MORBID ANATOMY 



1155 



The brain in pernicious cerebral fevers has its capillaries filled with sporu- 

 lating parasites and mononuclear macrophages containing degenerated para- 

 sites, while the arterioles and venules are freer, and only contain young forms. 

 Sometimes no parasites are to be seen, and only pigment in the endothelial 

 cells, which may be swollen and fatty, or may be found free in the vessel, 

 and may have parasitic inclusions. The nerve cells may be affected, showing 

 damage to or disappearance of Nissl's bodies, and at times degeneration of 

 their nuclei, the whole cell being sometimes filled with small granules. There 

 may be fibrolysis — i.e., degeneration of the neurofibrils — only small argento- 

 phile granules remaining. Rod-like cells attached to the processes of the 

 ganglion cells may be seen. The punctiform haemorrhages are due to the 

 diapedesis of apparently normal red cells. Occasionally the cerebro-spinal 

 fluid is increased, and there may be a slight lymphocytosis. 



B. Morbid Anatomy of Chronic Malaria. — -The lesions of 

 chronic malaria fall principally upon the spleen, the liver, and the 

 bone-marrow. There are no records of post-mortems on persons 

 suffering from chronic malaria due to Plasmodium malarice. 



1. Lesions due to Plasmodium vivax. — -The best recorded 

 case of this infection is that given by Ewing of a man who suffered 

 from the disease for about a year, and died from endocarditis about 

 three months after the last attack. 



The spleen was enlarged, firm, and dark, and contained parasites and pig- 

 ment in endothelial cells about the Malpighian bodies. Some haemosiderin 

 could also be seen. The liver showed no gross signs indicating malaria, but 

 microscopically, pigment was collected in large intracellular masses in the 

 portal canals and slightly in a few endothelial cells throughout the lobule. 

 Macrophages also contained pigment. The marrow was but slightly pig- 

 mented, showing a few endothelial cells with black pigment. 



2. Chronic Malaria without Definition of the Parasite.— 

 These lesions are generally due to Laverania malaricB, and, as stated 

 above, affect the spleen, liver, and bone-marrow. 



The spleen is always enlarged, often considerably, and is firm in consistence, 

 but its colour varies from a slate to a dark red, which depends upon the amount 

 of pigment deposited therein. Usually there are some adhesions, indicating 

 old perisplenitis. On section it generally appears quite black, but this depends 

 upon the amount of pigment ; the capsule is thickened ; the Malpighian follicles 

 stand out clearly, as they are enlarged and non-pigmented. Microscopically 

 the capillary vessels are seen dilated and separated by splenic pulp, or by 

 connective tissue containing giant cells. The pigment may be diffused 

 through the organ, but is generally either collected around the follicles or 

 extracellular, and contained in the lymphatics of the arterioles or septa, both 

 of which are thickened. 



The liver is larger and harder than usual. If pigment is present, it will 

 usually be gathered around the periphery of the lobules, which will, therefore, 

 stand out clearly. Later the pigment becomes perivascular, and finally dis- 

 appears. The capillaries or lymph-spaces may be considerably dilated, and 

 the liver cells atrophied by pressure. On the other hand, proliferation of 

 the hepatic cells and repair of the damage may be seen taking place. Atrophy 

 of the liver is not usual, but may occur in old people from thrombosis of the 

 portal vein, and is then associated with necrosis. 



The bone-marrow is usually pigmented, and of a chocolate hue in the small 

 bones, while in the long bones it may be reddish, except, perhaps, in the very 

 centre. This colour is due to the replacement of the fat by vascular tissue. 



3. Malarial Cachexia. — This may be acute when it develops 

 after a few attacks of fever, but more commonly it comes on as a 

 sequela to chronic malaria. 



