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

266 INJURIES OF NERVES.
Counter-irritaiion.— Of the many counter-irritants which
I have employed, the most useful are lotions of oil
of turpentine,
which may be applied cold or hot, as we need
slight or severe irritation. When a rag, dipped in hot
turpentine and covered with rubber or oiled silk, is laid
on the skin, we get the most powerful stimulation which
this agent affords. No agent affects more unequally different
persons, so that some care may be needed in using
it. I have known it to produce for hours the most unbearable
pain, while some patients seem scarcely to feel it at
all.
I do not know why we gain by using an irritant
over very large surfaces, extending far beyond the region
involved ;
but advantage certainly seems to arise from it.
I recall, in this connection, the case of a soldier, whose
whole arm was insensible from a fall on the shoulder.
He suddenly recovered full feeling after the entire limb
and back had been severely blistered by exposure to the
sun. In injuries of nerves we rarely see sensation fully
and perfectly restored ;
and for a long time, even in the
best cases, the power
defective.
Treatment of pain, neuralgia,
to localize touch is more or less
causalgia.
— Neuralgic pain
from nerve injury may depend upon pressure or the presence
of foreign bodies, and, if such causal relations can be
made out, its relief, of course, becomes in some cases easy;
but in general we shall have only to settle the question of
whether the nerve be inflamed or in a state of sclerosis;
while, if neither of these states can be shown to exist, we
have to fall back upon the pathological phantom which
we call irritation, and are driven then, and indeed very
often, in every case, to treat the pain alone, without true
knowledge of its immediate cause.
The treatment of the pain from acutely-inflamed nerves
is
simply that of inflammation, which has already been
described in full.