Trend differences in cervical spinal cord injuries before and after the coronavirus disease 2019 pandemic.

STUDY DESIGN: Cross-Sectional Study. OBJECTIVES: To investigate the changes in the characteristics of cervical spinal cord injuries (CSCI) before and after the coronavirus disease 2019 (COVID-19) pandemic among patients transported to our hospital in Japan. SETTING: Hospital with an emergency center in Chiba, Japan. METHODS: Patients eligible for the study were those transported within 24 h of injury and diagnosed with cervical spinal cord injury between January 2018 and December 2021 at our hospital. Medical records were retrospectively examined to investigate the number and characteristics of patients with CSCI. The clinical variables of patients with CSCI were compared according to the time of admission as related to the COVID-19 pandemic: 2018-19 (before) or 2020-21 (after). RESULTS: The total number of patients with CSCI from 2018 to 2021 was 108, with 57 before the COVID-19 pandemic and 51 after the COVID-19 pandemic. The number of severe cases with an injury severity score (ISS) of >16 decreased after COVID-19 (p < 0.05). Falls on level surfaces were the most common cause of injury both before and after COVID-19. Although the ranking of traffic accidents decreased after COVID-19, among those, the number of bicycle injuries tended to increase. CONCLUSIONS: The number of serious cases with an ISS > 16 decreased, presumably because of the decline in high-energy trauma due to the background decrease in the number of traffic accidents.

Decoding of unimanual and bimanual reach-and-grasp actions from EMG and IMU signals in persons with cervical spinal cord injury.

Objective. Chronic motor impairments of arms and hands as the consequence of a cervical spinal cord injury (SCI) have a tremendous impact on activities of daily life. A considerable number of people however retain minimal voluntary motor control in the paralyzed parts of the upper limbs that are measurable by electromyography (EMG) and inertial measurement units (IMUs). An integration into human-machine interfaces (HMIs) holds promise for reliable grasp intent detection and intuitive assistive device control.Approach. We used a multimodal HMI incorporating EMG and IMU data to decode reach-and-grasp movements of groups of persons with cervical SCI (n = 4) and without (control, n = 13). A post-hoc evaluation of control group data aimed to identify optimal parameters for online, co-adaptive closed-loop HMI sessions with persons with cervical SCI. We compared the performance of real-time, Random Forest-based movement versus rest (2 classes) and grasp type predictors (3 classes) with respect to their co-adaptation and evaluated the underlying feature importance maps.Main results. Our multimodal approach enabled grasp decoding significantly better than EMG or IMU data alone (p<0.05). We found the 0.25 s directly prior to the first touch of an object to hold the most discriminative information. Our HMIs correctly predicted 79.3 ± STD 7.4 (102.7 ± STD 2.3 control group) out of 105 trials with grand average movement vs. rest prediction accuracies above 99.64% (100% sensitivity) and grasp prediction accuracies of 75.39 ± STD 13.77% (97.66 ± STD 5.48% control group). Co-adaption led to higher prediction accuracies with time, and we could identify adaptions in feature importances unique to each participant with cervical SCI.Significance. Our findings foster the development of multimodal and adaptive HMIs to allow persons with cervical SCI the intuitive control of assistive devices to improve personal independence.

Cervical spinal cord hemisection impacts sigh and the respiratory reset in male rats.

Cervical spinal cord injury impacts ventilatory and non-ventilatory functions of the diaphragm muscle (DIAm) and contributes to clinical morbidity and mortality in the afflicted population. Periodically, integrated brainstem neural circuit activity drives the DIAm to generate a markedly augmented effort or sigh-which plays an important role in preventing atelectasis and thus maintaining lung function. Across species, the general pattern of DIAm efforts during a normal sigh is variable in amplitude and the extent of post-sigh "apnea" (i.e., the post-sigh inter-breath interval). This post-sigh inter-breath interval acts as a respiratory reset, following the interruption of regular respiratory rhythm by sigh. We examined the impact of upper cervical (C2 ) spinal cord hemisection (C2 SH) on the transdiaphragmatic pressure (Pdi ) generated during sighs and the post-sigh respiratory reset in rats. Sighs were identified in Pdi traces by their characteristic biphasic pattern. We found that C2 SH results in a reduction of Pdi during both eupnea and sighs, and a decrease in the immediate post-sigh breath interval. These results are consistent with partial removal of descending excitatory synaptic inputs to phrenic motor neurons that results from C2 SH. Following cervical spinal cord injury, a reduction in the amplitude of Pdi during sighs may compromise the maintenance of normal lung function.

