The interconnectedness of the motor and nociceptive systems in the conditions of operative correction of spinal deformity

BACKGROUND: The risk of complex neurological disorders after surgical correction of spinal deformity raises the question of the need for special measures for their postoperative treatment. This requires a more detailed study of the mechanisms of interaction between the motor sensory and autonomic structures of the nervous system. AIM: The aim of the study is to search for a simple and informative method of testing the level of balance of the states of the motor and nociceptive systems in patients with spinal deformity of various etiologies in the conditions of its surgical treatment. MATERIALS AND METHODS: A retrospective analysis of the results of electromiographic and esthesiometric examinations of 87 patients (30 male, 57 female) aged 15.6 ± 0.6 years with spinal deformities of various etiologies was carried out. RESULTS: The scatterograms of the paired values of the electromyogram amplitude at the maximum voluntary tension m. tibialis anterior and the heat pain perception thresholds are best approximated by a polynomial of the third degree. But the approximation is acceptable only for electromyographic patterns with an unsaturated structure in the preoperative period. The nonlinear nature of the coupling of the intensity of the electrical activity of the muscle with the heat pain perception threshold contains a significant linear component. After surgical correction of spinal deformity, the approximation quality is reduced to a state of random noise. The reason for this is: postoperative increase in nociceptive activity and the consequences of anesthetic support. CONCLUSIONS: In patients with spinal deformity, there is a correlation between the levels of voluntary muscle activity and the settings of the nociceptive system, expressed in the values of the heat pain thresholds. The nature of the coupling is expressed in the inverse relationship between the pain threshold and the amplitude of the electromyogram at maximum arbitrary voltage. This type of dependence is quite consistent with well-known physiological phenomena. The maximum severity of this interconnectedness for unsaturated patterns of the electromyogram indicates that the condition for its manifestation is a specific regime of stem centers that regulate the posture-tonic activity of muscles in patients with axial skeleton disorders.