Charcot Marie Tooth Disease

Charcot-Marie-Tooth Disease: What Is It?

There is a peripheral nerve disorder known as Charcot-Marie-Tooth disease, or CMT for short. This is an inherited condition where the nerves on the spinal cord and brain’s surfaces are affected. These peripheral nerves connect the body to the central nervous system. The three scientists who discovered the disease—Henry Tooth, Pierre Marie and Jean-Martin Charcot – were the ones that the disease was named after. It is also often called personal muscular atrophy or hereditary motor and sensory neuropathy.

This is actually one of the most common neurological disorders that is inherited in the United States, according to the National Institute of Neurological Disorders and Stroke, and affects one in every 2,500 people.

CMT Causes

Since it is congenital, people inherit it from at least one of their parents and will have it from birth. CMT occurs due to at least one defective gene and disturbs the structure and function of the axons and sheaths of the nerves – the layers that insulate around the nerves.

There are rare cases where people have been born with the disease even though neither parent suffers from the defective gene.

There are five different types of the disease with separate causes:

#1: this is where there is a duplication of the chromosome 17 or a mutated gene is inherited. It instructs the body in making the proteins to generate the protective myelin sheath around the nerve. This form of CMT is the most common of all.

#2: This is where the axon of the nerve cell is defected, due to the mitofusin 2 gene.

#3: This is a rare one that is caused by the PMP-22 or P0 gene being mutated. It also goes by the name of Dejerine-Sottas disease.

#4: This happens due to several genes mutating, including the GDAP1, MTMR2, MTMR13, NCG1, PRX, FDG4, EGR3, SH3TC2 and the FIG4.

CTMX: The fifth type is due to a mutation on the X chromosome in the connexin-32 protein.

The Charcot-Marie-Tooth Disease Symptoms

Most of the sufferers will have symptoms in their adolescent years but it can also take until mid-adulthood for them to appear. The nerves controlling the voluntary activities for the muscles are affected.

Most of the common symptoms include:

  • Trouble standing
  • Tripping regularly
  • Weak legs
  • Taking high steps while walking
  • Trouble walking

The physical signs of the disease are:

  • Inverted lower legs
  • Deformity of the feet

As the disease progresses, some patients struggle with moving their wrists, hands, feet, fingers and tongue

Getting a DMT Diagnosis

To be able to diagnose CMT, your doctor will need to do a series of tests to test the reason and amount of nerve damage. These tests include a nerve biopsy, genetic tests, a nerve condition study and an electromyography.

The genetic tests will help to check for the defects in your genes to determine the reason for the CMT and requires a sample of your blood.

The electromyography involves a thing needle being inserted into your muscle and it is attached to a machine by a wire. You will need to relax and flex the muscle and the machine will measure the amount of electrical activity in the muscle.

A surgeon is required for the nerve biopsy and will remove part of a calf nerve to test it. Upon examining, the surgeon will be able to see if there is CMT in the nerve.

A nerve conduction study can be done to test for the electrical signals function. Small electrodes are placed into the skin and will transmit a little electricity. If there is a weak response, it is possible that you have CMT.

CMT Treatments

The most common form of treatment is physical therapy, which involves light exercises and stretches. This will improve the strength of the muscle and prevent any muscle loss (atrophy).

Those with a great loss in the extremities will usually be given devices to help with pushing, grabbing and reaching items.

To help prevent injury because of the weakness in the muscles and to offer extra stability, splits, braces and other orthopedic devices are used. Those who struggle to grip will usually have thumb splints.

Surgery may be required for those with a severe deformity to the foot.