158 PATHOLOGY OF TYPHUS IN MAN 



sponded with the histological findings. Several brains showing 

 the most extensive lesions histologically gave no gross evidence 

 whatever of cortical lesions. We have concluded that the 

 degree of injection and the presence or absence of edema of 

 the brain found at autopsy is influenced by other factors, 

 circulatory and toxic, and that the specific lesions of typhus 

 do not necessarily markedly alter the appearance of the brain. 

 Careful analysis of the autopsies fails to correlate any type of 

 case or complication with the brains that were of striking ap- 

 pearance at autopsy. 



One gross evidence of lesions due to typhus in the brain 

 is the presence in section of the brain, particularly of the basal 

 ganglia, pons and mid-brain of what are apparently promi- 

 nently engorged blood vessels, which cannot be made to dis- 

 appear upon pressure. These have proved to be small vessels 

 surrounded by zones of hemorrhages into the perivascular 



" spaces." 



3. PATHOLOGICAL HISTOLOGY 



The first observation of a distinctive lesion in typhus was 

 made by Fraenkel (1914, 1915) in skin removed from living 

 patients. He described acute lesions of the blood vessels with 

 thrombosis and perivascular accumulations chiefly composed 

 of cells derived from the adventitia and peri-adventitial ele- 

 ments, but containing lymphocytes and polymorphonuclear 

 leucocytes. These lesions he held to be specific for typhus. 

 Fraenkel's findings and his conclusions in regard to the 

 specificity of the skin lesions were confirmed by Aschoff (1915), 

 Poindecker (1916), Ceelen (1916 1 - 2 ), Bauer (1916), Kyrle and 

 Morawetz (1916), von Chiari (1917, blood vessels of the con- 

 junctiva), Jaffe (1918 1 ' 2 - 3 - 4 ), Herzog (1918), Kurt Nicol (1919), 

 and a number of others. The same lesions were found in 

 Mexican typhus in 1920 by Wolbach and Todd. Jaffe has 

 perhaps written most extensively about the lesions in the 

 skin. 



Other lesions distinctive for typhus were found in the central 

 nervous system by von Prowazek (1915), in man and animals 



