[Subclinical sensory-motor deficit after surgical correction of the spinal deformity]. / Subklinicheskii sensomotornyi defitsit posle khirurgicheskoi korrektsii deformatsii pozvonochnika.

AIM: A quantitative evaluation of the relationship between the level of postoperative motor deficit and the intensity of reaction of pyramidal tract to the correction of spinal deformity. MATERIAL AND METHODS: The correction of spinal deformities of different etiology was performed under neurophysiological control for 87 patients (30 men, 57 women), aged 15.6±0.6 years. Reaction intensity of pyramidal tract was evaluated using the scale developed by the authors. RESULTS: The relationship between the intensity of intraoperative reaction of somatic motor system and EMG-signs of postoperative subclinical motor deficit in temperature-and-pain sensitivity disorders was shown. CONCLUSION: EMG evaluation of the level of intensity of subclinical motor deficit in combination with changes in temperature-and-pain sensitivity after the spinal deformity correction complies the reaction intensity of somatic motor system to surgical aggression. Neurologists should pay more attention to the patients with V type reaction not only during postoperative period, but before the next stage of surgery.

[Quantitative characterization of risk of iatrogenic damage to pyramidal tracts based on data of intraoperative neuromonitoring during surgical correction of spinal deformities]. / Kolichestvennaia kharakteristika riska iatrogennykh povrezhdenii piramidnykh putei po dannym intraoperatsionnogo neiromonitoringa pri khirurgicheskoi korrektsii deformatsii pozvonochnika.

OBJECTIVE: Development of a quantitative indicator for the risk level of intraoperative iatrogenic motor disorders in the process of surgical correction of spinal deformity based on current neurophysiological monitoring data. MATERIAL AND METHODS: 288 patients 12.6±0.35 y.o. underwent surgical correction of spinal deformities under the control of intraoperative neuromonitoring. The nature of changes in motor evoked potentials was assessed according to the earlier proposed ranking scale. The incidence of different variants of changes in the rank values of the state of the pyramidal system during the operation and the resulting postoperative motor disturbances was calculated. RESULTS: By comparing probabilities of various changes in the conduction properties of pyramidal tracts during surgery with the incidence of the observed motor deficiencies we quantitatively assessed the possible correlation between these phenomena. We propose a method for calculating the risk index for postoperative motor disorders depending on the maximum rank of the pyramidal system's response to surgical aggression. CONCLUSION: The developed system of ranking evaluation of changes in motor evoked potentials during surgical correction of spinal deformity makes it possible to quantify the risk of postoperative motor disorders and, accordingly, to monitor the level of anxiety for a neurosurgeon during individual stages of surgical intervention.

Morphofunctional Changes in the Tibial and Peroneal Nerves in Shin Lengthening Using High Speed Daily Distraction Technique.

A sustained decrease in the M-response amplitudes of m. gastrocnemius and m. tibialis anterior was revealed during experimental orthopedic shin lengthening in dogs using Ilizarov external fixator with an automated drive (distraction 3 mm/day in 120 steps). Transverse contraction of intrafascicular content (by 13.2%), endoneural hypervascularization (by 28-95%), axonal degeneration and myelin decompactization, and destructive changes of no more than 5% fibers were detected in the tibial nerve. In the peroneal nerve, the contraction reached 17.3%. Endoneurium hypovascularization (by 12%), axonal degeneration and demyelinization, and destructive changes of more than 20% fibers were detected in 6 of 9 experiments.

Muscle spindles in elongation of the extremity: proprioceptive conflict or activity deficit?

Comparison of electrophysiological and morphological parameters of shin muscles of experimental animals during shin elongation by Ilizarov's method indicates involvement of muscle spindles into reconstruction of the skeletal muscular tissue in response to its dosed distraction, which results in temporary deficit of specific somatosensory afferentation.

[Functional state of lower extremities muscles at the patients with shin congenital defects before and after treatment with Ilizarov device].

Results of examination (dynamometry, electromyography, ultrasonography) of 34 patients aged 6 to 23 years before and after treatment with Ilizarov's method are analyzed. Decrease of dynamometry and electromyography parameters, ultrasonic data are evidence of hard structural and functional disorders of motor system of these patients. Decrease of force and activation characteristics of tested muscles of operated extremity after removal of external fixator relates to high level of central protective inhibition and prolonged afferentation dysbalance at somatosensory system. Degree of recovery is limited and depends on patient age: recovery resources are presented at children before 8 years, but at juveniles they are depleted during the growth.