598 PHYSIOLOGY CHAP. 



on the opposite side, with little or no difference from those due to 

 ablation of the excitable area of the cortex. All four animals died 

 in violent attacks of epilepsy, one after about three months, the 

 other three a month or rather more after the operation. 



Lo Monaco's attempts to extirpate the lenticular nucleus more 

 or less completely were less successful and conclusive, since this 

 involves removal, simultaneously, or by a preceding operation, of 

 a considerable area of cortex from the parietal and temporal lobe, 

 and thus produces partial loss of sight and hearing. In certain 

 experiments of partial destruction of the lenticular nucleus with- 

 out injury to the internal capsule, the sensory and motor symptoms 

 are similar to those that follow destruction of the head of the 

 caudate nucleus. 



We may, therefore, conclude from the results obtained by 

 various physiological methods that the functions of the two nuclei 

 of the corpus striatum do not differ from those of the sensory- 

 motor area of the cortex. 



The clinical and auatomo-pathological facts that can throw 

 light on the physiology of the corpus striatum in man are scanty, 

 but highly important, as they confirm and partially supplement 

 the incomplete results of experiment. 



Charcot (1876) assumed that when lesions of the caudate and 

 lenticular nucleus are confined to these parts, and do not involve 

 the capsule, they either run a latent course or, if motor paralysis 

 ensues, it is invariably slight and transitory. 



Nothnagel (1877), on the other hand, held that concomitant 

 lesions of 'the capsule were not necessary to produce complete 

 or incomplete motor paralysis, as was also believed by Gowers 

 and Oppenheim. To account for the disappearance of the 

 symptoms, he assumed that the function of one nucleus may be 

 supplemented by the homonymous nucleus on the opposite side, 

 or that the lenticular of one side may be supplanted by the 

 caudate of the same side, or vice versa. This strengthens the 

 view that the two nuclei have the same function. 



Von Monakow distinguishes the effects of haemorrhagic lesions 

 from those of softening. The latter for the most part run a latent 

 course ; the former, on the contrary, produce a typical hemiplegia 

 that gradually disappears, which he believed to be due to com- 

 pression of the capsule. Brissaud (1895) held the same opinion. 



Mingazzini (1908), from the observations of nine lesions 

 limited to the lenticular nucleus, demonstrated unmistakably 

 that motor paresis of one whole side of the body, usually accom- 

 panied by diminution of muscular, painful, tactile and thermal 

 sensibility, is the symptom most frequently observed during life. 

 Mingazzini has no doubt that special motor paths run from the 

 lenticular nucleus (putamen) to the internal capsule, in association 

 with the pyramidal tract. 



