Spinal Tract Research Articles

White matter spinal tracts impairment in patients with degenerative cervical myelopathy evaluated with the magnetization transfer saturation MRI technique.

Prospective case-control study. We investigated the use of the magnetization transfer saturation (MTsat) technique to assess the structural integrity of the spinal cord tracts in individuals with clinically significant degenerative cervical myelopathy (DCM) and associated disability. Novosibirsk Neurosurgery Centre, Russia. A total of 53 individuals diagnosed with DCM and 41 patients with cervical radiculopathy underwent high-resolution MRI of the cervical spinal cord via the magnetization transfer technique. The MRI data were processed using the Spinal Cord Toolbox (v5.5), with MTsat values determined for each spinal tract and compared between the two groups. Furthermore, associations between MTsat values and the clinical disability rates of patients were investigated. A significant decrease in the MTsat of the ventral spinocerebellar tract was observed in the DCM group compared to the control group (adjusted p < 0.001). There was a trend towards lower MTsat values in the rubrospinal tract in the DCM group (adjusted p = 0.08). Additionally, a decrease in MTsat values in the lateral funiculi of the spinal cord was found in patients with DCM (adjusted p < 0.01). Furthermore, a trend toward a positive correlation was observed between the JOA score and the MTsat values within the ventral spinocerebellar tract (R = 0.33, adjusted p = 0.051). The findings of our study indicate that demyelination in patients with DCM affects mainly the ventral spinocerebellar and rubrospinal tracts, and the extent of changes in the ventral spinocerebellar tract is related to the severity of the condition.

92 - Spinal cord injury-induced lower urinary tract dysfunction in mice can be improved by imidazoline 2 receptor activation

92 - Spinal cord injury-induced lower urinary tract dysfunction in mice can be improved by imidazoline 2 receptor activation

Treatment of neurologic pathology and inflammation in Machado-Joseph disease through in vivo self-assembled siRNA.

Machado-Joseph disease, also known as Spinocerebellar ataxia type 3 (MJD/SCA3), is a fatal autosomal dominant hereditary ataxia characterized by cerebellar ataxia resulting from the abnormal expansion of CAG repeats in exon 10 of the ATXN3 gene. Presently, there is no effective treatment for SCA3. Small interfering RNAs (siRNAs) are emerging as potential therapeutic strategies to specifically target the disease-causing mutant ATXN3 (mATXN3) protein. However, the delivery efficiency of siRNAs remains a major obstacle for clinical application, particularly in brain disorders. This study aimed to develop a synthetic biology strategy to reprogram the host liver as a tissue chassis to induce and deliver in vivo self-assembled siRNAs (IVSA-siRNAs) to target the ATXN3 gene. A synthetic construct directed by a cytomegalovirus promoter was designed to encode a neuron-targeting rabies virus glycoprotein tag and mATXN3-siRNA. After intravenous injection, the synthetic construct was taken up by mouse livers, which were then reprogrammed to enable the self-assembly, production, and secretion of small extracellular vesicles (sEVs) encapsulating mATXN3-siRNA. The sEV-encapsulated mATXN3-siRNA was further transported through the endogenous circulating system of sEVs, crossing the blood-brain barrier and reaching the cerebellar cortex and spinal cerebellar tract, where they silenced the ATXN3 gene. Treatment with the synthetic construct for 8 or 12 weeks led to significant improvements in motor balance ability and reduction of cerebellar atrophy in YACMJD84.2 transgenic mice. The number of Purkinje cells in the cerebellar cortex was significantly increased, and the loss of myelin basic protein was reduced. Moreover, the quantity of neurotoxic nuclear inclusion bodies and the expression of glial fibrillary acidic protein, which promotes neuroinflammation in activated astrocytes, were decreased significantly. The synthetic construct facilitated the generation and delivery of IVSA-siRNA to the cerebellar cortex and spinal cerebellar tract, thereby inhibiting the expression of mATXN3 protein. This treatment successfully addressed motor impairments, alleviated neuropathological phenotypes, and mitigated neuroinflammation in YACMJD84.2 transgenic mice. Our strategy effectively overcomes the primary challenges associated with siRNA therapy for cerebellar ataxia, offering a promising avenue for future clinical treatments.

Differential effects of exercise and hormone treatment on spinal cord injury-induced changes in micturition and morphology of external urethral sphincter motoneurons.

