Thoracic Spinal Segments Research Articles

Degeneration of the nucleus pulposus affects the internal volumetric strains and failure location of adjacent human metastatic vertebral bodies.

Intervertebral disc (IVD) degeneration is suspected to affect the distribution of stress and strain near the vertebral endplates and in the underlying bone. This scenario is worsened by the presence of metastatic lesions on the vertebrae (primarily thoracic vertebrae (60-80 %)) which increase the risk of fracture. As such, this study aimed to evaluate the effect of IVD degeneration on the internal volumetric strains and failure modes of human metastatic vertebral bodies. Five human thoracic spinal segments including one vertebra with lytic metastases and one radiologically healthy vertebra (control) were in situ tested in pure compression within a μCT scanner (isotropic voxel size = 39μm). Each specimen was tested in the elastic regime before and after inducing mock IVD degeneration (enzymatic degeneration with collagenase); and at failure after IVD degeneration. The volumetric strain field was measured using a global Digital Volume Correlation approach (BoneDVC). After IVD degeneration, larger maximum (+187 %, P = 0.002, 95 % CI= [-4447, -1209]) and minimum (+174 %, P = 0.002, 95% CI= [1679, 4258]) principal strains were observed in both metastatic and control vertebrae, with peak differences in correspondence of the IVD anulus fibrosus. IVD degeneration caused a transversal fracture pattern in the vertebrae with failure location onset in the middle portion of the vertebral body and in the cortical shell. In conclusion, IVD degeneration was found to be a key factor in determining the failure mode, suggesting the clinical relevance of including IVD level of degeneration to assess patients' risk of spinal instability. STATEMENT OF SIGNIFICANCE: Vertebrae can be affected by pathologies, like bone metastases, while intervertebral discs tend to degenerate during life. Generally, these structures and pathologies are studied separately. In this study, we explored the effects of artificial intervertebral disc degeneration on the mineralised tissues of the vertebrae with metastases. We observed that the induced intervertebral disc degeneration changes the mechanical behaviour of the vertebral trabecular bone. We believe that the findings of this study may influence the scientific community to develop new clinical tools for the prediction of the risk of fracture in vertebrae with spinal metastases, including the degeneration of the intervertebral discs as a parameter.

Neuroprotective agents ineffective in mitigating autonomic dysreflexia following experimental spinal cord injury

Loss of supraspinal cardiovascular control and secondary damage following spinal cord injury (SCI) lead to cardiovascular dysfunction, where autonomic dysreflexia (AD), triggered by stimuli below the injury, can cause uncontrolled blood pressure (BP) surges, posing severe health risks such as stroke and seizures. While anti-inflammatory neuroprotective agents have been studied for motor recovery, their impact on cardiovascular function remains under investigated. The objective was to assess the efficacy of four clinically approved neuroprotective agents in promoting cardiovascular recovery following SCI. Male Wistar rats received contusion at the third thoracic spinal segment (T3). Fluoxetine, Glyburide, Valproic acid, and Indomethacin were first administered at 1h or 6h post-SCI, and every 12h for two weeks thereafter. Four weeks following SCI, hemodynamics were measured at rest and during colorectal distension. Locomotor function was assessed prior to SCI and weekly for four weeks after SCI, using the Basso-Beattie-Bresnahan (BBB) locomotor scale. Quantitative comparisons of lesion area were performed. Contrary to the published literature, Indomethacin and Valproic acid resulted in high morbidity and mortality rates 60% and 40% respectively) within 2-3days of administration. Fluoxetine, and Glyburide were well-tolerated. There were no differences in change in systolic BP with colorectal distension compared to control i.e., all experimental groups experienced severe episodes of AD [F(6, 67)=0.94, p=0.47]. There was no significant difference in BBB scores in any experimental group compared to control [F(18, 252)=0.3, p=0.99]. No between-group differences were observed in tissue sparing at the lesion epicentre [F(6, 422)=6.98, p=0.29]. Despite promising beneficial effect reported in previous studies, none of the drugs demonstrated improvement in cardiovascular or motor function. Indomethacin and Valproic acid exhibited unexpected high mortality at doses deemed safe in the literature. This emphasizes the necessity for reproducibility studies in pre-clinical research and underscores the importance of publishing null findings to guide future investigations.

