in] Post-amputation Chain/ex in flic Cerebral Cortex 49 



"Ces cellules, tres atrophiees, ne pirstMitrnt. pas la moindre trace d'elements chromatophiles. A 1'interieur 

 du protoplasms, on voit une masse. variable .-.uiiine ctendue, constitute par lc soi-disant piginnnt de la cellule 

 nerveuse. 1'art'ois, lorsque lo pigment orrupe t.rnit Fintericur de la cellule, celle-ci so presente sous 1'aspect 

 d'un bloc jaunatre dc[iourvu pivsi|iic onnpletement de prolongements, on bien n'en posscdant qu'un, deux, 

 trois tout au plus, ot etant aussi tres courts. Le noyau et le nucK'ole sont tres atrophiees et occupent, 

 tantdt roxtrc'mite superieure, cello qui regards vcrs la surface du cerveau, tan tot la base, ou meme encore 

 luu des prolongements." 



" La vesieule micleaire, reduite de volume, presente une membrane ,\ contour plus ou moins irregulier, 

 repliee parfois sur elle-mume ; le nucleole, tres-pale, est petit, et d'autrcs fois au contraire Ijien colore'. Sa 

 forme est variable, rond, ovale, rt'niform." 



" Les prolongenients protoplasmiques ont disparu a pen pres cotnpletement ; ceux qui restent sont amincis, 

 cffiles et tres courts. Le cylindraxe presente les memes alterations et sa colline d'origine est pen apparente." 



While ilarinesco figures and evidently attaches much importance to this condition, he 

 is unable to tell us in exact terms how long after the initial lesion it appears, and also 

 In i\v long it lasts ; the only information he supplies is that in his cases of old-standing lesion 

 the giant cells had entirely disappeared, and that in one case of capsular destruction of 

 nine weeks' duration signs of reaction were already apparent. 



In concluding the paper containing these observations Marinesco generously credits von 

 Monakow with the prior discovery of similar changes, he also mentions that Dotto and 

 Pusateri obtained like results in the examination of a brain showing an old capsular lesion, 

 and that Ballet and Faure produced similar effects by experimental section of the motor 

 projection fibres in their cerebral course. 



That changes of this kind should occur in the motor cells, in cases of severance of 

 their axons at a point so little removed as the internal capsule, and that they should 

 supervene rapidly, is only what we might expect, but the result of Marinesco's next series 

 of observations is more remarkable. He examined the Rolandic area in six cases of lesion 

 of the spinal cord with secondary descending degeneration of the pyramidal tracts, the 

 duration of the disease varying between 4 and 24 months, and in every case similar 

 alterations were found, affecting the giant cells in the upper third of the precentral gyrus 

 and paracentral lobule. In those cases in which the disease had only lasted a few months, 

 early signs of " reaction a distance," viz. simple swelling of the cell body, central chroniato- 

 lysis and slight nuclear dislocation, were alone observed, but in cases of older duration the 

 alteration was much more pronounced and actual atrophy of the cell body was seen. 

 Further, in a case of syringomyelia with descending degeneration, which had been going 

 on for several years, in addition to atrophy, a distinct reduction in number of the giant 

 cells had occurred. In none of these cases were cells seen exhibiting the phenomena of 

 reparation. 



Reviewing the situation as it now stands, we find that "reaction a distance" has been 

 seen in the giant cells of Betz in consequence of severance of the axonal prolongation, either 

 in its encephalic or its spinal course ; it may also be stated as a law, that the intensity 

 and precocity of the reaction vary according to the position of the neuronic interruption, 

 being greater, for instance, when the lesion is in the internal capsule than when it occurs 

 in the spinal cord. 



In all the conditions mentioned in the preceding paragraphs, we have had to deal with 

 an interruption of the primary motor neurone, that is, the connecting link between the cortical 

 motor cell and the anterior cornual cell of the spinal cord ; and not only may we say that 



c. 7 



