Drs Martin and Ensalada provide insight to the use of electrodiagnostic studies in diagnosing carpal tunnel syndrome (CTS). In a recent review D’Arcy and McGee found that in patients presenting with hand dysestheias the findings that best distinguish between patients with electrodiagnostic evidence of CTS and patients without it are hypalgesia in the median nerve territory, classic or probable Katz hand diagram results, and weak thumb abduction strength.
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.1
Electrodiagnosis is the diagnostic test of choice, although studies have reported sensitivities ranging from 49% to 84% and specificities of 95% to 97%.2 The evaluating physician must be thoughtful both in the diagnosis and in the rating of entrapment disorders.
