Charcot-Marie-Tooth Disease Clinical Presentation

Updated: Jun 21, 2018
  • Author: Divakara Kedlaya, MBBS; Chief Editor: Vinod K Panchbhavi, MD, FACS  more...
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Presentation

History

Patients with Charcot-Marie-Tooth (CMT) disease have a significant family history. This history varies depending on the inheritance and penetrance pattern of the particular disorder (see Etiology). Spontaneous mutations also have been reported.

The age of presentation varies, depending on the type of CMT disease. Onset usually occurs in the first two decades of life.

Slowly progressing weakness beginning in the distal limb muscles generally is noted; it typically occurs in the lower extremities before it affects the upper ones. A subgroup of patients with CMT 1A may present with proximal muscle wasting and weakness.

Patients initially may complain of difficulty walking and frequent tripping due to foot and distal leg weakness. Frequent ankle sprains and falls are characteristic. Parents may report that a child is clumsy or simply not very athletic. As weakness becomes more severe, foot drop commonly occurs. Steppage (that is, gait in which the individual must lift the leg in an exaggerated fashion to clear the foot off of the ground) also is common.

Intrinsic foot muscle weakness commonly results in the foot deformity known as pes cavus. Symptoms related to structural foot abnormalities include calluses, ulcers, cellulitis, and lymphangitis.

Hand weakness results in complaints of poor finger control, poor handwriting, difficulty using zippers and buttons, and clumsiness in manipulating small objects. The hand may be affected at all ages in children with CMT 1A; that hand problems in these patients may be underrecognized in the early stages of disease, causing potential delay in therapy. [33]

Patients usually do not complain of numbness. This may be because patients with CMT disease never had normal sensation and, therefore, simply do not perceive their lack of sensation.

Pain (musculoskeletal and neuropathic types) may be present. Muscle cramping is a common complaint. [34]

Autonomic symptoms usually are absent, but a few men with CMT disease have reported impotence.

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Physical Examination

Distal muscle wasting may be noted in the legs, resulting in the characteristic stork leg or inverted champagne bottle appearance.

Bony abnormalities commonly seen in long-standing CMT disease include pes cavus (high-arch foot), probably analogous to the development of claw hand in ulnar nerve lesion. Pes cavus has an occurrence rate of 25% in the first decade of life and 67% in later decades. Selective denervation of intrinsic foot musculature (particularly of the lumbricals), rather than imbalance of lower-leg muscles, seems to be the initial mechanism causing reduced ankle flexibility and forefoot cavus deformity. [35] Other foot deformities also can occur (see the image below).

Foot deformities in 16-year-old boy with Charcot-M Foot deformities in 16-year-old boy with Charcot-Marie-Tooth disease type 1A.

Spinal deformities (eg, thoracic scoliosis) occur in 37-50% of patients with CMT 1.

Deep tendon reflexes (DTRs) are markedly diminished or are absent. Vibration sensation and proprioception are significantly decreased, but patients usually have no sensory symptoms.

Patients may have sensory gait ataxia, and a Romberg test usually yields positive results. The Romberg test is performed by having the patient stand upright with the feet together and the eyes closed. The examiner observes the patient's body movement relative to a perpendicular object behind him or her (eg, a door or window). Pronounced, sometimes irregular swaying, or occasionally even toppling over, constitutes a positive result. The key point is that the patient's unsteadiness increases when his or her eyes are closed.

Sensation of pain and temperature is usually intact. Essential tremor is present in 30-50% of patients with CMT disease. Sensory neuronal hearing loss is observed in 5% of patients. Enlarged and palpable peripheral nerves are common. Phrenic nerve involvement with diaphragmatic weakness is rare but has been described. Vocal cord involvement and hearing loss can occur in rare forms of CMT disease.

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Complications

Because of the loss of protective sensation distally in all four limbs, patients with CMT disease are susceptible to skin breakdown or burns, nonhealing foot ulcers, and, in severe cases, bony deformities of bilateral feet. As mentioned previously, orthoses are required for treatment of foot drop or to accommodate bony foot deformities. If not fitted properly, the orthoses themselves become a source of skin breakdown secondary to associated distal sensory impairment.

The presence of maternal CMT disease is associated with an increased risk of complications during delivery. This increase is related to a higher frequency of emergency interventions during birth. [31]

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