Functional deficits in carpal tunnel syndrome.

BACKGROUND Carpal tunnel syndrome (CTS) is a major occupational illness in the US. The Wisconsin Test is a quantitative computer-controlled test battery designed for measuring sensory and psychomotor function. Subjects were recruited from industrial jobs at high-risk for CTS to determine if subtle sensory and motor deficits were observable in a working population. Outcomes were studied for potential use as an injury surveillance instrument. METHODS A total of 208 subjects participated (72 males and 136 females). Participants completed a symptom survey, were given a physical examination, administered nerve conduction tests, and were tested using the Wisconsin Test battery. RESULTS The greatest functional deficits were observed when nerve conduction findings were positive and were accompanied by either positive symptom survey outcomes or positive physical exam findings. The presence of symptoms alone were not significantly associated with motor deficits and no significant sensory threshold differences were observed among subjects categorized using any single criterion (i.e., nerve conduction, symptom reports, or examination). CONCLUSIONS Measurable and quantifiable sensory and psychomotor deficits were observed in a working industrial population, and were greatest when positive symptoms or physical exam was accompanied by positive nerve conduction test findings. These data show that clinical criteria used in the diagnosis of CTS corresponds with functional psychomotor and sensory impairments measured in these tests.