Spinal cord injury (SCI) results in lesions that destroy tissue and spinal tracts, leading to deficits in locomotor and autonomic function. We have previously shown that after SCI, surviving motoneurons innervating hindlimb muscles exhibit extensive dendritic atrophy, which can be attenuated by treadmill training or treatment with gonadal hormones post-injury. We have also shown that following SCI, both exercise and treatment with gonadal hormones improve urinary function. Animals exercised with forced running wheel training show improved urinary function as measured by bladder cystometry and sphincter electromyography, and treatment with gonadal hormones improves voiding patterns as measured by metabolic cage testing. The objective of the current study was to examine the potential protective effects of exercise or hormone treatment on the structure and function of motoneurons innervating the external urethral sphincter (EUS) after contusive SCI. Gonadally intact young adult male rats received either a sham or a thoracic contusion injury. Immediately after injury, one cohort of animals was implanted with subcutaneous Silastic capsules filled with estradiol (E) and dihydrotestosterone (D) or left blank; continuous hormone treatment occurred for 4 weeks post-injury. A separate cohort of SCI-animals received either 12 weeks of forced wheel running exercise or no exercise treatment starting two weeks after injury. At the end of treatment, urinary void volume was measured using metabolic cages and EUS motoneurons were labeled with cholera toxin-conjugated horseradish peroxidase, allowing for assessment of dendritic morphology in three dimensions. Locomotor performance was improved in exercised animals after SCI. Void volumes increased after SCI in all animals; void volume was unaffected by treatment with exercise, but was dramatically improved by treatment with E + D. Similar to what we have previously reported for hindlimb motoneurons after SCI, dendritic length of EUS motoneurons was significantly decreased after SCI compared to sham animals. Exercise did not reverse injury-induced atrophy, however E + D treatment significantly protected dendritic length. These results suggest that some aspects of urinary dysfunction after SCI can be improved through treatment with gonadal hormones, potentially through their effects on EUS motoneurons. Moreover, a more comprehensive treatment regime that addresses multiple SCI-induced sequelae, i.e., locomotor and voiding deficits, would include both hormones and exercise.

Descending Motor Pathways

The brain is the origin of the descending motor pathways or tracts. These are responsible for the origination or modification of motor activity. This action is performed by motor signals, which transmitted from the brain and target lower motor neurons. Motor control is a chief task of the central nervous system (CNS). It can be recognized as the initiation of signals to coordinate muscle contraction of the body and head, aiming to keep a posture or to make a movement (transition between two postures). A large amount of the CNS is included in the process of motor control. The term "motor neuron, also known as motoneurons" may refer to single or one type of neurons responsible for the movement. However, this is not the truth. Actually, the “motor neuron” describe two categories of neurons, the “upper and lower motor neurons”. They are significantly different in their origins, synapses, pathways, neurotransmitters and developed lesions due to their affection. Motor neurons are essential constituents of two different circuits “the upper and lower motor circuits”. These circuits control both voluntary and involuntary movements. This was achieved by the connection of higher centers with muscles and glands Descending tracts of the motor system are originating mainly from two parts, the cortex and the brainstem. Tracts originating from the cortex control the voluntary movements and adjust posture relating to voluntary movement. Furthermore, the descending pathways are subdivided into (pathways) describing their start and termination. These are (1) corticospinal and corticobulbar, (2) cortico-reticulo-spinal, (3) cortico-rubro-spinal (4) cortico-tecto-spinal, (5) vestibulo-spinal and (6) raphe–spinal and ceruleus–spinal tracts (aminergic pathways) Pyramidal tracts, originating in the cortex and carry motor fibres to the spinal cord and brain stem. It is subdivided into corticospinal and Corticobulbar tracts. The extrapyramidal tracts originate in the brainstem. Then carry motor projections to the spinal cord. These tracts are primarily concerned with the control of the involuntary and automatic innervations for all musculature (e.g., muscle tone, balance, posture and locomotion).

Value of Spinal Cord Diffusion Imaging and Tractography in Providing Predictive Factors for Tumor Resection in Patients with Intramedullary Tumors: A Pilot Study.

