682 Ossifying luiiamuiation of the Dura Mater of the Si^iual Cord. 



fibres with every movement of the vertebral colmnn. Animals 

 sometimes cry out without any apparent cause, and still more 

 when getting up, lying down, or making other movements. 

 About the same time, but sometimes earlier, and at other times 

 later, motor disturbances are observed. These may for a com- 

 paratively long time be due simply to pain or to muscular 

 spasms caused by pain. The animal is easily fatigued, is un- 

 willing to go up or down stairs and does so with difficulty, lies 

 down cautiously and is very averse to moving the head or neck. 

 During movement, the limbs are not flexed as much as normal, 

 the gait is consequently more or less stiff, and in exceptional 

 cases the animal may walk on its fore legs only. These symp- 

 toms may persist for a variable length of time or they may 

 completely disappear, the animal appearing perfectly healthy 



Fig. 97. Maximal extension of the hind legs in ossifying spinal meningitis. (The 

 sijecimen shown in fig. 9G was obtained from this animal.) 



There may, however, be more striking symptoms. The 

 muscular contractions become exaggerated, and owing to the 

 increased tension of the extensors and adductors, the limbs are 

 held in the position of maximal extension and adduction (fig. 

 97), and passive movements are possible to a limited extent 

 or not at all. As a result of the compression of the motor 

 nerve roots, and even of the cord itself, the symptoms of paraly- 

 sis become more pronounced until in almost every case there 

 is paraparesis or paraplegia, the paralysis being either sjonmet- 

 rically bilateral or appearing to be more severe on one side 

 than on the other. The paralysis is most severe in the hind 

 quarters, but in rare cases, it affects the fore quarters, but to 

 a less extent. Paralysis limited to the fore limbs is possible 



