The Kamath & Stothard six-item weighted score for estimating the probability of carpal tunnel syndrome. Intended for GP consultation support - not patient self-assessment. Nerve conduction studies remain the gold standard for confirmation.
Clinical context. Score each item for the hand being assessed. Two items are history; four are examination findings. A score >12 carries ~80% probability of CTS on NCS; a score ≤5 makes CTS unlikely. For bilateral symptoms, score each hand separately.
Context
History
Nocturnal numbness Hx
Numbness or tingling at night; wakes the patient or present on waking. Classic "shaking out the hand" pattern.
4.0 pts
Numbness in median nerve distribution Hx
Symptoms primarily in thumb, index, middle, and radial ring finger (volar surface). Symptoms outside this distribution reduce likelihood.
3.5 pts
Examination
Thenar muscle weakness or atrophy Exam
Abductor pollicis brevis strength ≤4/5 on MRC scale, or visible wasting of the thenar eminence. Late finding - indicates significant nerve compromise.
5.0 pts
Positive Phalen test Exam
Wrist held in full flexion for 60 seconds reproduces numbness or tingling in the median nerve distribution. Sensitivity ~68-80%, specificity ~59-73%.
5.0 pts
Positive Tinel sign Exam
Percussion over the carpal tunnel at the wrist reproduces tingling in the median nerve distribution. Sensitivity ~50-58%, specificity ~67-77%.
4.0 pts
Loss of 2-point discrimination Exam
Static 2PD >5 mm on the volar pulp of index or middle finger (median nerve territory). Indicates significant sensory nerve fibre loss; least reliable item inter-rater.
4.5 pts
References - Kamath V & Stothard J. A clinical questionnaire for the diagnosis of carpal tunnel syndrome. J Hand Surg Br. 2003;28(5):455-9. · Atroshi I et al. Diagnostic properties of nerve conduction tests in population-based carpal tunnel syndrome. BMC Musculoskelet Disord. 2003;4:9. · Graham B et al. Validity and responsiveness of the CTS-6. J Hand Surg Am. 2006. · Meems M et al. Sensitivity, specificity, and reliability of CTS-6 administered by medical assistants. Am J Surg. 2024.
For GP consultation support only · Not for patient self-assessment · Clinical findings must be interpreted in context
CTS-6 Score
0
/ 26.0 points
No items selected
Tick positive findings above to generate a probability estimate.
0 of 6 items positive
Score interpretation
≤ 5
CTS unlikely. NCS probably not required for diagnosis.
6-12
Equivocal. ~25% probability. NCS may be useful.
> 12
Likely CTS. ~80% probability. Consider treatment or pre-surgical NCS.
Complementary tools
Katz Hand DiagramClassic / Probable / Possible / Unlikely classification. Highest accuracy of all clinical instruments when correctly categorised.
BCTQ / Boston CTS-Q11-item symptom severity scale + 8-item functional scale. Better suited to monitoring treatment response than diagnosis.