Signs and symptoms may include a limp or paralyzed arm, lack of muscle control in the arm, hand, or wrist, and lack of feeling or sensation in the arm or hand. Although several mechanisms account for<unk> es, the most common is nerve compression or stretch. Infants, in particular, may suffer<unk> es during delivery and these present with typical patterns of weakness, depending on which portion of the<unk><unk>  is involved. The most severe form of injury is nerve root avulsion, which usually accompanies high-velocity impacts that commonly occur during motor-vehicle collisions or bicycle accidents. Disabilities Based on the location of the nerve damage,<unk> es can affect part of or the entire arm. For example, musculocutaneous nerve damage weakens elbow flexors, median nerve damage causes proximal forearm pain, and paralysis of the ulnar nerve causes weak grip and finger numbness. In some cases, these injuries can cause total and irreversible paralysis. In less severe cases, these injuries limit use of these limbs and cause pain. The cardinal signs of<unk>  then, are weakness in the arm, diminished reflexes, and corresponding sensory deficits. # 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". # In Klumpke's paralysis, a form of paralysis involving the muscles of the forearm and hand, a characteristic sign is the clawed hand, due to loss of function of the ulnar nerve and the intrinsic muscles of the hand it supplies.
Brachial plexus injury
Posterior cord syndrome
Diastematomyelia
Spinal cord injury
Central cord syndrome
Syringomyelia
Accessory nerve disorder
Cernunnos deficiency