MicroRNA-133b Dysregulation in a Mouse Model of Cervical Contusion Injury.

Our previous research studies have demonstrated the role of microRNA133b (miR133b) in healing the contused spinal cord when administered either intranasally or intravenously 24 h following an injury. While our data showed beneficial effects of exogenous miR133b delivered within hours of a spinal cord injury (SCI), the kinetics of endogenous miR133b levels in the contused spinal cord and rostral/caudal segments of the injury were not fully investigated. In this study, we examined the miR133b dysregulation in a mouse model of moderate unilateral contusion injury at the fifth cervical (C5) level. Between 30 min and 7 days post-injury, mice were euthanized and tissues were collected from different areas of the spinal cord, ipsilateral and contralateral prefrontal motor cortices, and off-targets such as lung and spleen. The endogenous level of miR133b was determined by RT-qPCR. We found that after SCI, (a) most changes in miR133b level were restricted to the injured area with very limited alterations in the rostral and caudal parts relative to the injury site, (b) acute changes in the endogenous levels were predominantly specific to the lesion site with delayed miR133b changes in the motor cortex, and (c) ipsilateral and contralateral hemispheres responded differently to unilateral SCI. Our results suggest that the therapeutic window for exogenous miR133b therapy begins earlier than 24 h post-injury and potentially lasts longer than 7 days.

Medulla and cervical cord contrast-induced encephalopathy detected by neuromonitoring during coil embolization of posterior circulation aneurysms.

Understanding the risks of contrast-induced encephalopathy (CIE), a serious complication of contrast agents, is crucial in endovascular treatment. We present the case of a 73-year-old woman who developed CIE in the medulla and cervical cord during coil embolization for unruptured left basilar-superior cerebellar artery and basilar artery tip aneurysms. The CIE was identified via neuromonitoring. In this case, spinal cord ischemia might have occurred due to reduced perfusion pressure after inserting the distal access catheter (DAC) in the vertebral artery. Multiple injections of contrast medium via the DAC during coil embolization likely contributed to an unusual form of CIE. Extreme caution is warranted during endovascular treatments involving the posterior circulation, due to the relatively high incidence of contrast-mediated encephalopathy, which can lead to severe consequences such as perforator infarction. Neuromonitoring is very useful for the early detection of neurological changes, particularly because intraoperative angiography may not reveal all irregularities.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Alterations in the spinal cord, trigeminal nerve ganglion, and infraorbital nerve through inducing compression of the dorsal horn region at the upper cervical cord in trigeminal neuralgia.

BACKGROUND: Idiopathic trigeminal neuralgia (TN) cases encountered frequently in daily practice indicate significant gaps that still need to be illuminated in the etiopathogenesis. In this study, a novel TN animal model was developed by compressing the dorsal horn (DH) of the upper cervical spinal cord. METHODS: Eighteen rabbits were equally divided into three groups, namely control (CG), sham (SG), and spinal cord compression (SCC) groups. External pressure was applied to the left side at the C3 level in the SCC group. Dorsal hemilaminectomy was performed in the SG, and the operative side was closed without compression. No procedure was implemented in the control group. Samples from the SC, TG, and ION were taken after seven days. For the histochemical staining, damage and axons with myelin were scored using Hematoxylin and Eosin and Toluidine Blue, respectively. Immunohistochemistry, nuclei, apoptotic index, astrocyte activity, microglial labeling, and CD11b were evaluated. RESULTS: Mechanical allodynia was observed on the ipsilateral side in the SCC group. In addition, both the TG and ION were partially damaged from SC compression, which resulted in significant histopathological changes and increased the expression of all markers in both the SG and SCC groups compared to that in the CG. There was a notable increase in tissue damage, an increase in the number of apoptotic nuclei, an increase in the apoptotic index, an indication of astrocytic gliosis, and an upsurge in microglial cells. Significant increases were noted in the SG group, whereas more pronounced significant increases were observed in the SCC group. Transmission electron microscopy revealed myelin damage, mitochondrial disruption, and increased anchoring particles. Similar changes were observed to a lesser extent in the contralateral spinal cord. CONCLUSION: Ipsilateral trigeminal neuropathic pain was developed due to upper cervical SCC. The clinical finding is supported by immunohistochemical and ultrastructural changes. Thus, alterations in the DH due to compression of the upper cervical region should be considered as a potential cause of idiopathic TN.

