Cord Segments Research Articles

Case report: Nonsimultaneous bilateral triceps tendon rupture and surgical repair in a healthy dog

A 7-year-old female spayed Australian shepherd dog was presented for an acute onset of inability to stand. On physical examination, the dog was unable to support weight on the thoracic limbs. On neurological examination, the thoracic limbs had absent hopping and paw placement and reduced withdrawal reflexes bilaterally. The remainder of the neurological examination was normal. The anatomic lesion localized to the C6-T2 spinal nerve roots, spinal nerves, or the named nerves of the thoracic limb, bilaterally. A lesion affecting the ventral gray column of the C6 through T2 spinal cord segments was considered less likely. In an effort to exclude an orthopedic disorder from consideration, radiographs of the shoulders, elbows, and manus were normal. Magnetic resonance imaging of the cervical and cranial thoracic vertebral column was normal. Analysis of synovial fluid from the carpi, elbows, and shoulders were normal. Ultrasonography of the triceps muscle and tendon of insertion revealed bilateral, acute-subacute tears of the tendon at insertion of the triceps muscles, bilaterally. Magnetic resonance imaging of both elbows revealed complete avulsion of the triceps tendons bilaterally. Surgical repair of both tendons was performed using the Arthrex FiberLoop system combined with autologous conditioned plasma soaked in a collagen sponge. Postoperatively, external coaptation was provided using Spica splints for 6 weeks followed by the use of soft padded orthotic braces for an additional 6 weeks. Concurrently, a front support wheelchair was used for 10 weeks postoperative. By 10 weeks postoperative, the dog was able to ambulate without support. To the authors’ knowledge, this is the first report of bilateral triceps tendon avulsion in a dog. Tendon avulsion occurred without a known history of trauma or predisposing metabolic abnormalities. Magnetic resonance imaging provided excellent anatomical detail that aided in surgical repair.

Axonal projection of the medullary expiratory neurons in the feline thoracic spinal cord

Expiratory neurons in the caudal ventral respiratory group extend descending axons to the lumbar and sacral spinal cord, and they possess axon collaterals, the distribution of which has been well-documented. Likewise, these expiratory neurons extend axons to the thoracic spinal cord and innervate thoracic expiratory motoneurons. These axons also give rise to collaterals, and their distribution may influence the strength of synaptic connectivity between the axons and the thoracic expiratory motoneurons. We investigated the distribution of axon collaterals in the thoracic spinal cord using a microstimulation technique. This study was performed on cats; one cat was used to make an anatomical atlas and six were used in the experiment. Extracellular spikes of expiratory neurons were recorded in artificially ventilated cats. The thoracic spinal gray matter was microstimulated from dorsal to ventral sites at 100-μm intervals using a glass-insulated tungsten microelectrode with a current of 150–250 μA. The stimulation tracks were made at 1 mm intervals along the spinal cord in segments Th9 to Th13, and the effective stimulating sites of antidromic activation in axon collaterals were systematically mapped. The effective stimulating sites in the contralateral thoracic spinal cord with expiratory neurons in the caudal ventral respiratory group (cVRG) occupied 14.4% of the total length of the thoracic spinal cord examined. The mean percentage of effective stimulating tracks per unit was 18.6 ± 4.4%. The distribution of axon collaterals of expiratory neurons in the feline thoracic spinal cord indeed resembled that reported in the upper lumbar spinal cord. We propose that a single medullary expiratory neuron exerts excitatory effects across multiple segments of the thoracic spinal cord via its collaterals.

