readily give rise to inspiration-pneumonia and its consequences, and, in addition, there may be danger of paralysis of the vagus. The treatment consists in the application of ice-bags to both sides of the occiput, and feeding by enemata, and subsequently through the stomach-tube.

EMBOLISM AND THROMBOSIS OF THE ARTERIES OF THE MEDULLA OBLONGATA.

Etiology.-Occlusion of the arteries of the medulla oblongata with plugs conveyed by the blood-stream-emboli-or by masses of fibrin that have formed in situ-thrombi-gives rise to necrotic softening of the tissue deprived of its blood-supply, and which, in accordance with its age, exhibits a varied color, and is designated red, yellow, and gray softening. The condition is not rarely one of multiple foci of softening, which may possibly be present also in the pons and the cerebrum. Smaller foci may undergo absorption, with the formation of cicatrices, while larger give rise to cysts, which are usually filled with clear fluid. Acute endocarditis or valvular disease of the heart generally constitute the source for emboli; less commonly, thrombotic deposits upon the intima of the aorta in the presence of arteriosclerosis or aortic aneurysm. Thrombosis, however, occurs as a result of arteriosclerosis of the medullary arteries, and less commonly as a result of arterial compression. Syphilis is not a rare cause for arteriosclerosis, especially for that involving the basilar artery.

Symptoms and Diagnosis.-Embolism and thrombosis of the medullary arteries may cause sudden death if they give rise to rapid paralysis of the nucleus of the vagus. In other instances

the clinical picture of acute or apoplectiform bulbar paralysis develops, and then the difficult diagnostic problem arises of determining whether this is due to embolism or thrombosis, and not to hemorrhage or acute inflammation. This problem can never be solved with certainty. Although the detection of valvular disease of the heart is rather indicative of embolism, and that of antecedent syphilis, particularly in young persons, points to thrombosis, hemorrhage may take place under either condition.

The symptoms of bulbar embolism and thrombosis vary in accordance with the vascular area obstructed, and a correct opinion is possible only from a knowledge of the blood-supply. The medulla oblongata receives its vessels from the two rertebral arteries and from the basilar artery resulting from their union. The trunk of the vertebral arteries gives branches only to the bulbar nerve-trunks, while from it originates the anterior spinal artery, which surrounds the nuclei of the hypoglossal and accessory nerves with a capillary network (Fig. 5). In addition, each vertebral artery gives off a posterior inferior cerebellar artery, which

supplies the olive and the choroid plexus of the fourth ventricle, as well as the pyramidal tract, with blood, either directly or through the intermediation of the posterior spinal artery arising from it. Finally, the basilar artery, through branches from its lower portion, supplies the nuclei of the vagus, the glossopharyngeal, and the auditory nerve with blood, while from its upper portion branches are given off for the nuclei of the facial, abducens,

FIG. 5.-Distribution of the arteries at the base of the brain (after Henle): ca, anterior cerebral artery or artery of the corpus callosum; coa, anterior communicating artery; cm, middle cerebral artery or artery of the fissure of Sylvius; ci, internal carotid artery; chi, choroid artery; cop, posterior communicating artery; cpo, posterior cerebral artery; cbs, superior cerebellar artery; cbia, anterior inferior cerebellar artery; and, auditory artery: ba, basilar artery; chip, posterior inferior cerebellar artery; e, right vertebral artery; spa, anterior spinal artery; spp, posterior spinal artery; Of olfactory nerve; Op, optic nerve: ocm, oculomotor nerve; trg, trigeminal nerve; ab, abducens nerve; fae, facial nerve; ac, auditory nerve; gl, glossopharyngeal nerve.

oculomotor, and trochlear nerves. Obstruction of the lower portion of the basilar artery is particularly dangerous, on account of the likelihood of paralysis of the vagus. Bulbar paralysis will be most extensive when a thrombus obstructs the basilar and the vertebral arteries simultaneously. According to Griesinger, this occurrence, as well as obstruction of the basilar artery alone, can be recognized from the fact that pressure upon both carotids

may be attended with loss of consciousness and general clonic muscular spasm, in consequence of cerebral anemia, although these phenomena at times appear also in persons with a patulous basilar

artery.

The treatment is the same as that for hemorrhage (p. 26). Antecedent syphilis will require inunctions of mercurial ointment (5.0-75 grains-daily) and the administration of potassium iodid (5.0: 200-75 grains : 64 fluidounces; 15 c.c.-1 tablespoonful— thrice daily).

ACUTE INFLAMMATION OF THE MEDULLA OBLONGATA (ACUTE BULBAR MYELITIS).

Acute bulbar myelitis is extremely rare, and occurs principally in the form of multiple small hemorrhagic foci, which in part are discovered only on microscopic examination. Fatty granule-cells, degenerated and disintegrating nerve-fibers, thickening and fatty degeneration of the vessels, and emigrated red blood-corpuscles constitute the principal elements of the inflammatory focus. The disease is attended with slight fever, and pursues the course of an acute or apoplectiform bulbar paralysis, and hitherto always with a fatal termination.

