THE SYMPATHETIC SYSTEM 331 



(6) LESIONS OF THE MEDULLARY CENTRES. These 

 are better known and are caused by the cilio spinal centre 

 becoming affected in syringomyelia, areas of sclerosis, 

 tabes, hematomyelia, tumors of the cord and its mem- 

 branes and in medullary compressions (Pott's disease, 

 bone tumors). 



(c) LESIONS OF THE KAMI COMMUNICANTES. The 

 oculo-sympathetic syndrome is quite often observed in 

 lesions of the inferior roots of the brachial plexus. 



Since the work of Mrs. Dejerine we know that: 



1. The tearing of the inferior roots alone of the brachial 

 plexus, and especially of the first dorsal nerve, will cause 

 the appearance of oculo pupillary phenomena. 



2. Cutting the 8th cervical and the 1st thoracic at 

 their junction will produce the same effects. 



3. The tearing of the superior roots (6th and 7th 

 cervical) or cutting them at their junction is never followed 

 by ocular disturbances. 



4. The section of the superior or inferior roots of the 

 plexus made 1 cm. beyond their junction does not cause an 

 oculo pupillary syndrome. 



This syndrome is, therefore, due to the cutting or tear- 

 ing of the rami communicantes of the first dorsal nerve 

 which contains motor fibres, which go to the iris; these 

 arise from the cord, pass in the inferior cervical ganglion 

 and travel up by means of the cervical sympathetic to the 

 eyeball. The observation of an oculo pupillary syndrome 

 can, therefore, localize the nerve injury between the cord 

 and the junction of the 8th cervical and 1st thoracic. 



(d) LESIONS OF THE SYMPATHETIC TRUNK AND ITS 

 GANGLIA. The oculo pupillary syndrome is met with in: 



1. Pleuro-pulmonary affections; pleurisy with effusion 

 (Chauffard and Loederich), apex tuberculosis with involve- 

 ment of the pleura (Souques), apical pleurisy (Sergent), 



