OF THE SPINAL CORD 209 



interference gives better results in these cases than 

 in those where the cord itself is affected. 



In a few cases recently recorded, where section of 

 posterior nerve roots had failed to reUeve pain, a 

 surgeon has divided the pain-path in the antero- 

 lateral region of the cord. To give success, this 

 should be done on both sides, although by far the 

 greater number of pain-fibres are crossed. Sherrington 

 worked out the path by dividing the mesencephalon 

 in dogs, after which injury they still turn and try to 

 bite and growl if a foot is hurt, although they cannot, 

 of course, psychically feel it. If then the spinal cord is 

 hemisected on the right side, painful stimuli appUed 

 to the right foot produce much liveher snapping and 

 growhng than the same on the left side. 



THE EXACT DIAGNOSIS OF INJURIES OF THE 



SPINAL CORD. 



The following lesions of the cord may be responsible 

 for symptoms of paralysis or anaesthesia after an 

 injury to the back. 



1. Simple concussion, the injuries being micro- 

 scopical or functional only, and the paralysis transient. 



2. Complete division of all the nervous elements. 



3. Pressure on the cord due to bone, callus, or a 

 foreign body not causing a total transection. 



4. Haemorrhage into the spinal membranes. 



5. Haemorrhage into the cord itself. 



6. Later complications such as myelitis, traumatic 

 neurasthenia, etc. 



This is not the place to consider all these in their 



14 



