Objective: In this study, we evaluated the role of residual supraspinal and afferent signaling and their convergence on the sublesional spinal network in subject diagnosed with complete paralysis (AIS-A). Methods: A combination of electrophysiologic techniques with positional changes and subject-driven reinforcement maneuvers was implemented in this study. Electrical stimulation was applied transcutaneously at the T9-L2 vertebra levels and the spinal cord motor evoked potentials (SEMP) were recorded from leg muscles. To test the influence of positional changes, the subject was placed in (i) supine, (ii) upright with partial body weight bearing and (iii) vertically suspended without body weight bearing positions. Results: Increase in amplitude of SEMP was observed during transition from supine to upright position, supporting the role of sensory input in lumbosacral network excitability. Additionally, amplitudes of SEMP were facilitated during reinforcement maneuvers, indicating a supralesional influence on sub-lesional network. After initial assessment, subject underwent rehabilitation therapy with following electrophysiological testing that reviled facilitation of SEMP. Conclusion: These results demonstrate that combination of electrophysiological techniques with positional and reinforcement maneuvers can add to the diagnostics of discomplete SCI. These findings also support an idea that integration of supraspinal and afferent information on sub-lesional circuitry plays a critical role in facilitation of spinal sensorimotor network in discomplete SCI.

Background/Objectives: Traumatic spinal cord (SC) injury (SCI) is a debilitating neurological condition. Minimally invasive approaches to monitor in real time the functional state of the neuromotor apparatus in animal models of SCI (at rest and movement) to assess effectiveness of therapy are needed in preclinical studies. We aimed to develop such a bioethically acceptable platform for SCI studies on non-human primates (Rhesus macaques). Methods: Epidural and myographic electrode implantation (EI) (wireless and wired, connected via a head plug) was performed. After EI, motor responses caused by electrical stimulation of the SC at the level of the cervical and lumbar thickening were recorded; electromyography of the limb muscles was recorded during quadrupedal movement of the animal on a treadmill with simultaneous assessment of movements’ kinematic parameters. Five weeks after EI, three animals underwent lateral hemisection of the SC in the C4–C5 segment under the control of a surgical microscope and intraoperative recording of motor- and sensory-evoked potentials. Results: Within 30 days after SCI, during treadmill testing, a decrease in electromyographic activity of the limb muscles and the volume of angular movement in the joints on the side of the injury was detected. Electrical stimulation at the L2–S1 segments of the SC at a frequency of 30 Hz led to the appearance of a locomotor pattern in the muscles of the hind limbs and an increase in the range of motion. Conclusions: Our platform can be used for pathophysiological studies of various neuromodulation modes and as a basis for the development of control neurointerfaces.

There are many reasons for postural disorder development, but dysfunction of the cervical spine muscles is the most disputable reason. The purpose of the study is to reveal the influence of latent myogenic trigger zones of the cervical muscles on postural resistance. Materials and Methods. The authors used the method of computer posturography. Latent myogenic trigger zones (LMTZs) were determined by an indurated nodule or bundle in the neck muscle and by hyperesthesia in this zona. Assessment of postural resistance in subjects with LMTZs was carried out using standard posturography tests and Romberg test. Both classical and vector indicators were evaluated in a standard sample. Results. In fact, only vector indicators changed significantly in subjects with multiple LMTZs (4 or more). Thus, a decrease in the equilibrium function quality was established, as well as an increase in the average linear velocity of the pressure center and an increase in the normalized vectorogram area if compared with the indices in the control group and the group with sporadic LMTZs (from 1 to 3). The obtained results indicate a postural control decrease in individuals with multiple LMTZs. Subjects with sporadic LMTZs demonstrated a significant decrease in classical and a number of vector indicators, which shows the improvement in postural resistance in this test group. In Romberg test, all subjects with LMTZs, regardless of the zone number, showed an increasd Romberg coefficient. Conclusion. Multiple LMTZs of cervical muscles can reduce postural stability through increased afferentation from the cervical proprioreceptors. It is more obvious during in case of eye control elimination. Keywords: latent myogenic trigger points, postural control, posturography, Romberg test. Выделяют множество причин развития постуральных нарушений, среди которых дисфункция мышц шейного отдела позвоночника является наиболее спорной. Цель исследования. Выявить влияние латентных миогенных триггерных зон шейной мускулатуры на постуральную устойчивость. Материалы и методы. Использовался метод компьютерной стабилографии. Латентные миогенные триггерные зоны (лМТЗ) определялись по наличию в мышце шеи уплотненного узелка или пучка и по повышенной болевой чувствительности в этой области. Оценка постуральной устойчивости у испытуемых с лМТЗ осуществлялась с помощью стандартного стабилографического тестирования и теста Ромберга. В стандартной пробе оценивались как классические, так и векторные показатели. Результаты. Показано, что у испытуемых с множественными лМТЗ (4 и более) достоверно изменяются только векторные показатели. Так, установлено снижение качества функции равновесия, а также повышение средней линейной скорости центра давления и увеличение нормированной площади векторограммы по сравнению показателями в группе контроля и группе с единичными лМТЗ (от 1 до 3), что указывает на снижение постурального контроля у лиц с множественными лМТЗ. У испытуемых с единичными лМТЗ отмечено достоверное снижение классических показателей и ряда векторных, что свидетельствует об улучшении постуральной устойчивости в данной группе испытуемых. В пробе Ромберга все субъекты с лМТЗ независимо от количества последних показали повышение коэффициента Ромберга. Выводы. Множественные лМТЗ шейной мускулатуры могут снизить постуральную устойчивость через усиление афферентации от шейных проприорецепторов, что наиболее выражено при элиминации зрительного контроля. Ключевые слова: латентные миогенные триггерные точки, постуральный контроль, стабилография, тест Ромберга.

Background/Objectives: Traumatic spinal cord (SC) injury (SCI) is a debilitating neurological condition. Minimally invasive approaches to monitor in real-time the functional state of the neuromotor apparatus in animal models of SCI (at rest and movement) to assess effectiveness of therapy are needed in preclinical studies. We aimed to develop such a bioethically acceptable platform for SCI studies on non-human primates (Rhesus macaques) Methods: Epidural and myographic electrode implantation (EI) (wireless and wired, connected via a head-plug) was performed. After EI, motor responses caused by electrical stimulation of the SC at the level of the cervical and lumbar thickening were recorded; electromyography of the limb muscles was recorded during quadrupedal movement of the animal on a treadmill with simultaneous assessment of movements’ kinematic parameters. Five weeks after EI, three animals underwent lateral hemisection of the SC in the C4-5 segment under the control of a surgical microscope and intraoperative recording of motor and sensory evoked potentials. Results: Within 30 days after SCI, during treadmill testing, a decrease in electromyographic activity of the limb muscles and the volume of angular movement in the joints on the side of the injury was detected. Electrical stimulation at the L2-S1 segments of the SC at a frequency of 30 Hz led to the appearance of a locomotor pattern in the muscles of the hind limbs and an increase in the range of motion. Conclusions: Our platform can be used for pathophysiological studies of various neuromodulation modes and as a basis for the development of control neurointerfaces.