BERIBERI.
BY DUANE B. SIMMONS, M.D.
DEFINITION.—Beriberi is a disease of inanition, most common in tropical countries, though found in high latitudes (41° N.), especially in low-lying seaboard towns, during the summer months, and is both endemic and epidemic. It is usually chronic in form, but is subject to exacerbations of varying degrees, and has for its characteristic symptoms anæsthesia of the skin, hyperæsthesia and paralysis of the muscles, anasarca, palpitation, cardiac and arterial murmurs (in the wet form), præcordial oppression, and abdominal pulsation.
HISTORY AND GEOGRAPHICAL DISTRIBUTION.—It was for a long time confounded with a great variety of other diseases. The Anglo-Indian physicians of Ceylon and the Malabar coast were no doubt the first to recognize the specific nature of the disease, though it is claimed that Chinese medical works of the thirteenth century contain a fairly accurate description of it.
The literature of beriberi, at the first glance, appears to be very meagre, as some of the most popular medical works make no mention of the disease at all, while others only give it a passing notice. Its bibliography, however, is very considerable, as may be seen in the exhaustive list in Billings' Index Catalogue, but for want of space we refer only to the most recent contributions to the subject. These are—an article by A. LeRoy de Mericourt;1 an essay by Tarissan, entitled Beriberi in Brazil; an article by Anderson,2 and an essay by myself.3
1 Dictionnaire Encyclopédique des Sciences Médicales, Paris, 1876.
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.
The cases of the subacute type are by far the most numerous. From this it is evident that the acute or pernicious type of the malady is, in most cases, only an exaggeration of the subacute, as observed in some other diseases, notably rheumatism and those of marsh malarial origin. The term pernicious is, strictly speaking, applicable to the wet form of the disease only, as the dry form is rarely, if ever, rapidly fatal. A marked case of wet beriberi is always to be regarded as dangerous, from the suddenness with which pernicious symptoms often declare themselves. In these the anasarca (which, as has been stated, constitutes the leading clinical difference between the two forms of the malady) plays an important rôle. It often happens that in the course of a few hours the local oedema in the extremities and the slight puffiness of the face become general and extreme, and the neck is enormously swollen by the distension of the veins, both deep and superficial. The pleural and pericardial sacs are more or less distended with serum, thus mechanically embarrassing the action of the organs they contain. The action of the heart now becomes laborious, the lungs oedematous and filled with coarse râles, and a terrible sense of suffocation comes over the patient, causing him to seek relief by constant change of position. The stomach is irritable, a greenish-yellow fluid is vomited, and death closes the scene. The acute stage of dry beriberi, on the contrary, is characterized by a rapid diminution of the fluids of the body and muscular atrophy.
The annual appearance in the same individual of either wet or dry beriberi, and its long continuance, constitute the chronic type of the disease.
MORBID ANATOMY.—The morbid anatomical changes in beriberi vary considerably with its form. Few, if any, observers claim seriously to have found in either the wet or dry form of the disease evidences of acute inflammatory action in any of the tissues or organs. The blood undoubtedly undergoes important morbid changes, whereby its nutritive and oxygenating power is impaired, indicating that this is a disease of inanition. This shows itself most markedly in necrobiotic and degenerative changes, especially in the muscular tissues, which are the seat of the leading morbid phenomena in all stages of both forms of this disease. The respiratory, digestive, and glandular systems rarely undergo morbid changes other than those of a secondary or passive kind, such as engorgement with serum and venous blood.
The condition of the organs contained in the cranial and spinal cavities is variable and inconstant. According to some observers, the substance of the brain and spinal cord is hardened. The greater number by far, however, have found it more or less softened.6 The heart in wet beriberi is habitually large and flabby, its muscular tissue softened and of a pale-yellow and macerated appearance. Its cavities are engorged with dark blood, sometimes fluid, but more often clotted. These clots are often voluminous in the right heart, semi-fibrinous, and extend into the pulmonary artery and great venous trunks, which are enormously enlarged. The cardiac muscular tissue I always found to have undergone metamorphic changes, varying from granular clouding to advanced fatty degeneration.7 The tissue of the paralyzed voluntary muscles undergoes degenerative changes in both forms of the disease. In the extreme atrophy of dry beriberi I have not unfrequently found many of the sarcolemma sheaths completely emptied of their contents. The power of regeneration in these cases is often wonderfully displayed by an almost complete restoration of the lost elements, and, in a corresponding degree, of the function of the part.
