Nerve Conduction Studies in the Upper Limb in the Malwa Region-Normative Data

Abstract

ABSTRACT Objective: To establish the normal electrophysiological data for the median and the ulnar nerves in normal healthy adults in the Malwa region of Punjab, India. Methods: Nerve conduction studies were performed prospectively in the upper limbs of 100 carefully screened, healthy individuals of either sex, who were between the ages of 20 and 60 years, by using a standardized technique. Results: Motor studies: The median distal latency (DL) in men was 3.4 (0.2) ms, the amplitude (CMAPA) was 10.80 (2.8) mV, the conduction velocity (MNCV) was 55.6 (2.5) m/s and the F-wave (min latency) was 27.57±2.54(21.5-34.2). In the ulnar nerve , the motor DL was 2.34 (0.25) ms, the amplitude (CMAPA) was 9.8(2.6) mV, MNCV was 63.4 (3.0) m/s and the F-Wave(min latency) was 26.29±2.12(21.6-34.7). In the sensory studies, the median nerve DL was 2.0(0.35) ms, SNCV was 53.4±3.0 m/s and the amplitude (SNAPA)was 59.3 (16.4) µV for men and it was 68.7(28.4) µV for women. For the ulnar nerve in men, the DL was 1.85(0.25)ms, SNCV was 55.5 (4.1) m/s and the amplitude(SNAPA) was 55.5 (18.4) µV for men and it was 64.9 (16.8) µV for women. Only the gender showed a statistically significant effect on the sensory nerve action potential for the median (p < 0.04) and the ulnar nerves (p < 0.041) . Conclusion: The normative conduction parameters of the commonly tested nerves in the upper limb were established in our EMG lab. The mean motor nerve conduction parameters for the median and the ulnar nerves correlated favourably with the existing literature data. However, for the sensory nerves, a higher value for the nerve action potential amplitude was demonstrated in this study.

Keywords

• nerve conduction study (ncs)
• compound muscle action potential amplitude (cmapa)
• sensory nerve action potential (snapa) median nerve
• ulnar nerve