Effect of Prolonged Use of Mobile Phone on Brainstem Auditory Evoked Potentials.

OBJECTIVES: Mobile phones are being widely used throughout the world. Electromagnetic waves generated from mobile phones have raised concerns as these may have adverse effects on human auditory system owing to the daily use of mobile phones. The purpose of current study was to evaluate the effects of long term mobile phone usage on auditory brainstem evoked responses (ABR). MATERIALS AND METHODS: A retrospective, cross-sectional, case control study was carried out in a tertiary care hospital. Total 100 healthy subjects aged 18 to 30 years of both the genders were selected, out of which 67 subjects were long-term GSM mobile phone users (using mobile phone for more than 1 year) and 33 were controls who were mobile phone non users. Both the groups were investigated for ABR and changes were studied in both the ears of cases and controls to ascertain the effects of electromagnetic exposure. RESULTS: No significant difference (p>0.05) was found in latencies, interpeak latencies and amplitudes of ABR waves between cases and controls. CONCLUSION: Our study shows that long term usage of mobile phones does not affect propagation of electrical stimuli along the auditory nerve to auditory brainstem centres.

Nerve conduction studies in the upper limb in the malwa region-normative data.

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.