DISEASES OF THE NERVOUS SYSTEM. 235 



What is the morbid anatomy? 



The lesions are mostly found in the cerebral arteries. Aneur- 

 isms are usually present. On section of the brain-substance, these 

 appear as small, dark bodies, the size of a pin's head. 



The hemorrhage may be cerebral, meningeal, or intra- 

 ventricular. 



Meningeal hemorrhage may take place outside the dura mater 

 or between it and the arachnoid, or between the arachnoid and 

 pia mater. 



The extravasations cause pressure on the adjacent structures, 

 and unless the products are absorbed motor paralysis occurs, fol- 

 lowed by degeneration of the various tissues involved. 



Give the causes. 



Injuries or fractures of the skull, rupture of aneurisms, dis- 

 eases of the walls of the vessels, overaetion of the heart; this con- 

 dition may be associated with certain general diseases. Heredity 

 comes into play, as does age. In older animals the vessels become 

 more brittle as a rule, and are thus prone to rupture. 



Give the symptoms. 



Symptoms of cerebral hemorrhage may be divided for study 

 into primary and secondary. 



The peimakt symptoms are vertigo, uneasiness, twitching 

 of musoles, the mucous membranes injected, and, if the hemor- 

 rhage be severe, unconsciousness and paralysis. 



In severe cases the pulse is full, slow, and hard; the respira- 

 tions are labored, deep, and stertorous; the temperature normal 

 or subnormal; the pupils usually dilated; the eyes turned in their 

 sockets; the head turned to one side; involuntary evacuations of 

 the bladder and bowels due to relaxation of the sphincters, and a 

 paralysis of a portion of the body, varying according to the situa- 

 tion of the hemorrhage. Secondary fever is usually present. 



The secondaby symptoms are changes taking place in various 

 tissues along the course of the paralyzed nerves. The reflexes are 

 greatly increased, there is flexion of parts of the extremities with 

 loss of co-ordinating power. Atrophy of muscles may result, al- 

 though it is not constant. 



How may cerebral hemorrhage be diagnosed? 



By the suddenness of the attack, by the head and eyes being 

 deviated to one side, by the subnormal fever being followed by 



