Etiology.—Myasthenia of the stomach and atonic dilatation are originated by some defect in the nervo-motor mechan isms of the stomach, which may be either congenital or acquired. A tendency to lack of general muscular tone, to flaccid ity of muscle-fibre, and to readily-pro duced partial atony of the same is in herent in many, and is perpetuated by an unhygienic mode of life. Improper eating, though a constant and the chief factor, is but one of many operative in the production of slight or considerable atonic dilatation in these. A chronically more or less imperfectly acting motor function, with or without fair secretion of gastric juice, permits the stomach to be rarely, if ever, free from food but for a short period in the twenty-four hours. Long-continued tendency to stagnation of food originates fermentative processes in the stomach, whether there be abnor malities of the secretory functions or not, and mild gastritis is eventually set up. This leads to atrophy of the muscle-fibre, and, as a result, the motor insufficiency is apt to steadily increase and the stom ach-walls to yield. Overeating, with im perfect mastication and excessive ha tion of fluids, tends to cause atonic dilata tion. Dilatation is the easier produced, the lower the motor tone of the indi vidual. Seine have, habitually from youth up, flabby voluntary muscles, which even systematic, properly-regu lated exercise fails to markedly toughen. These are apt to have a tongue the lateral aspects of which arc habitually indented by the pressure of the teeth. In such gastric atony is common, or at least may he readily produced.
Inattention to proper habits of eating and drinking in the line of excessive in dulgence leads to more or less increase in the gastric capacity and to the aug menting of symptoms of insufficiency. In many the loss of tone is shown in the tendency to either a partial or general descent of the abdominal viscera. There may be a general prolapse (splanchnopto sis) or simply dropping of the stomach (gastroptosis); this last is usually asso ciated with nephroptosis (looseness of the attachment and descent of the kidney, usually the right), and often conjoined with partial or general prolapse of the bowel (enteroptosis). These subjects, even if there be only combined gastropto sis and nephroptosis, without displace ment of the other viscera, have almost habitually gastric or gastrointestinal atony. Very commonly in the writer's experience a certain amount of gastric dilatation becomes superadded. Ewald holds that a vertically-placed stomach. not infrequently seen in those in whom the general or partial ptosis of the vis cera is a result of tight lacing, is always dilated. The writer has noted several exceptions to this, however. It has been held that obstruction exerted by pressure of a displaced right kidney on the de scending portions of the duodenum will originate dilatation through a tendency to partial obliteration of the bowel favor ing gastric stagnation. Doubtless in the
subject of gastric atony this is a con tributing factor, when present. Dis placed kidney is, however, so common in women without dilatation, though with gastroptosis, that this cannot be re garded as the common factor productive of gastric dilatation that certain writers imagine.
Marked loss of gastric motor tone may be of acute onset, so that dilatation will appear as an acute condition. Thus, atonic dilatation of the stomach has been noted to suddenly appear in the course of a protracted illness, such as typhoid fever. This form is due usually to para lytic superdistension of the stomach with gas, rarely as the result of fermentation. habitual distension of a more or less atonic stomach with food or drink would easily lead to increase in its capacity mechanically by the weight of the con tents tending to stretch the stomach wall, and through the production of gases, the result of fermentation of the stagnating contents. Excessive beer drinking is unquestionably a frequent cause of gastric atony and of subsequent dilatation. Dilatation may be set up in a comparatively short time by beer drinking in this way. It is unfortunate that even among college-lads of educa tion and presumed intelligence, and not solely among the lower classes, there is a tendency to abuse the stomach by bouts of excessive beer-drinking. The writer knows of city-bred medical students who have considered it a feat to drink in a short sitting an extraordinary amount of beer. Dilatation may easily, too, be set up by excessive water-drinking. Some decades ago a set of individuals, most of whom were uneducated, and ill-balanced mentally, following in the lead of Priess nitz, as concerns the employment of water in disease, advocated hydrotherapy as a cure-all. These issued numerous special treatises on the subject, generally advo cating, as a part of their system, two meals a day for all classes of individuals, and as much water-drinking as possible. Excessive appetite induced by long fast ing and impaired nutrition, the last as the result of the deprivation of animal food, naturally led to overdistension of the stomach at a meal, producing thus, doubtless, in many atony and finally dilatation. Many of the apostles of this set advocated the drinking of an enor mous quantity of water, especially on rising in the morning and on retiring at night. A mere megalogastria would not alone be thus produced; symptoms of dilatation naturally should soon be expected. Excessive water-drinking at the various spas is, no doubt, often the cause of a moderate amount of gastric dilatation. I have noted, at these, indi viduals drinking in the course of an hour an extraordinary number of glasses of water, fancying they were benefiting their health thereby. Undoubtedly those who attempt to live solely on milk and perform the ordinary duties of life lay a sure foundation for considerable dilata tion of the stomach. I have seen in stances of atonic dilatation so set up.