6 The former condition was undoubtedly observed in autopsies made of the dry or atrophic form of the disease, though this fact is not mentioned. The latter, or softened, condition of the cerebro-spinal contents belongs to the wet form of the disease (my own cases being of this kind). I regard this softening as not ante-mortem, but as consecutive to serous imbibition (as observed by Eismann and Sanders in chlorosis), and as taking place during the last moments of life or after death, when the vital forces no longer oppose themselves to the mechanical disintegrating power of the fluid with which the nervous as well as all the other tissues of the body are engorged.
7 I believe this to be the condition of the heart-muscle in all cases of death from the wet form of beriberi. In this opinion I am supported by Oudenhoven and many of the Dutch observers.
It would appear that in wet beriberi the heart is first weakened by paresis of the cardiac ganglia, with consequent incomplete emptying of its cavities. This, in connection with rapid degenerative changes in its muscular tissue, causes the walls to yield to the blood-pressure, producing dilatation and tricuspid insufficiency, with regurgitation and consequent capillary stasis and dropsy. Vaso-motor nerve-paralysis, acting at the same time on the pulmonary artery and arterioles, and on other large arterial trunks, probably gives rise to the murmurs heard in them. In the dry form of the disease the vaso-motor nerve-paralysis is less pronounced, and the degenerative changes in the muscular tissue of the heart slower, while the marked decrease in the fluids of the system and the great failure of nutrition tend toward atrophic changes. From this it follows that we usually have, instead of a large dilated heart, a small weak one, with a narrow tricuspid orifice instead of a dilated one; little or no intercostal pulsation, and hence less cardiac dulness; no venous distension or capillary stasis, and hence no dropsy.
PROGNOSIS.—In temperate climates the prognosis of uncomplicated beriberi is favorable in a majority of cases. In seasons of its epidemic prevalence, however, all cases of the wet form of the disease must be carefully watched, as it not unfrequently happens that grave symptoms suddenly appear at a time when no danger has been anticipated. An unfavorable prognosis may be ventured when, in a case of wet beriberi, relief is not obtained by free purging or when vomiting sets in. In dry beriberi the termination in death is exceedingly rare as a direct result of the action of the poison producing the disease, so that when death does occur it is chiefly from exhaustion. The time of recovery depends on the amount of muscular degeneration, and also upon the season of the year when the attack occurred, as all cases of both forms of beriberi usually get well without treatment during the winter months.
TREATMENT.—The well-established fact of the influence of certain localities in the production of beriberi makes the removal of the patient from them a hygienic measure of great importance, and this is frequently the only treatment necessary if it can be done early. The effect of the change is often almost magical, especially if it be made to an elevated locality and among the mountains.
Diet is an important element in the treatment of beriberi. At the head of the list of foods to be avoided is rice. Coarsely prepared grains, such as wheat, barley, certain kinds of beans,8 apparently because of more or less laxative properties, are preferable as articles of food.
8 A small red bean called adzuke, possessing both laxative and diuretic properties, is a favorite remedy with the Japanese for beriberi. It is used alone or mixed with rice, and is not unfrequently the only means resorted to for the successful cure of mild cases.
No drug has been discovered possessing specific properties in this disease. In the wet form, medication consists in the administration of drugs calculated to draw off the excess of serum in the areolar tissues and in the serous sacs. First in point of efficacy for this purpose are the hydragogue cathartics. In my own practice the sulphate of magnesia, in large and repeated doses, has given the best results; elaterium, a powder of jalap, squill, and digitalis, and, in fact, any medicine which will give frequent and copious stools, are sure to afford marked relief to the more urgent symptoms, and in many cases will alone effect a cure. Care must be taken, however, not to exhaust the patient, though I have never seen the judicious use of this method of treatment do harm.
Copious bleeding is recommended by Anderson, especially in the stage of greatest danger, but I have never been able to convince myself of its safety.
The almost specific virtue claimed by the old Indian physicians for treeak farook is no doubt due to its cathartic properties.
Diuretics are indicated for the same reason as cathartics, and any of the more active are productive of good results. They are too slow in their action, however, to be relied on otherwise than as adjuvants to cathartics. I have found juniper gin to answer an excellent purpose, both as a stimulant and diuretic, where there was danger of exhaustion from the free use of cathartics.
The medical treatment of dry beriberi differs materially from that of the wet disease. Cathartics and diuretics are alike useless, and the former injurious. The ordinary means, such as electricity, strychnia, frictions, etc., employed in cases of muscular atrophy and paralysis from other causes, are indicated when the active stage has passed, but they are useless, and even injurious, before this time. The muscular hyperæsthesia common to both forms of the disease may be generally greatly relieved by anodyne liniments containing aconite. The internal use of the latter is highly recommended by some. Hypodermic injections of morphia afford relief to the painful sense of constriction in the calves of the legs so often complained of.