Brachial Plexus Injury

Our Specialists for Brachial Plexus Injury

Brachial plexus reconstruction is one of the most technically demanding operations in peripheral nerve surgery, and outcomes depend heavily on the surgeon's volume and experience with nerve grafting, nerve transfers, and free muscle transfers. The UChicago team evaluates these injuries urgently because the window for a meaningful recovery closes within months.

Martin Herman, M.D., Ph.D.

Program Director, Neurological Surgery Residency

Dr. Herman is Program Director of the Neurological Surgery Residency and a complex spine surgeon who practices the full spectrum of spine and neurorestoration procedures. He co-developed a fully implantable wireless intraspinal microstimulation device for restoring motor function after spinal cord injury, with publications in Artificial Organs and Scientific Reports. He has been named a Top Chicago Doctor for over a decade. Dr. Herman is one of the UChicago neurosurgeons who evaluates peripheral nerve injuries alongside the plexus team, particularly for patients with associated cervical spine trauma or nerve root avulsions that need combined assessment. His role is making sure nothing at the spinal level is missed while the reconstructive plan for the arm is being built.

What Is a Brachial Plexus Injury?

Your brachial plexus is a bundle of nerves that starts at the side of your neck (from spinal nerves C5 through T1) and branches into every nerve that controls your shoulder, arm, and hand. When those nerves are stretched, torn, or ripped out of the spinal cord itself, you lose the ability to move or feel parts of your arm.

In adults, most serious brachial plexus injuries come from high-energy trauma — motorcycle and snowmobile crashes are by far the most common cause, followed by falls from height, sports collisions, and penetrating wounds. Roughly 1 in 100 major trauma patients has a brachial plexus injury, and the rate climbs close to 5% in motorcycle crashes.

The injury is typically sudden and dramatic: immediately after the accident, the arm hangs limp, often with a burning or crushing pain. Some people recover on their own within weeks as a mild stretch heals. Others have severed or avulsed (torn-out) nerves that will never recover without surgery. The hard part — and the reason expert evaluation matters — is telling those two groups apart quickly, because the clock is already running.

What Does It Feel Like?

Symptoms depend on which parts of the plexus are injured and how severely. The immediate picture is usually striking, but subtler patterns can develop over days.

Upper plexus injuries (C5-C6, sometimes C7)

• Shoulder that won't lift or rotate outward — the arm rests at the side, turned inward
• Inability to bend the elbow or bring the hand to the mouth
• Hand function is usually preserved
• Numbness along the outer shoulder and thumb side of the forearm

Lower plexus injuries (C8-T1)

• Weak or paralyzed hand and fingers — you can't grip, pinch, or spread the fingers
• Shoulder and elbow often still work
• A drooping eyelid, small pupil, and lack of sweating on one side of the face (Horner's syndrome) — a warning sign that the lowest nerve roots have been pulled out of the spinal cord

Total plexus injuries (C5-T1)

• A completely flail arm — no movement anywhere, from shoulder to fingertips
• Loss of sensation throughout the arm and hand
• Often severe, burning, constant pain — sometimes worse than the paralysis itself

Almost everyone with a serious plexus injury has significant neuropathic pain — described as burning, crushing, or electric shocks — and this can start within days of the injury. Pain is not a sign that things are getting worse; it reflects how the damaged nerves signal to the brain.

How Is It Diagnosed?

Diagnosing a brachial plexus injury is a combination of a careful physical exam, imaging, and electrical nerve studies — and it needs to happen quickly.

Physical examination

Your surgeon will test every muscle group in the shoulder, arm, and hand and grade each one on the MRC scale (0 = no movement, 5 = normal strength). The pattern of weakness tells us which nerve roots are involved. Signs like Horner's syndrome, a winged scapula, or a paralyzed diaphragm on the injured side strongly suggest that the nerves have been torn out of the spinal cord itself — a finding that changes the surgical plan.

MRI of the cervical spine and brachial plexus

A high-resolution MRI shows the nerve roots as they leave the spinal cord. The key finding we look for is a pseudomeningocele — a pocket of spinal fluid where a nerve root has been ripped away. MRI detects these root avulsions with about 93% sensitivity and is the single most important imaging test for planning surgery.

CT myelography

When the MRI is ambiguous, a CT myelogram — a CT scan performed after dye is injected into the spinal canal — gives a very clear picture of whether the nerve roots are still attached.

Electrodiagnostic studies (EMG and nerve conduction)

EMG and nerve conduction studies are typically done around 3-4 weeks after injury, once enough time has passed for the electrical signs of nerve damage to develop. These studies help separate nerves that are recovering on their own from nerves that are not — and they're repeated at intervals to watch for early recovery.

Why the timing of diagnosis matters

Here is the critical fact every patient and family needs to understand: muscles that are disconnected from their nerves start to die after about 12-18 months. Even if the nerves are later repaired, a muscle that has been denervated for too long will not function. That is why evaluation needs to happen within weeks of injury, and why surgical decisions generally can't be delayed past 3-6 months if a nerve reconstruction is going to work.

Types of Brachial Plexus Injury

Brachial plexus injuries are categorized two ways: by where along the nerve the damage occurred, and by which part of the plexus is affected. Both matter enormously for what surgery can accomplish.