Convolutional neural network based detection of early stage Parkinson’s disease using the six minute walk test

The heterogeneity of Parkinson’s disease (PD) presents considerable challenges for accurate diagnosis, particularly during early-stage disease, when the symptoms may be extremely subtle. This study aimed to assess the accuracy of a convolutional neural network (CNN) technique based on the 6-min walk test (6MWT) measured using wearable sensors to distinguish patients with early-stage PD (n = 78) from healthy controls (n = 50). The participants wore six sensors, and performed the 6MWT. The time-series data were converted into new images. The results revealed that the gyroscopic vertical component of the lumbar spine displayed the highest classification accuracy of 83.5%, followed by those of the thoracic spine (83.1%) and right thigh (79.5%) segment. These findings suggest that the 6MWT and CNN models may facilitate earlier diagnosis and monitoring of PD symptoms, enabling clinicians to provide timely treatment during the critical transition from normal to pathologic gait patterns.

Effects of exercise on autonomic cardiovascular control in individuals with chronic, motor-complete spinal cord injury: an exploratory randomised clinical trial.

Secondary analysis of a clinical trial. To assess the impact of 6 months of armcycle ergometry training (ACET), or body weight-supported treadmill training (BWSTT), on autonomic cardiovascular responses to a laboratory sit-up test (SUT) in individuals with chronic (≥1-year post-injury) spinal cord injury (SCI). Tertiary Rehabilitation Centre, Vancouver, Canada. Sixteen individuals with motor-complete (American Spinal Injury Association Impairment Scale A-B) SCI between the fourth cervical and sixth thoracic spinal cord segments, aged 39 ± 11 years, were assessed. Participants were randomized to receive 72 sessions of moderate-to-vigorous intensity ACET (n = 8) or passive BWSTT (n = 8). Changes in mean arterial pressure (finger plethysmography), hemodynamics (Modelflow® method), and heart rate/heart rate variability (HR/HRV; electrocardiography) were measured in response toa SUT before and after 6 months of exercise training. Spontaneous cardiovagal baroreflex sensitivity (cvBRS) was assessed using the sequence method. Neither ACET nor BWSTT impacted hemodynamic responses to SUT or the incidence of orthostatic hypotension (all P > 0.36). ACET increased HR (P < 0.01, ηp2 = 0.34) and high frequency (HF) power HRV responses (P < 0.01, ηp2 = 0.42) to SUT following 6 months of training while BWSTT did not. Consistent with this, cvBRS improved (P < 0.05, ηp2 = 0.16) only following ACET. Improvements in cvBRS were correlated with both the HR (r = 0.726, P < 0.0001) and HF power (r = -0.484, P < 0.01) responses to SUT. Six months of ACET, but not BWSTT, improved cardiovagal baroreflex control of HR but had no effect on BP responses to SUT in individuals with chronic, motor-complete SCI. Canadian Institutes of Health Research (CIHR) CLINICAL TRIAL REGISTRATION: NCT01718977.

Stochastic electrical stimulation of the thoracic or cervical regions with surface electrodes facilitates swallow in rats.

Aspiration pneumonia, a leading cause of mortality, poses an urgent challenge in contemporary society. Neuromuscular electrical stimulation (NMES) has been commonly used in dysphagia rehabilitation. However, given that NMES at motor threshold targets only specific muscles, it carries a potential risk of further compromising functions related to swallowing, respiration, and airway protection. Considering that the swallow motor pattern is orchestrated by the entire swallow pattern generator (the neural mechanism governing a sequence of swallow actions), a rehabilitation approach that centrally facilitates the entire circuit through sensory nerve stimulation is desirable. In this context, we propose a novel stimulation method using surface electrodes placed on the back to promote swallowing. The efficacy of the proposed method in promoting swallowing was evaluated by electrically stimulating sensory nerves in the back or neck. Probabilistic stimulus was applied to either the back or neck of male and female rats. Swallows were evoked by an oral water stimulus, and electromyographic (EMG) activity of the mylohyoid, thyroarytenoid, and thyropharyngeus muscles served as the primary outcome measure. Gaussian frequency stimulation applied to the skin surface of the thoracic back elicited significant increases in EMG amplitude of all three swallow-related muscles. Neck stimulation elicited a significant increase in EMG amplitude of the thyroarytenoid during swallow, but not the mylohyoid or thyropharyngeus muscles. While the targeted thoracic spinal segments T9-T10 have been investigated for enhancing respiration, the promotion of swallowing through back stimulation has not been previously studied. Furthermore, this study introduces a new probabilistic stimulus based on Gaussian distribution. Probabilistic stimuli have been reported to excel in nerve stimulation in previous research. The results demonstrate that back stimulation effectively facilitated swallow more than neck stimulation and suggest potential applications for swallowing rehabilitation.

