728 THE CEREBRAL CORT1 



there not been loss of sensibility in the paralysed limb, but in which no 

 trace of deficiency in sensibility, as compared with the opposite side, 

 could be detected. The fact that in numerous other cases defective 

 sensibility has been found, in no way affects the argument. For a 

 single case of cortical lesion, accompanied by muscular paralysis, careful 

 examination fails to detect any loss or affection of tactile sensibility, 

 is quite sufficient to invalidate the hypothesis that cortical muscular 

 paralysis must have its origin in tactile paralysis. The position as 

 based upon clinical observations is admirably summarised by Charcot 

 and Pitres 1 : " Les paralysies d'origine corticale s'accompagnent parfois 

 des troubles de la sensibilite cutanee on musculaire ; mais ces troubles 

 sensitifs eventuellement associes aux paralysies motrices, n'ont aucun 

 rapport constant et necessaire avec les lesions de la zone motrice. Les 

 centres moteurs corticaux de la region rolandique ne sont done pas des 

 organes sensitivo-moteurs." C. K. Mills 2 states that " innumerable cases 

 have been reported of lesions of the motor cortex without the slightest 

 impairment of sensibility. In several cases of excision of the human 

 cortex in the Rolandic region by surgical operations, careful studies of 

 the patients, by the writer and others, failed to show any impairment of 

 sensation." 3 



This being so, how then are we to explain the occurrence of a certain 

 number of cases (amounting, according to Charcot and Pitres, to about 

 one-third of those which have been carefully recorded), in which the 

 lesion of the Rolandic area is accompanied by a certain amount of 

 sensory disturbance ? This question is discussed by Charcot and Pitres 

 as follows : 



" Not only are the sensory disturbances not exactly coterminous with the 

 parts deprived of movement, but they also do not persist as do the motor 

 paralyses. They are almost always fugitive and changeable. Would they be 

 susceptible of alteration from one moment to another, of disappearing and 

 reappearing under the influence of slight causes, if they actually depend on the 

 destruction of corresponding perceptive centres'? This is very improbable. 

 Further, it is impossible, as some authors have attempted to do, to explain 

 motor paralysis of cortical origin by primary or concomitant disturbances of the 

 muscular sense, of tactile sensibility, or of the aggregation of sensations to which 

 the term ' kinaesthetic " 4 has been applied.' 



1 "Les centres moteurs corticaux chez 1'homme," Paris, 1895. Abundant statistics are 

 here given as well as a succinct account of the history of the subject up to the date of 

 publication. See also the cases quoted by Ferrier in " Cerebral Localisation," pp. 139-144. 



2 "The Nervous System and its Diseases," Philadelphia and London, 1898. 



3 I have lately had the opportunity of carefully testing a case in which, as the 

 result of a gunshot wound of the mesial surface of the right hemisphere of the brain, was 

 produced motor paralysis of the upper arm, trunk, and leg muscles (but not of the hand or 

 face). Although the left foot was completely paralysed, the slightest touch could be felt 

 upon it, and no difference in delicacy of discrimination of two points could be detected 

 between it and the right foot. Localisation of the exact position of the point touched was 

 imperfect upon the outer side of the leg and the dorsum of the foot only, but was perfect 

 upon the inner side of the leg and the plantar surface of the foot, although every part was 

 equally and completely paralysed for voluntary motion. Such slight defect in localisation 

 of tactile sensations as did exist was therefore independent of the muscular paralysis, and 

 was perhaps due to the fact that a part of the cortex other than that involved in the 

 production of the motor disturbance (or perhaps part of the thalamus options) was included 

 in the area of disturbance. 



4 The term " kinpesthesis " or sense of movement has been introduced by Dr. Charlton 

 Bastian, to denote all those impressions which are evoked by muscular movements, includ- 

 ing "cutaneous impressions, impressions from muscles, fasciae, tendons, and articular surfaces, 

 and in addition a set of unfelt or but little felt impressions which guide the activity of the 

 brain by the information (unconscious) which they afford us as to the different degrees of 



