748 PARALYSIS OF THE HIND EXTREMITIES. 



(2) Reflex irritability is completely in abeyance, and the animals 

 make no resistance to the operator's manipulations. This is always 

 the case where the seat of disease is in or behind the lumbar portion 

 of the cord. When in front of this spot, that is, in the dorsal region 

 or further forward, reflex irritability is not only retained, but may 

 often be abnormally pronounced (hyperesthesia), so that stimulation 

 of the skin, ligaments, or bones (slight blows, or pricks with a needle) 

 cause active contractions in the paralysed muscles. Continuous 

 contraction (cramp) may thus be caused (spastic paralysis). Nocard 

 saw increase of the tendon reflexes in a dog. 



(3) In grave lesions of the cord, sensiblity appears to be com- 

 pletely lost ; in myelitis spinalis it is at first not much impaired ; 

 its continuance points to injury of the posterior columns and of the 

 grey posterior cornua. In pressure paralysis, sensibility may some- 

 times be increased, as shown by Nocard's reported cases in dogs ; 

 movement of the paralysed hind-quarter produced acute pain 

 (paraplegia dolorosa). The examination of large animals is more 

 difficult, because sensation cannot be exactly gauged, reflex move- 

 ments being so difficult to distinguish from those caused by painful 

 sensations. 



(4) To the above cardinal symptoms of paraplegia are added 

 those of paralysis of the bladder, rectum, and tail. There is often 

 incontinence of urine, and faeces cannot be discharged without 

 assistance. This grouping of symptoms generally accompanies 

 pressure paralysis from fractures of vertebrse or of the sacrum, from 

 extravasation of blood into the vertebral canal, and in rarer instances 

 from tumours, but may also occur in concussion of the spinal cord. 

 The diagnosis must be based on the history of the case, its manner 

 of origin and course. In fractures of the vertebras, displacement 

 of fragments or crepitation may lie detected. 



The symptoms of incomplete paralysis show still greater variety ; 

 but even though it is not possible, in every case, to form an accurate 

 diagnosis, it is well, from the clinical standpoint, to distinguish two 

 kinds : — ■ 



(1) Paraplegia incompleta vera, vel spinalis (true incomplete or 

 spinal paralysis) ; and 



(2) Par. incompleta spuria (incomplete spurious paraplegia). 

 The causes of the first lie within, those of the second without the 

 vertebral canal. Paraplegia of the first kind, due to acute or chronic 

 inflammation of the spinal cord and its membranes, or to pressure 

 and degenerative processes in the medulla spinalis, declares itself 

 by the following symptoms :— 



