A bundle of connected nerves in the neck region of your spinal cord sends branches down into your shoulders, arms, and hands. This group of nerves is called the brachial plexus. These nerves control the motions of your wrists, hands, and arms, allowing you to raise your arm, type on your keyboard, or throw a baseball.
The brachial plexus nerves are sensory, too. For instance, they let you know that the pan you just grabbed with your hand is too hot to hold.
The brachial plexus can be injured in many different ways—from pressure, stress, or being stretched too far. The nerves may also be cut. Sometimes, brachial plexus injuries happen to babies during childbirth.
Facts about brachial plexus injuries
Brachial plexus injuries cut off all or parts of the communication between the spinal cord and the arm, wrist, and hand. This may mean that you can't work your arm or hand. Often, brachial plexus injuries also result in total loss of sensation in the area.
The severity of a brachial plexus injury varies. In some people, function and feeling returns to normal, while others may have lifelong disabilities because they can't use or feel a part of the arm.
During childbirth, large babies may be at an increased risk for brachial plexus injuries. A quick or emergency delivery, when the baby must be forcibly pulled out, can result in a brachial plexus injury because the baby's neck is often flexed severely in one direction. Babies in breech position (bottom end comes out first) and those whose labor lasts an unusually long time may also suffer brachial plexus injuries.
Symptoms depend on where along the length of the brachial plexus the injuries occur and how severe they are.
These are common symptoms of brachial plexus injuries:
No feeling in the hand or arm
Inability to control or move the arm, wrist, or hand
An arm that hangs limply
Types of brachial plexus injuries
Brachial plexus injuries are categorized according to how badly the nerves are damaged:
Avulsion. The root of the nerve is completely separated from the spinal cord (the most severe type).
Neuropraxia. The nerves are stretched (the least severe type).
Rupture. Part of the nerve is actually torn.
Neuroma. Scar tissue forms on the stretched nerve as it repairs itself.
Brachial plexitis. This is a rare syndrome for which no cause can be identified. It's also called Parsonage-Turner syndrome.
Brachial plexus birth injury—when the brachial plexus gets stretched during childbirth—is called Erb's palsy. Erb's palsy affects between one and two babies in every 1,000 births.
A doctor will generally examine your hand and arm and test for sensation and function to help diagnose a brachial plexus injury.
These are other diagnostic tests often used:
Imaging tests, such as an MRI scan or CT scan
Tests to determine nerve function and electrical activity, including a nerve conduction study and electromyogram
X-ray of the neck and shoulder area
Some brachial plexus injuries require surgery to repair the damage. Physical therapy can help you restore function in your arms and hands and improve range of motion and flexibility in stiff muscles and joints.
Brachial plexus injuries don't always need treatment. Some people, particularly babies with a brachial plexus birth injury, recover without any treatment, but it can take as long as several months for the injury to heal. Certain exercises can help with healing and function.
You may need regular checkups to watch the progress and healing of a brachial plexus injury. Checkups are especially important for babies and may be needed for as long as two years as the injury heals.
Calling the doctor
If you have had an injury to the neck or shoulder area and you can't feel or move your hand or arm, you should call your doctor to find out what's causing your symptoms.
For severe brachial plexus injuries, prompt surgical treatment could be needed to attempt to regain function. Without it, you might have a permanent disability and be unable to use your arm or hand.
If you have a brachial plexus injury resulting in a lack of feeling, you must take special care when dealing with hot items, razors, knives, or other objects that could harm you. A brachial plexus injury can keep you from feeling any other injury to the affected area, so you may not notice that you're hurt.
Key points to remember
Brachial plexus injuries often heal well if they aren't severe. Many people with minor brachial plexus injuries recover between 90 and 100 percent of the normal function of their arms.