CEREBRAL APOPLEXY. 223 



Cfilled a stroke of apoplexy, and is only absent when the haemorrhage 

 is slight, do not depend directly on the local injury of the brain, but 

 Dn its effect on the rest of the brain. We shall hereafter show that 

 the apoplectic fit usually occurs at the outset, but sometimes does not 

 come on till after the appearance of the paralysis. The stroke of 

 apoplexy rarely develops gradually and probably only does so when 

 the haemorrhage occurs slowly ; in most cases it comes on suddenly, 

 and the patient falls to the earth (often with a cry) as if " knocked 

 down." During the attack, consciousness is entirely lost, as well as 

 the power of feeling and moving. The sphincters also are generally 

 paralyzed, so that faeces and urine are passed involuntarily. Respira- 

 tory movements alone, which depend on the medulla oblongata, are 

 continued ; but the inspirations follow at long intervals, and are usually 

 loud and stertorous, since the paralyzed and pendulous soft palate is 

 thrown into vibration by the air. The patient has a peculiar appear- 

 ance, from the relaxed cheeks being puffed out with every expiration. 

 There is often vomiting at the commencement of the attack; the 

 pulse is very slow, the pupils contracted. 



It is usually supposed that the apoplectic fit is a result of the pres- 

 sure or bruising of the nerve-filaments and ganglion-cells of the entire 

 brain by the extravasation. However, it is evident that this pressure 

 can never exceed that of the blood in the cerebral arteries ; for, as 

 soon as the pressure in the parts around the arteries is as great as that 

 of the blood in the vessels, no more blood can escape from the latter. 

 But, from experiments that we can make on peripheral nerves, there 

 is no doubt that such a pressure is entirely insufficient to annul the 

 excitability of the nerve-filaments. The following fact also tends to 

 disprove the current explanation : If the symptoms of paralysis de- 

 pended on the pressure to which the filaments of the brain are sub- 

 jected in apoplexy, bleeding should remove these symptoms not only 

 in some but in all cases, provided enough blood be drawn to lessen 

 the pressure in the whole vascular system, particularly in the arteries. 

 Byrtl) who also speaks most decidedly against referring these symp- 

 toms to pressure on the brain, thinks that the accidents generally re- 

 ferred to " pressure on the brain " are due to a slight amount of con- 

 cussion ; but, apart from the fact that there is no such concussion in 

 cases of extravasation which are not of traumatic origin, no anatomi- 

 cal changes referable to such a cause can be found. We refer the 

 apoplectic fit to sudden compression of the capillaries, that is, anaemia 

 of the brain-substance. In all large haemorrhages this anaemia may 

 not only be recognized with certainty after death, but even during life 

 it shows itself by a very important symptom which is usually falsely 

 interpreted, that is, by a remarkable pulsation of the carotids. This 



