Charcot Marie Tooth Disease

Summary

Charcot-Marie Tooth Disease (CMT) is an inherited neurological condition that results in muscle wasting of the lower legs, feet, and hands. CMT effects the peripheral nervous system and results in muscle wasting and progressive change in the mechanical properties of the legs and feet. The impact of CMT on the foot is directly due to peroneal muscle atrophy. Small calves and high arched feet are the hallmarks of CMT. CMT is more common in men with an onset in the third decade of life.

Symptoms

• Progressive atrophy of the calf
• Progressive increase in the height of the arch
• Instability of gait

CMT patients will exhibit many of the same symptoms as other patients who have very high arches. In many cases, the fat pad beneath the metatarsal heads, just behind the toes on the bottom of the foot will thin, resulting in deep, painful calluses. Other CMT patients will have difficulty being able to wear lace-up shoes due to the height of the arch and the pressure that is focused on the top of the foot by a lace-up shoe. Additional symptoms include instability in gait, foot drop, claw toes and lateral ankle instability as a result of a plantarflexed 1st metatarsal and inverted heel.

Description

Charcot Marie Tooth Disease is also known as hereditary motor and sensory neuropathy (HSMN) and peroneal muscular atrophy. CMT affects 1 in 2,500 people with approximately 125,000 active cases in The United States. CMT is characterized by two types:

Type I

The characteristic findings of Type I CMT begin to develop in the late teens to early 20's. The most pronounced finding is the "stork leg deformity" that occurs as the peroneal muscles of the lower leg begin to atrophy (become weak.) Muscular wasting of the hands does occur but typically happens well after the onset of atrophy of the legs. The symptoms of Type I CMT become more pronounced over the course of the patient's lifetime.

Neurological findings of Type I CMT include:

• A decrease in the ability of the peripheral nerves of the hands and feet (a stocking glove distribution) to sense vibration, pain, and temperature

• Deep tendon reflexes are absent

• EMG testing shows slow nerve conduction velocities with prolonged distal latencies

• Enlarged peripheral nerves that can be palpated

Type II

Type II CMT occurs later in life and shows the same physical characteristics of CMT Type I.

Causes and contributing factors

CMT is an inherited condition caused by poor duplication of chromosomes prior to birth. Contributing factors are unknown. 

Differential Diagnosis

Clubfoot
Muscular dystrophy
Paralysis
Peroneal palsy
Stroke
Traumatic injury to the common peroneal nerve

Treatment

Currently, there is no available method to slow or stop the progression of CMT. Therefore, treatment is focused on management of symptoms. Many CMT patients require no treatment at all. Others find comfort in soft prescription orthotics or AFO braces that stabilize the leg.

When to contact your doctor

All suspected symptoms of CMT should be evaluated by your podiatrist, orthopedist or family doctor.

References: Pending

Author(s) and date

This article was written by Myfootshop.com medical advisor Jeffrey A. Oster, DPM. 

Competing Interests - None

Cite this article as: Oster, Jeffrey.  Charcot Marie Tooth Disease.  https://www.myfootshop.com/article/charcot-marie-tooth-disease

Most recent article update: November 21, 2020.
 

  Charcot Marie Tooth Disease by Myfootshop.com is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.