Genetic analysis of the false positive trisomy 7 and false negative trisomy 18 by NIPT-PLUS

To explore the cause of inconsistency between the results of trisomy 7 by expanded non-invasive prenatal testing (NIPT-PLUS) and trisomy 18 by prenatal diagnosis. A pregnant woman who received genetic counseling at Jiaozuo Maternal and Child Health Care Hospital on July 5, 2020 was selected as the study subject. NIPT-PLUS, systematic ultrasound and interventional prenatal testing were carried out. The middle segment and root of umbilical cord, center and edge of the maternal and fatal surface of the placenta were sampled for the validation by copy number variation sequencing (CNV-seq). The result of NIPT-PLUS indicated that the fetus has trisomy 7. Systematic ultrasound has shown multiple malformations including atrioventricular septal defect, horseshoe kidney, and rocker-bottom feet. However, QF-PCR, chromosomal karyotyping analysis, and CNV-seq of amniotic fluid samples all showed that the fetus was trisomy 18. Validation using multiple placental samples confirmed that the middle segment of the umbilical cord contains trisomy 18, the center of the placenta contained trisomy 7, and other placental sites were mosaicism for trisomy 7 and trisomy 18. Notably, the ratio of trisomy 18 became lower further away from the umbilical cord. The false positive results of trisomy 7 and false negative trisomy 18 by NIPT-PLUS was probably due to the existence of placental mosaicism. Strict prenatal diagnosis is required needed aneuploidy is detected by NIPT-PLUS to exclude the influence of placental mosaicisms.

Impaired communication at the neuromotor axis during Degenerative Cervical Myelopathy.

Degenerative Cervical Myelopathy (DCM) is a progressive neurological condition characterized by structural alterations in the cervical spine, resulting in compression of the spinal cord. While clinical manifestations of DCM are well-documented, numerous unanswered questions persist at the molecular and cellular levels. In this study, we sought to investigate the neuromotor axis during DCM. We use a clinically relevant mouse model, where after 3 months of DCM induction, the sensorimotor tests revealed a significant reduction in both locomotor activity and muscle strength compared to the control group. Immunohistochemical analyses showed alterations in the gross anatomy of the cervical spinal cord segment after DCM. These changes were concomitant with the loss of motoneurons and a decrease in the number of excitatory synaptic inputs within the spinal cord. Additionally, the DCM group exhibited a reduction in the endplate surface, which correlated with diminished presynaptic axon endings in the supraspinous muscles. Furthermore, the biceps brachii (BB) muscle exhibited signs of atrophy and impaired regenerative capacity, which inversely correlated with the transversal area of remnants of muscle fibers. Additionally, metabolic assessments in BB muscle indicated an increased proportion of oxidative skeletal muscle fibers. In line with the link between neuromotor disorders and gut alterations, DCM mice displayed smaller mucin granules in the mucosa layer without damage to the epithelial barrier in the colon. Notably, a shift in the abundance of microbiota phylum profiles reveals an elevated Firmicutes-to-Bacteroidetes ratio-a consistent hallmark of dysbiosis that correlates with alterations in gut microbiota-derived metabolites. Additionally, treatment with short-chain fatty acids stimulated the differentiation of the motoneuron-like NSC34 cell line. These findings shed light on the multifaceted nature of DCM, resembling a synaptopathy that disrupts cellular communication within the neuromotor axis while concurrently exerting influence on other systems. Notably, the colon emerges as a focal point, experiencing substantial perturbations in both mucosal barrier integrity and the delicate balance of intestinal microbiota.

Transcranial Magnetic Stimulation in the Diagnosis of Compressive Myelopathy at the Thoracolumbar Junction.

