Charcot-Marie-Tooth and Your Feet

Hal Ornstein, DPM, FASPS, and Gregory Stilwell, DPM, FACFAS

Common Foot Types Seen in CMT:

Foot Examination

Pes cavus: The most typical type, a high-arched foot with a rigid “cave” under the instep. Calluses are common on the balls of the feet. Chronic ankle sprains and foot drop are common, as well. Hammer toes, claw toes and corns on the toes are typical. The muscles within the foot itself (intrinsic muscles) atrophy, and cause the toes to curl up. Treatment ranges from wearing insoles to surgery.

Paralytic Flatfoot: A less common foot type, which usually requires some type of fusion in the arch to stabilize the progressive breakdown.

Foot Drop: Weakness in the muscles of the front of the calf cause foot drop; those with stronger muscles in the calf are better able to lift the front of the foot up. Bracing can be effective, and rocker bottom shoes and surgery to move stronger muscles to the top of the foot are all helpful.

Preventing and Treating Foot Problems

The key for people with CMT is to view all foot problems as potentially dangerous, to prevent them if possible, and to seek podiatric care as soon as possible if they occur.

Neuropathy can cause numbness, burning pain, and less ability to feel pain, heat or cold. Heating pads are notorious for causing severe burns that were never felt as they were occurring. When decreased sensation is present, serious problems, such as ulcers and gangrene, can occur without pain. Infection may go unnoticed and appropriate care may be delayed until it is too late; amputation may be necessary to save the person’s life. Daily observation of the feet is necessary by those with CMT or by a trusted guardian.

Deformities are very common in the ankles and feet of those with CMT because of progressive muscular weaknesses, causing imbalance of opposing muscle groups. Either surgical realignment or bracing with orthoses can work well. Many times, simple extra-depth shoes with soft inlays provide relief. Exercise, stretching, and massage can keep your flexibility and maintain as much strength as possible. Custom-molded braces and in-shoe orthotics are commonly used as well. Surgery has become much more common and effective when performed by a qualified foot and ankle surgeon. From straightening toes to lowering the arch and realigning the ankle joint, new techniques have greatly improved many patients’ mobility and agility. To treat the tripping commonly experienced from a foot drop deformity, carbon fiber lightweight braces fit into most shoes and are easy to fit around the calf. Surgical transfer of muscles to help stabilize drop foot is an effective procedure. Physical therapy is commonly prescribed to help develop a Home Exercise Program and speed up healing after surgery.

Ulcers can be caused by lack of blood circulating to the foot, lack of soft tissue protection, excessive callous tissue, infection, and pressure points caused by deformities. Some causes of injury and ulcers are wearing ill-fitting shoes, performing “self” surgery, applying electric heating pads or hot water bottles, and using ingrown toenail and corn remedies. If the circulatory response is adequate, most ulcers can be healed if diagnosed and treated early.

Skin changes in the foot can be caused by CMT. Dehydration is common since those with CMT can have less natural lubrication. Fissures and cracks in the skin develop, and, often, itching can become severe. Scratching can cause breaks in the skin that may become infected. Dryness can be helped by using a good skin cream daily on every part of the foot except between the toes.

Cuts, scrapes, blisters and puncture wounds can cause serious problems. To prevent such injuries, people with CMT should always wear some kind of footwear. While going barefoot, especially in sand or soft grass is a wonderful treat, it is dangerous for people with decreased “protective sensation.” If a foreign body such as a splinter punctures the skin, it can lead to an infection and cause drastic consequences if a podiatric surgeon doesn’t appropriately open the wound and extract the foreign body.

Ingrown toenails press on the surrounding skin, and if a person doesn’t have adequate sensation to feel the pressure, an infection can quickly develop. To treat the problem, a podiatric surgeon will drain the infection to relieve the pressure, prescribe an antibiotic, and recommend special home care to help the infection heal. A permanent surgical procedure can be done in the office to prevent reoccurrence.

Athlete’s Foot is a fungal infection commonly seen in people with CMT. This can affect nails as well, making them thick and painful. Many easy preventative solutions such as correct socks and OTC creams can be highly effective. However, if not treated, secondary bacterial infections that require vigorous treatment with antibiotics may develop.

Structural changes in the feet and ankles typically occur with CMT. As the nerves are affected by CMT, muscles become weak, and the bones those muscles control start to shift and cause bone and joint deformities. Again, if a person doesn’t have normal sensation, he or she may not feel the added pressure over boney prominences and develop a sore, an infection, or a full-fledged ulceration. A podiatric specialist can help prevent complications from CMT-caused foot and ankle deformity.