Charcot Marie Tooth (CMT) disease is the commonest neuromuscular disorder that is inherited as it affects 1 in 2500 individuals in the United States. It consists of inherited neuropathies that are unrelated to any metabolic disorder. Therefore, they are also known as hereditary motor and sensory neuropathies. The disease was coined after the physicians who first described it; namely, Jean-Martin Charcot, Pierre Marie and Howard Henry Tooth in 1886. Charcot Marie Tooth consists of a group of genetically different diseases having a similar clinical presentation. It is divided into different types that include Charcot Marie Tooth 1, CMT 2, CMT 3, CMT 4 and CMT X. All are demyelinating neuropathies, except Charcot Marie Tooth 2, which is an axonal disorder. These are further divided into different subtypes.(1)
Charcot Marie Tooth is mostly seen in individuals in their first or second decade of life. It is associated with gradual weakness of the muscles of the distal extremities along with wasting. This may lead to frequent tripping, ankle sprains, walking difficulty, steppage, foot drop, foot deformities including pes cavus and hammertoes. When the hand is involved, symptoms with difficulty in hand manipulations such as zipping, buttoning, writing, poor finger control are noted. Generally, sensory symptoms are not present due to the lack of sensations.(1)
Management Of Charcot Marie Tooth Disease
Till date, Charcot Marie Tooth is an incurable disease and can only be managed with various interventions and involves multiple disciplines including neurology, physical medicine, and rehabilitation, orthopedics, physical therapy, orthotics, genetics counseling, and psychiatry. Currently, no treatment exists to prevent the loss of myelin sheath, so better understanding of genetics and biochemistry of the disease gives hope for future treatment considerations. Currently, inserts and orthotics are the best possible nonoperative therapy for foot deformities.(1)
Patients having moderate to severe Charcot Marie Tooth disease can be managed with surgery. The toes that are clawed can be straightened, feet with high arches can be flattened and ankles that are not straight can be tightened. In the past, the only surgery that was practiced for Charcot Marie Tooth was the fusion of one or more joints in the foot. Since the advancement in the management of Charcot Marie Tooth, joint fusion is rarely required; however, it is important to intervene early that can be started with osteotomies to correct bony misalignment, tendon transfer for foot balance, and ligament reconstruction for ankle stabilization; these can improve the markedly improve the function and prevent further deformity.(2)
The clawing of toes is due to weakening of the intrinsic muscles of the foot and tibialis anterior muscle of the leg. This leads to hyperextension of the metatarsal-phalangeal joints and flexion of the small joints causing pain on the ball of the foot. This makes walking and wearing shoes difficult. Early symptoms can be managed with cushioned orthotics, and shoe modifications; however, progressed disease required surgical intervention. The soft tissue contractures release causes straightening of metatarsal-phalangeal joints and toes.(2)
The high arches of the foot lead to gait instability, pain on the soles of the foot and increased predisposition to an ankle sprain. Surgery helps in flattening of the foot that helps in even distribution of the stress on the soles of the foot along with the repositioning of the heel beneath the weight-bearing axis of the leg. Osteotomy, removal of pie-shaped wedge laterally along with tightening of the lax ankle ligament corrects the high arch that relieves the pain and increases endurance and stability of the gait.(2)
Transfer of tendons, especially early during the disease phase reduces the deformity progression. Since peroneus brevis tendon tends to weaken, the transfer of peroneus longus helps in maintaining the strength and avoiding deformity of the medial midfoot and increasing stability during standing and walking. The transfer of posterior tibial tendon can increase the strength of ankle and remove the need for a drop foot brace. Even flaccid paralysis of most muscle groups in the leg benefit from tendon transfer.(2)
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