Tests and diagnosis

By Mayo Clinic Staff

During the physical exam, your doctor may check for:

  • Signs of muscle weakness in your arms, legs, hands and feet
  • Decreased muscle bulk in your lower legs, resulting in an inverted champagne bottle appearance
  • Reduced reflexes
  • Sensory loss in your feet and hands
  • Foot deformities, such as high arches or hammertoes
  • Other orthopedic problems, such as mild scoliosis or hip dysplasia

Your doctor may also recommend the following tests, which can help provide information about the extent of your nerve damage and what may be causing it.

  • Nerve conduction studies. These tests measure the strength and speed of electrical signals transmitted through your nerves. Electrodes are placed on your skin and deliver small electric shocks that stimulate the nerve. Delayed or weak responses may indicate a nerve disorder such as Charcot-Marie-Tooth disease.
  • Electromyography (EMG). A thin needle electrode is inserted through your skin into the muscle to be tested. Electrical activity is measured as you relax and as you gently tighten the muscle. Your doctor may be able to determine the distribution of the disease by testing different muscles.
  • Nerve biopsy. A small piece of peripheral nerve is taken from the calf of your leg through an incision in your skin. Laboratory analysis of the nerve distinguishes Charcot-Marie-Tooth disease from other nerve disorders.
  • Genetic testing. These tests, which can detect the most common genetic defects known to cause Charcot-Marie-Tooth disease, are done by blood sample. Genetic testing may give people with the disorder more information for family planning. It's important to have genetic counseling before undergoing genetic testing so you know the pros and cons of testing.
Feb. 14, 2013

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