Computer Modeling of the Thoracic Spine in Children: Assessment of the Contribution of Rectified Kyphosis in the Possible Development of Adolescent Idiopathic Scoliosis

Introduction:: Adolescent Idiopathic Scoliosis is a spinal deformity. Its development can be linked to hypokyphosis in the thoracic region. Objective:: The present study proposed to investigate, through the finite element method, the biomechanics of the immature thoracic spine segment T5-T10 in normal and rectified kyphosis under axial load, flexion and extension. Materials and Methods: Intervertebral discs were modeled as hyperelastic material and vertebral bone as elastic linear material. The bone was divided into trabecular and cortical regions. Furthermore, discs were divided into nucleus pulposus and annulus fibrous. Results:: Results indicate greater instability of rectified segments with larger strain and displacements, mainly under extension. Conclusion:: It was concluded that the rectified model is predisposed to the development of scoliosis since higher deformations and displacements in this condition were observed, going in favor of the assumption that this factor would be one of the causes of Adolescent Idiopathic Scoliosis.

The highs and lows of lifting loads: SPM analysis of multi-segmental spine angles in healthy adults during manual handling with increased load

Introduction: Manual handling personnel and those performing manual handling tasks in non-traditional manual handling industries continue to suffer debilitating and costly workplace injuries. Smart assistive devices are one solution to reducing musculoskeletal back injuries. Devices that provide targeted assistance need to be able to predict when and where to provide augmentation via predictive algorithms trained on functional datasets. The aim of this study was to describe how an increase in load impacts spine kinematics during a ground-to-platform manual handling task. Methods: Twenty-nine participants performed ground-to-platform lifts for six standardised loading conditions (50%, 60%, 70%, 80%, 90%, and 100% of maximum lift capacity). Six thoracic and lumbar spine segments were measured using inertial measurement units that were processed using an attitude-heading-reference filter and normalised to the duration of the lift. The lift was divided into four phases weight-acceptance, standing, lift-to-height and place-on-platform. Statistical significance of sagittal angles from the six spine segments were identified through statistical parametric mapping one-way analysis of variance with repeated measures and post hoc paired t-tests.Results: Two regions of interest were identified during a period of peak flexion and a period of peak extension. There was a significant increase in spine range of motion and peak extension angle for all spine segments when the load conditions were increased (p &amp;lt; 0.001). There was a decrease in spine angles (more flexion) during the weight acceptance to standing phase at the upper thoracic to upper lumbar spine segments for some condition comparisons. A significant increase in spine angles (more extension) during the place-on-platform phase was seen in all spine segments when comparing heavy loads (&amp;gt;80% maximum lift capacity, inclusive) to light loads (&amp;lt;80% maximum lift capacity) (p &amp;lt; 0.001).Discussion: The 50%–70% maximum lift capacity conditions being significantly different from heavier load conditions is representative that the kinematics of a lift do change consistently when a participant’s load is increased. The understanding of how changes in loading are reflected in spine angles could inform the design of targeted assistance devices that can predict where and when in a task assistance may be needed, possibly reducing instances of back injuries in manual handling personnel.

Operative treatment of calcified thoracic disc herniation: A case report on natural fusion method following spinal canal decompression

Introduction. The literature describes several ways to approach the thoracic spinal segment, but there are still many dilemmas regarding what is best to do after a complete discectomy, regardless of the surgical approach chosen. The incidence of postoperative kyphosis is higher if a posterior surgical approach to the spine is performed, and there are no clearly defined indications for the application of intervertebral fusion (IF) after an anterior approach. The aim of the paper was to highlight the low morbidity of the transthoracic multidisciplinary approach, as well as a potential solution for a good, natural IF of the adjacent vertebrae without expanding and pro-longing the duration of the surgical procedure itself. Case report. A 44-year-old woman presented with severe anterior compressive myelopathy caused by a calcified thoracic disc herniation in the space between the T10-11 vertebrae. A minimally invasive, open, transthoracic approach was performed with decompression of the spinal canal at the specified level and IF was achieved with an autologous rib graft during the same procedure. Despite the relatively low incidence of postoperative spinal instability, one should not overlook a good chance to achieve IF and prevent long-term complications. A control examination of the thoracolumbar segment using the magnetic resonance imaging showed that there is no more compression of the spinal cord and also showed a good IF without an increase in the level of kyphosis. Conclusion. Significant thoracic disc herniation is a rare and challenging surgical lesion. The anterior mini-open transthoracic approach provides good exposure to the relevant structures and is considered minimally invasive. The benefits of subsequent IF after the transthoracic surgical approach should always be taken into account for each individual patient, thus minimalizing the post-operative morbidity.

