan to see what may be pressing on your nerves

It's important to treat any conditions that are causing nerve damage. In certain cases, that will allow your nerves to heal over time.

Treatment for symptoms depends on the type of peripheral nerve disorder you have, where it is, and how severe. Treatment options include:

• Braces or splints
• Over-the-counter patches and skin creams
• Prescription medicines
• Non-drug pain management, such as electrical stimulation or relaxation therapy
• Surgery to relieve pressure on a nerve

You can help prevent peripheral nerve disorders by:

• Managing health conditions that may cause nerve damage, especially diabetes
• Preventing falls and accidents
• Avoiding toxic substances
• Being careful to avoid repeated motions and body positions that press on your nerves
• Eating a balanced diet, exercising, limiting alcohol, and not smoking

NIH: National Institute of Neurological Disorders and Stroke