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

VARIETIES OF MECHANICAL INJURIES OF NERVES. 109
Stage fourth. Hypera^sthesia passes more deeply into
the tissues, and the exaggerated sensibilities become in
turn perverted, and are lost. Before entering upon this
anaesthetic condition, the tactile sense gives us false impressions
of roughness on the skin, and the sense of pain
fnrnishes the impression of peripheral burning. The successive,
and, so to speak, isolated way
in which each mode
of sensation vanishes, explains how it is
that, in this stage,
at the moment when tactile sensibility is abolished, the
sensibility to pain may remain unperverted, or exist for a
time in an extremely exaggerated shape. ^Nevertheless,
the deeper tissues continue in a condition of exalted sensibility.
The muscles are now subject to a feeling of
fatigue and weariness. Yague pains or cramps attack them,
and the movements become less and less eas3\ We have,
at length, muscular palsy, with general local anesthesia.
The pressure
is now taken oif, and at once the period
of decline beo^ins.
This, like that of the augmenting symptoms, has four
stages :
Stage first. For a brief period, not over two minutes,
the muscles remain palsied and the skin insensible, while
the deeper pains disappear.
Stage second. Passing backward, as it were, through
the changes of the first period, there is now slight and
improving muscular power. The sensibility to touch,
pain, and tickling returns, and although perverted and
hyperffisthetic, soon becomes nearly normal, the thermal
sense alone remaining very imperfect. After a time, which
varies from a few seconds to a minute, the third stage,
which the authors term intermediate, begins, and is
marked by normal motility and sensibility, and by continued
obtuseness to changes of temperature.
Stage fourth. The patient has sudden sense of cold,
which is centrifugal in its movement through the part