Facet joint involvement in the inflammatory rheumatic disease

The involvement of facet joints (FJ) in patients with inflammatory rheumatic disorders remains underexplored. This review aims to look at FJ disease from a rheumatologist's perspective, with the emphasis given to the clinical presentations and patterns of FJ engagement in axial spondyloarthritis (axSpA), psoriatic arthritis (PsA), rheumatoid arthritis (RA), and crystal-related arthropathies, and discussion of challenges in studying FJ in rheumatic disease. A systematic PubMed search using the pertinent keywords was performed, relevant articles extracted, and the acquired data critically assessed, interpreted, and organized according to the authors' experience and judgment. FJ involvement is common in patients with radiographic axSpA, occurs throughout the spine, but is more frequently seen in the thoracic segment. The existing data suggests that the FJ are primarily affected by the disease process, while altered spine biomechanics due to the presence of syndesmophytes at the same vertebral level contributes to the FJ fusion. Predominant involvement of FJ of the cervical spinal segment has been suggested in PsA; however, prevalence and clinical significance of FJ involvement in PsA is still markedly underexplored. RA-related FJ disease of the cervical spine in patients with poorly controlled RA is not uncommon and can be related to significant morbidity, while the burden of FJ involvement in the thoracic and lumbar spinal segments in RA is also underexplored. FJ disease is possible in the course of crystal-related arthropathies, but the high level of suspicion is a prerequisite for the timely diagnosis. The involvement of FJ in the course of inflammatory rheumatic disease is not uncommon. Prospective studies are needed to understand the epidemiology and significance of FJ disease in inflammatory rheumatic conditions.

Implantation of Surgical Paddle Electrodes Using Percutaneous Biportal-Endoscopic Technique for Spinal Cord Stimulation: An Anatomical Feasibility Study in Human Cadavers

BACKGROUND: Spinal cord stimulation is a technique in which different types of electrodes are placed in the spinal epidural space for neuromodulation. Surgical paddle electrodes (SEs) are usually implanted by a surgeon by performing open surgery with laminectomy. Recent advances in endoscopic spine surgery provide another option for minimally invasive SE implantation. OBJECTIVES: This anatomical study aims to examine the feasibility of implanting SEs in thoracic and cervical spine segments, discussing the specific advantages and disadvantages compared with previously reported methods. STUDY DESIGN: Laboratory study with Institutional Review Board No B2023-056. METHODS: Four fresh adult cadavers (2 women, 2 men) were operated on in this study. The posterior unilateral biportal endoscopic surgical approach, the accessibility to the intraspinal epidural space, and the technical possibilities and limitations of implantation of SEs were evaluated, as well as the surgical duration and complications. RESULTS: All the planned steps of the operation were successfully accomplished in all 4 cadavers. A total of 8 electrodes were successfully implanted through the working portal. Among them, 4 were located in the cervical segment and 4 in the thoracic segment. The proper position of the electrodes was also verified by fluoroscopy. No rupture of dura occurred during the operation. Except for the first cadaver, the duration of surgery did not exceed 1 hour. LIMITATIONS: Anatomical study on human cadavers, the quantity of cadavers, and the steep learning curve. CONCLUSIONS: The results of this anatomical study show that the SEs can be satisfactorily implanted in cervical and thoracic segments using the unilateral biportal endoscopic technique. KEY WORDS: Surgical paddle electrodes, spinal cord stimulation, unilateral biportal endoscopic technique, anatomical feasibility, anatomical study, cadavers, cervical, thoracic

Spinal kinematic variability is increased in people with chronic low back pain during a repetitive lifting task

