Epilepsy. Falling Sickness. 49 



irritations coming from lesions of the most varied kind, acting on 

 a specially susceptible brain will rouse the cerebral centres to an 

 epileptic explosion. Thus epilepsy has been found to be asso- 

 ciated with lesions of the following kinds : 



ist. Brain lesions of almost every kind, including malformations. 



2nd. lycsions of the walls of the cranium. 



3d. Disorders of the cerebral circulation. 



4th. I^esions of the spinal cord. 



5th. Morbid states of the circulating blood (excess of urea, 

 uric acid, creatinin, lead poisoning. ) 



6th. Reflected irritation, as from dentition, worms, sexual ex- 

 cesses, injuries to certain nerves, notably the sciatic, or to par- 

 ticular parts of the skin. 



ist. Brain lesions. Those which affect the medulla and the 

 cortical convolutions around the fissure of Rolando would be ex- 

 pected to be implicated because these centres preside over the 

 principal motor actions of the body and limbs. Yet though 

 these parts are found to be affected with various morbid lesions 

 in a certain number of cases of epilepsy, such lesions are ex- 

 ceptional, rather than the rule. In 20 cases of epilepsy in man, 

 15 showed no lesion whatever of the brain. Blocq and Marinesco, 

 pupils of Charcot, recently made a critical examination of the 

 medulla and Rolandic cortex in nine cases that died during the 

 fit. All showed granular bodies (degenerated myelin or blood 

 pigment) in the perivascular sheaths but they found these in dis- 

 seminated sclerosis and even in healthy brains as well. The neuro- 

 glia cells of the first cortical layer contained black granules. 

 Otherwise four cases had no change, while five showed sclerosis of 

 the cortex. The medulla was sound in all cases excepting one 

 which showed punctiform haemorrhages. Visible lesions may be 

 present in other parts of the brain ; Wenzel long ago claimed 

 constant lesion of the pituitary body. Beside the cerebral cortex, 

 lesions have been found in the bulb, the hypoglossal nucleus, 

 the olivary body, the hippocampi, the thalamus, the corpus 

 striatum, the quadrigemini, the cerebellum, etc. Hughlings- 

 Jackson who made an extended investigation of the subject con- 

 cludes that any part of the gray matter of the encephalon may 

 become over-excitable and give rise to a convulsive attack. Not 

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