2 Guy's Hospital Reports.
3 Chinese Maritime Customs Medical Report (1880).
For a long time beriberi was supposed to have a peculiar territorial limitation. It is now known to be more or less prevalent on all the islands and shores of Eastern Asia and Africa from Japan to the Cape of Good Hope, and in Brazil.
ETIOLOGY.—I know of no disease in regard to which a greater diversity of opinion exists as to its cause. Indeed, as one has observed, "autant d'auteurs, autant d'opinions diverses." Ten years' study and observation of the malady under a great variety of circumstances and conditions have led me to the definite conclusion that its exciting cause is a specific poison or germ, having many striking resemblances in its mode of production to paludal or marsh miasm, though entirely distinct and separate from it. A great variety of predisposing causes, however, exert a powerful influence in rendering individuals or classes susceptible to the disease, such as age, sex,4 occupation, race, mode of life, diet, and climate.
4 Women suffer from the disease much less frequently than men.
CLINICAL HISTORY AND SYMPTOMS.—There are three forms of the disease: 1st. Beriberi hydrops (wet beriberi), in which there is a hydræmic condition of the blood, distension of the general areolar tissue, with serum, and effusion into the serous cavities. 2d. Beriberi atrophia (dry or atrophic beriberi), in which there is a notable deficiency of fluids in the vessels and areolar tissue, and atrophy of the muscles. 3d. Mixed beriberi, in which the above forms lose the sharp lines of distinction and merge into each other. Cases complicated with dysentery, diarrhoea, and especially with continued fevers of the typhoid type, are not uncommon.5 These last, besides being of grave prognosis, are frequently very embarrassing and difficult of diagnosis.
5 Some authors have designated fatty or convulsive forms of the disease, which I think unnecessary.
In general terms, wet beriberi may be divided into two stages—the prodromic stage and the stage of attack; and into several types—the acute or pernicious, and the chronic. From the very insidious nature of the approach of the disease, sometimes extending over a period of several weeks, it is often very difficult, or even impossible, to determine the exact time of its invasion. It is generally admitted that a residence of some weeks in an infected locality is necessary before any decided symptoms make their appearance. As in many other diseases of slow development, the symptoms of the prodromic stage are certain not easily defined feelings of indisposition, such as an occasional sense of chilliness, inaptitude for mental exertion, and especially a tired feeling in the lower extremities. A period of uncertain length now intervenes, during which the characteristic symptoms appear and constitute the stage of attack. The first of these symptoms is, generally, anæsthesia of the skin over the anterior tibial muscles, in the tips of the fingers, and around the mouth, in the order given. Paralysis in varying degrees next declares itself in certain groups of muscles, usually those immediately underlying the regions of anæsthesia. One of the consequences of this is a drooping of the toes, causing the patient while walking to lift the feet high so as to clear the ground, thus occasioning the peculiar gait noticed by many observers as characteristic of the disease. A sense of constriction in the muscles of the calves is experienced at the same time, arising from a veritable contraction, which causes their apparent enlargement and hardening, with tension of the tendo achillis. A feeling of tightness in the chest usually accompanies this condition, due, no doubt, to partial paralysis of the muscles of respiration. If firm pressure be now made upon the muscles in various parts of the body, a greater or less degree of tenderness will be found to exist in many of them, and especially those occupying the posterior part of the leg, back of the forearm, inside of the arm, and upper part of the chest. Tenderness of the periosteum of the long bones and a peculiar roughness of their surfaces often exist also. Palpitation of the heart, especially on making any considerable exertion, is a frequent and often troublesome symptom, even at this stage of the disease.
Up to this point the above symptoms are common to both the wet and dry forms of the malady, and to them the characteristic features either of beriberi hydrops or atrophia are now added. The first manifestation of anasarca, the pathognomonic symptom of wet beriberi, is in an oedematous condition of the areolar tissue of the anterior part of the legs. This, in reality, is more or less general even at an early stage of the disease, as is evident from the plump appearance of the patient and a certain sallow-white color of the skin, especially of that of the face. In uncomplicated cases the temperature is normal, or it may be at times a little below the normal point. There is also little or no increase in the frequency of the pulse. Its quality, however, is changed, and somewhat characteristic for both forms of the disease. Thus in the wet form it is full, large, and easily compressible, indicating a great diminution of arterial tone, while in the dry form there is nearly an opposite condition. If the heart be now examined, a decided systolic murmur will be heard, most distinctly over the pulmonary valves; and in most cases of wet beriberi it exists in all the large arterial trunks. The heart furnishes the usual signs of dilatation and want of tone. In the dry form the cardiac murmurs are either slight or wanting altogether, and the area of cardiac dulness is variable, and frequently diminishes as the disease advances.
In both wet and dry beriberi the appetite is little impaired in the earlier stages, but if in the former the stomach is over-distended, there is increased præcordial oppression, and sometimes sudden death. The bowels in the wet form are sluggish, and urine scanty; in the other there is but little deviation from the normal in these respects.