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

VARIETIES OF MECHANICAL INJURIES OF NERVES. 127
3Iuscidar lyressure from spasm.— Pressure by muscles in
a state of chronic spasm might be said to belong to the
same category of doubtful causes, were it not for Rom-
statement that he had
berg's occasionally seen enduringspasm
of the scaleni cause compression of the brachial
plexus,e'with resultant numbness, anaesthesia, and oedema
from venous constriction.
Compression of the facial {seventh) nerve by the forceps. — This
accident, although long known to accoucheurs, seems to
have received its first correct physical explanation from
Dubois,* who pointed out the mode in which the nerve
is
affected, and showed that the resultant palsy cannot be
due, as was supposed, to cerebral pressure.
The thesis of AI. Landouzy appears to have been the
first published collection of cases.
In certain labors, the blade of the forceps makes pressure
either upon the diverging branches of the portio
dura or upon the main trunk of the seventh, just in
front of its
outlet from the temporal bone,— an accident
rendered possible in the infant by the slight development
of the mastoid process and the comparative softness of
the parts connected with the auditory meatus and jaws.
When the force is exerted unequally on the dividing
filaments
of the nerve, the result will be seen in an incomplete
palsy of some parts of the face, and a more perfect
loss of motion in others. f
The features are found drawn to the sound side, the
tongue and palate being unalfected, which has at least
been the case in Landouzy's cases and in those which I
have encountered.;}: These circumstances usually sufiice
* Landouzy, These, Essai sur I'Heniiplegie faciale chez les Enfants nouveau-nes.
Paris, 1839.
t Op. cit.
X I shall elsewhere discuss the views of Romberg, Todd, and Saunders
vis to the value of palatal palsy in deciding the seat of the paralyzing