Neurogenic Arthropathy in Charcot-Marie-Tooth Disease

Robert E. Tooms, M.D.


Charcot-Marie-Tooth disease (peroneal muscular atrophy) is an uncommon, but not rare, hereditary neurological disease. One or more patients with this condition will be found on the active roster of almost any large orthopedic service or crippled children's clinic. The disorder is characterized by a progressive flaccid paralysis of the muscles in the distal portion of the extremities, especially the peroneal and anterior tibial muscles in the leg, and the intrinsic muscles in the hand, giving rise to the typical cavus and equinovarus foot deformity and claw hand so characteristic of the disease. The onset is usually in childhood and males are affected somewhat more often than females. As the disease slowly progresses with the passage of years, the muscle paralysis may ascend the limbs, but the muscles of the pelvic and shoulder girdles, the trunk, and the face remain unaffected. Early in the course of the disease deep tendon reflexes are lost in affected areas. Mild sensory aberrations, usually diminution of pain and temperature sensation with some loss of light touch and vibratory sensation, are common, but marked sensory loss is rare. In fact, a review of the literature reveals very few reported cases with severe sensory loss.

Severe Sensory Loss

We have recently had the opportunity to examine and treat a patient with Charcot-Marie-Tooth disease who had such severe sensory loss in his feet that he developed trophic ulcers, chronic osteomyelitis, and neurogenic arthropathy (Charcot joints). The rare occurrence of such severe sensory loss in Charcot-Marie-Tooth disease seems to warrant our reporting the case history of this individual.

Case History

J.E., a Negro male born Jan. 10, 1950, was initially seen in the Memphis Crippled Children's Clinic on Dec. 2, 1957, at the age of seven years. He was brought to the Clinic by his parents because of difficulty in walking. The parents dated the onset of his gait disturbance to the time when he was three years of age, and felt that it followed an acute febrile episode. No history of gait abnormalities in other family members was elicited. Examination of the child at that time revealed definite weakness of the dorsiflexors and everters of both feet without significant sensory disturbance. There was questionable weakness about the hamstring muscles, but no upper-extremity weakness. A definitive diagnosis was not made, but it was felt that the child had either early Charcot-Marie-Tooth disease or possibly residual muscle paralysis from poliomyelitis. He was placed in bilateral below-knee braces and was subsequently followed as an out-patient in the Crippled Children's Clinic.

Definite Diagnosis Made

As J.E. grew older his disease progressed and a definite diagnosis of Charcot-Marie-Tooth disease was made. Sensory alterations remained a minor aspect of his disease. He developed a severe, widespread, infected atopic dermatitis which precluded any type of surgical procedure. His skin disease proved refractory to all dermatologic treatment and he was, therefore, continued in braces. By 1960 he had developed rather pronounced intrinsic weakness in both hands, and at approximately this time a younger brother developed early findings of Charcot-Marie-Tooth disease. He was intermittently lost to follow-up and was not seen at all from December 1964 until March 1967, at which time he was 17 years old. His severe dermatitis had completely cleared and he was felt to be a good surgical candidate.

Surgery Performed

Because of the extensive muscle weakness distal to his knees which had developed during this period of time, a surgical treatment program was formulated to consist of bilateral two-stage pantalar arthrodeses plus an opponensplasty, and modified Bunnell intrinsic tendon transfers in each hand. He was accordingly admitted to the Baptist Memorial Hospital in May 1967, at which time a simultaneous fusion of the left ankle and a triple arthrodesis of the right foot were performed (Fig. 1 and Fig. 1 , top). During the convalescent period an opponensplasty and Bunnell intrinsic tendon transfers were performed in the left hand. In July 1967 similar procedures were performed in the right hand. The results of his hand surgery were quite good and have remained good.

In September 1967, a right ankle fusion was done (Fig. 1 ). Both ankle fusions became solid, but the triple arthrodesis performed in the right foot failed to fuse. X-rays revealed bone destruction in the subtalar and talonavicular areas (Fig. 1 , top). Initially, it was thought that this destruction might be due to a low-grade infection, but extensive evaluation failed to corroborate such a diagnosis. It soon became apparent that the bone lysis was, in fact, due to the development of neurogenic arthropathy or Charcot joints. The parents refused any further surgery on the feet and the patient was, therefore, placed back in below-knee braces. By mid-May 1969, he had developed a very large and deformed right ankle (Fig. 1 , bottom left), with only slightly less severe changes in the left foot and ankle (Fig. 1 , bottom). Marked sensory changes were now present in both feet and legs, extending at least to the mid-calf level. Ambulation was extremely difficult and shoe fitting had become quite a problem.

Ulcers Develop

When seen in January 1970, J.E. had developed draining, trophic ulcers on the plantar surface of both feet. He was hospitalized and treated conservatively with antibiotics at bed rest. The trophic ulcers completely healed and he was discharged from the hospital approximately one month later. When he returned to the out-patient clinic in April 1970, he had developed recurrent trophic ulcers on the plantar surface of both feet and had a large, swollen, and fluctuant left ankle (Fig. 1 ). At this point it was felt that an amputation was indicated.

