The brachial plexus is a network of nerve fibers, arising from the spine and divided into three major branches, formed by the ventral ramie of the lower four cervical and first thoracic nerve roots. These nerves enable movements and sensation of scapular, pectoral and arm muscles. Injury of these nerves may affect scapular, shoulder, elbow, wrist, hand and finger muscles. Dysfunctional and affected muscles vary depending on the severity of injury and the part of injured nerve. Brachial plexus injuries often occur at birth and are medically referred to as ‘obstetric’ brachial plexus injuries. In addition to congenital causes, injury may occur as a result of a trauma, thoracic outlet syndrome, radiation, tumoral spread, brachial neuritis, or associated with vascular problems, e.g. aneurysm, resulting in compression.
Brachial plexus injury may be caused by breech presentations when the body and the neck excessively tilt to one side, or by normal births (with the head) when the body and neck excessively tilt to one side during going out, resulting in stretched nerves as well as by newborns with higher birth weight and a larger head than the mother’s birth canal. The symptoms including a newborn being unable to equally move both of the arms; color change and swelling of the affected arm; the affected arm falling down to one side when holding in the arms, difficulty in determining, the affected hand being unable to make a fist or fingers being unable to grasp a finger, and lateral swelling of clavicle should be indicative to parents and pediatricians for brachial plexus paralysis.
If the patients show improvement in two weeks, this will indicate good prognosis. The magnetic resonance (MRI) is the best imaging method in diagnosis. Electrodiagnostic study gives information on time, degree, prognosis and localization of the injury.
The treatment starts with exercises and physical therapy. Electrical stimulation and botulinum toxin injection may help recovery in some children with brachial paralysis.
In paralyzed patients, a surgical therapy is required if the patients show no improvements in 3 months during either babyhood or adolescence. In a surgical intervention to the nerves, the network of nerve fibers making up brachial plexus is accessed by a cervical and/or axillary incision. The ruptured nerves are repaired by microsurgical methods. The ailing nerve tissues with a scar are removed to repair the nerves. For repair of nerves too injured to repair, an adjacent nerve to nerve fibers forming brachial plexus is transferred, or a nerve used less somewhere else in the body is implanted in the injured part. For irreversible paralysis despite medical treatments, functional muscles are surgically replaced by dysfunctional muscles (Tendon transfer) to regain the lost functions. Teamwork is crucial to surgical cases. Rehabilitation program should be continued after the surgery as before the surgery.