Aim. To correlate electroneuromyigraphic (ENMG) manifestations of post-operative motor deficit developed in patients after spinal deformity correction with qualitative evaluation of the severity of intra-operative pyramidal disorders according to protocol of intra-operative neuromonitoring (IONM). Material and methods. ENMG data of 87 patients aged 6—43 years with spinal deformities of different etiology were analyzed before and after surgical correction and were correlated with intra-operative neuromonitoring course. Results. We have identified five types of the intraoperative reaction of pyramidal system to surgical aggression. Severity of postoperative motor deficit was the most pronounced after the fifth type of reaction according to electromyography (complete prolonged oppression of motor evoked potentials). Conclusion. We suggested the scale of intra-operative pyramidal disorders severity that is satisfactorily correlated with functional surgical outcomes which are reflected in the dynamics of particular and integral characteristics of voluntary and evoked bioelectrical activity of the lower limb muscles. This fact makes possible to use safely the above-mentioned protocol for IONM, to predict postoperative motor disorders and to formulate reasonably the recommendations for postoperative management.