258 DISEASES OF THE BRAIN. 



and no caries of the temporal bone can be found, it is almost equally 

 improbable that there is encephalitis. While these points are gen- 

 erally true, they have in some cases led to erroneous diagnosis. 

 Autopsy has revealed abscesses of the brain where there had been no 

 injury of the head or caries of the cranial bones. There have also 

 been cases where patients wiih cerebral tumors have had a blow on 

 the head, and occasionally Ine previously latent brain-disease had 

 not become manifest till after this injury. (These cases are analo- 

 gous to those where women first have their attention directed to a 

 carcinomatous mamma by a blow on it, and then consider it beyond 

 a doubt that it is due to the injury they have received.) But, prac- 

 tically, it is best only to think of these exceptional cases where thero 

 is sufficient reason. 



Encephalitis never affects the entire brain, but is always limited 

 to certain points ; nevertheless, at the commencement of the disease, 

 there are almost always signs of temporary irritation of the entire 

 brain or meninges, such as increased frequency or great slowness of 

 the pulse, increased bodily temperature, headache, dizziness, sleepless- 

 ness or restlessness, exciting dreams, psychical irritation, even mild 

 delirium, great sensitiveness to slight irritation of the organs of special 

 sense, bodily disquiet, and great weakness, etc. According to Gries- 

 inger, this violent commencing stage, which may be followed by quiet, 

 is almost pathognomonic of encephalitis and abscess of the brain. In 

 the criminal records there are numerous cases where the above symp- 

 toms were considered by the attending surgeon as traumatic fever, be- 

 cause they apparently disappeared without any traces, and the complete 

 recovery of the patient from the injury received was officially certified 

 to, while, after a time, there were unmistakable signs of a severe brain- 

 disease, and autopsy showed abscess of the brain as the fatal termina- 

 tion of the injury. Even in those cases where an injury of the skull 

 is followed at first by the symptoms of general irritation of the brain 

 and meninges, and subsequently by the above-described decrease of 

 all the cerebral functions, we should first think of abscess of the brain, 

 and attribute the absence of local symptoms to the location of the ab- 

 scess at a point where it does not interrupt the conduction of excite- 

 ment, in the centripetal and centrifugal cerebral filaments. 



The influence that local inflammations in the brain have on the rest 

 of the organ consists partly in their encroachment on the cranial cavity, 

 and chiefly on those chambers of the skull where they are located, 

 partly on the collateral hyperaemia and oedema in their vicinity, and, 

 lastly, partly on their injurious effect on the nutrition of the entire 

 brain. On the first of these factors depend the headache, the attacks 

 Df dizziness and vomiting, as well as the evanescent occurrence of pain, 



