Burners and Stingers (Cervical Nerve Root / Brachial Plexus Traction)

What it is. A burner or stinger is a transient, unilateral upper-limb injury: burning pain, paraesthesia and weakness after a blow, typically in collision sports such as American football. It most often affects the upper trunk of the brachial plexus, the C5-C6 distribution, so the deltoid, biceps and rotator cuff (supraspinatus and infraspinatus) are weak and the lateral arm and thumb are numb.

Time course. Symptoms are brief, usually resolving within seconds to minutes. Sensory symptoms often settle within minutes, but weakness or pain may persist for days or longer when the nerve injury is more severe.

Mechanisms. Three are recognised.

• Traction. Lateral flexion of the neck away from the affected side, with depression of the shoulder, stretches the upper trunk. Classic in younger athletes.
• Compression at Erb's point. The fixed brachial plexus is compressed between the shoulder pad and the superior-medial scapula. Evidence suggests this is a common mechanism in tackle football.
• Nerve-root compression. Neck extension with ipsilateral rotation narrows the intervertebral foramen. More common in older athletes with cervical spondylosis.

The red-flag rule. Stingers are typically unilateral, and that is the basis of the single most important clinical rule: a true stinger is unilateral and transient. Bilateral upper-limb symptoms, any lower-limb involvement, or neck pain or midline cervical tenderness are not a routine stinger presentation and raise concern for a cervical cord or spine injury, including transient quadriparesis (cervical cord neurapraxia, below). Assume the cord or spine is injured: immobilise, evaluate fully and image urgently.

Diagnosis. The diagnosis is clinical: a typical mechanism, transient unilateral upper-trunk symptoms, and a normal cervical spine with full painless range of motion once recovered. The differential:

• Cervical cord or spine injury (the red flag above)
• Cervical radiculopathy
• Peripheral nerve injury
• Thoracic outlet syndrome
• Rarely, an atypical anatomical cause such as a postfixed plexus

The examination map. The upper trunk is formed by C5 and C6, so the map is the same whether the lesion lies in the trunk or at the roots.

Traction stinger or radiculopathy. The common stinger is a post-ganglionic plexus injury from traction or compression, usually a transient neurapraxia that recovers fully. A nerve-root radiculopathy is the third mechanism, in the older spondylotic athlete. The features below separate them.

Why it matters. The distinction drives the work-up, because the root or spondylosis case is imaged, and it drives the prognosis. At the extreme, a true pre-ganglionic root avulsion (rare, high-energy) is a far graver, non-recovering lesion than a transient traction stinger. Full plexus anatomy is in the Brachial Plexus Anatomy topic, and the root lesion in Cervical Radiculopathy and Nerve Root vs Peripheral Nerve.

Bilateral or lower-limb symptoms point away from a stinger and towards cervical cord neurapraxia, so the entity itself has to be known.

What it is. Cervical cord neurapraxia (CCN), or transient quadriparesis, is a transient episode of bilateral sensory disturbance (burning, numbness, tingling) in both arms or all four limbs, with or without motor weakness or paralysis, after an axial load with hyperextension or hyperflexion. It is the mirror image of a stinger: bilateral and central (cord) rather than unilateral and peripheral (plexus), and the legs may be involved. Symptoms resolve completely, usually within minutes, sometimes up to 24 to 48 hours.

Why it happens. A transient cord compression or concussion, a "pincer" between osteophyte or disc and the ligamentum flavum, in a developmentally narrow cervical canal. The narrow canal means reduced functional reserve, with less CSF cushioning the cord.

Work-up. Immobilise the spine, then obtain an MRI for canal diameter, cord signal change, disc or ligament injury and instability. The Torg-Pavlov ratio screens on a plain lateral film but has a high false-positive rate, so MRI is preferred (see the Torg Ratio topic; frank cord injury is covered in Spinal Cord Injury).

Return to play. Controversial. A single episode with a normal canal, no instability and no cord signal change may return. Relative-to-absolute contraindications to collision sport:

• Congenital or developmental stenosis
• Cord signal change
• Instability
• Ligamentous injury
• Recurrent episodes

Return to play. The athlete returns only with full, painless cervical range of motion and normal upper-limb strength and sensation. A same-game return is acceptable for a brief, fully resolved first stinger with a normal examination, but not while any weakness, numbness or neck symptoms persist, because returning with a neurological deficit risks a more significant injury.

Persistent symptoms. Image the cervical spine, and add EMG and nerve conduction studies if weakness persists beyond about 2-3 weeks. The delay is deliberate: denervation changes (fibrillation potentials) take roughly two to three weeks to appear, so an EMG performed earlier can be falsely reassuring.

Recurrent stingers. Recurrence should prompt cervical imaging for the predisposing factors: cervical foraminal stenosis, congenital cervical canal stenosis (a low Torg-Pavlov ratio) and cervical spondylosis.

Prevention. Prevention includes neck and periscapular strengthening and proper heads-up tackling technique. Protective equipment, a cervical orthosis ('cowboy collar') and shoulder-pad modification, reduces recurrence, although the Markey study in the evidence below describes its own orthosis result as preliminary and gives no numbers for it.