ACUTE HYDROCEPHALUS. 



of disease designated as tuberculous basilar meningitis. This must be 

 distinguished from simple miliary tuberculosis of the meninges, where 

 the development of tubercle is not accompanied by inflammation and 

 exudation, because the symptoms and course of the two diseases differ 

 m some respects. Both basilar meningitis and simple tuberculosis of 

 the meninges almost always cause effusions of fluid in the ventricles, 

 and softening of their walls and the surrounding parts. The latter is 

 the result of maceration, or destruction of the brain-substance by a 

 simple transudation or inflammatory exudation. 



Tuberculous basilar meningitis, as well as miliary tuberculosis of 

 the meninges, rarely occurs, as a primary and independent disease, in 

 persons previously healthy. We must bear this in mind, as it is very 

 important for the differential diagnosis of the various forms of menin- 

 gitis. These diseases are most frequently parts of a general acute or 

 chronic miliary tuberculosis, or, at least, of one affecting most of the 

 organs of the body. This form of the disease has many victims among 

 those children of whom, when speaking of pulmonary tuberculosis, we 

 said they had a strong predisposition to pulmonary consumption, if 

 they did not die early of croup or hydrocephalus. These are not only 

 children with marked scrofulous diseases, but also the offspring of con- 

 sumptive or otherwise debilitated parents. They are badly nourished, 

 and not well developed physically, but are often very bright men- 

 tally ; have a fine skin, very perceptible veins, long eye-lashes, and a 

 blue sclera. Caseous degeneration of the bronchial and mesenteric 

 glands, caseous deposits in the lungs, and other old disturbances of 

 nutrition, which, along with fresh deposits of tubercle in different 

 organs, are found on autopsy of these children, if they finally die of 

 hydrocephalus, cannot usually be recognized with certainty during life ; 

 hence the brain-affection is regarded as a primary disease. The case 

 is different when the tuberculous inflammation or miliary tuberculosis 

 of the meninges attacks adults. For then the symptoms of meningeal 

 tuberculosis have either been preceded, for a short time, by those of 

 acute miliary tuberculosis, or, more frequently, for a long time, by those 

 of chronic consumption of the lungs. In other cases, tuberculous me- 

 ningitis and miliary tuberculosis of the nieninges accompany old 

 tuberculous affections, such as chronic pulmonary or cerebral tubercu- 

 losis, and cheesy degeneration of the bronchial and mesenteric glands, 

 but are not accompanied by fresh deposits of miliary tubercle in other 

 organs ; they form the only acute complication of these chronic tuber- 

 culous affections. Lastly, although rarely, tuberculous meningitis or 

 miliary tuberculosis of the meninges occurs, without any precedent 

 tuberculosis of other organs, in previously healthy persons, or during 

 convalescence from severe diseases, such as typhus, measles, etc. 



