The value of the history in the diagnosis of carpal tunnel syndrome.

Details of the clinical history were elicited by questionnaire from 8,223 patients with suspected carpal tunnel syndrome and compared with the neurophysiological findings. Distribution of symptoms to the radial part of the hand and nocturnal exacerbation of symptoms showed the strongest individual correlations with positive nerve conduction studies. The regression model derived from the complete questionnaire achieved an overall sensitivity of 79% and specificity of 55% for the diagnosis of carpal tunnel syndrome when compared with the nerve conduction study results as a gold standard. A simple regression model for evaluating the history compares favourably with widely used clinical signs in its ability to predict the findings of nerve conduction studies.