This pilot study aimed to investigate the interest of high angular resolution diffusion imaging (HARDI) and tractography of the spinal cord (SC) in the management of patients with intramedullary tumors by providing predictive elements for tumor resection. Eight patients were included in a prospective study. HARDI images of the SC were acquired using a 3T MRI scanner with a reduced field of view. Opposed phase-encoding directions allowed distortion corrections. SC fiber tracking was performed using a deterministic approach, with extraction of tensor metrics. Then, regions of interest were drawn to track the spinal pathways of interest. HARDI and tractography added value by providing characteristics about the microstructural organization of the spinal white fibers. In patients with SC tumors, tensor metrics demonstrated significant changes in microstructural architecture, axonal density, and myelinated fibers (all, p < 0.0001) of the spinal white matter. Tractography aided in the differentiation of tumor histological types (SC-invaded vs. pushed back by the tumor), and differentiation of the spinal tracts enabled the determination of precise anatomical relationships between the tumor and the SC, defining the tumor resectability. This study underlines the value of using HARDI and tractography in patients with intramedullary tumors, to show alterations in SC microarchitecture and to differentiate spinal tracts to establish predictive factors for tumor resectability.

Tempol, a Superoxide Dismutase Mimetic, Inhibits Wallerian Degeneration Following Spinal Cord Injury by Preventing Glutathione Depletion and Aldose Reductase Activation.

Spinal cord contusion injury results in Wallerian degeneration of spinal cord axonal tracts, which are necessary for locomotor function. Axonal swelling and loss of axonal density at the contusion site, characteristic of Wallerian degeneration, commence within hours of injury. Tempol, a superoxide dismutase mimetic, was previously shown to reduce the loss of spinal cord white matter and improve locomotor function in an experimental model of spinal cord contusion, suggesting that tempol treatment might inhibit Wallerian degeneration of spinal cord axons. Here, we report that tempol partially inhibits Wallerian degeneration, resulting in improved locomotor recovery. We previously reported that Wallerian degeneration is reduced by inhibitors of aldose reductase (AR), which converts glucose to sorbitol in the polyol pathway. We observed that tempol inhibited sorbitol production in the injured spinal cord to the same extent as the AR inhibitor, sorbinil. Tempol also prevented post-contusion upregulation of AR (AKR1B10) protein expression within degenerating axons, as previously observed for AR inhibitors. Additionally, we hypothesized that tempol inhibits axonal degeneration by preventing loss of the glutathione pool due to polyol pathway activity. Consistent with our hypothesis, tempol treatment resulted in greater glutathione content in the injured spinal cord, which was correlated with increased expression and activity of gamma glutamyl cysteine ligase (γGCL; EC 6.3.2.2), the rate-limiting enzyme for glutathione synthesis. Administration of the γGCL inhibitor buthionine sulfoximine abolished all observed effects of tempol administration. Together, these results support a pathological role for polyol pathway activation in glutathione depletion, resulting in Wallerian degeneration after spinal cord injury (SCI). Interestingly, methylprednisolone, oxandrolone, and clenbuterol, which are known to spare axonal tracts after SCI, were equally effective in inhibiting polyol pathway activation. These results suggest that prevention of AR activation is a common target of many disparate post-SCI interventions.

Utilizing neuroimaging visualization technology to enhance standardized neurosurgical training for Traditional Chinese Medicine residents: A neuroanatomical education study

ObjectiveThis study aims to address the difficulties encountered by Traditional Chinese Medicine (TCM) students in learning neuroanatomy during clinical training by utilizing neuroimaging visualization technology. Methods81 students were divided into a control group (40 students) and an observation group (41 students). The control group followed traditional teaching methods as prescribed by the curriculum, while the observation group received additional training with the neuroimaging visualization software DSI Studio. This included whole-brain neural fiber reconstruction and cortical spinal tract evaluation in the context of stroke. Upon completion of the training, both groups were assessed on neuroanatomical theory, case analysis, neurological examination, and clinical skills. The teaching effectiveness was compared based on assessment results and feedback from questionnaires administered to the observation group. ResultsThe observation group significantly outperformed the control group in theoretical knowledge, case analysis, and physical examination (P < 0.05). Over 90 % of students in the observation group reported via questionnaire that the integration of neuroimaging visualization technology significantly enhanced their understanding of neuroanatomy and clinical reasoning skills. ConclusionThe clinical teaching approach augmented with neuroimaging visualization technology significantly improves the standardized training outcomes for TCM neurosurgical residents.

Anatomical and functional analysis of the corticospinal tract in an FRDA mouse model.

