Relationship of age and sex to sensory conduction of the median nerve at the carpal tunnel and association of slowed conduction with symptoms.

A cross-sectional study of 471 randomly selected employees from 4 industries was performed to assess the prevalence of slowing of sensory conduction of the median nerve at the carpal tunnel as well as the effect of age and sex on slowing. The association between slowed conduction and symptoms of carpal tunnel syndrome (CTS) was also evaluated. Slowing was identified in 17% of the subjects and in 11% of the hands. The prevalence and the severity of slowing increased with increasing age of the subjects. Slowed conduction occurred more often among the women in the study, but this was shown to be an effect of age and not of sex. Slowing occurred six times more often in hands with symptoms of CTS than in those not reporting symptoms.