Definition.—A disease of the spinal cord due to a new growth in the gray substance about the central canal, which results in the formation of cavities.
Etiology.—Nothing definite is known as to the exciting cause, though trauma, syphilis, and the infectious diseases, especially typhoid fever, have been suggested as etiological factors. It occurs between the ages of fifteen and thirty years.
Pathology.—The disease is generally regarded as a gliosis with degeneration of the central portion of the cord, resulting in the formation of small cavities of various shapes. They are more frequently found in the dorsal and cervical regions, though the entire length of the cord may be involved. The posterior and posterolateral tracts are the most often involved; though generally independent of the central canal of the cord, they usually communicate with it.
"The wall of these cavities is generally composed of a firm fibrous tissue, or of myxomatous tissue. Its inner surface may or may not be lined with epithelial cells of the cylindrical variety. They usually contain a serous or hemorrhagic fluid, and occasionally a hyaline material." (Ranney.)
Symptoms.—There are three characteristic symptom groups:
- Modified sensibility, especially to pain, temperature, and to a certain degree, touch.
- Progressive muscular atrophy, with paralysis.
- Trophic disturbance, in the skin, muscles, bones, or joints. With these symptoms, there may be associated, as the disease progresses, spastic paraplegia, symptoms of transverse myelitis, or those due to involvement of the lateral, posterior, or in fact all the columns of the spinal cord.
The symptoms develop gradually, and usually make their appearance about the period of adolescence. As the cavity is most frequently located in the cervico-thoracic region, the arms and neck are the first to be affected. There are aching pains in the neck and arms, with numbness in the hands and loss of the pain and temperature senses. Weakness and atrophy of the muscles follow, attended by trophic changes, such as ulcers, brittleness of the nails, and painless felons.
Later, with the extension of the disease, spastic paresis of the legs follows, and the bladder and the rectum may be involved. From the involvement of the spinal muscles, curvature of the spine often accompanies the disease. With the progress of the disease the symptoms become more general, larger areas of modified sensibility take place, and more extensive trophic changes are noted. Charcot's joint, shoulder, or elbow, edema of the fingers, bullae, ulcers, felons, loss of nails, and brittleness of bones are noted.
If the posterior columns are involved, incoordination of the muscles occurs similar to that of locomotor ataxia.
The reflexes vary, and may be either lost or exaggerated. Where the disease extends to the medulla, the cranial nerves become involved, giving rise to bulbar symptoms.
Diagnosis.—The three characteristic and typical features—modified sensibility to pain and temperature, extreme muscular atrophy, with paralysis and trophic disturbances, to which may be added spasticity of the lower extremities—make the diagnosis comparatively easy.
Prognosis.—Although the disease may extend over a period of years, the prognosis is always bad, though death usually results from intercurrent diseases.
Treatment.—The treatment can only be symptomatic. The means to preserve the general health, climatic, hygienic, and dietetic, must be observed and conditions met as they arise.