Friedreich's ataxia (FRDA) is one of the most common hereditary ataxias. It is caused by a GAA repeat in the first intron of the FXN gene, which encodes an essential mitochondrial protein. Patients suffer from progressive motor dysfunction due to the degeneration of mechanoreceptive and proprioceptive neurons in dorsal root ganglia (DRG) and cerebellar dentate nucleus neurons, especially at early disease stages. Postmortem analyses of FRDA patients also indicate pathological changes in motor cortex including in the projection neurons that give rise to the cortical spinal tract (CST). Yet, it remains poorly understood how early in the disease cortical spinal neurons (CSNs) show these alterations, or whether CSN/CST pathology resembles the abnormalities observed in other tissues affected by FXN loss. To address these questions, we examined CSN driven motor behaviors and pathology in the YG8JR FRDA mouse model. We find that FRDA mice show impaired motor skills, exhibit significant reductions in CSN functional output, and, among other pathological changes, show abnormal mitochondrial distributions in CSN neurons and CST axonal tracts. Moreover, some of these alterations were observed as early as two months of age, suggesting that CSN/CST pathology may be an earlier event in FRDA disease than previously appreciated. These studies warrant a detailed mechanistic understanding of how FXN loss impacts CSN health and functionality.

Magnetic Stimulation of Gigantocellular Reticular Nucleus with Iron Oxide Nanoparticles Combined Treadmill Training Enhanced Locomotor Recovery by Reorganizing Cortico-Reticulo-Spinal Circuit.

Gigantocellular reticular nucleus (GRNs) executes a vital role in locomotor recovery after spinal cord injury. However, due to its unique anatomical location deep within the brainstem, intervening in GRNs for spinal cord injury research is challenging. To address this problem, this study adopted an extracorporeal magnetic stimulation system to observe the effects of selective magnetic stimulation of GRNs with iron oxide nanoparticles combined treadmill training on locomotor recovery after spinal cord injury, and explored the possible mechanisms. Superparamagnetic iron oxide (SPIO) nanoparticles were stereotactically injected into bilateral GRNs of mice with moderate T10 spinal cord contusion. Eight-week selective magnetic stimulation produced by extracorporeal magnetic stimulation system (MSS) combined with treadmill training was adopted for the animals from one week after surgery. Locomotor function of mice was evaluated by the Basso Mouse Scale, Grid-walking test and Treadscan analysis. Brain MRI, anterograde virus tracer and immunofluorescence staining were applied to observe the tissue compatibility of SPIO in GRNs, trace GRNs' projections and evaluate neurotransmitters' expression in spinal cord respectively. Motor-evoked potentials and H reflex were collected for assessing the integrity of cortical spinal tract and the excitation of motor neurons in anterior horn. (1) SPIO persisted in GRNs for a minimum of 24 weeks without inducing apoptosis of GRN cells, and degraded slowly over time. (2) MSS-enabled treadmill training dramatically improved locomotor performances of injured mice, and promoted cortico-reticulo-spinal circuit reorganization. (3) MSS-enabled treadmill training took superimposed roles through both activating GRNs to drive more projections of GRNs across lesion site and rebalancing neurotransmitters' expression in anterior horn of lumbar spinal cord. These results indicate that selective MSS intervention of GRNs potentially serves as an innovative strategy to promote more spared fibers of GRNs across lesion site and rebalance neurotransmitters' expression after spinal cord injury, paving the way for the structural remodeling of neural systems collaborating with exercise training, thus ultimately contributing to the reconstruction of cortico-reticulo-spinal circuit.

Multi-metric predictors of radiofrequency-treated trigeminal neuralgias.

