ACUTE HYDROCEPHALUS. 243 



Nevertheless, the disease is almost always easy to recognize and to 

 distinguish from other diseases. Characteristic peculiarities in the 

 sequence of the symptoms, distinct signs from which the original seat 

 of the affection and its subsequent extension may be determined, as 

 well as the very regular subacute course of the disease, almost always 

 give sufficient grounds for a certain diagnosis. At the commencement 

 it is a local disease, situated at some point on the base of the brain, 

 where numerous nerves start from that organ and run to the foramina 

 through which they leave the skull. Later, when the disease extends 

 to the ventricles, the local disease at the base becomes complicated, by 

 the excessive effusion in the ventricles and by extensive hydrocephalic 

 softening of the brain-substance, with diffuse disease of the cerebrum. 

 In accordance with this, among the most constant symptoms of basilar 

 meningitis are such as indicate irritation and afterward paralysis in 

 the parts supplied by the nerves of the eye, the vagus and medulla 

 oblongata. Among these are contraction and, later, dilatation of the 

 pupil, ptosis of the upper eyelids, vomiting, slowness and subsequent 

 frequence of the pulse, the peculiar changes of the respiration, and de- 

 pression of the abdomen, according to the results of Budge's observa- 

 tions. In the same way, corresponding to the course of the patho- 

 logico-anatomical changes, the functions of the cerebrum at first show 

 no marked disturbance, except the symptoms of so-called general cere- 

 bral irritation, while, as the disease advances, there is severe disturb- 

 ance, of the character that we have frequently mentioned as due to 

 compression of the capillaries by diseases encroaching on the space ; 

 such as loss of consciousness, epileptiform convulsions, paralysis of the 

 extremities, etc. In cases where this second set of symptoms is not 

 very marked, we may even conclude that the effusion in the ventricles 

 is not very large. Lastly, when the symptoms of paralysis are limited 

 to one side in certain cases, or are more decided on one side than on 

 the other, it is usually because the hydrocephalic softening is more ad- 

 vanced on one side than on the other. 



Although basilar meningitis, particularly its tuberculous form, and 

 miliary tuberculosis of the meninges, very rarely occur in persons pre- 

 viously healthy, we must not count among its premonitory symptoms 

 those of the diseases which it usually accompanies, On the other 

 hand, in most cases, especially in children, the violent symptoms char- 

 acteristic of a later stage of the disease are usually preceded for a time 

 by insidious and indefinite symptoms, which may correctly be consid- 

 ered as premonitory. Such children show a change of manner, have 

 no desire to play, like to sit in a corner, rest the head on the hands, are 

 sleepy, and dream a great deal. They do not always complain of 

 severe headache, and when they do it is especiallv in cases where therf 



