FUNCTIONS OF THE SPINAL CORD. REFLEX ACTION. 289 



heat was perceived by him, although the plate was applied hot enough to 

 cause vesication. At three different intervals, the patient took one-eignth of 

 a grain of strychnia three times a day. Great increase of susceptibility to 

 involuntary movements immediately followed, and they were excited by the 

 slightest causes. No convulsions of the upper extremities could ever be pro- 

 duced, however, by irritating their integument; though, under the influence of 

 strychnia, pulling the hair of the head, or tickling the chin, would occasion 

 violent spasmodic actions in them. Spontaneous convulsions of the palsied 

 parts, which occurred at other times, were more frequent and more powerful 

 after the use of strychnia. On the first return of voluntary power, the 

 patient was enabled to restrain in some measure the excited movements ; but 

 this required a distinct effort of the will ; and the first attempts to walk were 

 curiously affected, by the persistence of the susceptibility to excited involun- 

 tary movements. When he first attempted to stand, the knees immediately 

 became forcibly bent under him ; this action of the legs being excited by 

 contact of the soles with the ground. On the 95th day this effect did not 

 take place, until the patient had made a few steps ; the legs then had a 

 tendency to bend up, a movement which he counteracted by rubbing the 

 surface of the belly: this rubbing excited the extensors to action, and the legs 

 became extended with a jerk. A few more steps were then made; the 

 manoeuvre repeated, and so on. This susceptibility to involuntary movements 

 from impressions on the soles, gradually diminished ; and on the 141st day, 

 the patient was able to walk about, supporting himself on the back of a chair 

 which he pushed before him ; but his gait was unsteady, and much resembled 

 that of chorea. Sensation improved very slowly: it was on the 53d day 

 that he first slightly perceived the heat of the metal plate. 



369. This important case suggests many interesting reflections. Common 

 sensation was not so completely abolished as in the former instance; but of 

 the peculiar kind of impression, which was found most efficacious in exciting 

 reflex movements, no consciousness whatever was experienced. Not less 

 interesting was the circumstance, that convulsions could be readily excited by 

 impressions on surfaces above the seat of injury; as, by pulling the hair of 

 the scalp, a sudden noise, and so on. This proves two important points: 

 first, that a lesion of the cord may be such, as to intercept the transmission of 

 voluntary influence, and yet may allow the transmission of that reflected from, 

 incident nerves. Secondly, that all influences from impressions on incident 

 nerves are'diffused through the cord; for, in the instance adduced, the reflected 

 influence was undoubtedly not made to deviate into the cord by the morbid 

 condition of that organ, but followed its natural course of diffusion, being 

 rendered manifest in this case by the convulsions which were excited, in con- 

 sequence of increased activity of the motor function of the cord. It is further 

 interesting to remark, that, in the foregoing case, the reflex actions were very 

 feeble during the first seven days, in comparison with their subsequent energy; 

 being limited to slight movements of the feet, which could not always be 

 excited by tickling the soles. In another case of very similar character, it was 

 three days after the accident, before any reflex actions could be produced. It 

 is evident, then, that the spinal cord must have been in a state of concussion, 

 which prevented the manifestation of its peculiar functions, so long as this 

 effect lasted; and it is easy, therefore, to perceive, that a still more severe 

 shock might permanently destroy its power, so as to prevent the exhibition of 

 any of the phenomena of reflex action. 



370. It seems well established, then, by such cases, that the Spinal Cord, 



or small segments of it, may serve in Man as the centre of very energetic 



reflex actions ; when the voluntary power exercised through the Brain, over 



the muscular system, is suspended or destroyed. And it is further evident, 



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