Evaluation of neurovascular compression-related trigeminal neuralgia (NVC-TN) and its resolution through microvascular decompression are demonstrable by MRI and intraoperatively [Leal et al. (Atrophic changes in the trigeminal nerves of patients with trigeminal neuralgia due to neurovascular compression and their association with the severity of compression and clinical outcomes: Clinical article. J Neurosurg. 2014;120(6):1484-1495)]. Non-NVC-TNs treated by radiofrequency (RF) lack such detectable features. Multimodal integration of pre-surgical diffusion tensor imaging (DTI) and volumetry (VOL) with intraoperative neurophysiology (ION) could improve understanding and performance of RF among non-NVC-TN. We hypothesized that DTI disturbances' localization (central relay versus peripherally) rather than their values bares the most significant predictive value upon outcome and that ION could quantitatively both localize and assist RF of affected branches. The first pre-surgical step evaluated the differences between affected and non-affected sides (by DTI and VOL). Four TN's segments were studied, from peripheral to central relay: Meckel's cave-trigeminal ganglion (MC-TGN), cisternal portion, root entry zone (REZ) and spinal tract [Lin et al. (Flatness of the Meckel cave may cause primary trigeminal neuralgia: A radiomics-based study. J Headache Pain. 2021;22(1):104)]. In the second intraoperative step, we used both ION and patient's testimonies to confirm the localization of the affected branch, evolving hypoesthesia, pain reduction and monitoring of adverse effects [Sindou (Neurophysiological navigation in the trigeminal nerve: Use of masticatory responses and facial motor responses evoked by electrical stimulation of the trigeminal rootlets for RF-thermorhizotomy guidance. Stereotact Funct Neurosurg. 1999;73(1-4):117-121); Sindou and Tatli (Traitement de la névralgie trigéminale par thermorhizotomie. Neurochirurgie. 2009;55(2):203-210)]. Last and postoperatively, each data set's features and correlation with short-term (3 months) and long-term outcomes (23.5 ± 6.7 months) were independently analysed and blind to each other. Finally, we designed a multimodal predictive model. Sixteen non-NVC-TN patients (mean 53.6 ± SD years old) with mean duration of 6.56 ± 4.1 years (75% right TN; 43.8% V3) were included. After 23.5 ± 6.7 months, 14/16 were good responders. Age, gender, TN duration and side/branch did not correlate with outcomes. Affected sides showed significant DTI disturbances in both peripheral (MC-TGNs) and central-relay (REZ) segments. However, worse outcome correlated only with REZ-located DTI disturbances (P = 0.04; r = 0.53). Concerning volumetry, affected MC-TGNs were abnormally flatter: lower volumes and surface area correlated with worse outcomes (both P = 0.033; r = 0.55 and 0.77, respectively). Intraoperatively, ION could not differ the affected from non-affected branch. However, the magnitude of ION's amplitude reduction (ION-Δ-Amplitude) had the most significant correlation with outcomes (r = 0.86; P < 0.00006). It was higher among responders [68.4% (50-82%)], and a <40% reduction characterized non-responders [36.7% (0-40%)]. Multiple regression showed that ION-Δ-Amplitude, centrally located only REZ DTI integrity and MC-TGN flatness explain 82.2% of the variance of post-RF visual analogue score. Integration of pre-surgical DTI-VOL with ION-Δ-Amplitude suggests a multi-metric predictive model of post-RF outcome in non-NVC-TN. In multiple regression, central-relay REZ DTI disturbances and insufficiently reduced excitability (<40%) predicted worse outcome. Quantitative fine-tuned ION tools should be sought for peri-operative evaluation of the affected branches.

An injectable COL6-crosslinked HA-DTPH hydrogel promotes spinal tract-like structure organization during spinal cord regeneration

Serious spinal cord injury (SCI) often leads to disorganized axon regeneration, impeding the accurate projection of neural signals. This study aims to rebuild spinal tracts by targeting the collagen VI (COL6)-induced axonal fasciculation pathway, which is active during spinal cord development but diminishes in regenerating spinal cord. A thiol-modified hyaluronic acid hydrogel crosslinked with COL6 (HAPC) is proposed to reactivate spinal tract morphogenesis for regeneration. Neurites cultured on the HAPC substrate exhibited a straight-bundled pattern, contrasting with the straggly pattern observed in control groups that lacked COL6. The dynamics of axonal aggregation and proximal retraction are determined to drive the formation of straight axon bundles. Experiments on a rat spinal cord transection model demonstrates that treatment with HAPC significantly induces the organization of spinal tract-like structures and promotes the targeted projection of 5-Hydroxytryptamine (5-HT) axons, along with improved functional recovery. These findings highlight the role of COL6 in spinal tract self-organization and the potential of HAPC for treating clinical SCI.

