TUMORS OF THE BRAIN AND ITS MEMBRANES. 271 



In accordance with the slow growth of most cerebral tumors, the 

 development and extension of the local symptoms of irritation and 

 paralysis are usually slow and gradual. Many patients cannot state 

 exactly when their disease began. In doubtful cases this may de- 

 cidedly aid in the diagnosis, since, from such a course, we may exclude 

 most other local diseases of the brain. But not very rarely these local 

 symptoms come on suddenly ; this is chiefly the case where vascular 

 tumors are suddenly increased in size by overfilling of their vessels, 

 or by haemorrhage from them, or where the parts around them are at- 

 tacked by inflammation or softening, or by capillary haemorrhages. 

 If the tumor have previously run a latent course, and these symptoms 

 of paralysis come on suddenly, the case will most probably be mis- 

 taken for one of cerebral haemorrhage, and there are numerous in- 

 stances where the best diagnosticians have made mistakes in such cases. 

 If, on the other hand, there has been a suspicion of tumor of the brain, 

 the frequency of such incidents in the course of this disease should 

 prevent our being deceived. 



Attacks of epileptiform convulsions occur more frequently from 

 tumors of the brain than from any other local disease of that organ ; 

 but it is very remarkable and inexplicable that they occur almost 

 solely when the tumors are in the cerebrum, and especially when they 

 are near the cortical substance. 



In many cases psychical disturbances do not present themselves 

 throughout the disease. Indeed, it seems that the psychical functions 

 of the brain only suffer when the cortical substance of both hemi- 

 spheres is affected by organic disease, or by disturbance of circulation. 

 The correctness of this view is proved by the peculiarities of those 

 cases where the state of the psychical functions forms an exception to 

 the above. For the general mental ruin that we described when 

 speaking of abscess of the brain also occurs in cerebral tumors, when 

 they are accompanied by extensive chronic meningitis of the convex- 

 ity, or when the cortical substance of both hemispheres is the seat of 

 numerous tumors (cysticerci), or when then* capillaries are compressed 

 by encroaching tumors in both hemispheres, or by extensive secondary 

 effusions in the ventricles. 



In the rare cases where the tumors perforate the skull, the symp- 

 toms above described are accompanied by other symptoms, which are 

 very characteristic. The perforation usually takes place through the 

 parietal or temporal bones, near the root of the nose, more rarely 

 through the occipital bone. At the point of perforation the hair is 

 lost, the skin becomes red, and is traversed by varicose vessels ; ulcera- 

 tion of the integument is rare. We may often feel a bony margin at 

 the border of the tumor, which is generally soft and nodular. It is a 



