SIGNIFICANCE OF PHYLOGENETIC STUDIES 61 



later than the pyramidal tracts. The great number of foci, 

 regularly found in these areas, makes it conceivable, that an 

 injur}^ to these young systems may disturb the function 

 depending on these tracts. 



We know that disturbances of sensibility in sclerosis 

 multiplex are rarely intensive and persistent. In the views 

 I have advocated we must expect that the sense of deep 

 sensibility and of tactile discrimination are more frequently 

 disturbed. In regard to deep sensibility this is correct as 

 Finkelnburg has demonstrated and it is also proved by my 

 own experience. In many cases of sclerosis multiplex I 

 found that only the sense of deep sensation was damaged. 

 The tactile discrimination of two points is in these cases 

 still insufficiently examined. Research in this direction is 

 difficult, since patients with disseminated sclerosis are very 

 often slightly dement and therefore unsuitable for fine tests. 



The fact that the higher and the latest acquired functions 

 are by preference disturbed, is also liable to psychical altera- 

 tions. Recent researches have shown, that the cortex of the 

 forebrain is more often affected than was formerly thought. 

 The histological alterations are not so striking since the 

 gliafibres in the cortex are not so inclined to grow excessively 

 as in the other parts of the central nervous system. Al- 

 though these modifications in the cortex of the Telence- 

 phalon vary greatly in intensity and in localization, the 

 psychical phenomena of these sufferers are rather monot- 

 onous. The typical mental picture of patients with dis- 

 seminated sclerosis is a slight dementia. The radius of their 

 sight of their interest is smaller. They manifest a childlike 

 feeling of security and a defective control of their affective 

 Ufe. Although still more severe alterations of the psyche 

 may occur, this is an exception. Very commonly the 

 mental condition of these sufferers is reduced to that of a 

 child, to the socalled ^'puerilisme mentale'^ of the French 

 clinicians. 



