n^ G. H. MONRAD-KROHN. M.-N. K 



amongst which is the inversion of the plantar reflex à la Babixski. In 

 leprosy the feet are as a rule affected in exactly the same way as the 

 hands, while the plantar reflexes are most frequently lost. 



The coordijiatiou is in leprosy always surprisingly good, and ataxic 

 manifestations are as a rule missing, while in syringomyelia ataxia is not 

 at all rare and may even be very pronounced. — 



As far as the sensory (iisturbaiiccs are concerned, one has to consider 



1. differences as regards the distribution, and 



2. — - — the character of the sensory loss. 



1. As regards the former, the distribution in syringomyelia is a seg- 

 mentary one, i. e. the distribution is limited to the cutaneous fields which 

 correspond to the spinal segments affected. 



In leprosy, as in any other form of polyneuritis, the sensory loss is 

 found most pronounced in the distal parts of all four extremities, grading 

 off successively towards the proximal parts of the limbs. In some cases 

 the sensory loss may be more strongly pronounced in the area of certain 

 nerves. When this is the case in the area of the ulnar and the medial 

 cutaneous nerves of the arm and forearm, it may give a false impression 

 of segmentary distribution ; but this is rare and, as a rule, the differential 

 diagnosis can then be made from other evidence. 



2. The character of the sensory loss does not furnish any such reliable 

 point of distinction. In syringomyelia one frequently meets wnth the so- 

 called classical form of sensory dissociation, which consists in sensory loss 

 to stimuli of pain (pin prick), heat and cold, while the tactile sensation 

 remains intact. This is due to the fact that in some individuals the major- 

 ity of the fibres conducting tactile sensation, on entering the spinal cord 

 from the posterior roots, go straight into the posterior columns, thus es- 

 caping the syringomyelitic lesion of the grey substance, which, situated in 

 the posterior grey horn, will cause a unilateral loss of sensation to pain 

 and temperature in the corresponding cutaneous fields — when situated in the 

 commissura will cause a bilateral loss of sensation to pain and temperature 

 of similar segmental distribution, due to a lesion of the crossing fibres, 

 which conduct impressions of temperature and pain. There are, however, 

 as far as we can judge from the facts before us, considerable individual 

 differences in the arrangement of the conduction of the tactile sensation. 

 In some individuals the fibres for tactile sensation partly go with the fibres 

 conducting temperature and pain sensation. In these cases the above dis- 

 sociation will obviously not be complete. 



Therefore, whilst a complete dissociation in the classical sense of the 

 word (cpr. above) practically furnishes conclusive evidence of a lesion in 

 the grey substance of the cord — an incomplete dissociation may be found 

 in syringomyelia as well as in leprosy. All one can say is that the more 

 marked the dissociation, the less likelihood of leprosy, and vice versa. 