Diffusion tensor imaging within the healthy cervical spinal cord: Within- participants reliability and measurement error.

BACKGROUND: Diffusion tensor imaging (DTI) is a promising technique for the visualization of the cervical spinal cord (CSC) in vivo. It provides information about the tissue structure of axonal white matter, and it is thought to be more sensitive than other MR imaging techniques for the evaluation of damage to tracts in the spinal cord. AIM: The purpose of this study was to determine the within-participants reliability and error magnitude of measurements of DTI metrics in healthy human CSC. METHODS: A total of twenty healthy controls (10 male, mean age: 33.9 ± 3.5 years, 10 females, mean age: 47.5 ± 14.4 years), with no family history of any neurological disorders or a contraindication to MRI scanning were recruited over a period of two months. Each participant was scanned twice with an MRI 3 T scanner using standard DTI sequences. Spinal Cord Toolbox (SCT) software was used for image post-processing. Data were first corrected for motion artefact, then segmented, registered to a template, and then the DTI metrics were computed. The within-participants coefficients of variation (CV%), the single and average within-participants intraclass correlation coefficients (ICC) and Bland-Altman plots for WM, VC, DC and LC fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were determined for the cervical spinal cord (between the 2nd and 5th cervical vertebrae). RESULTS: DTI metrics showed poor to excellent within-participants reliability for both single and average ICC and moderate to high reproducibility for CV%, all variation dependent on the location of the ROI. The BA plots showed good within-participants agreement between the scan-rescan values. CONCLUSION: Results from this reliability study demonstrate that clinical trials using the DTI technique are feasible and that DTI, in particular regions of the cord is suitable for use for the monitoring of degenerative WM changes.

Effects of the walking independence on lower extremity and trunk muscle activity during straight-leg raising following incomplete cervical cord injury.

The purpose of this study was to compare the acceleration and surface electromyography (EMG) of the lower extremity and trunk muscles during straight-leg raising (SLR) in patients with incomplete cervical cord injury according to their levels of walking independence. Twenty-four patients were measured acceleration and EMG during SLR held for 10 s. Data were analyzed separately for the dominant and nondominant sides and compared between the nonindependent (NI) and independent (ID) groups based on their levels of walking independence. Frequency analysis of the EMG showed that the high-frequency (HF) band of the contralateral biceps femoris (BF) in the ID group and bands below the medium-frequency (MF) of the BF and the HF and MF bands of the rectus abdominis in the NI group were significantly higher during dominant and nondominant SLR. During the nondominant SLR, the low-frequency band of the internal oblique and the MF band of the external oblique were significantly higher in the NI group. The ID group mobilized muscle fiber type 2 of the BF, whereas the NI group mobilized type 1 of the BF and types 2 and 1 of the trunk muscles to stabilize the pelvis. This result was more pronounced during the nondominant SLR.

What contributes to disability in progressive MS? A brain and cervical cord-matched quantitative MRI study.

