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

SYMPTOMATOLOGY OF NERVE LESIONS. 143
existence in the centres; while we have also pointed
out that the reception of Brown- Sequard's theory would
necessitate belief in subsequent palsy of vessels and
vasal nerves as a far better explanation of the central
results of reflex irritations.
" Thus the stern physiological
law of rest after labor, of relaxation after contraction,
stands in the way of any idea which presupposes longcontinued
vasal spasm;"* and against
it also are a
number of satisfactory objections to the experiments
upon wdiich its author relied for its support. Moreover,
it has been loaded with needless conditions, which make
its
acceptance still more diihcult, since he has insisted
that in reflex palsies the centres afl^ected exhibit no lesion,
which seems inconceivable in the presence of either vascular
spasm or palsy, if these be long continued. Perhaps
if this justly distinguished observer had more freely
explained himself, some of these objections might have
after careful reading of my criticisms,
less weight, since he has been kind enough to assure me,
that our ideas differ
in reality less than I had conceived them to do.
Another theory supposes that in the ordinary instances
of long-continued irritation of a part, the reflected impressions
falling
— why we know not— on some particular
centre, either keep it in a state of excitement, resulting in
pain or muscular spasm, or else wear out or suddenly extinguish
its excitability so as to paralyze its dependent
muscles. It becomes us, however, to be cautious as to
the cases we include in this categor}^ since science is
daily opening new and different ways of accounting for
many phenomena which have hitherto been confidently
termed reflex. It is common, for example, so to explain
cases of palsy of a leg remotel}^ following a cut, a hurt
nerve, or a wounded or crushed toe-nail. Yet,
as we shall
* Paral. from Periph. Irrit., p. 33.