Charcot Marie Tooth

What is Charcot Marie Tooth (CMT)?

Charcot Marie Tooth (CMT) is the name commonly given to a group of neurological disorders affecting 1 in 2000 individuals. In CMT the nerves to the lower legs and arms slowly degenerate and there is a progressive weakness and wasting in the muscles they supply. Symptoms can vary considerably even between members of the same family, from almost no symptoms to severe foot drop and contractures in the hands. Some people with CMT have involvement of the sensory nerves and lose sensation as well as motor function. The condition is often classified according to which part of the nerve is involved. In CMT 1, the myelin sheath, which surrounds the nerve, is affected while in CMT 2 the central axon is degenerating. If you imagine a nerve is like a power cord, the myelin sheath is like the plastic coating, while the axon is similar to the copper wires inside the cord.

How Does a Child Get CMT?

CMT is an inherited neuromuscular disorder and as it is not one but a group of disorders, it can be passed on in many ways. The most common form is CMT 1 which is usually passed on to the child if one parent has the condition. Each child in a family then has a 50% chance of having CMT. Some children with CMT1 inherit the condition from both parents who carry a recessive gene but do not have symptoms. In this case the symptoms are often more severe and in some cases a wheelchair may be needed in later life. Sometimes the condition is inherited from the mother (X-linked).

What are the Signs of CMT1?

In the milder form of the condition people remain relatively mobile and with full independence. However there is weakness to a varying degree in the muscles on the outer side of the lower leg followed by a progression to other muscles of the lower legs and sometimes the forearms and hands as well. A high stepping gait is often adopted to help get good foot clearance when walking and because of uneven weakness around the ankles, they are less stable and prone to injury such as sprains.

When Does it Become Evident?

The signs become evident at different times, depending on the severity of the condition in each individual. If there is a known family history nerve conduction tests and DNA analysis will identify those family members who have the condition and help to identify the type of CMT.

What Problems are Children Likely to Encounter?

Weakness in the lower legs is likely to prevent the child from heel walking and running fast. They may appear clumsy. Foot drop can occur in the early days and a typical, high stepping CMT walk develops. Most children are able to participate in almost all physical activities with the guidance of their physiotherapist. Activities such as picking up small objects, doing up buttons and screwing and unscrewing jars are likely to be more difficult if the hands are involved. Weakness can affect all fine motor tasks (for example writing) and self-care, though most people are amazingly adept at retaining independence and function.

How does MontroseAccess Assist Children With CMT?

MontroseAccess physiotherapists will provide a programme of exercises to help strengthen the remaining muscle, though muscles which have lost their nerve supply cannot be strengthened. They will also teach the very necessary programme of stretches, to prevent contractures developing and activities to improve balance.

Orthotics plays a very big part in the management of CMT. Night splints are recommended to retain the range in the ankles and articulated AFOs (splints that allow ankle movement) are often used successfully to help with foot drop.

Occupational Therapists will care for the hands, all fine motor tasks and activities of daily living, both at home and school. Hand splints may be needed very occasionally.

A full range of MontroseAccess services are available to assist families, including respite, recreation, social work and speech pathology.