The disc level in the thoracolumbar junction at which measurement of the central motor conduction time in the lower limbs (CMCT-LL) is useful for a diagnosis remains unclear. Therefore, this study investigated the spinal vertebral level at which compressive myelopathy due to ossification of the ligamentum flavum in the thoracolumbar junction is detectable using CMCT-LL. We preoperatively measured CMCT-LL in 57 patients (42 men, 15 women; aged 35-85 years) with a single ossification of the ligamentum flavum from the T10-11 to T12-L1 disc levels and in 53 healthy controls. Motor evoked potentials after transcranial magnetic stimulation, compound muscle action potentials, and F waves were recorded from the abductor hallucis. Central motor conduction time in the lower limbs was calculated as follows: Motor evoked potential latency - (compound muscle action potential latency + F latency - 1)/2 (ms). Central motor conduction time in the lower limbs was compared between patients and controls. Compressive lesions were located at the T10 to 11 level in 27 patients, the T11 to 12 level in 28, and the T12-L1 level in 2. Central motor conduction time values in the lower limbs at the T10 to 11 level (19.9 ± 4.7 ms) and T11 to 12 level (18.1 ± 3.4 ms) were significantly longer than control values (11.8 ± 1.1 ms; P < 0.01). Central motor conduction time in the lower limbs was not calculated at the T12-L1 level because motor evoked potentials were not recorded in any patient. We confirmed that CMCT-LL was significantly longer in patients with ossification of the ligamentum flavum at the T10 to 11 and T11 to 12 levels because the S2 segment of the spinal cord is caudal at the T12 vertebral body level. Therefore, CMCT-LL is useful for diagnosing thoracolumbar junction disorders proximal to the T12 vertebral body level.

Biological differences and molecular mechanism of different peripheral nerves after injury.

The aim of the study was to analyze the apoptosis of neurons and the differences in expression of Bcl-2 and Bax protein in the neurons in the corresponding spinal cord segment after the repair of the tibial nerve (TN) and common peroneal nerve (CPN) in rats. 126 healthy male Sprague-Dawley (SD) rats aged 7-8 weeks were randomly divided into group A (control group), group B (TN was cut and sutured), and group C (CPN was cut and sutured), with 42 rats in each group. The spinal cord tissues of rats in different groups were stained with hematoxylin-eosin (HE) on the 1st, 3rd, 7th, 14th, 21st, and 28th day after surgery; the number of neurons in anterior horn of spinal cord, axon density (AD), axon passage rate (APR), and recovery rate (RR) of muscle cell cross-sectional area (MCCA) were calculated; and differences in the expression of Bcl-2 and Bax proteins in the three groups of rats were analyzed by immunohistochemistry. The results showed that there was no statistically significant difference in the muscle wet weight (MWW) RR of the three groups of rats on the 14th day after the surgery (p>0.05), and the MWW RRs of rats in groups B and C were higher at the 28th day after surgery in contrast to group A (p<0.05). The number of motor neurons in the anterior horn of spinal cord in group B was higher than that in group C at the 3rd, 7th, 14th, and 21st day after surgery (p<0.05); the MWW RR, MCCA, and CSARR of rats in group B were lower than those in group C (p<0.05); the proximal AD, distal AD, and APR in group B were higher than those of group C on the 14th and 28th day after the surgery (p<0.05); and there were no positive staining results in the spinal cord tissue of rats in group A after staining. The expressions of Bcl-2 and Bax in group B were higher observably than the expressions in group C (p<0.05), which indicated that the recovery ability of TN was stronger than that of the CPN; the expression of Bcl-2 and Bax in TN was notably higher than that of the CPN. The expression of Bcl-2 and Bax was related to cell apoptosis and nerve regeneration after nerve injury. It provided a reference basis for clinical diagnosis and treatment of peripheral nerves.

Peripheral Branch Injury Induces Oxytocin Receptor Expression at the Central Axon Terminals of Primary Sensory Neurons.

Considerable evidence suggests that oxytocin, as a regulatory nonapeptide, participates in modulatory mechanisms of nociception. Nonetheless, the role of this hypothalamic hormone and its receptor in the sensory pathway has yet to be fully explored. The present study performed immunohistochemistry, enzyme-linked immunosorbent assay, and RT-qPCR analysis to assess changes in the expression of the neuronal oxytocin receptor in female rats following tight ligation of the sciatic nerve after 1, 3, and 7 days of survival. Oxytocin receptor immunoreactivity was present in both dorsal root ganglia and lumbar spinal cord segments, but not accumulated at the site of the ligation of the peripheral nerve branch. We found a time-dependent change in the expression of oxytocin receptor mRNA in L5 dorsal root ganglion neurons, as well as an increase in the level of the receptor protein in the lumbar segment of the spinal cord. A peak in the expression was observed on day 3, which downturned slightly by day 7 after the nerve ligation. These results show that OTR expression is up-regulated in response to peripheral nerve lesions. We assume that the importance of OTR is to modify spinal presynaptic inputs of the sensory neurons upon injury-induced activation, thus to be targets of the descending oxytocinergic neurons from supraspinal levels. The findings of this study support the concept that oxytocin plays a role in somatosensory transmission.

