This disease, one of the most common inherited neurological disorders, affects motor and sensory nerves throughout the body. It is usually not life-threatening, and rarely affects the brain. CMT is also called hereditary motor and sensory neuropathy (HMSN), or peroneal muscular atrophy.
CMT is caused by a chromosome mutation that is inherited from one or both parents. This mutation results in defects in the fibers or protective sheath of the peripheral nerves (the nerves that send signals between the spinal cord and the other parts of the body). Because of these defects, the peripheral nerves do not function properly and are highly susceptible to damage.
CMT is a progressive disease that commonly begins to affect people in adolescence or early adulthood. In many cases, symptoms begin in the lower legs and feet. The person may experience pain, numbness, weakness muscle degeneration and problems with balance and coordination. The person may develop deformities of the feet such as high arches and hammertoes, and may experience foot drop (a difficulty in holding up the foot when the leg is lifted). Foot drop can cause changes in gait and frequent tripping.
CMT can cause similar problems in the hands and forearms, resulting in loss of fine motor skills. It can also cause partial sight loss or hearing loss and scoliosis in the spine.
CMT cannot be cured, but its symptoms can be treated. Treatment options may include physical and occupational therapy, braces and other orthopedic devices, and medications. In some cases, surgery may be necessary to correct deformities.