Locomotor Ataxia.

Synonyms.—Tabes Dorsalis; Posterior Sclerosis.

Definition.—A chronic disease characterized by degeneration and sclerosis of the afferent tract and posterior columns of the cord, and which results in muscular incoordination, sensory and trophic disturbances, loss of knee-jerk, and the Argyle-Robertson pupil.

Etiology.—The predisposing causes are age, sex, and race. The disease is rarely seen under twenty-five years of age, being most common between the ages of thirty and forty, and more frequently in men than in women, the ratio being about ten to one. It is much more common in white races than in the colored, and Jews are less seldom affected than Gentiles.

Syphilis bears a very important relation to tabes and is undoubtedly the most important of all predisposing causes. There is a history of syphilis in from seventy-five to ninety per cent of all tabetic cases. Thus Erb reports that eighty-nine per cent of three hundred cases in private practice, had a history of syphilis, while Mobius believes that tabes never exists without syphilis.

Among the more common exciting causes may be mentioned sexual excesses, great physical exertion, and exposure to wet and cold. It is more common in cities than in the country.

Pathology.—The basal or pathological lesion underlying tabes is a parenchymatous degeneration, resulting in sclerosis, and involving principally the sensory neurons, though the peripheral motor neurons are also not infrequently affected; in fact, although the principal lesion is in the posterior columns of the spinal cord, tabes may be said to be degenerative conditions affecting various parts of the entire nervous system. These degenerative changes begin in the posterior root-zones, advance into the tract of Lissaur and the columns of Burdach, Clark, and Gall, connective tissues ultimately largely replacing the nerve-fiber, the contraction of which causes compression of the cord. There may also be cerebral and medullary changes, as well as changes in the cranial nerves and their nuclei, and the peripheral nerves in the extremities. Blindness may result from gray degeneration of the optic nerve.

In some cases, trophic changes are seen in the bones, especially their articular surfaces.

Symptoms.—It is customary to divide the symptoms into three stages, though in some cases it is hard to separate the one from the other. They are the preataxic, the ataxic, and the paralytic.

1. THE PREATAXIC STAGE.—Although all tabetic cases do not begin in the same way, the most frequent and characteristic symptoms are as follows:

Pains.—Pains of lightning-like character occur in ninety per cent of the cases, and are sharp, stabbing, piercing, or cutting in character; they are usually in the lower extremities, though they may occur in the upper extremities, the face, stomach, or rectum.

They last only for a second or two and may be associated with a burning sensation. Occasionally herpes develops at the seat of pain. These attacks occur irregularly, and are apt to follow excesses, cold, and damp weather. In a few cases pain is absent.

Paresthesia.—Perverted sensation is often experienced; the patient complains of a numb or tingling sensation in the legs or feet, or an absence of normal sensation in the feet makes the patient feel as though walking on air-cushions or cotton.

The girdle pain, or sense of constriction about some part of the trunk, is not uncommon.

Loss of Knee-jerk (Westphal's Symptom).—This early and important symptom usually comes on gradually, and when associated with ocular symptoms and the lightning pains, is positively diagnostic.

Ocular Symptoms—These may appear very early in the disease, such as atrophy of the optic nerve resulting in impaired vision and frequently in blindness; ptosis—drooping of the eyelid; diplopia—double vision; the Argyll-Robertson pupil, a failure to contract to light, but contracts to accommodation, and the small contracted pupils, "pin points," spinal myosis.

Bladder Symptoms.—In some cases the earliest symptom noted is difficulty in emptying the bladder, the desire to micturate being frequent but unsatisfactory; as a result, there is a partial retention of urine, often resulting in cystitis. Incontinence of urine appears late in the disease. Loss of sexual desire and impotency not infrequently appear in the early stage.