BACKGROUND: We assessed the ability of a brain-and-cord-matched quantitative magnetic resonance imaging (qMRI) protocol to differentiate patients with progressive multiple sclerosis (PMS) from controls, in terms of normal-appearing (NA) tissue abnormalities, and explain disability. METHODS: A total of 27 patients and 16 controls were assessed on the Expanded Disability Status Scale (EDSS), 25-foot timed walk (TWT), 9-hole peg (9HPT) and symbol digit modalities (SDMT) tests. All underwent 3T brain and (C2-C3) cord structural imaging and qMRI (relaxometry, quantitative magnetisation transfer, multi-shell diffusion-weighted imaging), using a fast brain-and-cord-matched protocol with brain-and-cord-unified imaging readouts. Lesion and NA-tissue volumes and qMRI metrics reflecting demyelination and axonal loss were obtained. Random forest analyses identified the most relevant volumetric/qMRI measures to clinical outcomes. Confounder-adjusted linear regression estimated the actual MRI-clinical associations. RESULTS: Several qMRI/volumetric differences between patients and controls were observed (p < 0.01). Higher NA-deep grey matter quantitative-T1 (EDSS: beta = 7.96, p = 0.006; 9HPT: beta = -0.09, p = 0.004), higher NA-white matter orientation dispersion index (TWT: beta = -3.21, p = 0.005; SDMT: beta = -847.10, p < 0.001), lower whole-cord bound pool fraction (9HPT: beta = 0.79, p = 0.001) and higher NA-cortical grey matter quantitative-T1 (SDMT = -94.31, p < 0.001) emerged as particularly relevant predictors of greater disability. CONCLUSION: Fast brain-and-cord-matched qMRI protocols are feasible and identify demyelination - combined with other mechanisms - as key for disability accumulation in PMS.

Limited utility of adding 3T cervical spinal cord MRI to monitor disease activity in multiple sclerosis.

BACKGROUND: Performing routine brain magnetic resonance imaging (MRI) is widely accepted as the standard of care for disease monitoring in multiple sclerosis (MS), but the utility of performing routine spinal cord (SC) MRI for this purpose is still debatable. OBJECTIVE: This study aimed to measure the frequency of new isolated cervical spinal cord lesions (CSLs) in people with MS (pwMS) undergoing routine brain and cervical SC-MRI for disease monitoring and determine the factors associated with the development of new CSLs and their prognostic value. METHODS: We retrospectively identified 1576 pwMS who underwent follow-up 3T brain and cervical SC-MRI over a 9-month period. MRI was reviewed for the presence of new brain lesions (BLs) and CSLs. Clinical records were reviewed for interval relapses between sequential scans and subsequent clinical relapse and disability worsening after the follow-up MRI. RESULTS: In 1285 pwMS (median interval: 13-14 months) who were clinically stable with respect to relapses, 73 (5.7%) had new CSLs, of which 49 (3.8%) had concomitant new BLs and 24 (1.9%) had new isolated CSLs only. New asymptomatic CSLs were associated with ⩾ 3 prior relapses (p = 0.04), no disease-modifying therapy (DMT) use (p = 0.048), and ⩾ 3 new BLs (p < 0.001); ⩾ 3 new BLs (OR: 7.11, 95% CI: 4.3-11.7, p < 0.001) remained independently associated with new CSLs on multivariable analysis. Having new asymptomatic CSLs was not independently associated with subsequent relapse or disability worsening after the follow-up MRI (median follow-up time of 26 months). CONCLUSION: Routine brain and cervical SC-MRI detected new isolated CSLs in only < 2% of clinically stable pwMS. Developing new asymptomatic CSLs was associated with concomitant new BLs and did not confer an independent increased risk of relapse or disability worsening. Performing SC-MRI may not be warranted for routine monitoring in most pwMS, and performing only brain MRI may be sufficient to capture the vast majority of clinically silent disease activity.

An infratentorial dural arteriovenous fistula mimicking cervical myelopathy: A case report.

Dural arteriovenous fistulas may have insidious clinical presentations and are often challenging to diagnose. A small number of cases have been associated with perimedullary venous congestion and cord oedema, mimicking common pathologies, such as cervical myelopathy. We describe a case report of a patient presenting with a constellation of symptoms and radiological signs mimicking C5/6 cervical myelopathy secondary to disc herniation. The patient was managed with anterior cervical discectomy and fusion, with postoperative neurological deterioration unresponsive to steroid therapy. This prompted further investigation of other pathologies. An infratentorial Cognard 5 and Borden type 3 dural arteriovenous fistula was diagnosed on 6-vessel DSA and managed with onyx embolization. Marked improvement of neurological symptoms, notably bilateral lower limb weakness, was achieved postoperatively. In summary, this case demonstrates the importance of considering alternative, less common pathologies that involve the cervical spinal cord when neurological improvement is not achieved following decompressive surgery for cervical myelopathy.

