Although some brachial plexus injuries are caused by tumors, compression and irradiation, the main causes of most injuries are trauma during childbirth and trauma due to an accident.
The most common pattern of brachial plexus injury to the baby during a difficult childbirth is called Erb's palsy, and it affects shoulder motion and elbow flexion. In more serious cases, obstetric brachial plexus injury can affect the baby's entire arm (called global palsy).
In most babies with Erb's palsy, the brachial plexus injury heals without treatment, but about 10 percent of children will eventually need surgery. If the injury doesn't heal on its own in the first month, the baby should be evaluated at a center specializing in treating brachial plexus injuries.
If surgery is needed, Mayo specialists have found best results from performing surgery four to six months after birth, before the nerve damage becomes permanent.
A brachial plexus injury can also occur as a result of an accident, such as a motorcycle crash, sports injury or fall. The injury is classified according to severity:
Some people with stretch injuries due to accidents recover independently, but others require surgery if function isn't recovered within three to six months.