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

192 INJURIES OF NERVES.
Loss of thermal sense.— The sense of temperature
is lost
with that of pain and touch, and usually in like degree,
and the amount of its loss is,
of course, readily measured.
I have never seen it altered from nerve wounds without
affection of the pain- and tact-sense. Neither have I met
with any case of wound of a nerve which seemed to
involve
only loss of the muscular sense.
As concerns the separate existence of nerves of touch
and pain, some light
is cast by two cases — 27 and 28 — of
the Report on Nerve Wounds.
In the lirst of these, owing to a wound of the arm,
there was greatly lessened sense of pain, with no loss of
touch. The patient discriminated the compass-points as
well in the hand of the wounded side as in the otlier,
while, when blindfolded, a large needle could be run
to feel more
nearly through the palm without his seeming
than a slight pricking. I shall quote this case in full
when discussing muscular lesions. I do not think it quite
free from suspicion of central disease,
— the result of the
wound; but, as regards the other case, there cannot be any
doubt as to the purely peripheral nature of the changes
which resulted in very remarkable analgesia, with preservation
of the tactile and localizing sensation and that of
temperature. So complete was the loss of pain-sense that
the electric wire brush was felt but slightly, while it was
interesting to note that there was hypersesthesia of the
deeper tissues. There was total loss of motion below the
knee.
Pain.— When we touch or otherwise disturb
any part
of the trunk of a nerve containing sensory filaments, we
cause, if the irritation be feeble, subjective referred sensations,
such as formication. Warmth or cold so applied
usually occasions no sense of altered temperature in the
skin, but only pain in the ultimate neural distribution.
More severe mechanical disturbance, at any part of a