Thermal stimulus task fMRI in the cervical spinal cord at 7 Tesla.

Although functional magnetic resonance imaging (fMRI) is widely applied in the brain, fMRI of the spinal cord is more technically demanding. Proximity to the vertebral column and lungs results in strong spatial inhomogeneity and temporal fluctuations in B0 . Increasing field strength enables higher spatial resolution and improved sensitivity to blood oxygenation level-dependent (BOLD) signal, but amplifies the effects of B0 inhomogeneity. In this work, we present the first task fMRI in the spinal cord at 7 T. Further, we compare the performance of single-shot and multi-shot 2D echo-planar imaging (EPI) protocols, which differ in sensitivity to spatial and temporal B0 inhomogeneity. The cervical spinal cords of 11 healthy volunteers were scanned at 7 T using single-shot 2D EPI at 0.75 mm in-plane resolution and multi-shot 2D EPI at 0.75 and 0.6 mm in-plane resolutions. All protocols used 3 mm slice thickness. For each protocol, the BOLD response to 13 10-s noxious thermal stimuli applied to the right thumb was acquired in a 10-min fMRI run. Image quality, temporal signal to noise ratio (SNR), and BOLD activation (percent signal change and z-stat) at both individual- and group-level were evaluated between the protocols. Temporal SNR was highest in single-shot and multi-shot 0.75 mm protocols. In group-level analyses, activation clusters appeared in all protocols in the ipsilateral dorsal quadrant at the expected C6 neurological level. In individual-level analyses, activation clusters at the expected level were detected in some, but not all subjects and protocols. Single-shot 0.75 mm generally produced the highest mean z-statistic, while multi-shot 0.60 mm produced the best-localized activation clusters and the least geometric distortion. Larger than expected within-subject segmental variation of BOLD activation along the cord was observed. Group-level sensory task fMRI of the cervical spinal cord is feasible at 7 T with single-shot or multi-shot EPI. The best choice of protocol will likely depend on the relative importance of sensitivity to activation versus spatial localization of activation for a given experiment. PRACTITIONER POINTS: First stimulus task fMRI results in the spinal cord at 7 T. Single-shot 0.75 mm 2D EPI produced the highest mean z-statistic. Multi-shot 0.60 mm 2D EPI provided the best-localized activation and least distortion.

[Application of super-resolution and ultrafast ultrasound to reveal the characteristics of vascular blood flow changes after rat spinal cord injury at different segments].

Objective: To investigate the changes of spinal vascular blood flow in SD rats after cervical, thoracic and lumbar spinal cord injury (SCI) using super-resolution ultrafast ultrasound technology. Methods: A total of 9 SD rats were used to construct SCI models at different segments using a 50 g aneurysm clip. Super-resolution ultrafast ultrasound technology was used to perform vascular blood flow imaging on the spinal cord of rats before and after injury at 6 hours, obtaining quantitative information such as spinal cord vascular density and blood flow velocity. Results: Ultrasound imaging showed that after SCI, the vascular density in the thoracic segment decreased (18.16%±1.04%) more than in the cervical segment (11.42%±1.39%) and lumbar segment (13.88%±1.43%, both P<0.05). The length of the spinal cord with decreased vascular density in the thoracic segment [(4.80±0.34)mm] was longer than that in the cervical segment [(2.80±0.57)mm] and lumbar segment [(3.10±0.36)mm, both P<0.05]. After injury, the decrease of blood flow in the thoracic segment [(8.87±0.85)ml/min] was higher than that in the cervical segment [(4.88±0.56)ml/min] and lumbar segment [(6.19±0.71)ml/min, both P<0.05]. HE staining and Nissl staining showed that the proportion of cavity area after thoracic SCI (11.53%±0.93%) was higher than that in the cervical segment (4.90%±1.72%) and lumbar segment (7.64%±0.84%, both P<0.05). The number of Nissl bodies in the thoracic segment (18.0±5.3) was also lower than that in the cervical segment (32.3±5.1) and lumbar segment (37.0±5.6) (both P<0.05). Conclusions: There are different changes in vascular blood flow after SCI in different segments of rats. The same injury causes the most severe damage to blood vessels in the thoracic spinal cord, followed by the lumbar spinal cord, and the cervical spinal cord has the least damage.

