Brachial Plexus Injury

Shoulder

The brachial plexus refers to a complex web of large nerves that exit from the spinal cord in the neck and direct the movement and sensation of the entire upper limb.

Traumatic brachial plexus injuries, which are most commonly sustained in high speed motor vehicle accidents or while engaged in sporting events, affect the sensibility and muscle power in part of or the entire limb. Approximately 15% of brachial plexus injuries have an injury to the blood supply of the arm as well, and emergency surgery may be indicated.

The extent of spontaneous nerve recovery is unpredictable and generally imperfect. Frequent and thorough examination over the first three to six months following injury is necessary to document signs of nerve recovery, and additional imaging (such as MR neurography) or electrodiagnostic tests are often required.

One form of brachial plexus injury, often called Erb's palsy or Erb-Duchenne palsy, causes loss of sensation or paralysis in the upper arm. This injury usually affects infants during a difficult childbirth, however, it can also happen at any age after a trauma to the head and shoulder. In both cases, the head and neck are forcefully bent sideways, damaging the C5-C6 nerves of the upper trunk.

Overview of brachial plexus injuries

Neck Injuries Involving the Cervical Nerve Roots and Spinal Cord

"Burners," "Stingers," Brachial Plexus Injuries, Quadriplegia, and Quadriparesis
Neck injuries are a particular concern in contact sports such as football, and they require special attention because of the devastating consequences if they are severe. Cervical nerve root and spinal cord injuries are among the most common cervical spine neurologic (nerve) injuries.

Anatomy

The cervical spine refers to the seven cervical vertebras, bones in the neck that connect the back of the skull to the thoracic spine in the upper back. The muscles in the neck support and protect the vertebral bodies, cord, and nerve roots by absorbing forces transmitted to the neck directly, or through the head or trunk.

There are eight cervical nerve roots arising from the cervical spinal cord, which exit the vertebral canal through foramen (circular openings, or "windows", between the vertebras that house the spinal cord). The size or diameter of the vertebral canal and foramen vary in size, depending on the person.

After exiting the canal, the lower cervical nerve roots become interwoven with each other to form the brachial plexus, a series of nerves that supply sensation and motor function to the arms and hands.

Since the diameter of the vertebral canal and foramen differs on an individual basis, a small spinal canal or foramen can put the spinal cord or nerve root at increased risk for injury.

Diagnosing Nerve Root and Brachial Plexus Injuries

A common neck injury in football involves compression or stretching of a nerve root or the brachial plexus; referred to as “burners” or “stingers”, they make up approximately ten percent of all cervical spine neurologic injuries, and two thirds of all college football players experience at least one of these injuries. These injuries occur from either a pinching (compression) of the nerve on the same side the neck is flexed/extended or a stretching of the nerve on the opposite side of where the neck is flexed/extended.

Those affected may experience sharp, burning pain that may radiate into the shoulder and down the arm to the hand. The symptoms only occur on one side and may include weakness and paresthesia (numbness or tingling) in the involved extremity for several seconds to several minutes. Raising the arm (deltoid), flexing the elbow (bicep), and rotating the arm outwards (using the external rotator muscles of the rotator cuff) may be restricted as a result of motor weakness.

Physical exam should include a thorough sensory exam; a complete motor exam including the deltoid, biceps, and rotator cuff; and a Spurling’s provocative test. A Spurling’s test attempts to reproduce the symptoms of a burner by passive extension and lateral flexion (sideways movement) of the head and neck.

Electrodiagnostic testing or an MR neurogram may be used to identify which nerves are affected. X-rays and an MRI are indicated when there is persistent neurologic deficit or recurrent symptoms, to rule out an occult (hidden) fracture or a herniated disc.

Treatment

These injuries are more likely to occur in patients with poorly developed neck musculature. In older athletes, nerve root compression is more likely to occur in conjunction with a herniated cervical disc.