NEOPLASMS OF THE MEDULLA OBLONGATA.

Neoplasms occur but rarely in the medulla oblongata. One or several tuberculous nodules are present with relative frequency, although gliomata, fibromata, myxomata, papillomata, and gummata also have been observed. The new-growths may acquire the size of a walnut. At times they are wholly unattended with symptoms. In other instances general (diffuse) cerebral symptoms appear, particularly headache, vertigo, vomiting, eructation, choked dise, clonic convulsions, stupor, and progressive loss of memory. The gradual development of bulbar symptoms is alone distinctive of bulbar neoplasms, and these symptoms are generally due to increasing pressure upon the individual bulbar nuclei or upon the nerve-roots of the individual cerebral nerves arising from them. There is usually present paralysis of the tongue, the palate, the esophagus, and the laryngeal muscles.

The diagnosis is difficult. It is impossible to determine whether a neoplasm is situated in the medulla oblongata itself or has invaded the bulb from the vicinity.

The prognosis is unfavorable, as the treatment is promising of success only from the use of antisyphilitic measures in the presence of gummata.

IV. DISEASES OF THE BRAIN.

DIAGNOSTIC PRELIMINARY CONSIDERATIONS.

FOR the satisfactory diagnosis of diseases of the brain answers. must be given to three questions, namely: 1. Is disease of the brain at all present? and, if so, 2. What is its seat? and, finally, 3. Upon what anatomic alterations does it depend?

FIG. 6.-Convolutions of the convexity of the brain (after Ecker): of, superior (or first) frontal convolution; mf', middle (or second) frontal convolution: "", inferior (or third) frontal convolution; rew, anterior central (or ascending frontal) convolution; hew, posterior central (or ascending parietal) convolution; op', Superior parietal lobule; up", inferior parietal lobule, of which gspm represents the supramarginal and go the angular gyrus; of, superior (or first) temporal convolution: mt", middle (or second) temporal convolution: ut", inferior (or third) temporal convolution: oo', superior (or first occipital convolution; mo", middle (or second) occipital convolution; uo", inferior or third) occipital convolution: op, operculum; of, superior frontal suleus; usf, inferior frontal sulcus; fs, fissure of Sylvius, with its horizontal ramus on the right and its vertical ramus on the left: cf. central sulcus (fissure of Rolando; em, callosomarginal fissure: sip, interparietal fissure: fpo, parieto-occipital or occipital fissure: sf, superior (or first) and inferior (or second) temporal fissures: spe, vertical frontal (precentral) fissure: sof, transverse occipital sulcus; soli, inferior longitudinal occipital sulcus.

The presence of general or diffuse cerebral symptoms answers the first question in the affirmative; local or focal cerebral symp toms furnish the answer to the second question; and the clinical course of the disease affords the basis for an answer to the third question.

General or diffuse cerebral symptoms appear in connection with all possible diseases of the brain without reference to the situation and anatomic character of the latter. They result from alterations in the circulation and the pressure within the cranium, and they include headache, vertigo, vomiting, disorders of consciousness, general clonic convulsions, choked disc, ringing in the ears, changes in the rhythm and the frequency of the pulse and in the respiratory movements, and the like.

The local or focal symptoms vary with the seat of the disease in the individual case. Naturally, there are as yet numerous dead or silent points in the brain; that is, regions that may be destroyed without giving rise to distinctive symptoms, if to any. Among the focal symptoms a distinction must be made between those that are direct and those that are indirect. Direct focal symptoms depend upon destruction of a portion of the brain directly, and are persistent, as regeneration of brain-tissue does not take place. They are, therefore, designated symptoms of deficiency. The indirect focal symptoms are known also as remote symptoms, as they are due to changes in pressure and circulation induced by a remotely situated lesion upon a number of otherwise uninjured portions of the brain. If the alterations referred to disappear, the indirect focal symptoms also may subside. In the presence of recent disease the distinction between direct and indirect focal symptoms can scarcely ever be made with certainty. Only those phenomena that persist after the lapse of two months generally constitute the direct focal symptoms or symptoms of deficiency. As much of existing knowledge concerning focal symptoms as can be utilized in diagnosis will be indicated in the following.

FOCAL SYMPTOMS ATTENDING DISEASE OF THE CEREBRAL

CORTEX.

Upon the cerebral cortex disease of the anterior and posterior central convolutions, or, as they are sometimes also designated, the corticomuscular cortical region, is of especial importance. From the famous experiments on animals made by Hitzig, and which have been fully confirmed by observations on human beings, it is known that the central convolutions contain definite areas-motor cortical centers-irritation of which excites spasm, and destruction paralysis of definite groups of muscles and extremities upon the opposite side of the body. In the upper third of the anterior and the upper two-thirds of the posterior central convolution is situated the center for the leg (p. 31, Fig. 8), which upon the median aspect of the brain includes also the paracentral lobuie (p. 31, Fig. 7). In the middle third especially of the anterior central convolution is situated the arm-center (Fig. 8). In the lower third of the anterior and posterior central convolutions the facial