Objectives. Studies of interaction of somatosensory evoked potentials (SEPs) in the treatment of algesic myofascial syndroms by acupuncture.
Methods. 30 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 registered using standard method of stimulation n. medianus in the region of wrist on the side of algesic syndrome and on the contralateral side before and after the acupuncture in 4 GI point and in zone of trigger phenomena (local points).
Results. SEPs in exacerbation were characterised by assymetrical responses during stimulation of "health" and affected sides. For the most part the amplitude of early components of SEPs was higher during the stimulation on the side of algesic syndrome. The differences in cortex components (N20 and P27) between SEPs of the "health" and affected sides were not determined. On the side of the MAS the increase of the amplitude of the SEPs in C7 level and N 13 of two phases were registered. After acupuncture treatment by reducing method the increase of latencies of SEPs in Erb point and in C7 level (N9 and N13) with simultaneosly decrease of the amplitude of the both SEPs were revealed.
Conclusions. The increase 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.