2. ATAXIC STAGE.—The symptoms of the preataxic stage persist, though new symptoms appear. The lightning-like pains, however, tend to become less severe and recur at longer intervals. The ataxic symptoms, the incoordination of movement or loss of the muscle sense, is characteristic. The symptoms are first noticed in walking or standing. Thus, if while standing the patient closes his eyes, he can not maintain the erect position without swaying, or if he places the feet close together and closes the eyes, he is in danger of toppling over. (Romberg's Symptom.) In walking, the body is bent slightly forward, the legs are farther apart than normal, and he lifts the advancing foot, throws it outward and forward with a jerk, and brings it down with a slap or stamp. The patient depends for assistance upon a cane, and, later, needs one in each hand. When sitting or lying the patient can not place his heel upon his knee or describe a circle with his foot.

The incoordination may extend to the upper extremities, and is recognized by inability of the patient to execute the finer movements of the hands; this is first noticed in dressing, the patient laboring awkwardly in buttoning the collar or other clothing, or in attempting to pick up a pin or other small objects. If asked to touch his nose or ear quickly, especially with the eyes shut, or to bring the tips of the fingers together, he finds it impossible.

Sensory Symptoms.—In addition to the pains already described, areas of hyperesthesia or anesthesia appear, especially in the lower extremities.

Visceral crises are characterized by paroxysmal pains in the stomach, larynx, kidney, heart, bladder, rectum, and genitals. The gastric and laryngeal being the most common.

A gastric crisis, the most frequent, consists of paroxysms of pain and vomiting, with hyperacidity. Hematemesis may also occur. Paroxysmal pains occur in the other viscera above named.

Trophic Changes.—Of these changes, the most serious are the joint lesions, and are known as Charcot's joints. The knees are the most often affected, and resemble those of arthritis deformans. Serous effusion rapidly takes place, the ligaments soften, the articular ends of the bones become absorbed, and dislocations or fractures sometimes follow. Suppuration of the joint may occur. Herpes, local sweating, and perforating ulcers may also occur. A favorite location for an ulcer is on the foot back. of the big toe, on the heel, and in the rectum. Loss of the nails and hair may occur. Atrophy of the muscles does not occur till late in the disease.

3. PARALYTIC STAGE.—This is the culmination of the second stage. The patient is unable to walk, and is confined to his bed or chair. There is a loss of control of the sphincters of the bladder and rectum, the muscles waste, bed-sores are present, and in some cases the patient is blind and deaf.

Diagnosis.—The diagnosis is not difficult, no other lesion having so many characteristic symptoms, assimilating tabes. Thus, the loss of the knee-jerk, the incoordination as shown in the walk, the lightning-like pains, the various crises, and the Argyll-Robertson pupil, make a group of symptoms that can not be mistaken.

Prognosis and Course.—After the disease has become well established and the cord becomes sclerotic, recovery is not to be expected. The disease, however, is slowly progressive, and the patient may live for years, dying of some intercurrent affection, as pneumonia, tuberculosis, etc. The preataxic stage may last for several years, especially if atrophy of the optic nerve occurs; the stage of ataxia in such cases being postponed indefinitely, or, if present, the further course may be arrested. The disease runs from ten to thirty years, though, in rare cases, it lasts but a few months or years.

Treatment.—The treatment for tabes has not been attended with very great success. Rest in bed in the early stage when the pains are intense is to be advised, and antikamnia, phenacetin, and in extreme cases morphia, are to be used to allay' the pain. The antisyphilitics have not resulted in much benefit. Hygienic measures that tend to improve the general health, with outdoor life in an equable climate, give the best results. Massage and electricity are of some benefit. When the stage of loss of control of the bladder is reached, the patient should be instructed in the use of the catheter, and the means of keeping the instrument aseptic.

Echinacea may be tried as an agent to arrest degenerative processes.

Hydrastis, avena, phosphoric acid, camphor, chlorid of gold and sodium may be thoroughly tested according to the conditions presenting.

The diet should be generous and nutritious, as much food being allowed as can be digested.

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