The rational clinical examination. Does this patient have carpal tunnel syndrome?

CONTEXT: History taking and physical examination maneuvers, including Tinel and Phalen signs, are widely used for the diagnosis of carpal tunnel syndrome (CTS).

OBJECTIVE: To systematically review the precision and accuracy of history taking and physical examination in diagnosing CTS in adults.

DATA SOURCES: English-language literature was searched using MEDLINE (January 1966-February 2000) as well as bibliographies of relevant articles.

STUDY SELECTION: Studies of patients presenting to clinicians with symptoms suggestive of CTS in which findings from clearly described physical examination maneuvers were independently compared with electrodiagnostic testing. Twelve of 42 initially identified articles met these criteria and were included in the review.

DATA EXTRACTION: Two authors independently reviewed and abstracted data from all of the articles and reached consensus about any discrepancies.

DATA SYNTHESIS: In patients presenting with hand dysesthesias, the findings that best distinguish between patients with electrodiagnostic evidence of CTS and patients without it are hypalgesia in the median nerve territory (likelihood ratio [LR], 3. 1; 95% confidence interval [CI], 2.0-5.1), classic or probable Katz hand diagram results (LR, 2.4; 95% CI, 1.6-3.5), and weak thumb abduction strength (LR, 1.8; 95% CI, 1.4-2.3). Findings that argue against the diagnosis of carpal tunnel syndrome are unlikely Katz hand diagram results (LR, 0.2; 95% CI, 0.0-0.7) and normal thumb abduction strength (LR, 0.5; 95% CI, 0.4-0.7). Several traditional findings of CTS have little or no diagnostic value, including nocturnal paresthesias; Phalen and Tinel signs; thenar atrophy; and 2-point, vibratory, and monofilament sensory testing. Other less commonly used maneuvers, including the square wrist sign, flick sign, and closed fist sign, require validation by other studies before they can be recommended.

CONCLUSIONS: Hand symptom diagrams, hypalgesia, and thumb abduction strength testing are helpful in establishing the [corrected] electrodiagnosis of CTS. The utility of these results is limited, however, by problems inherent in using nerve conduction studies as a criterion standard. JAMA. 2000.