Laser-induced somatosensory evoked potentials: evidence of photosensitivity in peripheral nerves.
Irradiation of the skin overlying the median nerve at the wrist in humans with a low power (1 mW; 632.5 nm) helium-neon laser produced a somatosensory evoked potential obtained at Erb's point. This evoked potential had a latency equal to that observed after electrical stimulation of the same nerve. Prolonged exposure to laser (20 min, 3.1 Hz) resulted in a large (10-90%) decrease in the amplitude of the electrical evoked potential. Since this laser produces no detectable thermal change, the results imply that photochemical reactions alter neuronal activity.
D000328:Adult; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory; D006801:Humans; D007834:Lasers; D008475:Median Nerve / Q000502:physiology; D009424:Nervous System Physiological Phenomena; D010777:Photochemistry; D011930:Reaction Time / Q000502:physiology; D012867:Skin / Q000294:innervation / Q000528:radiation effects*