Electrophysiological evaluation of 140 hands with carpal tunnel syndrome.

AIM To study various electrophysiological parameters in clinically suspected carpal tunnel syndrome (CTS). MATERIAL AND METHODS Electrophysiological (EPS) evaluation of 70 patients (140 hands) of clinically suspected CTS was done as per AAEM recommendation. EPS grading was done as described by Padua, et al. RESULTS The mean age was 44.21 +/- 10.29 (range 24-66) years with female predominance (M:F 3:11). Sixty four (91.4%) patients had bilateral involvement. The mean EPS grade was 3.18 +/- 1.41. One hundred and six (75.5%) hands had moderate to severe (EPS grade 1-3) CTS. Median distal motor latency (DML) (mean 4.76 +/- 1.4 msec) was prolonged in 92 (65.71%) hands and was not recordable in seven (5%) hands. Median sensory distal latency (SDL) (mean 3.54 +/- 0.82 msec) was prolonged in 38 (27.1%) hands and not recordable in 49 (35%) hands. Sensory median mid-palm latency (MPL) (2.42 +/- 0.56 msec) was commonest EPS abnormality present in 128 (91.4%) hands. EMG was abnormal in 75% hands. CONCLUSION This study suggests incorporation of median sensory midpalm latency as a screening test for electrophysiological diagnosis of CTS. In addition, bilateral studies are recommended as there is bilateral involvement in 64 patients.