721p 
have occurred in which sensibility has been 
impaired or destroyed, while the posterior co- 
lumns remained ectly healthy. In a re- 
markable case related by Dr. Webster, there 
was complete paralysis of motion in the lower 
extremities, but sensibility remained; yet there 
was total destruction of the posterior columns 
in the lower part of the cervical region. Dr. 
Webster did me the favour to allow me to 
examine the spinal cord in this case, and I was 
struck with the complete solution of continuity 
of the posterior columns in the region of the 
neck: it was impossible in this case that the 
nervous force could have travelled along the. 
course of these columns, whether from above 
downwards, or from below upwards. Sucha 
.case as this shows distinctly that sensation may 
be enjoyed in the inferior extremities indepen- 
dently of the posterior columns, and if it does 
not prove that these columns are not the ordi- 
nary channels through which sensitive impres- 
sions are conveyed to the brain from parts sup- 
plied by spinal nerves, it at least shows that 
there must be some other channel besides them 
for the transmission of sensitive impressions. 
Other cases to the same purport are on re- 
cord. Mr. Stanley pablekor an account of a 
case of this kind in the twenty-third volume of 
the Medico-Chirurgical Transactions. He 
States, ‘there was no discoverable impairment 
of sensation in any part of either limb: on 
scratching, pricking, and pinching the skin, 
nowhere was any defect of feeling acknow- 
ledged by the patient. In the upper limbs 
there existed no defect, either of motion or 
sensation.” There was inability to expel the 
urine or retain the feces. The report of the 
post-mortem appearances in this case is not 
quite so exact as might be desired. The pos- 
terior half of the cord and the posterior co- 
lumns are spoken of as if synonymous; now 
it is evident that the posterior half of the cord 
consists of a great deal more than the posterior 
columns; it includes the posterior part of the 
antero-lateral columns. The record of the case 
States as follows: “ The substance of the cord 
throughout its posterior half or column, and 
in its entire length, from the pons to its lower 
end, had undergone the following changes of 
colour and consistence; it was of a dark brown 
colour, extremely soft and tenacious. The 
substance of the cord through its anterior half 
and entire length exhibited its natural whiteness 
and firm consistence ; and on making a longi- 
tudinal section of the cord through its centre, 
and in the antero-posterior direction, the boun- 
dary line between the healthy and diseased 
nervous matter was seen to be most exact: it 
was a straight and uninterrupted line from the 
pons to the lower end of the cord. The roots 
of the spinal nerves were unaltered.” 
Supposing that the posterior columns are the 
media of sensation to parts supplied by spinal 
nerves, we can by no means infer that the 
lesion in this case recorded by Mr. Stanley was 
sufficient to destroy sensation ; it cannot, how- 
ever, be conceded that, if this view were 
correct, such a lesion could exist without im- 
pairing sensation in some way or other, inas- 
PHYSIOLOGY OF THE NERVOUS SYSTEM. 
much as the whole of the posterior columns 
were involved in a notably diseased condition. 
The following case is related by Cruveilhier. 
A young amaurotic girl, paraplegic of move- 
ment only, died from some unknown cause. 
The spinal cord presented on its posterior sur- 
face in its entire length a large reddish-grey 
(gris-rosé) column, formed by. the »posterior 
columns. All the rest of the cord was per~ 
fectly healthy. sual t 
In a case recorded by Dr. Wm. Budd it is 
stated that the lower extremities were quite: 
deprived of motion, * but with sensation un= 
affected.” The disease was the result of a 
severe blow on the back from the boom of a 
ship, which led to a curvature of the: spine, 
formed by prominence of the dorsal vertebra: 
from the fourth to the ninth inclusive. After: 
death a portion of the cord, about: two inches 
in length, corresponding to the curvature, was 
found softened in the posterior columns... The: 
tissue was not diffluent, but became flaky and 
partially dissolved when a small and gentle 
current of water was poured on it. In this: 
case, no more than in that of Mr. Stanley, the 
lesion was not enongh to destroy sensation, but 
surely it was sufficient to impair it, ifsthe 
posterior columns are to be regarded as the 
channels of sensation.* ' 
Serres records the case of a woman who had 
been paraplegic for two months: sensibility 
was preserved in the lower extremities; the 
lesion consisted in disease of the posterior 
columns of the cord below the middle of the 
dorsal region.+ val 
In two cases which occurred in King’s Col- 
lege Hospital under my own care, the promi- 
nent symptom was impairment of the motor 
power, without injury to the sensitive; yet the 
seat of organic lesion in both was in the pos-— 
terior columns of the cord. | ie 
Nasse, in the paper before referred to, allades’ 
to several cases of the same nature, in which 
disease affected the posterior columns, but did 
not impair sensation. eee 
Longet, who is a warm advocate for t 
identity of function between the posterior 
and posterior columns, cites some instances in 
which total loss of sensibility coexisted. with 
degeneration of the posterior columns as. 
only lesion: in these cases, however, the pos: 
terior roots of the nerves were involved in the 
disease, and their function became impaired or 
destroyed in consequence. A case of 
kind, to be conclusive upon the point in 
tion, ought to exhibit complete destructi 
the posterior columns, or of a considerabl 
portion of them, with perfect integrity 0 
sterior roots and of the antero-lateral e¢ 
umns. If in such a case there were to 
of sensibility in the parts in nervous commun 
cation with the diseased portion of the spit 
cord, then, indeed, we would be justifie 
affirming that the antero-lateral columns too 
no part in propagating sensitive impressions 
and that the loss of sensibility was due to th 
morbid state of the posterior columns. P 
* Med.-Chirurg. Trans., vol. xxii. ; 
t Anat. Comp. du Cerveau, vol, ii., p. 221 
