Brainstem auditory evoked response changes following electro‐acupuncture therapy in chronic pain patients

Abstract

Brainstem auditory evoked responses were recorded in 17 patients with chronic pain who had been given electro‐acupuncture therapy. The absolute peak latencies of waves I to V, and interpeak latencies and amplitudes of waves I and V were analysed before electro‐acupuncture and compared with values obtained during electro‐acupuncture and 5 min after its termination after one, five and 10 sittings. At these sittings the intensity of pain was recorded with the help of a 100 mm visual analogue scale. Each patient had 10 sittings given on alternate days. The absolute peak latencies of waves I, II, and III were delayed significantly (p < 0.05) after 5 and 10 sittings and amplitudes of wave V decreased significantly (p < 0.05) after 5 and 10 sittings. Visual analogue scores also decreased significantly (p < 0.01) during these sittings. It was established that before and after 10 sittings of electro‐acupuncture, there was a significant positive correlation between visual analogue scores and the amplitude of wave V (p < 0.01). There was a negative correlation between visual analogue scores and absolute peak latencies of wave III at 1, 5 and 10 sittings, suggesting that there is a definite interaction between the electro‐acupuncture neural mechanism and the generators of brainstem auditory evoked responses in the lower brainstem. Copyright © 1994, Wiley Blackwell. All rights reserved