henne paralysis--is that most frequently
met with, and it is due to a lesion of the fifth anterior branch, or, it
may be, also of the sixth. The position of the upper limb is typical:
the arm and forearm hang close to the side, with the forearm extended
and pronated; the deltoid, spinati, biceps, brachialis, and supinators
are paralysed, and in some cases the radial extensors of the wrist and
the pronator teres are also affected. The patient is unable to supinate
the forearm or to abduct the arm, and in most cases to flex the forearm.
He may, however, regain some power of flexing the forearm when it is
fully pronated, the extensors of the wrist becoming feeble flexors of
the elbow. There is, as a rule, no loss of sensibility, but complaint
may be made of tickling and of pins-and-needles over the lateral aspect
of the arm. The abnormal position of the limb may persist although the
muscles regain the power of voluntary movement, and as the condition
frequently follows a fall on the shoulder, great care is necessary in
diagnosis, as the condition is apt to be attributed to an injury to the
axillary (circumflex) nerve.

The _lower-arm type_ of paralysis, associated with the name of Klumpke,
is usually due to over-stretching of the plexus, and especially affects
the anterior branch of the first dorsal nerve. In typical cases all the
intrinsic muscles of the hand are affected, and the hand assumes the
claw shape. Sensibility is usually altered over the medial side of the
arm and forearm, and there is paralysis of the sympathetic.

_Infra-clavicular injuries_, as already stated, are most often produced
by a sub-coracoid dislocation of the humerus; the medial cord is that
most frequently injured, and the muscles paralysed are those supplied by
the ulnar nerve, with, in addition, those intrinsic muscles of the hand
supplied by the median. Sensibility is affected over the medial surface
of the forearm and ulnar area of the hand. Injury of the lateral and
posterior cords is very rare.

_Treatment_ is carried out on the lines already laid down for nerve
injuries in general. It is impossible to diagnose between complete and
incomplete rupture of the nerve cords, until sufficient time has elapsed
to allow of the establishment of the reaction of degeneration. If this
is present at the end of fourteen days, operation should not be delayed.
Access to the cords of the plexus is obtained by a dissection similar to
that employed for the