[Immunochemical and electromyographic indicators for assessment of pain status in myofascial back pain syndrome].

Objective: A complex examination of patients with chronic myofascial pain syndrome (MPS).

Material And Methods: This study included 136 patients with MPS (66 men and 70 women). Pain was assessed using a Visual Analogue Scale (VAS). Investigation of profiles of natural antibodies (nAbs) to specific opioid peptides (β-endorphin and orphanin), biogenic amines (dopamine and serotonin), surface electromyography (SEMG) of m. errector spinae at the L3-L4 level bilaterally were performed. Measurements were done at 1st, 10th and 21st days of treatment.

Results: There was a significant decrease in pain intensity (by 71% in men and by 63% in women) accompanied by a decrease in muscle tension by 10-25% in group values of SEMG amplitudes, and by 34-38% as assessed by individual dynamics of SEMG amplitudes. All nAbs levels were elevated or high in the 1st day. The dynamics of nAbs levels was multidirectional. At the 21st day, there was the increase in the incidence of patients with high nAbs levels to opioid peptides (39-41% women and 33-39% men) and patients with normal nAbs levels to serotonin (59% men and 52% women), while the levels of nAbs to dopamine decreased to normal levels in women (56%) and remained elevated (50%) or highly elevated (17%) in men.

Conclusion: The dynamics of immune indicators correlates with pain intensity that possibly reflects the pathological changes in neural/humoral interactions in chronic pain. In this regard, monitoring of nAbs levels is prognostically relevant for assessment of risk of pain chronification.