Definition

A brachial plexus injury is damage to the network of nerves that send signals from the spinal cord to the shoulder, arm, and hand. The brachial plexus controls sensation and movement in the arm and hand. Sudden damage to the brachial plexus can cause weakness, loss of sensation, or movement in the shoulder, arm, or hand.

This injury can occur if these nerves are stretched, compressed, or, in severe cases, torn in the middle or torn from the spinal cord, typically due to sports or accidents (most commonly traffic accidents).

Causes

Damage to the upper brachial plexus usually occurs when the shoulder is forced downward while the neck stretches upward. Meanwhile, the lower brachial plexus is more prone to injury if the arm is forced over the head. Some injuries can occur in various ways, such as:

• Contact sports: Many football players experience minor brachial plexus injuries when the plexus is stretched beyond its limits during collisions with other players.
• Difficult births: Newborns can suffer brachial plexus injuries related to high birth weight, breech births, or prolonged labor. If the baby’s shoulder gets stuck in the birth canal, there is a higher risk of brachial plexus injury. The most common injury is to the upper nerves, known as Erb’s palsy, which causes weakness or loss of muscle function in the shoulder and arm.
• Trauma: Various traumas, such as motor vehicle accidents, motorcycle crashes, falls, or gunshot wounds, can cause brachial plexus injuries.
• Tumor and cancer therapy: Radiation therapy to the chest or neck can cause tumors to grow around or along the brachial plexus, compressing the plexus and spreading to the nerves. Radiation therapy to the chest can damage the brachial plexus.

Risk factor

Factors that increase the risk of brachial plexus injury include participating in contact sports, especially football and wrestling, or being involved in high-impact traffic accidents.

Symptoms

Symptoms of brachial plexus injury depend on the affected part of the nerve plexus and the severity. Injuries to the upper nerve roots can affect the shoulder, while injuries to the lower nerves will affect the arm, wrist, and hand. The most common symptoms of brachial plexus injury include:

• Numbness or loss of sensation in the hand or arm.
• Inability to control or move the shoulder, arm, wrist, or hand.
• A weak, limp arm.
• Severe burning, stinging pain in the shoulder or arm.

Brachial plexus injuries can range from mild to severe and may be temporary or permanent, depending on the type and extent of the injury. For example, a stretched nerve may cause pain for a week, while a torn nerve may cause chronic pain that requires physical therapy and surgery.

Diagnosis

Patients with brachial plexus injuries should be examined and treated promptly. The longer the muscles go without signals from the nerves, the lower the likelihood of regaining normal function, even if the nerve signals return.

Physical examination

Several direct examinations can help diagnose a brachial plexus injury. The brachial plexus controls specific parts of the shoulder, arm, and hand, so the doctor will examine the function of these specific parts. Additionally, some patients may exhibit signs indicating the nerve injury location:

• Horner’s syndrome: Symptoms include a constricted pupil, drooping eyelid, and the inability to sweat on the affected side of the face, indicating injury close to the spinal cord.
• Tinel’s sign: Shooting pain when the doctor traces along the nerve indicates injury away from the spinal cord. If Tinel’s sign moves down from the arm to the hand as recovery progresses, it indicates nerve repair.

The doctor may also check the strength and range of motion of the shoulder and arm.

Imaging tests

Imaging tests that may be performed include:

• X-ray: This is used to rule out fractures in the chest, shoulder, and arm. Chest X-rays are done to check for rib fractures or lung injuries. If you cannot take deep breaths during the test, the doctor may consider a lung function test to rule out nerve damage controlling deep breathing.
• CT scan: This is the most reliable test for detecting nerve injuries. Contrast dye is injected near the spinal cord in the neck to show injuries on the CT images. This test is typically done 3-4 weeks after the injury to allow any blood clots around the nerves to dissolve.
• Electrodiagnostic tests: These tests measure nerve conduction speed and electrical flow from the nerves to the muscles. They are crucial for confirming the diagnosis, locating the exact nerve injury, assessing severity, and checking nerve repair speed. Electrodiagnostic tests are usually performed 3-4 weeks after the injury, with follow-ups 2-3 months later to monitor nerve recovery.

Management

Brachial plexus injuries do not always require treatment. Some people, especially newborns or adults with neuropraxia (nerve damage), can recover without treatment, although it may take several weeks to months. Some exercises can help restore function, but severe injuries may require surgery. It is essential to see a healthcare provider after an injury.

Non-surgical therapy

Non-surgical treatments for brachial plexus injury include:

• Physical therapy: To learn exercises that restore arm and hand function and increase the range of motion and flexibility in stiff muscles and joints.
• Corticosteroid injections or creams: To reduce pain symptoms during recovery.
• Assistive devices: Such as braces, splints, and support pads.
• Pain medication: To manage pain.
• Occupational therapy: To learn how to perform daily activities like dressing and cooking, especially in cases of severe muscle weakness, numbness, and pain.

Surgical treatment

Surgical treatment may be necessary if the brachial plexus injury cannot heal on its own. Nerve tissue grows and heals slowly, so surgical results may take several years to become apparent. Procedures include:

• Nerve repair: Reconnecting torn nerves.
• Neurolisis: Removing scar tissue from the nerve tissue to improve function.
• Nerve grafting: Connecting torn nerves with healthy nerves from other parts of the body to guide nerve recovery.
• Nerve transfer: Attaching less critical but functional nerves to damaged nerves, allowing new growth space.
• Tendon and muscle transfer: Transferring tendon and muscle tissue from less critical areas to the arm to restore function.

This treatment must be discussed with a specialist to determine if you are a good candidate for surgery.

Complications

Complications of brachial plexus injury include:

• Joint stiffness: Paralysis of the arm and hand can lead to stiff joints, making movement difficult even if arm function is regained. Doctors often recommend physical therapy during recovery.
• Chronic pain: Due to nerve damage.
• Numbness: Numbness in the arm or hand increases the risk of unnoticed burns or injuries.
• Muscle atrophy: Nerves regenerate slowly, often taking years to recover after injury. During this time, muscles can shrink and weaken.
• Permanent disability: Recovery depends on factors such as age, type, location, and severity of the injury.

Prevention

Damage from brachial plexus injuries is often unavoidable, but the risk of complications can be reduced by:

For yourself

If you cannot use your arm and hand, physical therapy and range-of-motion exercises can prevent joint stiffness. Avoid heat and sharp objects, as numbness may prevent you from sensing them.

For your child

If you are the parent of a child with brachial plexus palsy, exercise your child's muscles and joints daily from a few weeks of age. This helps prevent permanent joint stiffness and keeps muscles healthy and strong.

When to see a doctor?

See a doctor immediately if you experience recurring tingling or burning, weakness in the arm or hand, neck pain, or symptoms in both arms simultaneously. The sooner you receive treatment, the higher the chances of the nerves functioning normally again.

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