The sensory interaction in mechanism of acupuncture in treatment of trigger phenomenes

George Ivanichev, Elena Bashirova
Kazan Medical Academy, 42001 5, Pushkin St.56, Kazan, Russia

Purpose is the study of interaction of somatosensory evoked potentials ( SEPs ) in the treatment of algesic myofascial syndroms by acupuncture.

Methods. 18 patients with myofascial algesic syndrome (MAS) of m.brachioradialis were investigated. MAS was characterised by palpable taut band in proximal part of m.brachioradialis and trigger pain in elbow joint. The neurophysiological complex ”Key-point” /Denmark/ was used. SEPs were reggisted using standard method of stimulation n.medianus in the region of wrist. At first the stimulation was performed on the side of algesic syndrome and on the contralateral side before and after the acupuncture in 4GI points and in zone of trigger phenomena /local point/.

Results. SEPs in exacerbation were characterised by asymmetrical responses during stimulation of “health” and invaded sides. For the most part the amplitude of early components of SEP was higher during the stimulation on the side of algesic syndrome. The differences between SEPs of the “health” and invaded sides were determined in amplitude of N20, P27 components. The increase of latencies of SEPs in Erb point and in C7 level took place after the acupuncture procedure by reducing method. The increase of SEP’s amplitude in spinal projections and a strongly marked decrease of amplitude in Erb’s point were revealed.

Conclusions. The change of amplitude and latencies of SEP’s components before treatment may be considered as hyperexcitability and hypersynchronization in activity of neurons responsive to somatosensory stimuls. Normalization of this data is consequence of afferent interaction on different levels of central nervous system, first of all in unspecific systems of brain stem.