Examination of neuro-inflammation and senescence in brainstem of aged mice latently infected with human alphaherpesvirus 1 (HSV-1)

Human alphaherpesvirus 1 (HSV-1) establishes life-long latency in sensory neurons in trigeminal ganglia (TG), brainstem neurons, and other CNS neurons. Two important segments of the brainstem were examined in this study: principal sensory nucleus of the spinal trigeminal tract (Pr5) because it receives direct afferent inputs from TG, and locus coeruleus (LC) because it is indirectly connected to Pr5 and LC sends axonal projections to cortical structures, which may facilitate viral spread from brainstem to the brain. The only viral gene abundantly expressed during latency is the latency associated transcript (LAT). Previous studies revealed 8-week old female C57Bl/6 mice infected with a LAT null mutant (dLAT2903) versus wild-type (wt) HSV-1 exhibit higher levels of senescence markers and inflammation in LC of females. New studies revealed 1-year old mice latently infected with wt HSV-1 or dLAT2903 contained differences in neuroinflammation and senescence in Pr5 and LC versus young mice. In summary, these studies confirm HSV-1 promotes neuro-inflammation in the brainstem, which may accelerate neurodegenerative disease.

Neuropathic Pain Secondary to Multiple Sclerosis: A Narrative Review.

Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system (CNS). Neuropathic pain in MS is a debilitating symptom that significantly impairs the quality of life for a substantial proportion of MS patients. Neuropathic pain in MS stems primarily from demyelination, axonal loss, CNS inflammation, and direct damage to the myelin sheath, leading to pain manifestations such as ongoing extremity pain, Lhermitte's phenomenon, and trigeminal neuralgia (TN). The pathophysiological mechanisms behind MS-related neuropathic pain are explored in this review, highlighting central sensitization, neural dysfunction, spinal thalamic tract dysfunction, and inflammatory processes that exacerbate neuronal damage. Neuropathic pain in MS necessitates comprehensive assessment tools and neurophysiological tests to differentiate neuropathic pain from other MS symptoms accurately. Treatment strategies for MS-related neuropathic pain encompass pharmacological interventions, including anticonvulsants and antidepressants, and emerging therapies targeting specific inflammatory processes. The review advocates for a holistic approach to management, incorporating innovative treatments and multidisciplinary strategies to address both the physical symptoms and psychosocial aspects of this disorder. This comprehensive overview underscores the importance of ongoing research into targeted therapies to improve patient outcomes and enhance the quality of life for those affected by MS.

Contribution of changes in the spinal cord and brain to the onset and progression of hand clumsiness symptoms in cervical spondylotic myelopathy.

Cervical spondylotic myelopathy (CSM) stands as the most prevalent form of spinal cord injury, frequently prompting various changes in both the brain and spinal cord. However, the precise nature of these changes within the brains and spinal cords of CSM patients experiencing hand clumsiness (HCL) symptoms has remained elusive. The authors aimed to scrutinize these alterations and explore potential links between these changes and the onset of HCL symptoms. Using the modified Japanese Orthopaedic Association (mJOA) scale, the authors classified CSM patients into two groups: those without HCL and those with HCL. The authors performed voxel-wise z-score transformation amplitude of low-frequency fluctuations (zALFF) and resting-state functional connectivity (FC) evaluations in the brain. Additionally, they used the Spinal Cord Toolbox to calculate the fractional anisotropy (FA) of spinal cord tracts. The analysis also encompassed an examination of the correlation of these measures with improvements in mJOA scores. Significant disparities in zALFF values surfaced in the right calcarine, right cuneus, right precuneus, right middle occipital gyrus (MOG), right superior occipital gyrus (SOG), and right superior parietal gyrus (SPG) between healthy controls (HC), patients without HCL, and patients with HCL, primarily within the visual cortex. In the patient group, patients with HCL displayed reduced FC between the right calcarine, right MOG, right SOG, right SPG, right SFG, bilateral MFG, and left median cingulate and paracingulate gyri when compared with patients without HCL. Moreover, significant differences in FA values of the corticospinal tract (CST) and reticulospinal tract (REST) at the C2 level emerged among HC, patients without HCL, and patients with HCL. Notably, zALFF, FC, and FA values in specific brain regions and spinal cord tracts exhibited correlations with mJOA upper-extremity scores. Additionally, FA values of the CST and REST correlated with zALFF values in the right calcarine, right MOG, right SOG, and right SPG. Alterations within brain regions associated with the visual cortex, the fronto-parietal-occipital attention network, and spinal cord pathways appear to play a substantial role in the emergence and progression of HCL symptoms. Furthermore, the existence of a potential connection between the spinal cord and the brain suggests that this link might be related to the clinical symptoms of CSM.

Direct comparison of Hoxb8-driven reporter distribution in the brains of four transgenic mouse lines: towards a spinofugal projection atlas.