By location of nerve damage

• Preganglionic (root avulsion) — the nerve root is ripped directly out of the spinal cord. There is no nerve stump to sew back to, so the avulsed nerve cannot be repaired end-to-end. These are the most severe injuries and typically require nerve transfers or free muscle transfers to restore function.
• Postganglionic (rupture or stretch) — the nerve is torn or stretched further away from the spinal cord. Postganglionic injuries leave nerve stumps that can often be repaired with nerve grafts, and they generally have better outcomes than avulsions.
• Neurapraxia (stretch without tearing) — the mildest form. The nerve fibers are shocked but intact and often recover on their own within weeks to months.

By level of the plexus

• Upper plexus (C5-C6) — Erb's palsy pattern — loses shoulder abduction, external rotation, and elbow flexion. Hand function is spared. This is the most favorable pattern for reconstruction, and distal nerve transfers often restore MRC grade 4 shoulder and elbow strength.
• Upper + middle plexus (C5-C7) — adds wrist and finger extension loss. Still reconstructible but more technically demanding.
• Lower plexus (C8-T1) — Klumpke's palsy pattern — the shoulder and elbow work, but the hand is paralyzed. Unfortunately, the hand is the hardest part of the arm to reinnervate — the intrinsic hand muscles are small, far from the injury, and often beyond the reach of regenerating nerve fibers.
• Total (pan-plexus, C5-T1) — a completely flail, insensate arm. Reconstruction is staged and realistic goals focus on elbow flexion, shoulder stability, and protective sensation rather than full recovery. Free functioning muscle transfer plays a major role here.

How Is It Treated?

The first 3-6 months: observation with a ticking clock

Not every plexus injury needs immediate surgery. Milder stretch injuries can recover on their own, and your team may observe you for signs of improvement with monthly exams and repeat EMGs. During this window, physical therapy is essential to keep the joints mobile and prevent stiffness that would undermine any surgery done later.

However, if there is no evidence of recovery by around 3 months — or if imaging shows root avulsions from the start — it's time to operate. Waiting beyond 6 months dramatically reduces the odds of a useful recovery, and beyond 9-12 months most reconstructive options off the table because the target muscles have become too atrophied to respond.

Nerve grafting (for ruptures with nerve stumps)

When a nerve is torn but the stumps can be identified, the surgeon removes the scarred ends and bridges the gap with nerve grafts — usually taken from the sural nerve in the leg, which you won't miss. Axons then regrow through the graft at roughly 1 mm per day, which is why full reinnervation can take 12-18 months.

Nerve transfers — the modern workhorse

In the last two decades, distal nerve transfers have transformed brachial plexus reconstruction. Instead of regrowing axons all the way from the neck, the surgeon reroutes a healthy, expendable nerve close to the target muscle. This means shorter regeneration distances, faster recovery, and better strength.

The most commonly used transfers at UChicago include:

• Oberlin transfer (ulnar to biceps) — a single fascicle of the ulnar nerve is rerouted to the biceps branch of the musculocutaneous nerve. Over 90% of patients recover MRC grade 4 elbow flexion, often within 6-9 months.
• Double fascicular transfer — the Oberlin transfer plus a median nerve fascicle rerouted to the brachialis muscle. Gives even stronger elbow flexion than the Oberlin alone.
• Spinal accessory to suprascapular nerve — restores shoulder abduction and external rotation by rerouting a branch of the nerve that powers the trapezius.
• Radial to axillary (triceps branch to deltoid) — restores deltoid function to complement the suprascapular transfer for a stable, usable shoulder.
• Intercostal nerve transfers — rib (intercostal) nerves are rerouted to the musculocutaneous nerve for elbow flexion when no in-arm donors are available, as in total plexus avulsion.

Free functioning muscle transfer

When a patient presents late — beyond 6-9 months — or has a total plexus injury with no usable nerve donors, we can import an entirely new muscle. The gracilis muscle is taken from the inner thigh along with its artery, vein, and nerve, transplanted to the arm, and wired up under the microscope to a working nerve (often an intercostal or spinal accessory). Over 6-18 months, the transplanted muscle reinnervates and produces useful elbow flexion or finger flexion. This is demanding surgery, but it's often the only option for devastating late-presenting injuries.

Pain management

Severe burning pain affects most patients with plexus injuries, and treating it aggressively is part of care. Medications like gabapentin and pregabalin, tricyclic antidepressants, and sometimes spinal cord stimulation or dorsal root entry zone (DREZ) procedures can all play a role.

What Are the Outcomes?

Outcomes depend on the severity of the injury, which roots are involved, how soon surgery happens, and — probably most importantly — the experience of the surgical team. Recovery is slow: even when everything goes right, strength typically takes 12-24 months to reach its peak, because axons regrow at only about a millimeter a day.

Here is what contemporary series and meta-analyses show for the most common reconstructions:

Two facts matter more than any others. First, timing: in series where surgery was performed within 6 months, average elbow flexion recovery is MRC grade 4 — in series where it was delayed past 6 months, average recovery drops to grade 1. Second, volume: brachial plexus outcomes are strongly tied to surgeon and center experience, because the operations are long, rare, and technically unforgiving. The best thing you can do after a plexus injury is get in front of a dedicated peripheral nerve team as soon as possible.

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