De novo aging-related NADPH diaphorase positive megaloneurites in the sacral spinal cord of aged dogs

We investigated aging-related changes in nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) in the spinal cord of aged dogs. At all levels of the spinal cord examined, NADPH-d activities were observed in neurons and fibers in the superficial dorsal horn (DH), dorsal gray commissure (DGC) and around the central canal (CC). A significant number of NADPH-d positive macro-diameter fibers, termed megaloneurites, were discovered in the sacral spinal cord (S1–S3) segments of aged dogs. The distribution of megaloneurites was characterized from the dorsal root entry zone (DREZ) into the superficial dorsal horn, along the lateral collateral pathway (LCP) to the region of sacral parasympathetic nucleus (SPN), DGC and around the CC, but not in the cervical, thoracic and lumbar segments. Double staining of NADPH-d histochemistry and immunofluorescence showed that NADPH-d positive megaloneurites co-localized with vasoactive intestinal peptide (VIP) immunoreactivity. We believed that megaloneurites may in part represent visceral afferent projections to the SPN and/or DGC. The NADPH-d megaloneurites in the aged sacral spinal cord indicated some anomalous changes in the neurites, which might account for a disturbance in the aging pathway of the autonomic and sensory nerve in the pelvic visceral organs.

Tube cystostomy is effective for urinary outflow management in dogs with intervertebral disk extrusion and ischemic myelopathy cranial to the L3 spinal cord segment: 61 dogs (2018-2022).

To describe the application and owner experience of tube cystostomy for management of upper motor neuron urinary bladder dysfunction secondary to intervertebral disk extrusion (IVDE) or ischemic myelopathy, and to report complications associated with cystostomy tube management. 61 dogs. Medical records of dogs with IVDE or ischemic myelopathy cranial to the L3 spinal cord segment that underwent tube cystostomy placement via a short, caudal ventral midline celiotomy were reviewed. Days from tube placement to hospital discharge, days from placement to tube removal, and complications were recorded. An owner questionnaire was distributed to ascertain ease of use and perceived time commitment. 58 dogs were diagnosed with IVDE, and 3 dogs were diagnosed with ischemic myelopathy. The modal neurologic grade at cystostomy tube placement was 4 (range, 3 to 5). The median number of days from cystostomy tube placement to hospital discharge was 1 (range, 0 to 3). Follow-up data was available for 56 dogs. The median number of days from cystostomy tube placement until removal was 19 (range, 3 to 74). Fifteen minor and 6 severe postoperative complications were reported, mainly inadvertent removal (n = 11) and peristomal urine leakage (6). Twenty-seven owners responded to the questionnaire and primarily reported that cystostomy tube use was easy (22/27) and perceived time commitment was low or minimal (20/27). Tube cystostomy facilitates early hospital discharge and allows at-home, extended urinary management in dogs recovering from upper motor neuron urinary bladder dysfunction secondary to IVDE or ischemic myelopathy. This technique is simple for owners to use.