Changes in spinal kinematic variability have been observed in people with chronic non-specific LBP (CNSLBP) during the performance of various repetitive functional tasks. However, the direction of these changes (i.e., less or more kinematic variability) is not consistent. This study aimed to assess differences in kinematic variability of the 3D angular displacement of thoracic and lumbar spinal segments in people with CNSLBP compared to asymptomatic individuals during a repetitive lifting task. Eleven people with CNSLBP and 11 asymptomatic volunteers performed 10 cycles of multi-planar lifting movements while spinal kinematics were recorded. For the three planes of motion, point-by-point standard deviations (SDs) were computed across all cycles of lifting and the average was calculated as a measure of kinematic variability for both segments. People with CNSLBP displayed higher thoracic (F=8.00, p=0.010, ηp2=0.286) and lumbar kinematic variability (F=5.48, p=0.030, ηp2=0.215) in the sagittal plane. Moreover, group differences were observed in the transversal plane for thoracic (F=7.62, p=0.012, ηp2=0.276) and lumbar kinematic variability (F=5.402, p=0.031, ηp2=0.213), as well as in the frontal plane for thoracic (F=7.27, p=0.014, ηp2=0.267) and lumbar kinematic variability (F=6.11, p=0.022, ηp2=0.234), all showing higher variability in those with CNSLBP. A significant main effect of group was not detected (p > 0.05) for spinal range of motion (ROM). Thus, people with CNSLBP completed the lifting task with the same ROM in all three planes of motion as observed for asymptomatic individuals, yet they performed the lifting task with higher spinal kinematic cycle-to-cycle variation.

Transesophageal echocardiography for thoracic spinal cord imaging and confirmation of epidural catheter placement in pediatrics

Transesophageal echocardiography (TEE) use continues to expand to include extracardiac applications. However, there is limited research investigating the use of TEE as a tool to confirm the position of the epidural catheter. This prospective observational study aimed to evaluate whether TEE could be used to visualize the anatomy of the thoracic spinal canal in pediatrics. A subsequent prospective case series was conducted to evaluate whether TEE could be used to assist in the placement of epidural catheters in pediatric surgical patients. Seventy-five patients (50 pediatric and 25 adult subjects) were enrolled. The operators attempted to identify four structures (spinal cord, cerebrospinal fluid, dura mater, epidural space) within the thoracic spinal canal with TEE. After demonstrating the feasibility of this technique for observing the spinal anatomy, 20 pediatric surgical patients were enrolled in a case series. These patients had epidural catheter placement, and the final catheter position was confirmed with TEE. The total number of thoracic spinal segment visualized in pediatric patients was 542 out of 550 (99%) segments, and 191 out of 275 (70%) segments in adult subjects (difference, 29% [95% confidence interval, 23-34]; p<0.001). Additionally, a case series of 20 pediatric surgical patients demonstrated successful caudal or epidural catheter placement at target spinal level in 17 cases. This observational study demonstrated the successful visualization of the thoracic spinal cord at virtually every level in pediatric patients. A subsequent case series demonstrated that TEE could be used to successfully confirm the position of the epidural catheter in the targeted thoracic spinal segment for pediatric surgical patients.

Proinflammatory and Immunomodulatory Gene and Protein Expression Patterns in Spinal Cord and Spleen Following Acute and Chronic High Thoracic Injury.

In addition to paralysis and loss of sensation, high-level spinal cord injury (SCI) causes sympathetic dysfunction that can lead to autonomic dysreflexia (AD) and chronic immune suppression involving splenic leukopenia. Evidence has shown that treatment with either gabapentin or blockade of TNFα mitigates maladaptive plasticity and the underlying hemodynamic dysfunction, spleen atrophy, and immune dysfunction associated with AD. Because significant improvements long term was noted following treatments only during acute stages of recovery, we sought to systematically examine changes in proinflammatory and immunomodulatory cytokines to ascertain the reason. Adult female Wistar rats underwent complete T4 spinal transection before euthanasia at systematic intervals from 3 days to 8 weeks after injury. Using qRT-PCR and meso scale discovery (MSD) assays, the gene and protein expression of TNFα and IFNγ in the spleen, upper thoracic (T4-9) and lumbosacral (L5-S6) spinal cords were analyzed. We found that spleen atrophy occurs in a biphasic manner compared to naïve controls, with significant decreases in the spleen mass noted at 3 days and 8 weeks after injury. Splenic TNFα mRNA and protein levels did not change significantly over time, while IFNγ gene expression dipped acutely with trends for increased protein levels at more chronic time points. TNFα protein increased significantly only in thoracic spinal cord segments from 3 to 14 days post-injury. IFNγ mRNA and protein levels remained unelevated in injured spinal cords over time, with trends for increased protein levels at 2 and 8 weeks in the lumbosacral segments. Novel temporal-spatial cytokine expression profiles reveal that TNFα protein levels are increased solely in upper thoracic segments after high thoracic SCI, while IFNγ remains unaltered. Splenic leukopenia and latent systemic immunosuppression are not associated with altered TNFα or IFNγ expression in the spleen or spinal cord.

