SECONDARY TROPHIC TROUBLES - DISEASES OF THE MUSCLES.
We shall not devote much time to a consideration of secondary trophic affections of the muscles. They are really an essential part of the diseases with which they are associated, and their description belongs rather to treatises dealing with these diseases. I shall, how ever, for the sake of completeness, review briefly their most striking features.
We may mention first among secondary trophic disturbances the atrophy consequent upon iylammation of the muscles. I have al ready remarked, in treating of myositis, how frequently atrophy fol lows upon inflammation, whether acute, subacute, or chronic, of muscular tissue. This group may be placed here as forming the con necting link between primary and secondary trophic disturbances. They are secondary in the sense that they are tributary to another disease, but they are related to the primary affections in that they are secondary to a disease wholly of the muscular tissue. Alongside of these atrophies it is proper to mention those which follow surgical affections of the muscles, such as wounds, ruptures, and contusions, the study of which has not occupied us in the present article.
Various local troubles may induce atrophy in the neighboring muscles. Thns diseases of the bones or articulations may interfere with the nutrition of the muscles in the neighborhood and finally lead to their atrophy. This might be called atrophy consecutive to lesions in the vicinity.
Then we have atrophies produced by what I would call fanctionoi inertia. In order to maintain itself in a normal state of nutrition the muscle has need of movement; and we know that exercise or massage, which is a form of passive exercise, exerts a very happy influence upon the growth and vitality of the muscular tissue. Therefore whenever for one reason or another a segment of a limb is immobi lized we find a diminution in volume of its muscular tissues. This is b2canse the circulation is less active and therefore nutritive material is brought to the part in greatly lessened amount.
We have next to mention the trophic affections secondary to dysc•usive. In this group of dvserasia I include all acute or chronic
general diseases which induce alterations of a nutritive character in the muscular tissue. In studying the various forms of myositis we saw that the infectious febrile diseases often induced of the in muscles. But myositis is not the only affection so caused, and we even more frequently see atrophy of the muscles. Indeed there is nothing more CO111111011 than to observe a very considerable atrophy following an attack of typhoid fever, and it is also often seen after small-pox, measles, diphtheria, and other acute diseases. It has been observed in malaria, and is of common occurrence in tubercu losis and cancer. In a word, whenever for one reason or another assimilation and nutrition are defective there is more or less marked inanition, and the muscular tissue, like all the others, suffers and un dergoes atrophy to a greater or less extent.
Various poisons exert a baneful influence on the muscles. I refer here only to chemical poisons and do not include in this category the poisonous products of bacteria—the toxins. I have in view espe cially two important substances, lead and alcohol. Mercury does not in general induce atrophy of muscular tissue.
The atrophy of lead poisoning affects chiefly the paralyzed mus cles, which are ordinarily the extensors of the hands and fingers, but atrophy has been observed alone not preceded by paralysis. Cases have been seen of lead atrophy of the hands which presented all the appearances of muscular atrophy of the Aran-Duchenne type, which will be referred to below.
In chronic alcoholism there are often muscular atrophies affect ing chiefly the lower extremities and sometimes producing deformi ties of the feet. These trophic troubles consecutve to alcoholic poi soning are, it must be said, under the direct influence of lesions of the peripheral nerves and ought perhaps to be described in the group of atrophies following nervous diseases, but the first etiological factor being an intoxication it seems more suitable to group these among the toxic atrophies.