710 Compression of the Spinal Cord, 



even on extremely slight irritation, and consequently it appears 

 as if the urine were trickling away owing to paralysis of the 

 sphincter, but that this muscle is uninjured is rendered obvious 

 by the fact that urination ceases when the pressure is removed, 

 and also that large quantities of urine collect in the bladder 

 during complete rest. In very rare cases of compression 

 of the lumbar portion of the cord there is observed paraly- 

 sis of the sphincter of the bladder and dribbling of urine, re- 

 laxation of the sphincter of the anus may also be seen. The 

 distribution of the motor and sensory disturbances according 

 to the position of the part of the cord that is sul^jected to 

 pressure, has been dealt Avith in connection with contusion of 

 the cord (see page 686). 



The occurrence of atypical cases is not rare. In some such 

 cases symptoms of paralysis follow disturbances which are in- 

 considerable, and which possibly have very little local effect. 

 It happens now and then that some intraspinal growth for a 

 long time causes no obvious symptoms and is then the cause 

 of the sudden onset of symptoms. In both cases the deviation 

 from the usual course of events is caused by crushing or 

 stretching of the cord or some of the nerve roots through 

 some sudden movement or excessive flexion of the spine, thus 

 causing either a unilateral traumatic lesion or probably some 

 interruption of conductivity due to a local disturbance of cir- 

 culation. 



Course. Corresponding to its nature the condition runs a 

 chronic course. In typical cases the disturbances increase until 

 there is complete paralysis which may be gradual, or there maj'' 

 be times at which the disease is at a standstill, or possibly 

 there may be some improvement. In other cases some slight 

 disturbance is followed by severe or complete paralysis, or 

 tliere may be severe symptoms of paralysis which are not pre- 

 ceded by any obvious disturbance. In cases of this kind in 

 small animals, the condition may abate for a certain lengih of 

 time or even completely disappear, but as a rule, after some 

 weeks, it makes its appearance again, and this may occur re- 

 peatedly. In exceptional cases the improvement is maintained 

 so long that from a clinical point of view the animal may be 

 said to have recovered. In the large animals such improve- 

 ments are not observed because of the development of bed- 

 sores or of hypostatic congestion of the lungs. 



In the majority of cases the disease terminates fatally, and 

 usually owing to complications. Bedsores develop quickly in 

 the larger animals, but are not absent in the later stages in 

 small animals. As a rule these lead to a general infection. The 

 rapid course of the disease in the larger animals is referable 

 to this and also to hypostatic congestion of the lungs. In com- 

 paratively rare cases tliere is catarrhal inflammation of the 

 urinary tract. 



