PAIN 



495 



Only a few of the reported sensations ha\e been de- 

 scribed as 'pricking.' However, Biemond (25) has 

 described a remarkable case in which a complex of 

 small confluent foci of softening was found in the 

 cortex and white matter of the right parietal opercu- 

 lum (see fig. 1 2) and in the cortex of the insula. This 

 lesion had been as.sociated with severe hypalgesia 

 over the entire left half of the body, as well as with 

 a constant deep 'drilling' pain throughout this area 

 worsened by any local stimulus. The senses of touch, 

 proprioception, attitude, stereognosis, vibration, 

 graphesthesia and discrimination were all intact ! In 

 figure 12 one sees also retrograde degeneration of a 

 fiber bundle passing into the posteroventral nucleus 

 of the thalamus where a marked cellular loss had 

 occurred. This loss was worse in the caudal portion 

 of the nucleus in which the spinothalamic fibers 

 principally terminate. He also reports two other 



less striking but similar patients in whom the findings 

 in life and at autopsy also suggest that the second 

 sensory area is related to the 'conscious pain sensa- 

 tion.' 



A review of the earlier literature discloses that the 

 lesion in Davison & Schick's (57) case 10 was largely 

 in the second sensory area but with involvement also 

 of the superior temporal and insular cortex. The 

 sensory findings, similar regarding pain to those in 

 Biemond's (25) case i, included spontaneous and 

 touch-evoked pains — although in this patient touch, 

 vibration and stereognosis were impaired also. This 

 case report, made before Adrian had described the 

 second sensory area, may in retrospect be taken as 

 confirmation of such an area in man and as adding 

 evidence that it is especially concerned with the 

 sense of pain. 



NUCLEUS LATERALIS 

 THALAMI 



NUCLEUS MEDIALIS 

 THALAMI 



NUCLEUS CENTRUM 

 MEDIANUM 



NUCLEUS VENTRALIS 



POSTEROMEDIALIS AND 



POSTEROLATERALIS 



_____CORPUS GENICULATUM 

 MEDIALE 



CORPUS GENICULATUM 

 LATERALS 



FIG. 12. Pain and the second sensory area in man. Fine diagonal hatching: areas of softening in the 

 parietal operculum and cortex of insula; these extended in varying degree from (he corona] plane 

 of the anterior commissure in front to that of the lateral geniculate body behind Heavy diagonal 

 hatching: retrograde degeneration of fiber bundle as seen in Weigert-Pal stain for myelin, passing 

 into posteroventral nucleus of thalamus via posterior part of internal capsule. Heavy dots: marked 

 cellular loss in nucleus ventralis posteromedialis and posterolateralis, especially in caudal portion 

 01 nucleus. [Based on data from Biemond (25).] 



