Charcot-Marie-Tooth disease (CMT) is a group of inherited conditions that damage the peripheral nerves.
CMT is also known as hereditary motor and sensory neuropathy (HMSN).
Charcot-Marie-Tooth is a degenerative nerve disease that usually appears in adolescence or early adulthood.
Muscle weakness, decreased muscle size, decreased sensation, hammer toes and high arches are symptoms.
The peripheral nerves are found outside the main central nervous system (brain and spinal cord). They control the muscles and relay sensory information, such as the sense of touch, from the limbs to the brain.
People with CMT may have:
- muscle weakness in the feet, ankles, legs and hands
- an awkward way of walking (gait)
- highly arched or very flat feet.
- numbness in the feet, arms and hands
For people with CMT, the nerves of the arms and legs work less well than usual. This happens gradually and leads to wasting of the muscles that are served by those nerves. The muscles of the feet, legs and hands are often most affected. Over time, they become weaker and harder to control.
The effects of Charcot-Marie-Tooth disease can vary widely. Some people may be only slightly affected – for example, high-sided shoes may be enough to deal with weakness of the legs and feet. Other people may need walking aids like sticks. Some people may need to use a wheelchair.
The onset of symptoms usually occurs in childhood or during the teenage years. The legs are most commonly affected first.
Symptoms of CMT are progressive and can include:
- weakness in the muscles of the hands and feet.
- ankle weakness, with ‘rolling-over’ – this is a common early symptom. Later, the person loses the ability to bend their foot upward
- handgrip is affected – it may become difficult to do things like open screw-top jars or turn taps
- high foot arches (this is known as ‘pes cavus’) and clawed toes
- high-stepping gait and ‘slapping’ of the feet on the floor while walking
- muscle wasting in the legs and arms
- poor balance and occasional falls
- loss of sensation, such as reduced ability to feel pain in the feet and hands
- scoliosis (abnormal sideways curvature of the spine) in some cases.
The symptoms of CMT usually start to appear between the ages of five and 15, although they sometimes don’t develop until well into middle age or later.
CMT is a progressive condition so the symptoms slowly get worse, making everyday tasks increasingly difficult.
Podiatry treatment of CMT is aimed at providing exercises, orthotics, footwear and aids in order to enhance walking and offload high pressure areas that can occur as a result of foot deformity.