In advanced phthisis, emaciation naturally leads us to inquire into the pre vious history, especially with regard to chest symptoms, if none such have been detailed ; emaciation unquestionably also attends chronic disease of the brain, but it ought to be enough that a suspicion of disease of the lungs is suggested ; auscultation cannot fail to reveal its existence when a vomica is already formed.
In early phthisis, with equal dissemination of tubercle through the lungs, the result of stethoscopic examination being less satisfactory, diagnosis i! sometimes at fault. The disease to which it bears the closest resemblance is continued fever with pulmonary congestion. The differences in the auscultatory signs will afterwards be noticed in describing diseases of the chest, but some times they cannot wholly be relied on ; and even when they are well defined. the mind is so apt to be satisfied with the explanation which " fever" affords. that careful examination is forborne in the depressed and delirious condition of the patient. In such circumstances, a correct history serves our beat guide: the points which it indicates are the existence of cough before the commencement of the present attack, the occurrence of both headache and delirium at an early period, with relation to the fever, and the wandering of the mind by day as well as by night. In conjunction with these we observe the more definite symptoms of heat of head, and vomiting, with a tongue not very much coated, and a pulse not remarkably quick in the first instance, but often variable and unequal.
As with the corresponding disease in infancy, the result of diagnosis is very unsatisfactory, revealing only the hopeless nature of the malady. Our appre. hensions, grave at any time when the brain is seriously implicated, assume a more gloomy aspect when we have been able to determine that tubercular disease is present in other organs ; nevertheless, we obtain by its means not only a safer guide to treatment, but information most useful in the varying phases of the disease, and most important in venturing to give a prognosis to the friends of the patient.
It has been stated that tubercular inflammation does not necessarily imply the presence of tubercles in the brain itself; and it is here only necessary to add, that their existence is not generally betrayed by any symptoms, even when found of considerable size after death, till inflammation occurs ; and the course of disease is very much the same whether there be tubercular mat ter in the brain or not. Even when we have evidence of previous disease of
the brain, and we may feel justified in believing that it is caused by tubercular deposit, because we can trace tubercle more or less clearly in other organs, still its absolute diagnosis is quite beyond human art. Its symptoms do not differ from those caused by the presence of any other morbid growth.
It occasionally happens that, after an acute attack, the disease lapses into a chronic form, consciousness is nearly perfect, but paralysis of one or more cranial nerves remains, with less distinct evidence of general cerebral disturb ance. In such cases the circumstance of previous febrile action, along with local lesion, points pretty definitely to the coincidence of inflammation and tumor ; and the probability is very great, in the case of children, that it is scrofulous inflammation and scrofulous tubercle.
§ 2. Simple Inflammation.—Acute simple inflammation of the brain is exceedingly rare as an idiopathic disease ; more frequently it is set up by injury or disease of bone, and now and then acute symptoms supervene in a.ease where there has been long-standing disease ; in all of these the general characters of the malady are the same, and the history can alone determine its cause and origin. The important antecedents may therefore be divided into two classes: (1), those which have reference to injury or disease of bone, such, for example, as a blow or fall, tumors or abscesses on the scalp, discharges from the ears and nose, or deafness from of the ear; and (2), those which bear more especially on the condition of the brain itself—viz., the occurrence of fits, whether apoplectic or epileptic, the existence of any form of pa ralysis, impairment of vision, or deafness without disease of the ear. These circumstances also tend to show which portion of the encephalon is the precise seat of inflammation ; but the deter mination of this is matter rather of curiosity than of practical importance in regard to treatment; it is enough for our purpose if we can determine that acute inflammation is going on within the cranium.