Conservative treatment consists of rest, possibly a neck brace, and over-the-counter pain relievers or anti-inflammatory medications. With persistent or recurrent symptoms, it is very important to have a thorough evaluation by an orthopaedic or neurology specialist. Very rarely is surgery indicated to relieve persistent pressure on a nerve, except when there is evidence of small foramen. In this setting, one option is to surgically enlarge these openings to give more space for the nerves.

Spinal Cord Injury with Transient Quadriplegia or Quadriparesis

Much more serious neck injury can result in quadriplegia or quadriparesis. Quadriparesis describes an episode of numbness or tingling, with possible motor change ranging from weakness (quadriparesis) to paralysis (quadriplegia) of all four extremities (arms and legs). These episodes most commonly last from ten minutes to forty-eight hours. There is usually no fracture or dislocation, but the event can be associated with a small (stenotic) spinal canal. With fracture or dislocation of the cervical spine and severe spinal cord injury, quadriplegia may persist and surgery may be indicated.

Quadriplegia or quadriparesis are caused by an acute episode of forced hyperextension, hyperflexion, or excessive loading of the cervical spine. It only occurs in about one out of 10,000 football players every season and is very highly associated with “spear tackling” or other head-first falls. The neck is usually flexed at least thirty degrees, and in this position the cervical spine loses its normal curve, causing the neck musculature to lose its ability to dissipate force.

After this injury, the athlete should not be permitted to return to play until radiographs and an MRI are obtained to prove there is no spinal cord swelling (edema) or instability (ligamentous injury). If these studies are normal, the athlete can return to play when there is painless range of motion of the neck and a return of full strength.

Although there is a fifty percent chance of the injury occurring again after return to play, there is no good data to suggest any long term disability. If the athlete has had multiple episodes or the symptoms last longer than thirty-six hours, they should not be allowed to return to play.

Radiographic proof of a small spinal canal or an episode associated with herniated disk or degenerative changes in the spine, are relative contraindications to return to play. There is some evidence to suggest that people with small spinal canals who experience an episode of transient quadriplegia could be at risk for permanent neurologic problems.

First Aid Treatment

There may be some benefit from giving high dose steroids to the patient at the time of spinal cord injury, but the evidence is not definitive. All of these injuries should be treated with full cervical spine precautions until any fractures, dislocations, or cervical spine instability can be ruled out.

In the setting of football, the helmet and shoulder pads are left in place until cervical spine instability has been ruled out. The facemask may be removed if access is needed to maintain the airway. If the airway appears to be compromised, cardiopulmonary resuscitative efforts should be carried out, but the neck must be stabilized as well. The patient should then be “log rolled” onto a back board and transported to the hospital.

Persistent symptoms with an associated small spinal canal may be treated with a cervical decompression and fusion. However, the extent and specific nature of these injuries may be quite varied; each requiring detailed evaluation and treatment options directed specifically to the injury at hand.

Diagnosis of brachial plexus injuries

Magnetic Resonance (MR) Neurography

Until recently, precisely localizing the site(s) of peripheral nerve damage was difficult, which made it challenging for doctors to accurately diagnose and treat peripheral nerve disorders.

Treatment of brachial plexus injuries

Brachial Plexus Injuries: New Advances In Treatment

Injuries to the brachial plexus (the nerves that conduct signals to the shoulder, arm, and hand) can have devastating consequences, including loss of function and chronic pain. Fortunately, new advances in nerve surgery can yield marked improvement in movement and function of the shoulder, elbow, and hand, while simultaneously diminishing pain.

Diagnosing brachial plexus injuries

In addition to performing a physical examination, orthopedists evaluate brachial plexus injuries using MRIs, CT scans, and electro-diagnostic tests.

Nonsurgical treatment

Patients with a stretch neurapraxia may be able to regenerate healthy nerve tissue. However, recovery is unpredictable. In such cases, the orthopedic surgeon conducts frequent and thorough examinations over the first three to six months following the injury and performs additional imaging and electro-diagnostic tests, as needed. If there is no recovery, the patient is assessed for internal damage to the nerve, and surgery may become necessary.