Hox genes govern rostro-caudal identity along the developing spinal cord, which has a well-defined division of function between dorsal (sensory) and ventral (motor) halves. Here we exploit developmental Hoxb8 expression, normally restricted to the dorsal cord below the obex, to genetically label spinal cord-to-brain ("spinofugal") axons. We crossed two targeted (knock-in) and two non-targeted recombinase-expressing lines (Hoxb8-IRES-Cre and Hoxb8-T2AFlpO; Hoxb8-Cre and Hoxb8-FlpO, respectively) with appropriate tdtomato-expressing reporter strains. Serial sectioning, confocal and superresolution microscopy, as well as light-sheet imaging was used to reveal robust labeling of ascending axons and their terminals in expected and unexpected regions. This strategy provides unprecedented anatomical detail of ascending spinal tracts anterior to the brainstem, and reveals a previously undescribed decussating tract in the ventral hypothalamus (the spinofugal hypothalamic decussating tract, or shxt). The absence of Hoxb8-suppressing elements led to multiple instances of ectopic reporter expression in Hoxb8-Cre mice (retinal ganglion and vomeronasal axons, anterior thalamic nuclei and their projections to the anterior cingulate and retrosplenial cortices and subiculum, and a population of astrocytes at the cephalic flexure) and Hoxb8-FlpO mice (Cajal-Retzius cells of the dentate gyrus, and mesenchymal cells of the choroid plexus). While targeted transgenic lines were similar in terms of known spinofugal projections, Hoxb8-IRES-Cre reporters had an additional projection to the core of the facial motor nucleus, and more abundant Hoxb8-lineage microglia scattered throughout the brain than Hoxb8-T2A-FlpO (or any other) mice, suggesting dysregulated Hoxb8-driven reporter expression in one or both lines. This work complements structural and connectivity atlases of the mouse central nervous system, and provides a platform upon which their reactions to injury or disease can be studied. Ectopic Hoxb8-driven recombinase expression may also be a useful tool to study structure and function of other cell populations in non-targeted lines.

Clinical Neurophysiological Methods Verify Improvement in the Motor Neural Transmission in Patients with Surgically Treated Idiopathic Scoliosis in Long-Term Follow-up

The evaluation of patients after the surgical correction of idiopathic scoliosis in a long-term follow-up with clinical neurophysiological methods has not been presented in detail. This study aimed to compare the results of neurophysiological studies in 45 girls with scoliosis of Lenke types 1–3 performed pre- (T0) and postoperatively, 1 week after surgery (T1) and 6 months after surgery (T2). The parameter values of the surface electromyography while attempting maximal contraction (mcsEMG) and the transcranial motor-evoked potentials (MEPs) recorded in the anterior tibial muscles, as well as the electroneurography (ENG) of the peripheral transmission in the peroneal nerve motor fibers, were compared. The results indicate that efferent neural conduction function both centrally and peripherally, and TA muscle function slightly improved immediately after the surgical correction of scoliosis, and further normalization appeared after six months in the long-term follow-up (at p = 0.03). The sEMG recordings indicate that half a year after surgical treatment in IS patients, the TA muscle motor unit recruitment function, as well as the muscle strength evaluated with Lovett’s scale, was comparable to the normal condition. The ENG recording results indicated a gradual reduction in the motor fiber injury symptoms, mainly of the axonal type, in the peroneal nerves. The surgeries also improved the lumbar ventral roots’ neural transmission to a normal functional status. The MEP amplitude parameter values recorded after the surgical scoliosis corrections in T1 indicated a slight improvement in the efferent transmission of neural impulses within the fibers of the spinal tracts; in the long-term T2 observation period, they reached values comparable to those recorded in healthy volunteers, bilaterally. Preoperatively (T0), the results of all the neurophysiological study parameters in the IS patients were asymmetrical at p = 0.036–0.05 and recorded as worse on the concave side, suggesting the lateralization of neurological motor deficits. One week postoperatively (T1), this asymmetry was recorded as gradually reduced, showing almost no difference between the right and left sides six months later (T2). The presented algorithm for the neurophysiological assessments performed in the pre-, intra-, and long-term postoperative periods using the mcsEMG, MEP, and ENG neurophysiological examinations, together with the clinical studies, may help in the comprehensive functional evaluation of the spinal cord tracts and ventral root neural conduction, which allows the detection of the subclinical neurological changes related to scoliosis itself and the consequences of the corrective surgery. Such an evaluation can also be significant in making final decisions regarding IS surgeries and their personalization after attempting conservative treatments with bracing and kinesiotherapy. Neurophysiological studies, as a sensitive biomarker, allowed us to predict and ascertain the final result of IS treatment in the long-term follow-up, which showed the health status of patients as being comparable to that of healthy volunteers.