Effect of spinal cord stimulation for thermal noxious stimulus pain threshold in Parkinson's disease

BackgroundParkinson's disease (PD)-related pain or PD pain is a frequent non-motor symptom and is treated with pharmacotherapy and non-pharmacologic therapies such as deep brain stimulation (DBS) and spinal cord stimulation (SCS). The mechanism of PD pain relief by DBS is thought to involve increased pain threshold to nociceptive stimulation, whereas the mechanism of SCS has not been elucidated. ObjectivePD pain relief by SCS may involve modulation of the pain thresholds in the spinal cord segments and supra-spinal actions. Therefore, we investigated the effect of SCS in patients who underwent SCS for intractable PD pain in the lower extremities by measuring pain thresholds to thermal nociceptive stimulation of the lower (leg) and upper (hand) parts of the stimulated spinal segment during SCS-off and SCS-on using quantitative sensory testing to determine the pain threshold. MethodsSeven PD patients with SCS in the lower thoracic spinal cord underwent measurements of cold sensory threshold, warm sensory threshold, cold pain threshold (CPT), and heat pain threshold (HPT). ResultsIn upper part of the stimulated spinal segment, CPT was significantly decreased during SCS-on compared to SCS-off (p < 0.01); whereas HPT was not significantly different. In lower part of the stimulated spinal segment, CPT was significantly increased during SCS-on compared to SCS-off (p < 0.05); and HPT was also increased (p < 0.05). ConclusionThis study shows that SCS raises the pain threshold to thermal nociception in PD patients. The primary mechanism of pain relief by SCS is thought to be segmental inhibition at the level of the stimulated spinal segments.

Epidural combined optical and electrical stimulation induces high-specificity activation of target muscles in spinal cord injured rats.

Epidural electrical stimulation (EES) has been shown to improve motor dysfunction after spinal cord injury (SCI) by activating residual locomotor neural networks. However, the stimulation current often spreads excessively, leading to activation of non-target muscles and reducing the accuracy of stimulation regulation. Near-infrared nerve stimulation (nINS) was combined with EES to explore its regulatory effect on lower limb muscle activity in spinal-cord-transected rats. In this study, stimulation electrodes were implanted into the rats' L3-L6 spinal cord segment with T8 cord transected. Firstly, a series of EES parameters (0.2-0.6 mA and 20-60 Hz) were tested to determine those that specifically regulate the tibialis anterior (TA) and medial gastrocnemius (MG). Subsequently, to determine the effect of combined optical and electrical stimulation, near-infrared laser with a wavelength of 808 nm was used to irradiate the L3-L6 spinal cord segment while EES was performed. The amplitude of electromyography (EMG), the specific activation intensity of the target muscle, and the minimum stimulus current intensity to induce joint movement (motor threshold) under a series of optical stimulation parameters (power: 0.0-2.0 W; pulse width: 0-10 ms) were investigated and analyzed. EES stimulation with 40 Hz at the L3 and L6 spinal cord segments specifically activated TA and MG, respectively. High stimulation intensity (>2 × motor threshold) activated non-target muscles, while low stimulation frequency (<20 Hz) produced intermittent contraction. Compared to electrical stimulation alone (0.577 ± 0.081 mV), the combined stimulation strategy could induce stronger EMG amplitude of MG (1.426 ± 0.365 mV) after spinal cord injury (p < 0.01). The combined application of nINS effectively decreased the EES-induced motor threshold of MG (from 0.237 ± 0.001 mA to 0.166 ± 0.028 mA, p < 0.001). Additionally, the pulse width (PW) of nINS had a slight impact on the regulation of muscle activity. The EMG amplitude of MG only increased by ~70% (from 3.978 ± 0.240 mV to 6.753 ± 0.263 mV) when the PW increased by 10-fold (from 1 to 10 ms). The study demonstrates the feasibility of epidural combined electrical and optical stimulation for highly specific regulation of muscle activity after SCI, and provides a new strategy for improving motor dysfunction caused by SCI.

