980 nm diode laser application in electroneurophysiology:: a LEP study

The aim of the present study was to test the feasibility of the 980 nm diode laser for LEP (Laser Evoked Potentials) studies. Human subjects were exposed to laser stimulation. After the pain tresholds of the subjects were determined with respect to laser power level, 1.5 times the threshold value was applied and laser evoked potentials were recorded using standard EEG techniques. LEPs were obtained due to right hand stimulation. Latency and amplitude values of LEPs were found in accordance with those reported in the literature. Statistical evaluation showed differences in the LEPs at C3 and C4 locations as a function of the sex of the subjects. The power levels used in the present study was three times less than the levels applied for Nd:YAG laser in the literature. The evoked potential parameters measured were in consistence with the data reported by earlier researchers. Moreover, it was found that, LEPs due to 980 nm wavelength irradiation can be recorded by applying less energy when compared to Nd:YAG laser. This result indicates the potential of diode laser for LEP studies.