Chronic Hydrocephalus. Dropsy of the Ventricles. 115 



Experimentally an approximate loss of sensation, intelligence, 

 spontaniety, will, and muscular power is produced in birds or 

 mammals deprived of their cerebral hemispheres. Colin's heifer, 

 which had been thus mutilated, would lie in torpor, and though 

 it could be made to get up and walk, it struck its head heedlessly • 

 against the wall, and retained in its mouth unchewed, the food 

 that had been placed there. He says of such cases : ' ' they live 

 a long time, move automatically, respire, digest, but they lose, 

 with the sensations, memory, judgment, will, and the most vital 

 instincts of their kind." 



In the dropsy of the ventricles the attenuation and atrophy of 

 the cerebral convolutions produce symptoms which approximate 

 closely to those resulting from their experimental ablation, so 

 that one may fairly attribute the general symptoms in the two 

 cases to the loss of their function. Many of the attendant symp- 

 toms, and especially the aberration of smell, sight, hearing and 

 taste, may be referred to the concomitant injuries of the basal 

 ganglia of the brain. 



We need not seek in one general answer to resolve the question 

 whether the dropsy or inflammation is the initial lesion. For our 

 present purpose it must suffice, that the dropsy with ansemia and 

 atrophy of the cerebral convolutions and basal ganglia produce 

 the symptoms of immobility. 



At the same time it is only logical to conclude that any morbid 

 condition of the cerebral circulation or of the brain or membranes 

 which leads to a corresponding amount of ventricular effusion, or 

 atrophy or destruction of the nerve centres, already designated, 

 will produce the symptoms characteristic of this disease. Thus 

 the different forms of meningitis, traumatic injuries to the 

 cranium, chronic encephalitis, cerebral softening or degeneration, 

 sclerosis, neoplasms of all kinds affecting the brain (cysts, choles- 

 teatoma, psammoma, melanoma, etc. ), and parasites may occasion 

 this disease. 



Prognosis. The disease is essentially incurable. . It may last 

 for years with little change except the winter improvement, but it 

 rarely subsides permanently. It is only in those cases in which 

 the symptoms have been deterfnined by a transient or removable 

 cause, as a moderate exudation or a parasite with a short term of 

 life that a favorable result may be looked for. Usually the im- 



