678 THE CEKEBRUM 



general seizures may be evoked. In many cases even weak stimuli 

 suffice, provided, of course, that the nervous system has been rendered 

 especially susceptible. Conditions of this kind often arise in the 

 course of eclampsia, uremia, and diabetes, after the toxins contained 

 in the blood have led to a constant discharge of supraminimal im- 

 pulses. Thus, Landois^ has succeeded in evoking tonic and clonic 

 spasms by spraying the motor areas with creatin, creatinin and urates. 

 The same results may be obtained with such agents as santonin, 

 physostigmin and bile, and even more readily in pregnant animals, ^ 

 in which the nervous system is in an especially irritable condition. 



Traumatic or Jacksonian epilepsy most commonly finds its 

 origin in tumors or in the pressure exerted upon the motor area by the 

 projecting pieces of bone of an old fracture. These seizures are 

 ushered in as a rule by a feeling of numbness and a tingling sensation 

 in the part to be affected first. Thus, if the motor points of the 

 muscles of the thumb are the seat of the excitation, the contractions 

 begin in this part and then spread to the muscles of the hand, forearm, 

 arm and shoulder, and later on to those of the face, trunk and leg. 

 Eventually they also involve the muscles of the opposite side of the 

 body. This orderly sequence or ''march" is also observed if the 

 contractions begin with the muscles of the toes or foot. When these 

 seizures are reproduced in animals, it is quite impossible to prevent 

 the spreading of the contractions from one side of the body to the 

 other by cutting the corpus callosum. Single muscles, however, 

 may be prevented from participating in the general convulsion by 

 ablation of the corresponding motor district. It seems, therefore, that 

 the aforesaid spreading is made possible through the mediation of the 

 subcortical paths and centers. 



These seizures may last a few seconds or several minutes. They 

 consist as a rule of a tonic and a clonic phase. To begin with, the 

 muscles remain tonically set, but presently show repeated attempts at 

 relaxation: These relaxations are separated from one another at first 

 by intervals of several seconds, but gradually become more frequent 

 toward the end of the convulsion. In consequence of these violent 

 muscular contractions, the body temperature most generally shows a 

 rise of several degrees, but consciousness is not lost unless the attack 

 is severe. This fact really serves as one of the differential signs between 

 Jacksonian and idiopathic epilepsy. The latter is a type of epilepsy 

 which must be assigned to general retrogressive changes of the cortex. 

 It need scarcely be mentioned that the traumatic type may be remedied 

 by removing its cause, the seat of the lesion being suggested by the 

 manner of progression of the muscular contractions. For example, 

 if the epileptic seizure begins with tonic and clonic spasms of the 

 muscles of the thumb, it is to be inferred that the difficulty chiefly 



1 Wiener med. Presse, 1887. 



^Bickel, Pfliiger's Archiv, Ixxii, 1898, 190, also: Blumenreich and Zuntz, Arch, 

 fiir Physiol., 1901. 



