What is the clinical significance of a positive Spurling's test?

Clinical Significance of a Positive Spurling's Test

A positive Spurling's test is highly specific (92-95%) for cervical radiculopathy and should be used to confirm the diagnosis when clinical suspicion exists, but its low sensitivity (30-70%) means a negative test does not rule out nerve root pathology.

Diagnostic Performance

The Spurling's test demonstrates asymmetric diagnostic characteristics that dictate its clinical utility:

High Specificity (Confirmation Tool)

• Specificity ranges from 84-95% across multiple studies 1, 2, 3, 4
• When positive, the test has a positive predictive value of 96.4% for soft lateral cervical disc prolapse 4
• The positive likelihood ratio is 3.28, meaning a positive test substantially increases the probability of cervical radiculopathy 5

Low to Moderate Sensitivity (Poor Screening Tool)

• Sensitivity varies widely from 30% to 95% depending on study methodology 1, 2, 3, 4
• The most recent meta-analysis reports pooled sensitivity of only 53% 5
• Sensitivity improves to 67% when neck rotation or extension is added to the maneuver 5
• Negative likelihood ratio of 0.28 means a negative test only modestly reduces probability of disease 5

Clinical Application Algorithm

When Spurling's Test is Positive:

1. High probability of nerve root compression - proceed with imaging studies (MRI or CT) 1
2. Particularly predictive of soft lateral disc herniation rather than hard osteophytic disease 4
3. Confirms clinical suspicion when combined with dermatomal pain, sensory changes, or motor weakness 3

When Spurling's Test is Negative:

1. Cannot exclude cervical radiculopathy - clinical suspicion should guide further workup 2, 5
2. Consider alternative provocative tests like Upper Limb Neurodynamic Test (ULNT) which has higher sensitivity (97%) but lower specificity 6
3. If symptoms strongly suggest radiculopathy, proceed with imaging regardless of negative test 1

Key Clinical Pitfalls

The test's low sensitivity is its major limitation - only 30-53% of patients with confirmed cervical radiculopathy will test positive 2, 5. This means:

• Do not use as a screening tool in low-probability patients
• Do not rely on it to rule out disease - its value lies in ruling in pathology when positive
• The test performs better with imaging as reference standard (sensitivity 67%) compared to electrodiagnostic testing (sensitivity 31%) 5

Evidence Quality Considerations

The 2025 meta-analysis 5 represents the highest quality synthesis, though it notes the test is "better suited for confirmation than screening." Earlier studies showed conflicting sensitivity results: Thoomes et al. (2002) reported only 30% sensitivity 2, while Shabat et al. (2012) reported 95% sensitivity 1. This discrepancy likely reflects different reference standards and patient populations.

The most clinically useful interpretation: A positive Spurling's test in a patient with arm pain radiating in a dermatomal pattern strongly indicates nerve root pathology requiring imaging workup, but negative results should not deter further investigation when clinical suspicion remains high.