You’ve probably heard the old expression, If you’ve got your health, you have everything. Well, that’s true, of course. But there are some simple things you can lose that can impact your life in a profound way. Take for instance the ability to bend your elbow.
Picture all the things you can’t do without elbow flexion — wiping your nose, putting on a pair of glasses, scratching your back, eating! These are just a few of the activities you lose control over when the brachial plexus is injured.
Brachial plexus injuries refer to stretching, avulsion, or rupture of a group of nerves that come from the spinal cord in the neck. Avulsion tells us the nerve root is torn from the spinal cord where it attaches. Rupture refers to a complete tear across the nerve dividing it into two or more parts. Plexus refers to the entire group of nerves as they first start out with several main branches that divide to form a much larger number of nerve groups.
These nerves provide both sensation (pain, temperature, touch, vibration) and motor function (muscle contraction) for the entire upper extremity including the shoulder, arm, wrist, and hand. Brachial plexus injuries are usually caused by some type of trauma such as a car accident, fall onto an outstretched arm (especially if the head and face are turned away from that side), and stretching or pulling on the hand, wrist, or forearm. Gunshot wounds, knife lacerations, and other blunt open injuries are also likely causes of nerve avulsion or rupture.
No two brachial plexus injuries are alike. And because of the complexity of diagnosing and treating them, the hand surgeons from Mayo Clinic who wrote this article attempt to help sort out all of the features of this injury. The goal is to help in setting up a plan of care for each patient and foster the best possible recovery. Most patients don’t get full use of the arm again but new microsurgical techniques have helped improve the prognosis.
The first thing the surgeon does when a patient arrives with a possible brachial plexus injury is get a good history of what happened, how it happened, and when it happened. Then a physical exam is performed including all sorts of special tests designed to figure out what got injured, where, and how bad is it. Identifying specifics about the nerve injury help provide the prognosis and treatment plan.
Imaging studies starting with an X-ray of the head, neck, spine, and upper arm may be followed up with CT scans, MRIs, and electrodiagnostic studies. There are even some specific tests that can be done to look for damage to the nearby blood vessels (common with some brachial plexus injuries) and that show avulsion injuries right at the level of the spinal cord.
Once all the information has been gathered, the best treatment for the injury is decided upon. Timing is everything because giving the nerve some time to rest and recover may yield spontaneous healing. Waiting too long (more than six months) may be too late as there can be irreversible changes that mean the nerve will never fire again. If that happens, then the muscle the nerve innervates (controls) will no longer contract. That’s how elbow flexion (or other motions) becomes difficult or even impossible.
Surgical procedures to reconstruct nerves that have been damaged can include nerve transfers, muscle or tendon transfers, nerve grafting, and arthrodesis or fusion of the affected joint(s). The authors of this article provide detailed descriptions of nerve reconstruction surgery. They discuss which nerves can be used in transfers and grafts for each of the nerves affected.
The surgeon must work with both the sensory and the motor sides of nerve function. Without proper sensation, the patient can be at risk for other burns or injuries. If enough time has passed since the injury (more than six months) and there hasn’t been much (if any) recovery of muscle function, it may be necessary to do a muscle transfer. The details of which muscles can be used and how to do the transfer are provided in this review article.
Surgery isn’t the end of treatment. After surgery there can be weeks and months of rehab to restore arm and hand function. If there’s been a loss of shoulder stability, the patient could also lose hand function. That’s when a shoulder fusion may be necessary. Hand function is very complex with muscles needed that can help us hold onto something (grasp) as well as release it. Fingers must be able to flex (bend), extend (straighten), and grip (pinch).
Some surgeons have tried using nerve tissue from donors (patients who have died and donated body parts) instead of reconstructing the injured patient’s damaged brachial plexus. This has not worked out as well as they had hoped. Many have returned to brachial plexus reconstruction for the best results.
Patients with brachial plexus injuries should be warned that the injured arm will probably never be good as new. A team of specialists who really understand these complex injuries will be needed to see the patient through to recovery.