Compression of the Spinal Cord.

Synonym.—Compression Myelitis.

Definition.—An impairment of function of the cord, due to gradual compression.

Etiology.—According to Taylor, of Guy's Hospital, the most common cause of compression of the cord is caries of the spine, not, as he says, from "angular curvature," which the caries produces, but from the inflammatory or caseous products, which form between the diseased bone and the external surface of the dura mater, destroying the posterior common ligament, and setting up an external pachymeningitis.

Of less frequent occurrence, acting as causes, may be named tumors, carcinomatous and sarcomatous growths, and aneurisms.

Pathology.—The alteration in the shape of the cord depends upon the amount of compression. The cord is flattened and may be narrowed, to one-half or one-third its natural diameter; myelitis follows, and the cord, in the early stage, shows some engorgement and softening, but later sclerosis follows, attended by "degeneration of the posterior columns above the lesion, and in the pyramidal tracts below the lesion."

The microscopical changes are those peculiar to myelitis. While the nerve-roots will show more or less impairment, many nerve-fibers will remain intact.

Symptoms.—In typical cases there are two groups of symptoms, one due to pressure upon the nerve-roots, the other to involvement of the cord itself. Pain, neuralgic in character, and darting along the course of the nerve, is characteristic of the first. There will be areas of anesthesia, "anesthesia dolorosa," and muscular spasms, followed by paralysis, loss of the reflexes, and atrophy of the muscles.

Areas of hyperesthesia frequently accompany the anesthesia. Occasionally, trophic disorders of the skin are present, zona, bullae, or eschars.

"The symptoms due to direct compression of the cord are those with which we are familiar in transverse lesions: paralysis, anesthesia, or other modifications of sensation, increased reflexes, often some vesical trouble, and generally spastic rigidity of the paralyzed muscles. The relation of anesthesia to paralysis varies much in different cases, and in the same case at different times. Loss of motion is, as a rule, the most prominent symptom, and anesthesia may be entirely absent. The activity of the reflexes is often in excess of the motor paralysis. It is another important feature, when the compression results from caries, that recovery may take place completely, or improvement may again be followed by relapse. The site of the compression, of course, determines some differences in the symptoms. Compression limited to one side will cause the pains to be unilateral, and the paralysis may be on the same side, the anesthesia on the opposite, as has been stated to be the result of strictly one-sided lesions. Cervical compression may be accompanied by alterations of the pupil, especially dilatation from irritation of the ciliospinal center, by cough and dyspnea, dysphagia, vomiting, or very slow pulse. The distribution of the paralysis is also sometimes striking: all four limbs may be paralyzed, the upper limbs being wasted, with diminished reflexes, as a result of compression of the nerve-roots or their centers. But the arms may be paralyzed as a result of compression above the origin of their nerves, and the muscles will then preserve their volume and their electrical reactions, while the reflexes are increased. In some such cases the legs remain unaffected. The distinctive features of compression of the lumbar region are paralysis, with flaccidity, wasting, diminution of the reflexes, paralysis of the sphincters, and tendency to bed-sores." (Taylor.) '

Diagnosis.—If caries of the vertebra be present and spinal symptoms appear within a few years after the removal of cancer of the breast, the diagnosis will be comparatively easy; if, however, compression of the cord occurs from the exudate before the evidence of caries appears, the diagnosis may be very difficult, especially if the root symptoms be absent.

Prognosis.—The prognosis is more favorable when due to caries than from other causes, though years may elapse before a cure is effected.

Treatment.—When, due to caries, some one of the many devices now in use should be selected to produce extension. It may be suspension, a favorite method in use a few years ago, or a plaster cast, or some mechanical appliance that secures hyperextension while in the recumbent state. Mere rest in bed has proven of much benefit, where it can be maintained for weeks or months. Where the disease is due to other causes, the treatment is generally unavailing. In general the treatment will be that used in tuberculosis.

The patient should be much in the open air, the diet should be easily digested, but nourishing. Arsenic, Howe's acid solution of iron, nux vomica, hydrastin, echinacea, and remedies of like character, will be used. Massage and electricity should be tried. Work along the line of orificial treatment, often does more for the patient than medication.

The Eclectic Practice of Medicine, 1907, was written by Rolla L. Thomas, M. S., M. D.