DISEASES OF THE NERVOUS SYSTEM.

SOME RECENT PROGRESS IN DISEASES OF THE NERVOUS SYSTEM.

TALBOT JONES, M.D., CHAIRMAN.

There is scarcely a saying that has a more general acceptance, and one withal more trite, than that medical science is advancing with rapid and steadily increasing velocity. It arrests the attention and challenges the admiration of every thoughtful physician. There can be no differences of opinion that new facts are almost daily discovered and a new impetus given to medical thought and discovery. Restless activity, unwearying research and patient investigation meet the beholder at every turn. The multiplication of specialists in medicine, though not without attendant evils, has stimulated research in various fields, and through their collective investigations the sum of medical knowledge has been greatly increased. Every appliance that humanity can suggest or ingenuity devise is now employed to control disease or prevent it.

Investigations made in experimental physiology and morbid anatomy have been so fruitful of results as to almost mark an epoch in recent medical progress.

Man is now no longer content to pursue the beaten paths of his predecessors; he brings to his aid the microscope, the chemist's retort, the thermometer, galvanism, the sphygmograph, and even spectrum analysis is made to aid him in his eager search after truth. This progress toward exact knowledge, however, is not confined to any

single department of medicine; every field is being industriously worked. There may be more brilliant discovery in one field than another, but in every one alike the laborers have caught the spirit of enthusiasm characteristic of this age, and are giving to the world their best discoveries.

Perhaps in no single department of investigation has greater success been achieved than in that of diseases of the nervous system. We have thought that it might not be without interest on this occasion to note some of the advances that have recently occurred in this important branch of medicine. We, of course, are aware of the fact that this will be somewhat of an innovation on the time-honored custom in this Society, as it is customary for the committees in making up their reports to select some one particular disease and restrict their writings and investigations to it.

There are reasons which impel us, for the nonce, to depart from this custom, the chief one being a firm conviction that diseases of the nervous system occupy a too subordinate position in the minds of physicians in Minnesota, and indeed throughout the Northwest. In England, on the continent of Europe and the eastern section of our own country, diseases of the mind, nervous diseases and electro-therapeutics occupy a position of commanding importance; not so in Minnesota. In the sections referred to some of the ablest minds in the profession are found devoting themselves exclusively to investigations connected with neurology and psychiatry, but it is generally admitted, in the Northwest these subjects excite but comparatively little interest, and their importance is underrated. Your committee, therefore, has thought that a paper on some recent progress in diseases of the nervous system, would be timely, and it is hoped that it will be the means of arousing more interest in this important department of medicine.

It need scarcely be said that to note all the recent advances, and give anything like an adequate description of each, would be altogether inconsistent with the limits of a single paper, or with your patience; therefore the subjects will be hastily treated-reserving for the last that which perhaps is of greatest importance.

Dr. Duchenne long ago directed attention to what he called sub-acute anterior spinal paralysis, which was characterized by the loss of power, with retention of sensation in the limbs, and followed by rapid wasting of the muscles. It differed from all acute, general or diffuse spinal paralysis which had heretofore been observed, and invariably, but slowly progressed to a fatal termination. The ultimate anatomical lesion, as in infantile paralysis, was an atrophy of the cells of the anterior cornua. In progressive muscular atrophy both the wasting muscles and paralytic phenomena are due to the shrinkage of nerve cells. Carter of Liverpool has recently published the histories of four cases of this hitherto hopeless malady cured by the hypodermic injection of strychnia, the internal use of phosphorous, and Charcot's white hot cautery applied along the spine. Other observers have since confirmed Carter's success. Closely allied to this subject is that of infantile paralysis. For a long time much obscurity attached to this disease, as may be inferred from its name, which implies a morbid condition of the spinal cord and observed only in children. Recent investigation, however, has revealed the anatomical lesions of the disorder, and it is now known that the same disease is not infrequently observed in the adult-the morbid anatomy of both apparently being identical. As the same form of disease, then, is encountered in the adult, the term infantile paralysis is now no longer appropriate, and the term poliomyelitis anterior acuta, first proposed by Kussmaul, expressing as it does the seat and character of the disorder, is the one probably by which it will be sub

sequently known. Recent investigations in morbid anatomy have shown that in infantile paralysis the anterior nerve roots undergo a change, both at their emergence from the cord and at their termination. They become thin, translucent, atrophied, and their peripheral endings show more or less degeneration. The changes, however, of most importance are observed in the cord itself. Without the aid of the microscope, no morbid alterations are discerned, but this instrument shows in certain sections of the cord, especially well marked in the dorsolumbar and cervical enlargements, the nervous substance to have undergone inflammatory softening, separation of nerve cells, and the presence of granulation corpuscles and free nuclei. The multipolar nerve cells in the anterior horns of the gray matter are shrunken, many of them markedly atrophied and all in a state of atrophic degeneration. Coincidently with these changes there occurs a decided hyperæmia of the cord-most of the blood vessels being distended to twice their former calibre, with more or less serous exudation into the substance of the marrow, and a hyperplasia of the neuroglia. The cord is not uniformly affected by these changes; they occur only in certain areas or patches. The softening may be observed on one side only, but in severe cases on both. This atrophic degeneration is not always confined to the anterior horns of the gray matter, but may extend to the adjacent antero-lateral or even posterior columns. The muscles supplied by these nerves undergo a marked change. Individual muscular fibres may disappear, and most of them become degenerated; fat-cells and granules appear, and there is a marked proliferation of the connective tissue. "Important changes occur in the joints; the articular surfaces are atrophied and eroded, the ligaments thinned and stretched, and the articulations relaxed. By reason of these great deformities, the worst forms of club-foot are produced." All of these facts regarding the morbid anat

omy of polio-myelitis anterior acuta have been acquired in recent times, for in no systematic work on practice, unless written within the last year or two, will any description be given of its pathology.

Athetosis, allochiria (Med. Record, 1881,) and pseudo-hypertrophic spinal paralysis have recently been added to the list of nervous diseases, for a description of which we search medical treatises in vain. One of the most important articles that has appeared for years is a paper of Da Costa and Longstreth (Am. Jour. Med. Sciences), who, after an exhaustive investigation of the subject, have arrived at the conclusion that all the morbid processes embraced under the generic term of Bright's disease of the kidney are directly due to antecedent structural changes in the great abdominal ganglia of the sympathetic. The nature of this nerve change is akin to, if not identical with, fatty degeneration. They show that the neural change is primary and causative, the alterations in the kidney being secondary.

Localization of cerebral lesions has been largely studied, and attracted great attention, during the last decade, and very decided advances have been made in this subject, which still continues to engross the attention of the medical profession. Our increased knowledge is due to investigations in morbid anatomy and experimental physiology, and also to clinical observations. The important investigations made by Fritsch and Hitzig in 1870, by electrization of the cerebral hemispheres in the lower orders of animals, gave results of capital importance. These experiments, which at once attracted great attention to the subject, were quickly followed by those of Ferrier, though the latter were far more comprehensive in their scope and valuable in their results.

Other workers soon began to labor in the same field, and the result of the investigations of Broca, Schiff, Vulpian and others is now well known to the scientific world.