Charcot-Marie-Tooth disease (hereditary)

Alternative names:

hereditary peroneal nerve dysfunction; neuropathy - peroneal (hereditary); progressive neuropathic (peroneal) muscular atrophy

Symptoms:

• weakness (decreased muscle strength, independent of exercise) of the hips, legs, or feet
• "slapping" gait (walking pattern--when walking the feet hit the floor hard)
• foot drop (unable to hold foot horizontal)
• foot deformity (called foot drop--the foot points downward)
• progressive leg deformity
• "stork leg" appearance (loss of lower leg muscle mass)
• decreased sensation or numbness in the foot or leg

Note: Later, similar symptoms may appear in the arms and hands; this includes hand deformities (the hand develops a claw-like shape).

Signs and tests:

An examination of the skin by touch (palpation) reveals nerve bundles under the skin in the demyelinating form of the disorder. The stretch reflexes in the legs are absent. There is loss of muscle control and atrophy (loss of muscle mass) in the foot or leg. There is difficulty with lifting up the foot (dorsiflexion) and with toe-out movements (eversion).

• A muscle biopsy or nerve biopsy may confirm the diagnosis.
• Nerve conduction tests are often performed to distinguish axonal from demyelinating forms of the disorder.
• Gene marker studies will probably be available soon. (They may already be developed.)