Amputations Performed

J.E. was admitted to the Baptist Memorial Hospital and on May 8, 1970, a left below-knee amputation with immediate prosthetic fitting was performed. He was discharged from the hospital two weeks later, ambulatory with crutches. The amputation stump healed per primum and at three months postoperative he was fitted with a hard-socket, patellar-tendon-bearing prosthesis which he has worn subsequently without difficulty.

In October 1970, he again presented at the out-patient clinic with recurrent ulcers and infection of the right foot and requested that this limb also be amputated (Fig. 1 , bottom right). He was, therefore, readmitted to the Baptist Hospital and on Oct. 9, 1970, a right below-knee amputation with immediate prosthetic fitting was performed. He was discharged from the hospital two weeks later, ambulatory with crutches and using a temporary prosthesis on the right side and a definitive prosthesis on the left. Three months postoperatively the right lower extremity was fitted with a hard-socket, patellar-tendon-bearing prosthesis. He has continued to wear this prosthesis without difficulty.

Discussion

There are still a great many unresolved questions concerning Charcot-Marie-Tooth disease, although the condition has been known for almost a century. There is general agreement concerning the hereditary nature of the disease, but the exact mode of transmission remains somewhat debatable. Most authors presently agree that the disorder is inherited as an autosomal dominant trait. Review of a limited number of pathological specimens has shown that the basic pathological changes in the condition are degenerative in nature. These changes have been described by various authors as occurring in the peripheral nerves, nerve roots, spinal ganglia, anterior horn cells, posterior columns, and even the pyramidal tracts. In their description of the disease the standard neurological textbooks make no mention of severe sensory loss, although all point out that sensory alterations are a definite feature of the disease1,2,6.

There are many reports in the literature concerning Charcot-Marie-Tooth disease. Some analyze large series of patients4,5 and others describe long-term follow-up of a limited number of patients7. With the exception of the report of England and Denny-Brown4, there is essentially no mention in the literature of patients with Charcot-Marie-Tooth disease who demonstrate severe sensory changes, neurogenic arthropathy or patients requiring amputations because of their disease. These authors reported a series of 57 cases of Charcot-Marie-Tooth disease. Eighteen of these patients were examined personally by the authors and the remainder were reviewed from records and by discussion with other family members. Only two of these 57 cases demonstrated severe sensory changes in their extremities: one required a below-knee amputation and the other an above-knee amputation because of trophic ulcers and chronic osteomyelitis in the feet. In their paper England and Denny-Brown reproduced an x-ray of the foot of one of the two patients requiring amputation. This x-ray showed changes about the ankle joint consistent with neurogenic arthropathy. These authors believed that the pathological changes in Charcot-Marie-Tooth disease occurred primarily in the nerve roots and proposed the name "hereditary radicular neuropathy" for the condition. In a subsequent paper, Denny-Brown3 discussed the entity known as hereditary sensory radicular neuropathy and demonstrated microscopic findings in the nervous system obtained at autopsy which revealed pathologic changes confined to the dorsal roots and dorsal root ganglia. He suggested that this condition is the sensory counterpart of the usual case of Charcot-Marie-Tooth disease and proposed that patients with severe Charcot-Marie-Tooth disease, including marked sensory changes, possibly had a combination of the two disorders with both the anterior and posterior nerve roots involved. This hypothesis seems very reasonable and could account for the condition of the case reported here.

Summary

Severe sensory changes are unusual in Charcot-Marie-Tooth disease and have rarely been reported in the literature. The case history of a patient with this condition, including severe sensory aberrations, is reported in detail and a hypothesis for the cause of severe sensory loss in conjunction with Charcot-Marie-Tooth disease is discussed.

Robert Tooms is Chief, Child Amputee Clinic, Children's Hospital Memphis, Tennessee

References:
1. Alpers, Bernard J., Clinical neurology, Ed. 2. F. A. Davis Company, Philadelphia, 1954. 
2. Baker, A. B., Clinical neurology, Ed. 2, Vol. 4. Hoeber-Harper, New York, 1962. 
3. Denny-Brown, D., Hereditary sensory radicular neuropathy. J. Neurol., Neurosurg., and Psychiat., 14:237, 1951. 
4. England, A. C, and D. Denny-Brown, Sensory changes and trophic disorders in peroneal muscular atrophy (Charcot-Marie-Tooth type). A.M.A. Arch. Neurol. & Psychiat., 67:1, 1952. 
5. Jacobs, J. E., and C. R. Carr, Progressive muscular atrophy of the peroneal type (Charcot-Marie-Tooth disease). J. Bone Joint Surg., 32-A:27, 1950. 
6. Merritt, H. H., Textbook of neurology, Ed. 4. Lea & Febiger, Philadelphia, 1967. 
7. Swartz, A. R., Charcot-Marie-Tooth disease: A forty-five year follow-up. Arch. Neurol., 9:623, 1963.