Brachial Plexus Palsy
What is Brachial Plexus Palsy?
The brachial plexus is network of nerves that extend from the neck into the arm. Five major nerves (given the symbols C5, C6, C7, C8, & T1) exit from the spinal cord in the neck to provide movement and feeling to the arm and hand. In Brachial Plexus Palsy, any one of these five main nerves may be injured. When the upper nerves (C5, C6, +/-C7) are injured, this is called an Upper Trunk (Erb’s) Palsy. Where nearly all nerves are injured, this is called a Total or Complete Brachial Plexus Palsy.
What are the symptoms of Brachial Plexus Palsy?
When nerves of the brachial plexus are injured, the electrical signals in them stop traveling to or from the brain. Muscles of the arm and hand no longer receive electrical signals from the brain to make them work. These muscles turn off and the patient may become weak or paralyzed in the shoulder, elbow, wrist, and/or hand. Not only can patients lose strength, they can also lose feeling in the skin of the arm and hand. Patients may refer to this as numbness.
What causes Brachial Plexus Palsy?
Brachial Plexus Palsy may occur during birth, following trauma, or from radiation, tumor, or a virus. Depending on the situation, the nerve can be injured by stretch, rupture, avulsion, or direct damage. In stretch-type injuries, the inner part of the nerve remains together but is its outer cover and blood supply are pulled apart. In rupture-type injuries, the nerve completely snaps and leaves two free ends that are no longer talking to each other. In avulsion-type injuries the nerve is directly pulled off its electrical source in the spinal cord. In direct damage, the nerve is injured by radiation or tumor or by the virus turning it off.
How is Brachial Plexus Palsy diagnosed?
Brachial Plexus Palsy can generally be diagnosed by the history and by physical exam looking for signs of weakness or numbness along the shoulder, elbow, wrist, and/or hand. In situations where the diagnosis is unclear, a nerve conduction and muscle study can be ordered to obtain more information on the health of the individual nerves and their muscles. An MRI can also provide a picture as to the type of brachial plexus injury.
What are the treatments for Brachial Plexus Palsy?
Treatment of Brachial Plexus Palsy begins and ends with occupational therapy. An occupational therapist scores the strength of each muscle group. The amount of motion at each joint is measured to identify areas that are tight. Patients then begin stretching exercises to keep the joints loose and work on strengthening. At each visit, the muscle scores and joint motion will be compared. Patients who are not making gains over several months are advised to undergo surgical treatment.
Surgery is recommended when it is believed that the chances of achieving further recovery are better with nerve reconstruction than waiting for the nerve to heal on its own. Patients should understand that there isn’t an unlimited time that you can wait to fix the nerves. By 12-18 months, the nerve permanently loses its connection to the muscle. After then, even if the injured nerve is reconstructed, it won’t be able to tell the muscle to contract. Taking that into account, and the fact that a repaired nerve heals at 1 mm a day, the timing of surgery directly depends on the location of paralysis. If the hand is paralyzed, surgery is offered by 3 to 4 months to give the nerve enough time to reach its muscles before that special connection is irreversibly lost. If the elbow is paralyzed, surgery is offered by 4 to 6 months. For shoulder paralysis, surgery may be offered by 6 to 9 months.
Surgical treatment focuses on healing the injured nerve(s). This may include one or more of the following: 1) removing scar tissue from around the nerve to allow the electrical signals to travel more easily across the nerve (nerve decompression / neurolysis); 2) cutting out the scar tissue that is filling the nerve gap and bridging it with a sensory nerve (nerve graft); 3) selecting a motor nerve from a healthy but less important muscle group and transferring it to an injured nerve that is more important to shoulder, elbow, or hand function (nerve transfer).
What happens after surgery for Brachial Plexus Palsy?
Brachial plexus surgery is performed under general anesthesia and can last several hours. After surgery, patients are typically wrapped in a shoulder and elbow sling to protect the nerve reconstruction against motion. For most nerve transfer procedures, patients may only need an overnight hospital stay and are discharged to home the following morning. If rib (intercostal) nerves are used as nerve transfers, patients may be admitted overnight in the Intensive Care Unit as a precaution to monitor their breathing and then stay for 3-4 days before being discharged to home. During the hospital stay, pain specialists place the patient on medications that specifically treat nerve pain. Three to four weeks after surgery, patients may take off their elbow and shoulder sling. At this point, full stretching is permitted except in patients with intercostal nerve transfers. Patients with rib (intercostal) nerve transfers must wait a total of 8 weeks before stretching the shoulder to avoid pulling the nerve connections apart. Patients will be followed closely by occupational therapists, who will use electrical stimulation to gently help the nerves turn back on. Each patient’s recovery is different.