Presumable role of tennis in the evolution of listesic damage: focus on the technical gesture of the forehand in open stance in amateurs

Although there is an individual style by virtue of which each athlete interprets the basic technical gesture by mediating it according to their own biomechanical characteristics, most tennis instructors suggest executing the forehand in open position or, borrowing the term from the English language, in open stance (shoulders parallel to the net) as there is a potential increase in ball speed. All, however, to the detriment of the integrity of the spinal tract, especially in genetically and anatomically predisposed subjects (Lisi, 2018). Without wanting to go into the merits of professional tennis, the Authors advise - in those who approach racket sport as an amateur without ambitions of excellence - the use of the traditional closed position (shoulders perpendicular to the net) or, at least, a semi-open stance as it is sufficient to limit any harmful consequences at the level of the spine and to maintain one's competitive performance (Lisi, 2018).

178 Brains on the Pitch: Investigating the Neurophysiological and Neurocognitive Effects of Repetitive Head Impacts in Adolescent Female Soccer Players During a Single Season

INTRODUCTION: Repetitive exposure to head impact in contact sports has raised concerns for potential long-term structural and functional neurologic effects. This relationship has been minimally explored in female athletes, with conflicting results arising from the limited reports on this topic. METHODS: Prospective cohort design with pre- and post-season assessments of neurocognitive function, transcranial magnetic stimulation (TMS), and diffusion tensor imaging (DTI). Neurocognitive battery evaluated processing speed, memory, and executive function domains via computerized (ImPACT) and paper-and-pencil testing. TMS assessments included motor evoked potential onset; interhemispheric conduction times; intercortical and intracortical inhibition. DTI measures included fractional anisotropy (FA) for white matter tracts of interest, including: posterior limb of internal capsule; cortical spinal tract; corpus callosum - selected for common involvement in traumatic brain injury within other studies. RESULTS: One player was officially diagnosed with concussion and was included in analysis. Neurocognitive performance was intact relative to same aged peers, and there were no significant differences over the season based on mean reliable change indices (-0.79-0.93). Paired t-test analysis indicated that the TMS measures were not significantly different between the two timepoints. Furthermore, DTI FA values and TMS measures were not notably different pre- versus postseason. CONCLUSIONS: In this cohort of high school female athletes, we did not observe significant anatomic, physiologic, or functional effects from repetitive head impacts. Our findings contradict previous studies that showed significant neurophysiologic and neurocognitive changes, even in the absence of clinically-observed concussion. Further research is needed to fully understand the long-term consequences of repetitive head impacts in female athletes and to develop effective strategies for mitigating potential risks.

Evaluation of the structural integrity of different spinal cord tracts with magnetization transfer ratio in degenerative cervical myelopathy.

Degenerative cervical myelopathy (DCM) is a common cause of spinal cord dysfunction. In this study, we explored the potential of magnetization transfer ratio (MTR) for evaluating the structural integrity of spinal cord tracts in patients with clinically significant DCM. Fifty-three patients with DCM and 41 patients with cervical radiculopathy were evaluated using high-resolution cervical spinal cord magnetic resonance imaging (MRI), which included the magnetization transfer technique. MRI data were analyzed with the Spinal Cord Toolbox (v5.5); MTR values in each spinal tract were calculated and compared between groups after correction for patient age and sex. Correlations between MTR values and patients' clinical disability rate were also evaluated. A statistically significant reduction in the average MTR of the spinal cord white matter, as well as the MTR of the ventral columns and lateral funiculi, was revealed in the DCM group (adjusted p < 0.01 for all comparisons). Furthermore, reductions in MTR values in the fasciculus cuneatus, spinocerebellar, rubrospinal, and reticulospinal tracts were found in patients with DCM (adjusted p < 0.01 for all comparisons). Positive correlations between the JOA score and the MTR within the ventral columns of the spinal cord (R = 0.38, adjusted p < 0.05) and the ventral spinocerebellar tract (R = 0.41, adjusted p < 0.05) were revealed. The findings of our study indicate that demyelination in patients with DCM primarily affects the spinal tracts of the extrapyramidal system, and the extent of these changes is related to the severity of the condition.