Introduction: Carpal tunnel syndrome (CTS), a common peripheral entrapment neuropathys due to impairment of median nerve function. Diagnosis of CTS is based on clinical signs and symptoms and confirmed by electrodiagnostic studies. Ultrasound imaging is noninvasive, offers high temporal and spatial resolutions and can provide dynamic anatomical information regarding structure and kinetics.

Aims and Objectives: 1.To find the validity of using ultrasonography before and after provocative exercises for diagnosed CTS patients with nerve conduction studies. 2. To find out the cut off values of median nerve cross sectional area in our population in diagnosis of CTS and to compare it with NCS using a Receiver Operating Characteristic (ROC) curve.

Methodology: This is a study of diagnostic test tool evaluation. 29 patients diagnosed as CTS with nerve conduction studies, were taken for ultrasound before and after exercise and studied the cross sectional area of median nerve at wrist and tabulated.

Results: the cut off values of median nerve area in diagnosis of moderate and severe CTS is calculated. Predictive power of median nerve cross sectional area also is calculated.

Conclusion:  As per the present study, the mean value of cross sectional area is 0.108 (pre exercise) and 0.125 ( post exercise) is diagnostic.

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Dr Mangalanandan

Associate Professor, Department of Radiodiagnosis, Pushpagiri Medical College, Thiruvalla, Kerala, India