Spinal fMRI demonstrates segmental organisation of functionally connected networks in the cervical spinal cord: A test-retest reliability study.

Resting functional magnetic resonance imaging (fMRI) studies have identified intrinsic spinal cord activity, which forms organised motor (ventral) and sensory (dorsal) resting-state networks. However, to facilitate the use of spinal fMRI in, for example, clinical studies, it is crucial to first assess the reliability of the method, particularly given the unique anatomical, physiological, and methodological challenges associated with acquiring the data. Here, we characterise functional connectivity relationships in the cervical cord and assess their between-session test-retest reliability in 23 young healthy volunteers. Resting-state networks were estimated in two ways (1) by estimating seed-to-voxel connectivity maps and (2) by calculating seed-to-seed correlations. Seed regions corresponded to the four grey matter horns (ventral/dorsal and left/right) of C5-C8 segmental levels. Test-retest reliability was assessed using the intraclass correlation coefficient. Spatial overlap of clusters derived from seed-to-voxel analysis between sessions was examined using Dice coefficients. Following seed-to-voxel analysis, we observed distinct unilateral dorsal and ventral organisation of cervical spinal resting-state networks that was largely confined in the rostro-caudal extent to each spinal segmental level, with more sparse connections observed between segments. Additionally, strongest correlations were observed between within-segment ipsilateral dorsal-ventral connections, followed by within-segment dorso-dorsal and ventro-ventral connections. Test-retest reliability of these networks was mixed. Reliability was poor when assessed on a voxelwise level, with more promising indications of reliability when examining the average signal within clusters. Reliability of correlation strength between seeds was highly variable, with the highest reliability achieved in ipsilateral dorsal-ventral and dorso-dorsal/ventro-ventral connectivity. However, the spatial overlap of networks between sessions was excellent. We demonstrate that while test-retest reliability of cervical spinal resting-state networks is mixed, their spatial extent is similar across sessions, suggesting that these networks are characterised by a consistent spatial representation over time.

Influence of Blood Pressure on Acute Cervical Spinal Cord Injury Without Fracture and Dislocation: Results From a Retrospective Analysis.

OBJECTIVE: The objective of this study was to investigate the influence of blood pressure on the severity and functional recovery of patients with acute cervical spinal cord injury (SCI) without fracture and dislocation. METHODS: A retrospective case control study analyzed the data of 40 patients admitted to our orthopedics department (Beijing Tiantan Hospital, Capital Medical University) from January 2013 to February 2021. They were diagnosed as acute cervical SCI without fracture and dislocation. Gender, age, height, weight, history of hypertension, postinjury American Spinal Injury Association grade, postinjury modified Japanese Orthopaedic Association (mJOA) score, postoperative mJOA score, 1-year follow-up mJOA score, preoperative mean arterial pressure (MAP), intramedullary T2 hyperintensity, and hyponatremia were collected. The patients were divided into groups and subgroups based on their history of hypertension and preoperative MAP. The effects of history of hypertension and preoperative MAP on the incidence of T2 hyperintensity, hyponatremia, the improvement rate of the postoperative mJOA and 1-year follow-up mJOA scores were analyzed. RESULTS: Patients with history of hypertension had a lower incidence of intramedullary T2 hyperintensity than patients without history of hypertension (P < 0.05). Patients with history of hypertension and patients with a higher preoperative MAP had better neurological recovery at 1 year of follow-up (P < 0.05). CONCLUSIONS: Blood pressure has great influence on acute cervical SCI without fracture and dislocation. Maintaining a higher preoperative MAP is advantageous for better recovery after SCI. Attention should be paid to the dynamic management of blood pressure to avoid the adverse effects of hypotension after SCI.

Traumatic cervical spinal cord injury: Comparison of two different blood pressure targets on neurological recovery.

