Quantitative sensory thresholds in carpal tunnel syndrome.

Thresholds for vibration and temperature sensation were quantitated at the second and fifth digits of 23 patients (28 hands) with symptomatic, electromyographically confirmed, carpal tunnel syndrome. Thresholds were determined in 23 age-matched controls. Abnormal sensory threshold data confined to the second digit, apparently related to carpal tunnel syndrome, was found in only 3 (11%) of 28 symptomatic hands. There was no apparent relationship between sensory thresholds and the degree of median nerve abnormality as determined by electromyographic nerve conduction studies. Focal demyelination with minimal axonal loss as is seen in mild or moderate carpal tunnel syndrome appears to be more readily detected by electromyographic nerve conduction studies than by quantitative sensory testing.