What is brachial plexopathy and how does it occur?

Brachial plexopathy occurs when there is damage to the brachial plexus. The plexus is a collection of nerve roots coming together from the neck. These nerves form peripheral nerves that provide sensation and motor function to the shoulder, biceps, triceps, forearm, wrist and hand.

Damage to the brachial plexus may occur from stretching injuries (e.g. birth trauma, auto accident, work related injury), direct injury, radiation therapy injury or possibly pressure from a tumor. In the worst case scenario, the brachial plexus can be torn.

Injuries may occur in contact sports like football, difficult births such as breech presentation, and trauma such as motorcycle or boating accidents.

Additional causes of plexopathy can be drug or toxin exposure, viral infection, or possibly a complication of general anesthesia. For instance, positioning for hours that stretches the plexus.

Most of the time, brachial plexus traumatic injuries occur when the shoulder is forcefully pushed down while the head is pushed up and away.

What are the symptoms of plexopathy?

The brachial plexus is complicated. It combines several nerve roots into a bundle that ends up turning into peripheral nerves. Injury to the plexus may result in multiple problems that may include:

• Decreased or absent reflexes
• Muscle atrophy in the affected nerves
  

  The brachial plexus turns cervical nerve roots into peripheral nerves.

• Weakness in arm, hand, wrist or shoulder
• Sensory abnormalities depending on injured area – this may include burning, tingling, pain, numbness

With brachial plexus injuries, these exams will be inconsistent in what they show. A person may have a complete inability to lift up the arm, significant weakness of the wrist only, deformity of the extremity, or a combination of findings.

How is it diagnosed?

A comprehensive musculoskeletal exam of the upper extremity will evaluate the range of motion, reflexes, muscle tone and strength, and sensation.

Additional tests necessary may include an electromyogram, nerve conduction study, MRI, blood tests and a chest x-ray.

How is it treated?

At times, recovery occurs on its own. If the nerves are not torn, it may be that the nerves will regenerate effectively with function returning fully.

• Pain from the plexopathy may need pain medications that are either over the counter or prescription.  These medications may include narcotics, anticonvulsants (phenytoin, gabapentin), tricyclic antidepressants (amitryptaline), or others.
• Physical therapy can help maintain and improve range of motion and muscle strength.
• If an underlying condition is uncovered such as diabetes is discovered or a viral issue, these should be addressed head on to improve outcomes.
• Braces and splints can help considerably with the ability to use your arm and hand.
• Surgery may become necessary if nerve compression is apparent, or recovery plateaus and tendon transfers become necessary.

What are the outcomes?

Outcomes with brachial plexopathy are variable. If the injury is due to stretch, all function may return or only a partial recovery may occur. Pain may not resolve and can persist.  If a cause can be identified and treated, a good recovery is a distinct possibility.

Potential outcomes may consist of partial paralysis, partial sensation loss, contractures.