Low occurrence of MRI spinal changes in elite climbing athletes; a cross-sectional study

ObjectivesTo examine the occurrence of magnetic resonance imaging (MRI) changes in the thoracolumbar spine among elite climbing athletes.MethodsAll climbers of the Swedish national sport climbing team (n = 8), and individuals having trained for selection to the national team (n = 11), were prospectively included. A control group, matched in age and sex, were recruited. All participants underwent a thoracolumbar MRI (1.5 T, T1- and T2-weighted imaging), evaluated according to Pfirrmann classification, modified Endplate defect score, Modic changes, apophyseal injuries and spondylolisthesis. Pfirrmann ≥ 3, Endplate defect score ≥ 2 and Modic ≥ 1 was defined as degenerative findings.ResultsFifteen individuals, 8 women, participated in both the climbing group (mean age 23.1, SD 3.2 years) and the control group respectively (mean age 24.3, SD 1.5 years). In the climbing group, 6.1% of the thoracic and 10.6% of the lumbar intervertebral discs showed signs of degeneration according to Pfirrmann. One disc with a grade above 3 was present. Modic changes in the thoracic/lumbar spine were prevalent in 1.7%/1.3% of the vertebrae. Degenerative endplate changes according to the Endplate defect score were found in 8.9% and 6.6% of the thoracic and lumbar spinal segments of the climbing group, respectively. Two apophyseal injuries were found, while no participants displayed signs of spondylolisthesis. There was no difference in point-prevalence of radiographic spinal changes between climbers and controls (0.07 < p < 1.0).ConclusionIn this small cross-sectional study, only a low proportion of elite climbers displayed changes of the spinal endplates or intervertebral discs, as opposed to other sports with high spinal loads. Most observed abnormalities were low grade degenerative changes and did not differ statistically compared to controls.

A candidate protective factor in amyotrophic lateral sclerosis: heterogenous nuclear ribonucleoprotein G.

Heterogenous nuclear ribonucleoprotein G is down-regulated in the spinal cord of the Tg(SOD1*G93A)1Gur (TG) amyotrophic lateral sclerosis mouse model. However, most studies have only examined heterogenous nuclear ribonucleoprotein G expression in the amyotrophic lateral sclerosis model and heterogenous nuclear ribonucleoprotein G effects in amyotrophic lateral sclerosis pathogenesis such as in apoptosis are unknown. In this study, we studied the potential mechanism of heterogenous nuclear ribonucleoprotein G in neuronal death in the spinal cord of TG and wild-type mice and examined the mechanism by which heterogenous nuclear ribonucleoprotein G induces apoptosis. Heterogenous nuclear ribonucleoprotein G in spinal cord was analyzed using immunohistochemistry and western blotting, and cell proliferation and proteins (TAR DNA binding protein 43, superoxide dismutase 1, and Bax) were detected by the Cell Counting Kit-8 and western blot analysis in heterogenous nuclear ribonucleoprotein G siRNA-transfected PC12 cells. We analyzed heterogenous nuclear ribonucleoprotein G distribution in spinal cord in the amyotrophic lateral sclerosis model at various time points and the expressions of apoptosis and proliferation-related proteins. Heterogenous nuclear ribonucleoprotein G was mainly localized in neurons. Amyotrophic lateral sclerosis mice were examined at three stages: preonset (60-70 days), onset (90-100 days) and progression (120-130 days). The number of heterogenous nuclear ribonucleoprotein G-positive cells was significantly higher in the anterior horn of the lumbar spinal cord segment of TG mice at the preonset stage than that of control group but lower than that of the control group at the onset stage. The number of heterogenous nuclear ribonucleoprotein G-positive cells in both central canal and surrounding gray matter of the whole spinal cord of TG mice at the onset stage was significantly lower than that in the control group, whereas that of the lumbar spinal cord segment of TG mice was significantly higher than that in the control group at preonset stage and significantly lower than that in the control group at the progression stage. The numbers of heterogenous nuclear ribonucleoprotein G-positive cells in the posterior horn of cervical and thoracic segments of TG mice at preonset and progression stages were significantly lower than those in the control group. The expression of heterogenous nuclear ribonucleoprotein G in the cervical spinal cord segment of TG mice was significantly higher than that in the control group at the preonset stage but significantly lower at the progression stage. The expression of heterogenous nuclear ribonucleoprotein G in the thoracic spinal cord segment of TG mice was significantly increased at the preonset stage, significantly decreased at the onset stage, and significantly increased at the progression stage compared with the control group. heterogenous nuclear ribonucleoprotein G expression in the lumbar spinal cord segment of TG mice was significantly lower than that of the control group at the progression stage. After heterogenous nuclear ribonucleoprotein G gene silencing, PC12 cell survival was lower than that of control cells. Both TAR DNA binding protein 43 and Bax expressions were significantly increased in heterogenous nuclear ribonucleoprotein G-silenced cells compared with control cells. Our study suggests that abnormal distribution and expression of heterogenous nuclear ribonucleoprotein G might play a protective effect in amyotrophic lateral sclerosis development via preventing neuronal death by reducing abnormal TAR DNA binding protein 43 generation in the spinal cord.

