Part 25

Treatment is hopeless, since if they have invaded the brain, the tumors are likely to be multiple in the organ, and numerous and widely scattered elsewhere.

PSAMMOMATA (GRITTY TUMORS) OF THE BRAIN.

As already noted these sandy tumors are often the advanced stage of cholesteatomata, the abundance of the phosphate of lime leading to its precipitation in the neoplasm. The same cretaceous deposit often takes place in old standing tumors of other kinds, as in melanoma, and fibroma so that the sandy neoplasm may be looked upon as a calcareous degeneration of various forms of intracranial tumors. The same tendency to calcareous deposit is seen in the tuber cinereum (pineal body) of the healthy brain which has taken its name from the contained gritty matter. This tendency to the precipitation of earthy salts may be further recognized in the osteid tumors which occasionally grow from the dura mater.

The gritty tumors are especially found in the older horses in which the tendency is greatest to extension of ossification and calcic degenerations.

Like other tumors these may attain a considerable size before they give rise to any very appreciable symptoms, but having attained a given development—often the size of a walnut, they become the occasion of nervous irritation, delirium and disorder, as indicated under encephalic hyperæmia and inflammation, cholesteatomata, etc. There may, however, be drowsiness, stupor, coma, or paralysis as the exclusive symptom, or there may be spasms and convulsions.

MYXOMA OF THE BRAIN.

Myxoma is a tumor in which mucoid elements or a gelatinoid degeneration and infiltration containing mucin is a prominent feature. The mucous tissue which constitutes the tumor may differ little from ordinary connective tissue except that the intercellular spaces contain mucin. Histologically the tissue consists of cells embedded in a homogeneous matrix. The cells may be of various forms, round, (in recent formations) and spindle-shaped or star-shaped, but especially the latter, in the older. When incised a fluid containing mucus escapes in greater or less abundance. While this has properties resembling albumen it is distinguished by the fact that the precipitate thrown down in it by alcohol is softened and redissolved on the addition of water. The precipitate thrown down in an albuminous liquid is insoluble in water.

The formation of this mucous exudate is liable to be followed by fat so that Virchow considered it as antecedent to fat formation. This is especially noticeable in the early stages of the cholesteatomata of the choroid plexus of the horse, in which, as observed by Fürstenberg, Lassaigne, and Verheyen, the new formation is at first a myxoma, which later becomes filled up with cholesterine.

Recent observations tend to discredit the alleged distinctive character of myxoma. The meshes of all connective tissue contain a perceptible amount of mucin. Œdematous subcutaneous connective tissue contains this mucin in greater proportion and approximates to the condition of mucous tissue. The umbilical cord, which has been long advanced as the physiological type of mucous tissue, has been shown to consist of ordinary connective tissue with an abundance of fluid in its meshes.

Koster denies that the myxoma is a special type of tumor, and holds that it is only a condition that may arise in any tumor which contains connective tissue. In other words, myxoma is only an œdematous condition of the connective tissue neoplasm—fibroma, sarcoma, carcinoma, etc.—due to passive congestion or other circulatory disturbance.

As seen in the brain of the horse the formation is usually of the nature of a myxo-lipoma, as the final outcome is usually the cholesterine bearing mass. In other cases the connective tissue spaces become further distended with the viscous, gelatinoid liquid and form veritable cysts—myxoma-cystoides.

In tumors of this kind affecting the choroid plexus the chain of symptoms is essentially the same as given under cholesteatoma and the prognosis is nearly equally grave. It need only be said that in recent cases in which there is as yet little permanent tissue, measures may sometimes be hopefully adopted, to secure the reabsorption of liquid constituents, and even perchance to remove some obvious cause of passive congestion upon which the effusion depends.

ACROMEGALY. HYPERTROPHY OF THE PITUITARY BODY.

Like other portions of the brain the pituitary body is subject to degenerations and diseases of various kinds. This is particularly mentioned here because of the occasional association of its hypertrophy with the trophic processes of different parts of the body. Along with an over-development of the limbs, and less frequently of the body, an enormous increase of the hypophysis has been found, and the one condition has naturally been set down as the result of the other. In some such instances, of overgrowth, however, some other blood glands, such as the thyroid or thymus, have been found to be hypertrophied, so that at present it is difficult to do more than notice the association observed between the two conditions.

CEREBELLAR DISEASE.

Cerebellum and coördination. Pressure on adjacent parts renders results uncertain. Generic symptoms, ataxia, titubation. Marked symptoms with rapid morbid progress. Treatment: tonic, hygienic.

