What is the clinical significance and management of a positive Spurling sign (Spurling test) in a patient?

Clinical Significance and Management of a Positive Spurling Sign

A positive Spurling sign strongly indicates cervical radiculopathy and should prompt immediate imaging (preferably MRI) and appropriate specialist referral for patients with persistent symptoms.

What is the Spurling Sign?

The Spurling test is a provocative maneuver used to diagnose cervical radiculopathy by compressing the cervical nerve roots. The test involves:

1. Having the patient extend, laterally flex, and slightly rotate their neck toward the symptomatic side
2. Applying axial compression (downward pressure) on the top of the patient's head

A positive test reproduces the patient's radicular symptoms (pain, tingling, numbness) radiating from the neck into the shoulder and arm, often past the elbow.

Diagnostic Accuracy

• Sensitivity: Moderate to high (55-95%) depending on technique 1, 2, 3
• Specificity: Very high (86-98%) 2, 3

Research shows that the most effective variation of the Spurling test includes:

• Extension and lateral bending of the neck
• Addition of axial compression for maximum diagnostic value 1

This combination produces the highest pain scores and most distal radiation of symptoms, making it the most reliable for detecting cervical radiculopathy 1.

Clinical Significance

A positive Spurling sign indicates:

1. Nerve root compression or irritation in the cervical spine
2. Narrowing of the intervertebral foramen where nerve roots exit
3. High probability of cervical radiculopathy requiring further evaluation

The test is particularly valuable because of its high specificity - when positive, it strongly suggests cervical nerve root pathology, with a 95% sensitivity and 94% specificity according to correlation with imaging studies 2.

Management Algorithm for Positive Spurling Sign

Immediate Assessment:

1. Document pain characteristics:

   • Distribution (neck, shoulder, arm, hand)
   • Quality (sharp, burning, tingling)
   • Severity (using VAS scale)
   • Exacerbating and relieving factors

2. Perform additional neurological examination:

   • Motor strength testing of upper extremities
   • Sensory testing in dermatomes
   • Deep tendon reflexes
   • Shoulder abduction test (relief of symptoms with abduction suggests radiculopathy)

Diagnostic Workup:

1. Imaging:

   • MRI of cervical spine (preferred first-line imaging) 4
   • CT scan if MRI is contraindicated
   • Plain radiographs may be appropriate in some cases

2. Electrodiagnostic studies (if diagnosis remains uncertain):

   • EMG/NCS to confirm radiculopathy and identify specific nerve roots

Treatment Approach:

1. Conservative management (for mild to moderate symptoms):

   • Exercise therapy with or without other treatments 4
   • Activity modification
   • Physical therapy focusing on cervical spine
   • NSAIDs (limited evidence but commonly used) 4
   • Neuropathic pain medications (gabapentin, pregabalin) for persistent symptoms

2. Interventional procedures (for severe or persistent symptoms):

   • Epidural corticosteroid injections (preferably interlaminar approach) for acute/subacute pain 4
   • Pulsed radiofrequency adjacent to dorsal root ganglion for chronic pain 4

3. Surgical consultation for:

   • Progressive neurological deficits
   • Severe or persistent pain despite conservative treatment
   • Significant functional impairment
   • Imaging showing significant compression requiring decompression

Common Pitfalls and Caveats

1. False negatives can occur if:

   • The test is performed incorrectly (insufficient extension or rotation)
   • The pathology is at multiple levels
   • The symptoms are intermittent

2. False positives can occur in:

   • Shoulder pathology that mimics radicular symptoms
   • Myofascial pain syndromes
   • Thoracic outlet syndrome

3. Test variations matter:

   • Different variations of the Spurling test have different sensitivity levels
   • The most effective combination includes extension, lateral bending, and axial compression 1

4. Patient tolerance:

   • Some variations (especially those including rotation with compression) may be poorly tolerated 1
   • Start with gentler maneuvers and progress as tolerated

Conclusion

The Spurling test is a valuable clinical tool for diagnosing cervical radiculopathy with high specificity. When positive, it should prompt appropriate imaging (preferably MRI) and management based on symptom severity and duration. The test should be performed carefully, with attention to proper technique to maximize diagnostic accuracy.