Injuries of nerves and their consequences - Reflex Sympathetic ...

VARIETIES OF MECHANICAL INJURIES OF NERVES. 113
somewhat, so as to place the nerve between two caoutchouc
bags of mercury, gave, on the whole, the same
general result. For the sciatic nerve a few seconds — ten
to thirty
— of the pressure of a mercury column, eighteen
to twenty inches high, broke the communications between
two portions of a nerve. Relieved from pressure, the
nerve speedily recovered.
It seems impossible to look upon this as other than a
mere mechanical disturbance of the tubal contents, and a
like mechanical restoration of their needed conditions for
activity.
It is needless to speculate here upon the very suggestive
character of these observations in a physiological point
of view. Pathologically considered, they are not less
interesting.
Remembering the delicate nature of the neural tissues, it
seems inconceivable that twenty inches of mercury should
not destroy them utterly. Moreover, what is the change
which really takes place, and does it seem possible that
the axis cylinders could be so broken as to refuse their
office, and yet so reunite in a few seconds as to be fit
again
for functional duty?
From another standpoint the experiment seems to widen
the breach between nerve force and electricity ,
there being,
as regards the latter, no analogy to this observation.
I have made careful examinations of nerves which have
been thus treated by compression. In all of them were
noted some evidences of congestion, but the chief lesion
lay in a very extensive disturbance of the contents of the
nerve tubes. In some of them I could find scarcely an
much as
unaltered nerve tube,' the neural tissues looking
they do seven or eight days after section. Yet through
the tubes so disturbed the nerve force still has power to
travel.
These observations appear to me full of importance