BACKGROUND: Controversy exists whether blood pressure augmentation therapy benefits patients suffering from spinal cord injury (SCI). This retrospective comparative study was designed to assess the impact of two different mean arterial pressure (MAP) targets (85-90 mmHg vs. 65-85 mmHg) on neurological recovery after traumatic cervical SCI. METHODS: Fifty-one adult patients with traumatic cervical SCI were retrospectively divided into two groups according to their intensive care unit (ICU) MAP targets: 85-90 mmHg (higher MAP group, n = 32) and 65-85 mmHg (lower MAP group, n = 19). Invasive MAP measurements were stored as 2-min median values for 3-7 days. The severity of SCI (AIS grade and neurological level) was evaluated upon ICU stay and during rehabilitation. Neurological recovery was correlated with individual mean MAP values and with the proportion of MAP values ≥85 mmHg upon the first 3 days (3d-MAP%≥85 ). RESULTS: The initial AIS grades were A 29.4%, B 17.6%, C 31.4%, and D 21.6%. AIS grade improved in 24 patients (47.1%). During ICU care, 82.0% and 36.8% of the measured MAP values reached ≥85 mmHg in the higher and the lower MAP groups, respectively (p < .001). The medians of individual mean MAP values were different between the groups (90.2 mmHg vs. 81.4 mmHg, p < .001). Similarly, 3d-MAP%≥85 was higher in the higher MAP group (85.6% vs. 50.0%, p < .001). However, neurological recovery was not different between the groups, nor did it correlate with individual mean MAP values or 3d-MAP%≥85 . CONCLUSION: The currently recommended MAP target of 85-90 mmHg was not associated with improved outcomes compared to a lower target in patients with traumatic cervical SCI in this cohort.

EphrinB2 knockdown in cervical spinal cord preserves diaphragm innervation in a mutant SOD1 mouse model of ALS.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by motor neuron loss. Importantly, non-neuronal cell types such as astrocytes also play significant roles in disease pathogenesis. However, mechanisms of astrocyte contribution to ALS remain incompletely understood. Astrocyte involvement suggests that transcellular signaling may play a role in disease. We examined contribution of transmembrane signaling molecule ephrinB2 to ALS pathogenesis, in particular its role in driving motor neuron damage by spinal cord astrocytes. In symptomatic SOD1G93A mice (a well-established ALS model), ephrinB2 expression was dramatically increased in ventral horn astrocytes. Reducing ephrinB2 in the cervical spinal cord ventral horn via viral-mediated shRNA delivery reduced motor neuron loss and preserved respiratory function by maintaining phrenic motor neuron innervation of diaphragm. EphrinB2 expression was also elevated in human ALS spinal cord. These findings implicate ephrinB2 upregulation as both a transcellular signaling mechanism in mutant SOD1-associated ALS and a promising therapeutic target.

Chronic Adaptations in the Dorsal Horn Following a Cervical Spinal Cord Injury in Primates.

Spinal cord injury (SCI) is devastating, with limited treatment options and variable outcomes. Most in vivo SCI research has focused on the acute and early post-injury periods, and the promotion of axonal growth, so little is understood about the clinically stable chronic state, axonal growth over time, and what plasticity endures. Here, we followed animals into the chronic phase following SCI, to address this gap. Male macaques received targeted deafferentation, affecting three digits of one hand, and were divided into short (4-6 months) or long-term (11-12 months) groups, based on post-injury survival times. Monkeys were assessed behaviorally, where possible, and all exhibited an initial post-injury deficit in manual dexterity, with gradual functional recovery over 2 months. We previously reported extensive sprouting of somatosensory corticospinal (S1 CST) fibers in the dorsal horn in the first five post-injury months. Here, we show that by 1 year, the S1 CST sprouting is pruned, with the terminal territory resembling control animals. This was reflected in the number of putatively "functional" synapses observed, which increased over the first 4-5 months, and then returned to baseline by 1 year. Microglia density also increased in the affected dorsal horn at 4-6 months and then decreased, but did not return to baseline by 1 year, suggesting refinement continues beyond this time. Overall, there is a long period of reorganization and consolidation of adaptive circuitry in the dorsal horn, extending well beyond the initial behavioral recovery. This provides a potential window to target therapeutic opportunities during the chronic phase.