CHAP. XI.] OFFICE OF THE COLUMNS OF THE CORD. 317 



sensibility ; that perfect sensibility is compatible with total destruc- 

 tion of the posterior columns in some particular region, the posterior 

 roots remaining intact : and others have occurred in which sensi- 

 bility has been impaired or destroyed, while the posterior columns 

 remained perfectly healthy. In a remarkable case, related by Dr. 

 Webster, there was complete paralysis of motion in the lower 

 extremities, but sensibility remained;* yet there was complete 

 destruction of the posterior columns in the lower part of the cervi- 

 cal region. Similar cases have been put on record by Mr. Stanley 

 and by Dr. W. Budd. Dr. Nasse, of Bonn, refers to several cases 

 of the same kind, observed by himself or others.f We have our- 

 selves seen two cases in which the prominent symptom was great 

 impairment of the motor power without injury to the sensitive ; 

 yet the seat of organic lesion in both was in the posterior columns 

 of the cord. Such a case as that of Dr. Webster* s appears to us to 

 be conclusive, so far as the following proposition extends, namely, 

 that sensation may be enjoyed in the inferior extremities indepen- 

 dently of the posterior columns; and that, even if those columns be 

 sensitive, there must be some other channel for the transmission of 

 sensitive impressions besides them. 



We are not aware of any well-observed case in which the motor 

 power persisted after extensive lesion of the antero-lateral columns; 

 on the contrary, we believe it may be laid down as the general 

 rule, that lesion of those columns always impairs both the motor 

 and the sensitive functions to an extent proportionate to the amount 

 of morbid structure. 



Pathological observations, then, appear to warrant the conclusion 

 that the antero-lateral columns are compound in function, both 

 sensitive and motor; but they do not justify us in attributing 

 sensitive power to the posterior columns. 



Direct experiments on the anterior and posterior columns of the 

 cord are surrounded by difficulties, which embarrass the experi- 

 menter, and weaken the force of his inferences. The depth at 

 which the cord is situate in most vertebrate animals, its extreme 

 excitability, the intimate connexion of its various columns with 

 each other, so that one can scarcely be irritated without the partici- 

 pation of the others, the proximity of the roots of its nerves to each 

 other, and the difficulty of irritating any portion of the cord itself 

 without affecting either the anterior or the posterior roots, are great 



* Med. Chir. Trans., vol. xxvi. 



t Untersuchungen zur Physiologie und Pathologie. Bonn, 1835-36. 



