284: DISEASES OF THE BRAIN. 



thinner, harder, and of a pale or light-brown color. The ventricles 

 are dilated and filled with serum. There is also a quantity of fluid in 

 the subarachnoid meshes (hydrocephalus ex vacuo). 



.SYMPTOMS AND COURSE. Although, as we have previously men- 

 tioned, agenesis of one side is not always accompanied by psychical 

 disturbances, still it is rare to find cases where we dare assert that one 

 side of the brain fully replaces the other. Far the greater number of 

 patients suffer from weakness of intellect, and many from decided 

 idiocy. The organs of special sense, particularly the eye, are usually 

 very insensitive, and the excitability of the sensory nerves of the par- 

 alyzed half of the body is diminished. The most important and ap- 

 parent symptoms are paralysis and a peculiar and excessive atrophy 

 of the side of the body opposite to the atrophied brain. The paralysis 

 is not usually complete, so that the patients can generally perform 

 some imperfect movements. The paralysis is ordinarily combined 

 with contractions. The atrophy of the paralyzed side affects all the 

 tissues, the bones not excepted, so that the thin and short extremities 

 of a grown person appear like those of a child. Most patients suffer 

 from epileptic attacks. As the other functions of the body are usually 

 well performed, the disease itself is rarely fatal. But the patients 

 seldom attain old age. Their power of resistance to intercurrent dis- 

 eases is lessened, and they succumb to them more readily than other 

 persons would. 



The primary atrophy of the brain, which develops chiefly in old 

 persons, and secondary atrophy, which accompanies apoplexies, partial 

 necrosis, and other local brain-diseases, are characterized by gradual 

 weakening of the psychical functions, loss of memory, slowness of 

 thought, absent and childish manners, as well as dulness of the senses, 

 and gradual weakening of the motor power, unsteadiness of motion, 

 trembling, incomplete control of the sphincters, etc. 



The atrophy of the brain found on autopsy of insane patients, who 

 have suffered from paralytic idiocy, belongs to the terminal symp- 

 toms observed in that form of insanity during life, to the symptoms of 

 mental weakness and idiocy, but not to the monomania which pre- 

 ceded the mental paralysis, or to the intercurrent maniacal and apo- 

 plectiform attacks. These are rather to be referred to the precedent 

 meningitis, which is rekindled from time to time during the subse- 

 quent course. At the stage of the disease when the psychical exalta- 

 tion of the patient decreases, when the insane ideas and hallucinations 

 lose their richness and reality, when the thoughts are confused, mem- 

 ory defective, symptoms of paralysis also begin to appear in the motor 

 sphere ; and the more the signs of psychical weakness increase, the 

 more extensive and marked become the signs of motor paralysis. The 



