A system of practical medicine. By American authors. Vol. 4

by Unknown

In the course of chronic Bright's disease disturbances of vision occur dependent on three different conditions: (1) There may be a loss of vision, usually temporary, without any discoverable lesion of the eye. (2) There may be simple neuro-retinitis. (3) There may be the characteristic nephritic retinitis with hemorrhages and fatty degeneration of the retina. These two forms of retinitis are often the first symptoms of renal disease.

Neuralgic pains, most frequently referred to some part of the head or face, but also to other parts of the body, are prominent symptoms in some cases.

The Blood.—Both in acute and chronic Bright's disease the patients often become markedly anæmic and pale. This change in the color of the patient corresponds to an alteration of the composition of the blood with the details of which we are not as yet fully acquainted. The blood seems to be thinner and more watery.

Cerebral Symptoms.—Headache, drowsiness, stupor, sleeplessness, delirium, coma, muscular twitchings, and general convulsions are of frequent occurrence. The headache and drowsiness may continue during the course of the disease for many months. The stupor, sleeplessness, delirium, coma, muscular twitchings, and general convulsions are apt to occur in attacks which last for several days, and then pass away or terminate in the death of the patient. With such cerebral symptoms are often associated dyspnoea, vomiting, increased temperature, and diminution in the excretion of urine. The entire group of symptoms is commonly known by the name of uræmia.

It is a matter of great practical importance to determine the cause of these cerebral symptoms, for otherwise there can be no rational treatment of them. It is evident that such cerebral symptoms must depend upon anatomical changes in the brain or its membranes, or upon a change in the composition of the blood which circulates through the brain, or upon the quantity of blood supplied to the brain.

It is to be remembered that such cerebral symptoms occur most frequently with the atrophic form of chronic diffuse nephritis; that they are often the first symptom of renal disease; that the same person may have several such attacks, with no cerebral symptoms during the interval; that the urine is usually, but not always, diminished during the attack, and becomes more abundant when the attack ceases; that such attacks also occur with the chronic congestion of the kidney due to cardiac disease, in pregnant women without kidney disease, and with diseased arteries and high arterial tension without kidney disease.

Anatomical changes in the brain or its membranes do exist in a considerable number of cases of chronic Bright's disease. Chronic meningitis with thickening of the pia mater and an increase of serum is quite common; anæmia and oedema of the brain-tissue are often seen. But there are a great many cases with cerebral symptoms without such lesions, and with such lesions without cerebral symptoms.

The composition of the blood is undoubtedly changed in most of the cases with cerebral symptoms. It is natural to look for such changes as are due to perversion of the excretory function of the kidneys, and to ascribe the cerebral symptoms to the poisoning of the blood by urea, by urea transformed into carbonate of ammonia, or by the other excretory matters which should be eliminated by the urine. Moreover, it has been demonstrated that there is a very marked increase in the amount of urea contained in the blood in such cases. On the other hand, we find that suppression of urine with accumulation of urea in the blood may exist for a long time without cerebral symptoms if the suppression is due to obstruction of the ureters; that with chronic congestion of the kidney, puerperal convulsions, and diseased arteries urea is excreted in fair amount, although cerebral symptoms exist; and that even in cases of cerebral symptoms with chronic diffuse nephritis there may be no increase of urea in the blood.

In most of the cases with cerebral symptoms, however, there are other changes in the composition of the blood, concerning the exact nature of which we are still ignorant. In most cases of chronic Bright's disease the patients become pale and the blood is thin and watery; and this is also often the case with chronic congestion of the kidney and with diseased arteries. In pregnancy the quantity of blood is said to be increased: in cholera a considerable part of the fluid portions of the blood is lost.

Changes in the amount of blood in the brain may be due to lesions of the cerebral arteries or to contraction of these arteries; to changes in the arteries in other parts of the body; to organic disease or functional disorder of the heart; or to a change in the whole amount of blood contained in the body.