Integrative transcriptomic analysis of the amyotrophic lateral sclerosis spinal cord implicates glial activation and suggests new risk genes.

Amyotrophic lateral sclerosis (ALS) is a progressively fatal neurodegenerative disease affecting motor neurons in the brain and spinal cord. In this study, we investigated gene expression changes in ALS via RNA sequencing in 380 postmortem samples from cervical, thoracic and lumbar spinal cord segments from 154 individuals with ALS and 49 control individuals. We observed an increase in microglia and astrocyte gene expression, accompanied by a decrease in oligodendrocyte gene expression. By creating a gene co-expression network in the ALS samples, we identified several activated microglia modules that negatively correlate with retrospective disease duration. We mapped molecular quantitative trait loci and found several potential ALS risk loci that may act through gene expression or splicing in the spinal cord and assign putative cell types for FNBP1, ACSL5, SH3RF1 and NFASC. Finally, we outline how common genetic variants associated with splicing of C9orf72 act as proxies for the well-known repeat expansion, and we use the same mechanism to suggest ATXN3 as a putative risk gene.

Retrospective analysis of restoration of the anatomy of the damaged thoracic and lumbar spinal motion segment using transpedicular repositioning device

Objective. To carry out a retrospective analysis of the restoration of the anterior and posterior vertebral body heights and the elimination of deformation of the anterior spinal canal wall caused by thoracic and lumbar spine injury, based on the data of spiral computed tomography (SCT).Material and Methods. The study analyzed SCT data and case histories of 50 patients with thoracolumbar spinal cord injury operated on at different times after injury: up to 10 days – Group 1 and 11–30 days – Group 2. All patients underwent spinal reposition using a transpedicular device. The preoperative and postoperative SCT parameters were compared with the initial ones, which were calculated. The restoration of vertebral body heights and the elimination of deformation of the anterior spinal canal wall were compared in two groups depending on the distraction of interbody spaces and changes in the angle of segmental deformity.Results. In Group 1, the anterior and posterior dimensions of the vertebral body were restored, on average, by 95.3 ± 1.9 and 96.9 ± 1.4 % of the initial height; in Group 2 – by 87.4 ± 4.2 and 96.6 ± 1.8 %, respectively. The maximum restoration of the anterior dimensions of the vertebral bodies was achieved with distraction of the anterior interbody spaces closer to 100 % of the original size in the first and second groups. The maximum recovery of the posterior dimensions of the vertebral bodies was obtained by distraction of the posterior interbody spaces by 97 % or more of the original dimensions. The maximum elimination of the displacement of bone fragments from the spinal canal was obtained by distraction of the interbody spaces to a distance close to 100 % of the initial one, and when the obtained angle of segmental deformity coincided with the initial one.Conclusion. In the first 10 days after the injury, a greater percentage of the restoration of the anterior and posterior vertebral body heights and a decrease in the deformation of the anterior wall of the spinal canal were obtained. It was possible to maximally eliminate the deformation of the anterior wall of the spinal canal and restore the height of the anterior and posterior walls of the damaged vertebra by approaching the obtained dimensions of interbody spaces and the angle of segmental deformity to the initial ones.

