Nerve Injuries in the Upper Limb

Study Notes

Nerves perform several functions: motor, sensation, proprioception, reflexes, and autonomic (sweating, pilomotor, and vasomotor)

Neuropraxia: temporary loss of function, reversible within hours to months, caused by compression, blunt blows, or shock injuries
Axonotmesis: severe crush or contusion, loss of axon and myelin sheath continuity, equal loss of motor and sensory components, rate of axonal growth varies between 1-3mm per day
Neurotmesis: severe contusion, stretch, or lacerations, loss of axon, myelin sheath, and encapsulating connective tissue continuity, complete loss of motor, sensory, and autonomic function

History
Clinical Examination: weakness, wasting, flaccidity, loss of sensation (pain, temperature, fine touch), loss of sweating

Erb's Palsy: nerve injury affecting the movement of the shoulder, arm, and hand, caused by shoulder dystocia of newborn baby, traction injury of upper trunk of brachial plexus (C5-6)
Klumpke's Paralysis: form of paralysis involving the muscles of the forearm and hand, resulting from a brachial plexus injury, affecting the eighth cervical (C8) and first thoracic (T1) nerves
Claw Hand: occurs due to laceration of Ulnar nerve at wrist joint, paralysis of interossei and flexors of the wrist and fingers
Wrist Drop: sign of Radial nerve injury, usually as a result of dislocation of humerus at the shoulder joint or fractures of humerus