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

DIAGNOSIS AND PROGNOSIS OF INJURIES OP NERVES. 225
There is another peculiarity which separates
all extracentral
nerve lesions from cerebral, and also from spinal
disease : hut I do not feel that as yet it is available to any
larsre extent. I noticed some vears asjo that in even the
gravest lesions of nerve trunks if a touch were felt at all, it
was felt with no remarkable delay; while in many central
palsies, if severe, and especially in such as result from
extensive spinal malady, the time required for transmission
to the seusorlum was, as Cruveilhier pointed out, very
largely increased,— so much so, indeed, as to be readily
estimated in a rough way by the hand of a watch beating
quarter seconds, or still better by a metronome. The
cause of this difference is still obscure to me, nor is it
easy to see why diffuse sclerosis, for example, should so
retard a sensory impression, while injured nerve fibres
have no such eftect.*
Prognosis. — The form of injury to the nerve has a large
influence upon the prognosis, which, however, is always
grave, so far as complete functional recovery is concerned,
in every instance of severe nerve lesion. In the larger
number of cases of pressure by growths, such as exostoses,
aneurism, or intra-pelvic tumors, the ultimate fate
of the case depends, of course, on our power to remove
the cause of pressure.
For reasons not as yet clear to me, a contusion is often
apt to give rise to more prolonged and serious injury than
other forms of mechanical disturbance apparently more
capable of locally destroying the nerve. Probably a
bruised nerve is more likely to pass into neuritis than
even one which has been wounded.
Partial nerve wounds have been considered more serious
than entire division, but to this I can scarcely give a full
assent. The cases of intense neuralo-ia from lancet wounds
* See San. Com. Med. Keport, p. 438.