Meyer, Data of Modctn Neurology. 303 



aesthesias with or without hysterical stigmata, or stereognostic 

 disorders, etc. 



In the objective motor sphere we look out for affections of 

 the muscles and groups of muscles in reflex and complex activ- 

 ities (referring them in a similar manner as in the sensory sphere 

 to special nerves, plexus, or segments, according to their dis- 

 tribution) and the character of the disorders present. If we 

 find any disorder anywhere, we have to examine first for those 

 symptons which are associated with lesions of the segmental 

 efferent neurones (the dhect motor neurones of Goldscheider). 

 This is necessary, because motor syviptonis produced by any 

 disorder of a inechanisvi will only come out clearly, if the links 

 between it and the muscle arc in a normal condition. It is 

 therefore of great importance that we know very valuable tests 

 for the condition of the segmental efferent (direct motor) neu- 

 rones. The cardinal points (flaccid paralysis with atrophy of 

 the muscles, absence of reflexes and electrical reaction of de- 

 generation) are to be excluded in every instance before a dis- 

 order is looked for beyond. With a lesion of the indirect mo- 

 tor neurones (the cerebral efferent or voluntary motor appara- 

 tus) we associate an involvement of certain groups of muscles 

 coordinated for special movements and joints, a tendency to 

 rigidity, usually no atrophy, exaggerated reflexes and clonus, 

 but normal electrical reaction, i. e. none of the symptoms asso- 

 ciated with lesions of the direct or segmental motor neurones. 

 Another group of symptoms is characteristic for mechan- 

 isms of a more specialized, perhaps psychical character, com- 

 monly called the group of psychic motor disorders, usually in- 

 volving the entire limb (for instance both legs) or only special 

 uses of the limbs (astasia-abasia, etc.). 



A further type of motor disorders which requires inves- 

 tigation is formed by the ataxias, associated either with lesions 

 of the motor cortex and the affi:;rent cerebral neurones, the fillet 

 (motor ataxia), with tumors of the frontal lobe (?), with lesions 

 of the cerebellar apparatus and also with affections of the af- 

 ferent segmental neurones (tabes and pseudo-tabes), forms which 

 experience teaches us to distinguish ; the motor ataxia existing 



