Brachial Plexus Injury

Overview

The brachial plexus is the bundle of nerves that runs from the spinal cord in the neck through the shoulder and down the arm. It controls movement and sensation in the shoulder, arm, and hand. A brachial plexus injury damages this network, and can range from a temporary loss of function to a complete, disabling paralysis of the limb.

These injuries are time-sensitive. The window for successful nerve repair is limited, so early specialist evaluation gives the best chance of meaningful recovery.

Brachial plexus anatomy

The brachial plexus is formed from five nerve roots that leave the spinal cord in the lower neck and upper chest: C5, C6, C7, C8, and T1. These roots combine and divide as they travel under the collarbone and into the arm. Different parts of the plexus power different movements:

• Shoulder stability, lifting, and external rotation
• Elbow bending and elbow straightening
• Wrist and finger extension
• Hand opening, grip, and fine finger movement
• Sensation from the shoulder down to the fingers

Understanding which movements and sensations are lost helps localize which part of the plexus is injured.

Types of injury

Brachial plexus injuries are not all the same. The treatment plan depends on the level and severity of nerve damage.

• Stretch injury: the nerve is stretched but not completely torn. Mild stretch injuries can recover, while severe stretch injuries may not.
• Rupture: the nerve is torn away from itself but not from the spinal cord. These injuries often require nerve grafting or reconstruction.
• Avulsion: the nerve root is pulled out from the spinal cord. The root cannot simply be reattached, so treatment usually relies on nerve transfers or other reconstructive strategies.
• Scar or compression: the nerve remains in continuity but is trapped in scar tissue or compressed by surrounding structures.

Some patients have a mixture of injury types across different roots, which is why detailed mapping is essential.

Symptoms

• Weakness or complete paralysis of the shoulder, arm, or hand
• Numbness or loss of sensation in part of the arm
• A limp or “waiter’s tip” position of the arm
• Burning or shock-like nerve pain
• Muscle wasting in the affected limb over time
• Shoulder instability, subluxation, or pain from loss of muscle support
• Loss of elbow bending, hand grip, or finger control
• Severe deafferentation pain after root avulsion

Causes

• High-energy trauma such as motorcycle, car, and sports accidents
• Falls and penetrating injuries (cuts, gunshot wounds)
• Stretch injuries during a difficult birth (obstetric brachial plexus injury)
• Tumors or radiation affecting the nerve network
• Surgical or anesthetic positioning injuries

Risk factors

• Participation in contact or high-speed sports
• Motorcycle use and high-risk occupations
• Difficult or assisted deliveries (for newborns)
• Prior radiation to the neck, chest, or shoulder region

When to see a doctor

Seek prompt specialist evaluation for any persistent weakness, numbness, or pain in the arm after an injury — especially if the arm is partly or fully paralyzed. Because nerve repair is time-sensitive, do not wait to see whether function returns on its own; early assessment preserves the most treatment options.

Urgent review is especially important after high-energy trauma, penetrating injury, rapidly worsening weakness, severe nerve pain, or complete loss of shoulder and elbow function. If there is no meaningful recovery over the first weeks to months, the surgical window can narrow quickly.

Diagnosis

Dr. Barone evaluates each injury with a detailed clinical examination, imaging (such as MRI or CT myelography), and electrodiagnostic studies (EMG and nerve conduction studies) to map exactly which nerves are affected and whether they are likely to recover on their own. This assessment determines whether observation, repair, or reconstruction offers the best outcome — and how quickly surgery should be considered.

The evaluation asks several questions:

• Which roots, trunks, cords, or terminal nerves are affected?
• Is the injury a stretch injury, rupture, avulsion, compression, or scar-related problem?
• Are any muscles showing signs of reinnervation?
• Are there donor nerves available for transfer?
• Which functions matter most for the patient’s goals?
• Is pain neuropathic, mechanical, or both?

Electrodiagnostic testing is often repeated over time because the pattern of recovery can become clearer as the injury evolves.

