MENINGITIS. 457 



also been described, principally in Germany. It seems almost un- 

 known in France, and French literature contains no well-authenticated 

 case. 



Furthermore, an epizootic cerebro-spinal meningitis of sheep, or 

 rather of lambs, has been described in Germany, in Italy, and in 

 France. These descriptions are all open to many objections. It 

 seems that under the term "cerebro-spinal meningitis" have been 

 grouped cases of enzootic tetanus, doubtful cases of poisoning, and 

 particularly cases of coenurosis in the first stage of development. We 

 therefore discard these descriptions, which differ too much among 

 themselves to be of any value. 



Causation. Meningitis occurs in the ox and sheep as a complica- 

 tion of wounds in the cranial region, accompanied by Assuring of the 

 bone, periostitis, abscess formation, etc. 



It is also seen as a complication of fractures of the horns, and old- 

 standing catarrh of the facial sinuses. In the sheep it follows parasitic 

 catarrh due to the larvae of oestridae. 



The meningitis appears, according to circumstances, in the forms of 

 local meningitis, anterior frontal meningitis, basilar meningitis, etc. 

 Finally, it may develop as a complication of different diseases, such as 

 gangrenous coryza, purulent infection, subparotid abscess, suppurative 

 phlebitis, suppuration of the eye or of the orbit, etc. 



Symptoms. It is difficult to detect and interpret the first symjjtoms 

 shown, because these chiefly consist in dulness, want of appetite and 

 constipation, without any particular fever. At a later stage, excessive 

 excitability is produced by noises, by changes of light, or by handling. 

 Careful examination of the patients shows a change in their expression, 

 rapidly followed by contraction and inequality of the pupils or deviation 

 of the visual axis (strabismus, squinting). The pulse becomes irregular, 

 as also the respiration. The appetite is entirely lost, and it is not 

 uncommon to note a contraction of the muscles of the neck and jaws, 

 as well as inability to move about and symptoms similar to those of 

 dropsy of the cerebral ventricles. 



The chronic form is rare. 



Lesions. The lesions comprise local or general hyperaemia and 

 exudative inflammation of the pia mater and arachnoid, together with 

 the formation of false membranes or of pus in the subdural space. 

 The meninges are partially adherent, and the superficial layers of the 

 brain are also inflamed by contiguity of tissue. 



Diagnosis. The diagnosis must be based on the disturbance of 

 vision, movement, and appetite, and on the course of the symptoms, 

 as well as on the external signs in the case of such diseases as are 

 prone to become complicated with meningitis. 



