CEREBRAL LOCALIZATION 163 



well as the adjacent pyramidal tracts, and so set 

 up spasticity, unless the whole cord is functionally 

 divided, in which case impulses descending from 

 Deiter's nucleus (possibly in the vestibulospinal 

 tract), are also cut off, and a flaccid paralysis 

 results. 



It is, however, true that irritation of the cortex, 

 such as may be present just after a traumatic lesion, 

 or during the growth of a tumour, may cause early 

 contracture, so we should regard the presence of 

 rigidity as an equivocal sign, but absence of rigidity 

 as evidence of a cortical lesion. 



The frontal cortex lying in front of the motor region 

 is described as a " silent area," and extensive 

 tumours, degenerations, or injury may produce few 

 or no symptoms. In a case under the writer's care 

 a wound one inch deep into the brain caused by a 

 chopper, from the vertex to the nose, made absolutely 

 no difference to the woman's character, capacity, 

 or intelligence, and indeed produced no symptoms 

 at all beyond concussion, although she was under 

 observation for many months. In the famous 

 American crowbar case, where a large part of the 

 frontal cortex on both sides was destroyed, there was 

 no paralysis, but on returning to work the man, 

 previously a capable foreman, had become weak, 

 vacillating, inattentive, and profane. There are 

 quite commonly signs of mental dullness in patients 

 with frontal lesions. In cats there are, after excisions 

 of the frontal cortex, changes in the disposition, 

 and recently acquired tricks may be lost. 



