50 Veterinary Medicine. 



only may the lesion be iij any part of the brain, but it may be of 

 any kind : meningitis, cerebritis, softening, tubercle, tumor, hy- 

 datid, embolism, or dropsy. Marie Bra found an extreme asym- 

 metry of the cerebral lobes in epileptics. Kussmaul and others 

 found stenosis of the vertebral canal and asymmetry of the two 

 lateral halves of the medulla. 



2nd. Cranial lesions. These consist largely in blows or 

 falls upon the head, with ostitis, periostitis, fractures with de- 

 pressions, fibrous neoplasia implicating or not the meninges and 

 pressing on the- brain, haemorrhages from minute arteries, etc. 

 The diagnosis of such lesions will often open a way to a success- 

 ful treatment. Baker found most of the severe cases from head 

 injuries. 



3d. Disorders of the cerebral circulation. Burrows, 

 Kussmaul and Turner showed that in animals, loss of conscious- 

 ness and epileptiform convulsions followed on cerebral anaemia 

 caused by profuse bleeding or by compression of the carotids. 

 The same has been observed in surgical cases after ligation of 

 one common carotid. Hermann caused convulsions in a rabbit 

 by ligating both anterior and posterior venae cavae. 



4th. Lesions of the Spinal Cord. Brown-Sequard deteriiiined 

 epileptiform convulsions by transverse section of one half of the 

 spinal cord, or of its superior, lateral or inferior columns. The 

 later development of the doctrine of interrupted spinal inhibition, 

 suggests that, many of the seizures in question are but exaggera- 

 ted spinal reflexes, which are no longer restrained by cerebral in- 

 hibition. That all are not of this spurious kind may be fairly 

 inferred from his further demonstration that bruising of the great 

 sciatic in animals tended to produce epilepsy. In such cases the 

 irritation of certain areas by pinching the skin, served to produce 

 a seizure. Not only so, but the animals in which such artificial 

 epilepsy had been induced tended to transmit the infirmity to 

 their progeny. The prevailing view of epilepsy however, would 

 consider such lesions as sources of peripheral irritation by which 

 the brain is affected sympathetically, while the real explosion is 

 the result of the sudden discharge of the pent up excitement 

 caused in the encephalic centres by the irritation at such distant 

 points. 



