220 DISEASES OF THE BRAIN. 



San, as we have often shown, have no other direct result than partial 

 paralysis. Since the destruction of certain portions of the brain, par- 

 ticularly in the medulla of the cerebrum, does not cause any perceptible 

 disturbance of function, we may readily understand that small haemor 

 rhages, as well as other diseases of those parts, may occasionally es- 

 cape recognition during life. 



We have designated the corpus striatum and thalamus opticus as 

 the most frequent seat of haemorrhage ; a destruction of these parts, or 

 of the pedunculi cerebri, induces paralysis of the opposite half of the 

 body. We may readily determine that the paralysis, resulting from 

 destruction of the above parts, only depends on interruption of the 

 conduction between the organs acting in thought and will and the 

 motor nerves and muscles ; the power to think and will is unimpaired. 

 After the apoplectic seizure, during which there is complete loss of 

 consciousness, has passed off, if we ask the patients to give us the 

 affected hand, they show their desire to fulfil the request, by taking the 

 paralyzed hand in the other one, whose nerves and muscles are under 

 the control of their will, in order to accomplish the act. On the other 

 hand, in recent cases, every motor nerve on the paralyzed side, to which 

 we apply the induced current, causes contraction in the muscles sup- 

 plied by it. Hence the only failure is in the communication between 

 the central excitory apparatus and the motor nerves. This interrup- 

 tion has no effect on those movements of the paralyzed side that occur 

 in a reflex manner without the influence of the will ; for patients, who, 

 as a result of apoplexy on the left side, cannot move the right arm or 

 leg, move the right side of the thorax just as well as the left during 

 respiration. And the connection between the motor nerves and those 

 nerve-filaments and ganglion-cells which are excited during certain 

 states and feelings of the mind is not always removed with the inter- 

 ruption of conduction at present under consideration. This is shown 

 by the fact that some patients who cannot make the motions of laugh- 

 ing or crying on the one side of the face, at our request, can do so 

 when they do not will to do it, but when their feelings lead them to 

 do so. In the same way, the interruption of conduction of the impulses 

 of the will, from the central organs to the motor filaments, does not 

 necessarily imply that the communication of the latter with sensory 

 and with other motor filaments is interrupted. On the contrary, we 

 find that occasional reflex movements sometimes remain undisturbed 

 in the paralyzed parts, or even occur more readily, so that it appears 

 as if, when the excitement of the motor filaments is no longer subject 

 to the will, it occurs more readily than it otherwise would. Paralysis 

 of half the body, due to destruction of the corpus striatum and thalamus 

 of one hemisphere, is characterized by its limitation to the muscles of 



