Electroacupuncture and laser stimulation treatment: evaluated by somatosensory evoked potential in conscious rabbits

Tooth pulp generated somatosensory evoked potential (TPSEP) recordings were used to evaluate analgesic responses to Electroacupuncture (EA) and laser stimulation (Ls) treatments in Dutch-hybrid male rabbits. TPSEP recorded 100 trials at 30 minute intervals for 120 minutes. Three groups, EA, Ls and control were analyzed. The EA group received intermittent 4 Hz, intensity 2-10 volts electro-stimulation for twenty minutes. In the Ls group, a gallium aluminium arsenide (GaAlAs) laser diode with wavelength 780 nm, switched pulse frequency 9720 Hz, energy density 0.6 J/point was employed. Both EA and Ls groups received stimulation of the points Ho-ku (LI-4) and Tzu-San-Li (ST-36). Results showed tooth pulp generated noxious stimulation produced a consistent late near-field SEP waveform, which is similar to those recorded in humans and correlated to the sensation of pains, thus confirming that tooth pulp stimulation is a reliable dolormetric index. EA and Ls TPSEP recordings showed decreased peak-wave amplitude in late near-field components. These decreases correlate to analgesia. This technique provides an objective and reliable dolormetric index.