THE EFFECT OF ACUPUNCTURE STIMULATION ON THE MIDDLE LATENCY AUDITORY-EVOKED POTENTIAL

The effects of acupuncture stimulation (AS) on the middle latency auditory evoked potentials (MLAEPs) were studied in 19 normal male volunteers. Scalp recordings mere made from 21 points (including Cz) and posterior auricular muscle (PAM) electrodes referenced to the linked mastoid. Four components of MLAEPs (Po, Na, Pa and Nb) and two components of PAM reflex (N-12 and P-17) were statistically analyzed for changes in latency and amplitude. Wave phase of Po and Na reversed to N-12 and P-17, respectively, and the peak-to-peak amplitude of Po-Na, Na-Pa, Pa-Nb and N-12-P,7 showed a marked increase during AS to the ipsilateral side whereas no change in latency mss detected. Each component's isovoltage topographic maps and dipole locations were calculated to be near both PAM (Po and Na) and temporal positions (Pa and Nb) during AS. These data showed that AS can promote MLAEPs activity and these signals (Po and Na) may originate from increased activity in N-12 and P-17 of the PAM refIex, respectively, and that the auditory cortex of the temporal gyrus is the generator substrate of Pa and Nb.