Long‐term neuroprosthetic hemotherapy treats autonomic dysreflexia after spinal cord injury

Disrupted descending supraspinal control results in a hyper‐excitable sympathetic nervous system connectome after spinal cord injury (SCI). A condition termed “autonomic dysreflexia” (AD) results, which is characterized by severe elevations in blood pressure that are life‐threatening. There are no effective therapies for AD. Long‐term epidural stimulation below the level of the SCI can promote functionally‐relevant plasticity of volitional motor circuits, and this paradigm may prevent the hyper‐excitable sympathetic connectome after SCI.Here we studied the potential rehabilitative effect of long‐term epidural stimulation, as well as the mechanisms that are responsible for the development of AD. For this experiment, we compared SCI rats that underwent 30 minutes of epidural stimulation 5x/week for 6 weeks to SCI rats receiving normal care. Long‐term epidural stimulation abrogated AD induced by colorectal distension (p&lt;0.0001; Figure 1). Viral tracing of ascending propriospinal neurons was also performed in these groups. Long‐term epidural stimulation normalized the sympathetic connectome as the axons and synapses were significantly reduced compared to SCI rats (p=0.0021; p=0.0127). We next performed chemogenetic silencing of excitatory and inhibitory interneurons, as well as sympathetic preganglionic neurons, in the lower thoracic spinal segments while experimentally inducing AD. Preliminary data indicate that AD is, at least in part, mediated by excitatory interneuronal connections to sympathetic preganglionic neurons.Long‐term epidural stimulation may be an effective hemotherapy for preventing AD after SCI. This project may provide direction for basic and clinical research to develop treatments for sympathetic nervous system dysfunction after SCI, and thereby improve health and patient quality of life over the long term.

Biomechanics of the spine in fracture of the spine before and after surgical treatment. Biomechanical experiment

The study covers biomechanical behavior of the thoracic spine segment with a comminuted compression fracture of the Th11 vertebral body, with various options for the injured spinal motion segment fixation (SMS). The following fixation options were considered: short-segment transpedicular system (TPS); short-segment TPS, supplemented with an intermediate screw inserted into the damaged vertebra; short-segment TPS, supplemented with intermediate screws inserted into the damaged vertebra. Models of spinal segments with damage to the vertebral body are built on the basis of patient computed tomography data in Mimics Materialize, 3-Matic Materialize and SolidWorks software. Fixing element models, as well as their introduction into the model of the spine segment, are performed in SolidWorks. Materials assigned to the models were considered to be linear, elastic, and isotropic. The boundary conditions and loading of the models are performed in the FEP ANSYS 19.2. The loading of the models corresponded to the position of a person standing, flexion, extension, lateral bending and axial rotation. The numerical solution of the theory of elasticity problem was carried out in the FEP ANSYS. The field of total displacements in the models, equivalent von Mises stresses in fixing structures and vertebrae were calculated. The range of motion was measured in the spinal motion segment, including that within the injured vertebra. The study revealed a redistribution of equivalent von Mises stresses, which reduces the load on the injured vertebra, as well as a decrease in the mobility of the injured vertebra when installing the TPS, supplemented with an intermediate screw, regardless of the side of its installation.

Can the Rhomboid Major Muscle Be Used to Identify the Thoracic Spinal Segment on Ultrasonography? A Prospective Observational Study.

We investigated the thoracic segment corresponding to the inferior margin of the rhomboid major muscle (RMM) using ultrasound (US) to evaluate its potential as a reliable anatomic landmark for segment identification. A prospective observational study. An operating room. Patients who underwent procedures around the thoracic spine. Four hundred segments corresponding to the RMM's inferior margin were identified through the use of paravertebral sagittal US and confirmed by fluoroscopy in 100 participants in the prone position with upward and downward shoulder rotation, comprising four datasets (up-right, up-left, down-right, and down-left). The US identification of the RMM's inferior margin was dichotomously scored (clear vs ambiguous). Each dataset was divided into two groups (dominant segment group vs remaining segments group), which were compared. Factors relevant to the dominant segment associated with the RMM's inferior border were determined through univariable analyses. The T6 segment was observed most commonly (59.5%) along the RMM's inferior border on paravertebral sagittal US acquired in the prone position, followed by T5 (25.0%), T7 (12.8%), and T4 (2.7%). The segments corresponding to the RMM remained unchanged by shoulder posture in most participants (n = 74, 74%). The RMM's inferior border was clearly distinguishable in 330 cases (82.5%). When the RMM's inferior border was clearly identified, the corresponding segment was likely to match T6 in all datasets, with odds ratios ranging from 3.24 to 6.2. The RMM's inferior border over the transverse process corresponded to T6 most frequently on paravertebral sagittal US, and its deep fascia was clearly visible in most cases.