Correlation of clinical grading, physical tests and nerve conduction study in carpal tunnel syndrome.

Background and aims Carpal tunnel syndrome (CTS) is a common debilitating condition. As the reliability of CTS-specific physical tests and its clinical grading remain a matter of debate, we determined the correlations between these assessments with nerve conduction study (NCS). Methods In this cross-sectional study, patients with uni or bilateral CTS, which was confirmed in electrodiagnosis, were enrolled. Clinical grading was based on the modified criteria of the Italian CTS Study Group. Numeric Pain Rating Scale (NPRS) and Boston Questionnaire (BQ) were used. Physical tests [Phalen's, reverse Phalen's, Tinel's and manual carpal compression test (mCCT)] were performed by a single blinded neurologist. A p-value<0.05 was considered statistically significant. Results A total of 100 patients (age=47.48±11.44 years; 85% female) with 181 involved hands were studied. The majority of hands (59.7%) were classified as grade 2 of clinical grading. On NCS, hands with mild (64%), moderate (27%) and severe (9%) CTS were identified. Sensory (velocity, latency and amplitude) and motor parameters (latency and amplitude) were significantly correlated with clinical grades (p-value<0.001). The correlation of NPRS (p-value=0.009) and BQ (p-value<0.001) scores with NCS was significant. None of the physical tests were significantly correlated with NCS in terms of result or duration (p-value>0.05). Conclusions We found that physical tests are not a reliable screening method for evaluation of CTS severity. However, the BQ and clinical grading can be more valuable due to their significant correlation with NCS. Implications Physicians might benefit from employing clinical grading and BQ in practice for better assessment of CTS severity.