Timing matters

Timing is one of the most important parts of brachial plexus care. Some injuries are observed briefly to see whether spontaneous recovery begins. Others, such as sharp lacerations or clear severe injuries, may require earlier repair.

For many traumatic stretch or rupture injuries, reconstruction is often considered within the first several months if recovery is not occurring. Waiting too long can allow irreversible muscle atrophy and loss of motor endplates, making nerve reconstruction less effective. In late presentations, tendon transfers, joint fusion, free functional muscle transfer, or prosthetic reconstruction may become more relevant than nerve repair.

Surgical priorities

Brachial plexus surgery is planned around functional priorities. It may not be possible to restore every movement, so the team focuses on the functions that give the greatest useful independence.

Common priorities include:

• Stabilizing the shoulder
• Restoring shoulder external rotation when possible
• Restoring elbow flexion
• Restoring elbow extension in selected cases
• Improving hand grasp or positioning
• Restoring protective sensation when possible
• Reducing severe neuropathic pain

Treatment

• Nerve repair and nerve grafting
• Nerve transfers to restore key movements such as elbow flexion and shoulder stability
• Neurolysis (freeing nerves from scar tissue)
• Free functional muscle transfer for selected late or severe injuries
• Tendon transfers and joint fusion for selected reconstruction goals
• Bionic limb reconstruction in selected cases of severe injury
• Management of nerve pain
• Coordination with dedicated hand therapy and rehabilitation

Surgical options explained

Exploration and intraoperative testing: In selected cases, surgery begins by exposing and testing the injured nerves. This helps determine whether signals cross the injured segment and whether neurolysis, grafting, or transfer is most appropriate.

Neurolysis: If a nerve is intact but trapped in scar tissue, freeing it may improve the environment for recovery.

Nerve grafting: If a nerve is ruptured, the damaged segment can be removed and bridged with donor nerve graft. The sural nerve from the leg is commonly used as a donor sensory nerve; this can leave a patch of numbness near the foot or ankle.

Nerve transfer: If the original pathway cannot be repaired, a nearby functioning nerve can be redirected to power a critical muscle. Examples include transfers to improve shoulder stability, shoulder external rotation, or elbow flexion.

Free functional muscle transfer: In severe or delayed cases, a muscle such as gracilis from the thigh can be transplanted to the arm with its blood supply and nerve connection to restore a key function such as elbow bending or basic grasp.

Tendon transfer or joint fusion: When nerve recovery is no longer possible or incomplete, orthopedic reconstruction can improve positioning, stability, or useful movement.

Bionic limb reconstruction: In selected severe injuries where the limb has poor function despite reconstruction, amputation with a myoelectric prosthesis may be discussed as a functional option. This is not a treatment for nerve pain, but it may help selected patients achieve grasp or positioning goals.

Pain after brachial plexus injury

Pain can come from more than one source. Neuropathic pain may feel burning, electric, crushing, or shock-like and is especially common after root avulsion. Mechanical pain can come from shoulder instability, weak muscles, poor limb support, or secondary joint problems.

Treatment may include neuropathic pain medication, therapy, bracing or shoulder support, spinal cord stimulation, or in selected severe avulsion pain cases, DREZ lesioning. Pain treatment is individualized and may be separate from the plan to restore movement.

Dr. Barone’s approach

As a fellowship-trained peripheral nerve surgeon and neuroscientist, Dr. Barone combines established microsurgical techniques with an active research program in nerve repair and neural interfaces. Each plan is tailored to the injury pattern, the patient’s goals, and the time since injury — with honest discussion of realistic recovery.

Recovery & outlook

Recovery after nerve surgery is gradual. Nerves regrow slowly — often about an inch per month — so meaningful improvement may take many months and is supported by a structured hand-therapy program.

Therapy is not optional after reconstruction. Patients often need splinting, range-of-motion work, strengthening, motor re-education, pain management, and training to use new nerve pathways. After nerve transfer, the brain must learn to activate a muscle through a different donor nerve signal.

Full normal recovery is uncommon after severe traumatic brachial plexus injury. A successful plan is one that restores the most valuable functions possible, reduces complications, supports the limb, and improves quality of life.