Brachial Plexus Injury

The brain sends and receives messages from the body through the nervous system. The nervous system is made up of the brain, spinal cord, and nerves. Nerves are the body’s “telephone wiring” system that carries messages between the brain and the rest of the body. Some nerves carry messages from the brain to muscles to make the body move, while other nerves carry messages about pain, pressure, or temperature from the body to the brain. There are also nerves that carry multiple kinds of information through different small fibers within the nerve. These small fibers can also cross between nerves, creating a network of connected nerves called a plexus.

The brachial plexus is a group of nerves that start at the spinal cord in the neck and travel down the arm (Figure 1). These nerves control the muscles of the shoulder, elbow, wrist, hand and fingers. The nerves of the brachial plexus also carry information about pain, pressure, and temperature from the fingers, hand, elbow, arm and shoulder to the brain. When the brachial plexus is injured, any or all of these important functions can be affected.

Figure 1
The brachial plexus is a network of nerves between the neck and shoulder. Their branches form the nerves that go into the arm, forearm and hand.

Causes

There are many ways the brachial plexus can be injured. An injury can occur from the nerves being stretched, having pressure applied to the nerve, or a sharp injury causing a direct cut to the nerve.

Stretching can occur when the head and neck are forced away from the shoulder, such as during a motorcycle or car accident. In newborn babies, stretching can also occur during vaginal delivery if the shoulder gets stuck as the baby is being pushed out. Stretching can happen along a nerve, causing it to swell or bruise. If the stretch is severe enough, it can tear a nerve completely or cause the nerves to tear out of their connection to the spinal cord.

Pressure can be caused by an injury to the anatomy around the brachial plexus, such as a fracture of the first rib or a shoulder dislocation. Swelling from bleeding or bruising of the surrounding area, or a tumor growing near the brachial plexus, can also cause pressure on the nerves.

The brachial plexus can also be directly cut with a traumatic injury from a sharp object or a forceful object like a bullet. It is also possible that a nerve in the brachial plexus could accidentally be cut during another surgery in the neck, shoulder, or arm.

Signs and Symptoms

Brachial plexus injuries are nerve injuries. The signs and symptoms of brachial plexus injury will be different depending on what nerve is injured, the type of injury, and the severity of the injury. Signs and symptoms may include:

  • Change in sensation: This can include numbness or a “pins and needles” sensation, or difficulty knowing where the arm is in space. Some may experience a combination of these sensations.
  • Weakness: Depending on the severity of the injury, the injured arm may only be weaker than usual in the shoulder, elbow, hand and fingers. In some cases, the muscles may not work at all, causing the arm to be limp.
  • Pain: This is a frequent symptom after nerve injury. Pain can occur at the location of the injury, such as the neck or shoulder, but can also be located anywhere in the injured arm and cause a shooting pain sensation.

Diagnosis

Diagnosis of brachial plexus injuries starts with a careful physical exam. Your doctor will check the strength of the muscles in your shoulder, arm, elbow, and hand and fingers. He or she will also test your sensation in different areas of the arm.

Additional testing to get images of the brachial plexus may be recommended. This can include an MRI, CT scan, or myelography. These are all tests your doctor may use to understand the area and extent of injury.

Your doctor may also recommend electrodiagnostic testing, which can be called a Nerve Conduction Study (NCS) or Electromyogram (EMG). These tests can be useful for diagnosing a brachial plexus injury because they measure the electrical activity carried by nerves for both muscle movement and sensation. Your doctor may recommend repeating this test after several weeks or months to check your recovery.

    Treatment

    Treatment of a brachial plexus injury will be different depending on what nerve is injured, the type of injury, and the severity of the injury. The most important first step in treatment is evaluation by a doctor who has experience treating brachial plexus injuries. They can determine the type and severity of the injury and make appropriate recommendations for treatment.

    Types of treatment for brachial plexus injuries include:

    • Observation: If you have a mild brachial plexus injury, your doctor may recommend watching and waiting to see if you recover on your own. You will come back for repeated examinations with your doctor to make sure your nerves are recovering.
    • Therapy: Most patients with a brachial plexus injury will need therapy to recover and help treat pain. While waiting for muscles to recover, therapy can help prevent joints from getting stiff. As your muscles recover, therapy can help strengthen them. Therapists can offer techniques to help nerves recover, such as ultrasound therapy.
    • Surgery: In the case of severe brachial plexus injuries, or injuries that do not recover on their own, surgery may be required. The type of surgery will depend on which nerves are injured and which functions have been lost. Very mild brachial plexus injuries can undergo a procedure called a neurolysis, where scar tissue is cleaned up around the nerves helping them function better. Some nerve injuries can be repaired with surgery to put the nerve back together. Other injuries are treated by replacing the function of an injured nerve with another nerve, called a nerve transfer. Some injuries that result in muscle weakness can be treated by moving another muscle to replace the weaker one, called a tendon transfer.
    Most patients will need a combination of these treatments for their brachial plexus injury. If surgery is required, more than one surgery may be necessary to improve function as much as possible.


    Recovery

    Recovery from brachial plexus injury will be different depending on what nerve is injured, the type of injury, the patient’s age, and the severity of the injury. Some brachial plexus injuries are minor and will completely recover in several weeks. Other injuries are severe enough to cause permanent disability in the arm, even with the best possible treatment. In general, younger patients tend to recover faster and more completely than older patients. More severe injuries take longer to recover, and a patient may never return to normal function after a severe brachial plexus injury.

    Though brachial plexus injuries are complicated to diagnose and treat, timely evaluation by a hand or brachial plexus surgeon can maximize function.


      © 2024 American Society for Surgery of the Hand

      This content is written, edited and updated by hand surgeon members of the American Society for Surgery of the Hand. Find a hand surgeon near you.

      Find a hand surgeon near you
      Using this search tool means you agree to the user agreement and disclaimer.