GID—CCENUROSIS 229 



tumor varies in size from a pea to a hen's egg. Other tumors 

 occurring in the brain substance are gliomas, gliosarcomas, 

 melanosarcomas, and very rarely carcinomas. Some of the 

 chronic infectious diseases may produce growths in the brain 

 such as tuberculosis, actinomycosis and botryomycosis. 



In the meninges, fibromas, lipomas, angiomas, sarcomas, 

 epitheliomas, papillomas, and dermoid cysts have been noted. 



Symptoms. — Due to the slow growth of brain tumors they 

 rarely produce any symptoms during life. A tumor the size of 

 a hen's egg (melanoma) has been found in the brain of a horse 

 without the animal seeming in any way disturbed by it. 



In rare instances brain tumors may produce periodical 

 increases in -intracranial tension, especially after vigorous 

 exercise, causing symptoms of transient cerebral excitement, 

 followed by depression, or the patient may show symptoms of 

 chronic hydrocephalus. More rarely the symptoms closely 

 simulate acute meningo-encephalitis or encephalitis, the 

 animal dying in a short time. Sometimes brain tumors pro- 

 duce epileptiform seizures, cerebral ataxia, forced movements, 

 hemiplegia, blindness, and an abnormal carriage of the head! 

 Congestion of the papilla is thought by some observers sig- 

 nificant of brain tumor, and is a probable cause of the blind- 

 ness (amaurosis). 



Diagnosis. — The diagnosis is obviously extremely difficult. 

 The gradual development of the symptoms, both general and 

 topical, the congestion of the papilla, and the absence of 

 fever point to the condition. In rare cases in which the tumor 

 leads to a deformity of the cranium the diagnosis is easier. 

 The clinical symptoms of chronic hydrocephalus, chronic 

 meningo-encephalitis, abscess, and parasites of the brain so 

 closely resemble those of tumor in many cases that an accu- 

 rate diagnosis becomes impossible. 



Treatment.— Treatment for brain tumor in animals is rarely 

 of avail. In man they are occasionally removed surgically. 



GID. C(ENUROSIS. 



Definition. — Gid is a chronic parasitic disease of sheep and 

 cattle, due to the presence of the Ccenurus cerebralis in the 

 brain and very rarely in the spinal cord. 



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