The brachial plexus is a network of nerves that originate near the neck and shoulder. These nerves begin at the spinal cord in the neck and control the hand, wrist, elbow, and shoulder. Brachial plexus injury can stop signals to and from the brain, preventing the muscles of the arm and hand from working properly, and causing loss of feeling in the area supplied by the injured nerve. Pressure or stretching injuries can cause the fibers that carry the
information to break and stop the nerve from working, without damaging
the cover. Some brachial plexus injuries are minor and will completely recover in
several weeks. Other injuries are severe enough that some permanent
disability involving the arm can be expected.
Complex Regional Pain Syndrome
Complex regional pain syndrome, also known as chronic regional pain syndrome, is characterized by pain, swelling and abnormal sympathetic nerve activity in the affected hand or extremity. The pain is out of proportion to the injury that triggered it. Complex regional pain syndrome is usually associated with an injury, which can sometimes be as minor as a paper cut or small bruise. It causes nerves to misfire and send frequent or constant pain signals to the brain. The sympathetic nerves become overactive, causing intense burning or aching pain, along with swelling and changes in skin color, moisture, and temperature.
Nerve Injury
Nerves are fragile and nerve injury can be caused by pressure, stretching, or cutting. Pressure or stretching injuries can cause the fibers carrying the information to break and stop the nerve from working, without disrupting the insulating cover. When a nerve is cut, both the nerve and the insulation are broken. Nerve injury can cease the transmission of signals to and from the brain, preventing muscles from working and causing loss of feeling in the area supplied by that nerve. When nerve fibers are broken, the end of the fiber farthest from the brain dies, while the insulation stays intact, leaving empty tubes which used to carry the nerve fibers. The end that is closest to the brain does not die, and after some time may begin to heal. If the insulation was not cut, the nerve fibers may grow down the empty tubes until reaching a muscle or sensory receptor.
