Treatment. In most cases this is hopeless. Tumors, bony and calcic growths, tubercles, degenerations and absorption of nervous tissue are practically beyond remedy. A blood extravasation may be largely absorbed, leaving only the permanent changes in the nervous tissue. In this time is the main element. Actinomycosis may sometimes be successfully met by a course of potassium iodide, when, if the nervous lesions are slight, a fair recovery may be secured. In the majority of cases, however, the practitioner is limited to measures for palliation of suffering by atropia, chloral, phenacetin, etc., or by nerve stimulants like nux in small doses, or by weak currents of electricity. In meat producing animals, it is often the best course to fatten rapidly, or to turn over at once to the butcher.
DILATATION OF THE CENTRAL CANAL OF THE SPINAL CORD. SYRINGOMYELIA.
This means literally a cavity in the spinal cord but is applied to cavities formed by dilatation of the central spinal canal, or by an excavation in the nervous tissue immediately adjacent and usually communicating with a dilated segment of the canal. In man it is usually the result of an active proliferation of the epithelial cells of the canal, blocking the same, or extending into the adjacent nervous tissue in the form of a glioma. In different cases in dogs it occurred as the result of pressure. It has been seen in dogs, cats and Guinea pigs, as a casual lesion and as the result of experiment.
In a case reported by Lienaux it extended for practically the whole length of the cord, varying in form and size at different points. In the lumbar portion it was only slightly dilated, in the dorsal it was very irregular with prolongations into the gray matter, toward the cervical enlargement, its transverse section resembled an inverted V, and in the anterior cervical part it was unevenly rounded. Notable changes were cell proliferation and subsequent degeneration with the formation of cavities, thickening of the neuroglia, and compression and even obliteration of the vessels with circumscribed areas of necrosis, terminating also in cavity formation.
Symptoms. These vary with the nervous structures invaded, atrophied or destroyed. Invasion of the anterior horns of gray matter, causes trembling and muscular wasting. The implication of the superior horns determines more or less marked anæsthesia. Hyperæsthesia, spasms, paresis and paraplegia are also seen but no symptom nor group of symptoms is diagnostic of the exact lesion.
Treatment is manifestly hopeless.
NEURASTHENIA IN PREGNANT EWES.
Causes: inactivity, lowered muscular and nervous tone, twin pregnancy, approach of parturition, dry (clover hay) ration, concurrent diseases. Symptoms: moping, anorexia, depression, stupor, blindness, paresis, lethargy. Prevention: open air life, exercise, high muscular condition, avoidance of debilitating and relaxing conditions. Treatment: hygienic, nerve tonics, attend to concurrent diseases.
Neurasthenia has been defined as an incompetency of the nervous system, leading to early fatigue, and inability to recuperate from the prostrate condition. Pending a better knowledge of the affection, I have given this name to an asthenic affection seen in pregnant ewes when nearing the completion of the period of gestation.
Causes. In a large number of cases I have found several conditions so constant, not to say invariable, that they seem to deserve special attention in the list of causes: