Ultrasonographic Assessment of Median Nerve in Carpal Tunnel Syndrome in Comparison with Nerve Conduction Studies

Background: Carpal Tunnel Syndrome (CTS) is a common peripheral neuropathy often affecting the dominant hand and interfering with daily activities. While nerve conduction studies (NCS) remain the diagnostic standard, high-frequency ultrasound (USG) and color Doppler are increasingly used for detecting early structural changes. This study evaluated the diagnostic utility of these sonographic methods in comparison to NCS. Material and Methods: This cross-sectional study was conducted at a tertiary care hospital in central India over one year. A total of 110 clinically suspected CTS patients were included after screening for eligibility. Median nerve assessment was performed using a high-frequency linear probe (7–13 MHz). Sonographic parameters including cross-sectional area (CSA), flattening ratio, palmar bowing of flexor retinaculum, and intraneural vascularity were measured and correlated with NCS grading. Results: Of 110 patients, 92 demonstrated intraneural vascularity. CSA was significantly higher in vascularity-positive patients. ROC analysis identified CSA as the most accurate parameter (AUC 0.80), followed by flattening ratio and palmar bowing. CSA values progressively increased with advancing NCS grades. Doppler vascularity showed 85% sensitivity and an overall diagnostic accuracy of 84.5%. Conclusion: High-frequency ultrasound, particularly CSA measurement, correlates well with NCS severity and serves as a reliable, non-invasive diagnostic tool. Doppler vascularity adds supplementary diagnostic value when combined with structural parameters.

Keywords: Carpal Tunnel Syndrome, Median Nerve, High-Frequency Ultrasound, Color Doppler, Nerve Conduction Studies, Cross-Sectional Area.