Carpal tunnel syndrome: correlation of the severity of the clinical picture and electrophysiological studies

Purpose: This study aimed to correlate the severity of carpal tunnel syndrome (CTS) in terms of the clinical picture with electrophysiological studies to determine whether the severity could be predicted through one measure based on correlations with another.Methods: This cross-sectional correlational study enrolled 96 patients (139 hands) whose nerve conduction studies (NCS) confirmed the diagnosis of CTS, and to whom the Boston Carpal Tunnel Questionnaire (BCTQ) was administered to determine the subjective and clinical CTS severity. The severity of both measures was correlated. Results: The patients’ mean age was 49.84±12.23 years. Most (67.7%) were female. The NCS severity grades were as follows: mild, 46%; moderate, 32.4; severe, 9.4%; and very severe, 12.2%. The sensory and motor NCS parameters were significantly correlated with the BCTQ severity. The patients’ overall mean scores for symptom severity had substantive predictive accuracy for the patients’ CTS severity measured with the NCS. Similarly, most of the functional severity score items had significant predictive accuracy for the patients’ NCS-based carpal tunnel severity score.Conclusion: The clinical severity of CTS was strongly correlated with the severity based on nerve conduction. This correlation was more notable for symptom severity scores than for functional status scores. Night pain and numbness demonstrated the strongest associations of all BCTQ items with the NCS. Although clinical severity (based on the BCTQ) predicts the nerve conduction severity, we still recommend performing NCS for patients with a clinical diagnosis of CTS as a confirmatory objective measure and for medico-legal reasons.