278 DISEASES OF THE BRAIN. 



chronic hydrocephalus, the continued employment of cold douche baths 

 deserves most confidence. 



CHAPTER XV. 



SEROUS EFFUSIONS IN THE INCOMPLETE SKULL HYDROCEPHALUS 



CONGENITUS. 



ETIOLOGY. It is most probable that congenital dropsy of the brain 

 is due to inflammation of the ventricular walls that has occurred during 

 foetal life. The etiology of the disease is entirely obscure. Some 

 women have had several hydrocephalic children, without any apparent 

 cause. 



ANATOMICAL APPEARANCES. In congenital hydrocephalus the 

 amount of serum, usually clear and limpid, effused into the cerebral 

 cavities, is occasionally very small, while it sometimes amounts to six 

 or ten pounds. In such cases the ventricles are distended to large, 

 thick-walled sacs, the brain-substance around them is thinned, and 

 often atrophied to a layer only a few lines thick ; the corpora striata 

 and optic thalami are flattened and pressed apart, the corpora quad- 

 rigemina flattened, the commissures stretched and thinned. The sep- 

 tum is occasionally broken through, and the floor of the third ventricle 

 is often thinned and projecting. The pons and cerebellum appear 

 compressed from above downward. 



Where the effusion is not large, the skull preserves its normal size ; 

 where it is large, on the other hand, it is almost always decidedly dis- 

 tended. Even at birth the head is usually enlarged, but becomes still 

 larger after birth, and may be distended to two feet in circumference. 

 In such cases the cranial bones, especially the frontal and parietal 

 bones, are very large, and are, at the same time, very thin. The mem- 

 branous interstices also, especially the fontanels, are very wide. The 

 forehead is prominent, the roofs of the orbits are depressed, and they 

 are transformed into narrow, transverse slits ; the squamous portions 

 of the temporal bones and the occipital bone are more horizontal. The 

 ossification, which is delayed, takes place from formation of points of 

 ossification in the membranous interspaces, or even from the formation 

 of innumerable small bones. The cranium, which, previous to the 

 ossification, was very thin, often becomes thick subsequently, and, in 

 many cases, such a skull retains an asymmetrical or remarkable spheri- 

 cal form. 



SYMPTOMS AND COURSE. Many children, born with hydrocephalus, 

 die at birth or shortly after. In others, during the first weeks of life, 

 if the skull be not enlarged, no symptoms of the disease can be 

 observed. This is due partly to the difficulty of judging of the cere- 



