INVESTIGATING NERVE INJURIES IN THE UPPER LIMB

INVESTIGATING NERVE INJURIES IN THE
UPPER LIMB


What You Should to Know
? Nerve Anatomy and Histology
? Types of Nerve Injury
? Causes of Nerve Injury
? Diagnosis of Nerve Injury
? Some Examples of Nerve Injury


What does a nerve do?
? Motor
? Sensation
? Proprioception / Co-ordination
? Reflexes
? Autonomic
– Sweating / pilomotor / vasomotor




Types of Nerve Injury
? Neuropraxia
Transient interruption in neural conduction. There is
temporary loss of function which is reversible within
hours to months of the injury.
It may be caused by compression, blunt blows or shock
injuries to the nerve. There is frequently greater
involvement of motor function than sensory function with
autonomic function being retained.


? Axonotmesis
A severe crush, contusion with loss of continuity of the
axon and its myelin sheath however the internal epineurial
and endoneurial tubules are intact.
There is equal loss of both motor and sensory
components. Rate of axonal growth varies between 1-3mm
per day


Neurotmeses
Severe contusion, stretch or lacerations the axon and
myelin sheath along with the encapsulating connective
tissue lose their continuity.
There is complete loss of motor, sensory and autonomic
function. If only the endoneurial tube is damaged the
outcome is better.

ERB’S PALSY
• The position of the limb, under such
conditions, is characteristic: the arm hangs by
the side and is rotated medially; the forearm is
extended and pronated. The arm cannot be
raised from the side; all power of flexion of the
elbow is lost, as is also supination of the
forearm". The resulting biceps damage is the
main cause of this classic physical position
commonly called "waiter s tip.“