288 MANUAL OF EQUINE MEDICINE. 



due to irregularity or disturbance of the cerebral circula- 

 tion, has been described as staggers. 



Section I. 



DISEASES OF THE BRAIN. 



ACUTE INFLAMMATION OF THE BRAIN AND ITS 

 MEMBRANES. 



Synonyms. — Encephalitis, cerebritis, phrenitis, menin- 

 gitis. 



Acute inflammation of the cerebrum, or hemispheres of 

 the brain, termed cerebritis, encephalitis, or phrenitis, is 

 usually associated in the horse with meningitis, or inflam- 

 mation of the meninges or coverings of the brain ; and we 

 therefore describe these two affections together. 



Etiology, — Inflammation of the brain and of its coverings 

 is usually due to direct injury, as blows on the head, or to 

 disease of the bones of the cranium. 



This inflammation sometimes supervenes in some of the 

 specific fevers, and may also be due to exhaustion or ex- 

 posure to the heat of the sun. 



Of epizootic cerebro-meningitis, or cerebro-spinal fever^ 

 we have already treated. 



Symptoms. — Practically, it is almost impossible to dis- 

 tinguish between inflammation of the brain itself and in- 

 flammation of its membranous coverings, and, indeed, as we 

 have already intimated, these two aff'ections are usually 

 associated together. 



When the membranes of the brain are primarily aff'ected, 

 the symptoms are characterized by the suddenness of their 

 onset. They consist at first in great excitement, with con- 

 vulsions or spasms, and are followed by a stage of depres- 

 sion. 



Encephalitis is not characterized by such a sudden onset. 



