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

222 INJURIES OF NERVES.
motor loss, with no distinct warning in the way of sensory
disturbances.
I have, indeed, great doubt as to our capacity to distinguish
the form of injury from the resultant symptoms
alone. In a recent case, where there was the probability
of intra-pelvic neuritis from cancer, and the certainty of a
fractured thigh, with great amount of callus, so situated
as to make likely some nerve pressure, I was unable
positively to ascribe the signs present to either possible
cause.
There are so many ways in which slow intra-pelvic
that a sure test of tbe
pressure on nerves may occur,
presence of compression has always been
most desirable.
As regards the accepted signs of pressure,
it is quite
clear that, when clinically applied, they are not competent
to guide us, because the various degrees of pressure may
bring about, as we have seen, the utmost variety of symptomatic,
results. In proof of this I need only refer to the
case of the lad lately quoted, and to the various histories
of nerve pressure already related.
Still more important, practically, is the decision as to
whether certain neural symptoms
be due to central diseases
or to peripheral causes, such as intra-pelvic or other
pressure. When the question lies between nerve lesion
and cerebral disease, it is, as a rule, easily settled. Cerebral
palsies have a peculiar history, are sudden in their
onset, and are more often destructive of motion alone
than of this with sensation. They are also more peculiarly
distinguished by the fact that in them the muscles
remain excitable under electric currents. Indeed, in the
early stages of cerebral palsies with tendency to contraction
(early rigidity), they are over-excitable, while the instances
in which, late in old cases, they have their electric
excitability lessened are very rare, and depend, I suspect,
upon some of those singular peripheral neural changes