Whatever functions are exercised by the cerebellum there is no doubt of its control over muscular coördination. It is quite true that disease of any other part of the brain causing effusion, exudation or intracranial pressure will more or less completely arrest the functions of the cerebellum just as disease of the cerebellum producing intracranial pressure will derange the functions of other parts of the encephalon. The general symptoms produced in this way cannot therefore be accepted as indicating the precise localization of an intracranial disease. Dullness, stupor, coma, dilated pupils, choked discs, optic neuritis, and vomiting, are in this sense generic symptoms, which may in the absence of fever indicate dropsy, exudation, apoplexy, tumor, concussion or other lesion, and with hyperthermia may indicate encephalitis or meningitis. But if in the absence of these symptoms and of aural disease there should appear ataxia, swaying unsteady gait, and staggering, there is a strong presumption of cerebellar disease. This may also be manifested by the other and generic symptoms already mentioned only the diagnosis is not then so certain. Again cerebellar disease may exist without the ataxia and lack of balance, but probably only in cases in which the progress is slow and the organ has had ample time to accommodate itself to the as yet comparatively restricted lesions. The result may be a mere defect of muscular tone, or it may extend to an almost absolute loss of contractility, or it may be of any intermediate grade.

Treatment, which is eminently unsatisfactory, consists in improving the general health and tone, by corroborant medicines and conditions of life, and training the muscles by carefully graduated exercise and even electricity.

BULBAR PARALYSIS. DISEASE OF MEDULLA OBLONGATA.

Impaired innervation of bulbar nerves. Paresis of lips, tongue, and larynx. Roaring. Rapid pulse. Glycosuria, albuminuria. Ptosis. Twitching eyelids. Dysphagia. Paralysis. Treatment, rest, cold to head, laxatives, nerve stimulants, tonics, electricity.

The bulb is intimately connected with the origin of the hypoglossal, glosso-pharyngeal, spinal accessory, vagus, facial, and trifacial nerves and active disease in the bulb is therefore likely to entail impairment of the function of several of these nerves. In man this is recognized in chronic progressive bulbar paralysis, which almost always affects the lips, tongue and larynx advancing steadily though slowly to a fatal termination. In degenerative lesions there is modified voice, difficulty of swallowing, rapid pulse, and laryngeal paralysis (especially of the arytenoid muscles). The implication of the root of the vagus may be inferred from the arrest of inhibition of the heart, and from glycosuria or albuminuria. Occasionally the ocular and palpebral muscles are involved causing ptosis, or twitching of the muscles. When the facial (7th) nerve is implicated, paralysis of one or both sides of the face may be marked, including often the ears. When the glosso-pharyngeal, the difficulty of swallowing is a prominent feature, and when the spinal accessory, spasm or paralysis of the neck. In the worst cases death supervenes early, by reason of interference with the respiratory and cardiac functions.

The treatment of these affections is usually very unsatisfactory, though in meat producing animals it may sometimes be desirable to preserve them in preparation for the butcher. Rest, in hyperæmic cases, cold to the head and purgatives, and in those in which fever is absent, small doses of nerve stimulants (strychnia) and tonics (phosphorus, phosphates, ammonia-sulphate of copper, zinc sulphate, silver nitrate) may be tried. A course of arsenic and carefully regulated electrical stimuli may at times give good results.

LOCO POISONING. OXYTROPIS LAMBERTI. ASTRAGALUS MOLLISSIMUS

Astragalus Hornii: A. Lentiginosus: A. Mollissimus: Oxytropis Lamberti: O. Multifloris: O. Deflexa: Sophora Serecia: Malvastrum Coccinium: Corydalis Aurea. In dry regions. Cause, a psychosis. Emaciation. Lassitude. Impaired sight. Illusions. Vice. Refuses other food. Contradictory views. Experiments by Dr. Day.

The term loco is of Spanish origin and has come to us through the Spanish speaking residents on the cattle raising plains and the Pacific Coast. The word is defined to mean mad, crazy, foolish. It has been applied indiscriminately to a disease in stock manifested by these symptoms, and to a variety of leguminous plants, found growing on the western lands and supposed to cause the disease in question. The plants complained of are Astragalus Hornii, and A. Lentiginosus (Griesbach) in California, A. Mollissimus (Torrey) and Oxytropis Lamberti (Purshiana) in Colorado and New Mexico. Other allied species, and like these found also in the other Rocky Mountain States, Sophora Serecia, Oxytropis Multifloris, O. Deflexa, Malvastrum Coccinium, and Corydalis Aurea var. Occidentalis have been less confidently charged with producing the disease.

These plants grow on poor, dry, sandy or gravelly soils, and having great power of resisting drought, are often in fair growth, and present an abundant mass of leaves when surrounding vegetation is withered up. Hence, it is alleged, the animals are driven to use it when nothing else is obtainable and once accustomed to it, the desire for more becomes a veritable craze or neurosis, and the victim searches for it and devours it to the exclusion of other food.

The following quotations may serve to illustrate the effects alleged:

Among the symptoms first noticed are loss of flesh, general lassitude and impaired vision; later the animal’s brain seems to be affected; it becomes vicious and unmanageable and rapidly loses both flesh and strength. Frequently when approaching some small object it will leap into the air as if to clear a fence. The patient also totters on its limbs and appears as if crazy. After becoming affected it may linger many months, or a year, but usually dies at last from the effects of the complaint. (Dr. Vasey. Report of Dept. of Agriculture, 1884).