Abstract 163: Total Spinal Cord Infarction, An Underrecognized Postoperative Complication

Introduction Spinal cord infarctions (SCI) are scarce entities, constituting only 0.3‐1% of all strokes, with complete or posterior spinal cord involvement detailed in the case below being even rarer. Often caused by sudden interruption of blood flow to the spinal cord due to embolic phenomena, intrinsic factors such as connective tissue disease, and due to intra/post‐operative hypotension leading to ischemia or infarction. The resultant acute spinal cord dysfunction manifests as; motor weakness, loss of senses of pain and temperature, altered proprioception, bowel and bladder dysfunction Spinal blood supply comprises of the anterior spinal artery (ASA) and the two posterior spinal arteries, with supply to the spinal arteries being derived from various regional arteries: C1‐T3 is supplied by the vertebral arteries, T3‐T7 is served by a branch from the intercostal arteries, and the Adamkiewicz artery supplies T8 to the medullary conus. The thoracolumbar level is primarily supplied by only a small number of radicular arteries, originating from segmental branches of the aorta, specifically the posterior intercostal and lumbar branches, which extend towards the intervertebral foramina where they split into the anterior and posterior radicular arteries. The largest radicular artery, commonly referred to as the arteria radicularis magna of Adamkiewicz (or main anterior radicular artery), typically arises on the left between T9 and T12, but may be located on the right or emerge anywhere from T5 to L4 in approximately 17% of cases. This extensive segment of the spinal cord only is typically supplied by only two or three small radicular branches, occuring between the lower cervical and mid‐to‐lower thoracic levels, making it a watershed zone. Methods Case report and literature review Results 73‐year‐old woman with history of hypertension, long‐term smoking, extensive peripheral vascular disease, R lung cancer (in remission after 3 rounds of radiation, and newly diagnosed calcified heterogeneous left renal mass concerning for malignancy status‐post right femoral access with embolization of left lumbar arteries at the level of L1‐L3 with 800 micrometer particles and tungsten‐platinum coils on 12/19/22), transferred from a surgical center on 12/21/22 for post‐operative paraparesis (R›L), paresthesia , urinary retention, and constipation initially thought to be post‐anesthetic effects. MRI T and L spine with and without contrast demonstrated diffusion restriction from the level of T10 to the conus suggestive of anterior and posterior spinal cord infarct, thought to be in the setting of recent embolization with extensive atherosclerotic burden. Neurological exam significant for lower extremity paraparesis ( R 2/5 , L 3/5) with T10 sensory level to pin‐prick and temperature, hyporeflexia, and absent proprioception in bilateral lower extremities. Full dose aspirin and high intensity statin was started with patient managed conservatively due to presentation outside window for thrombolysis. Conclusion Spinal cord infarcts typically present with motor weakness due to ASA occlusion however, sensory level and proprioceptive loss as accompanying factors are important considerations to rule in total cord (anterior + posterior) infarcts, especially in post‐op patients undergoing thoraco‐lumbar access/embolization as earlier recognition may make them eligible for treatments such as thrombolysis.

Quercetin Ameliorates Neuropathic Pain after Brachial Plexus Avulsion via Suppressing Oxidative Damage through Inhibition of PKC/MAPK/ NOX Pathway.

Brachial plexus avulsion (BPA) animally involves the separation of spinal nerve roots themselves and the correlative spinal cord segment, leading to formidable neuropathic pain of the upper limb. The right seventh cervical (C7) ventral and dorsal roots were avulsed to establish a neuropathic pain model in rats. After operation, rats were treated with quercetin (QCN) by intragastric administration for 1 week. The effects of QCN were evaluated using mechanical allodynia tests and biochemical assay kits. QCN treatment significantly attenuated the avulsion-provoked mechanical allodynia, elevated the levels of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) and total antioxidant capacity (TAC) in the C7 spinal dorsal horn. In addition, QCN administration inhibited the activations of macrophages, microglia and astrocytes in the C6 dorsal root ganglion (DRG) and C6-8 spinal dorsal horn, as well as attenuated the release of purinergic 2X (P2X) receptors in C6 DRG. The molecular mechanism underlying the above alterations was found to be related to the suppression of the PKC/MAPK/NOX signal pathway. To further study the anti-oxidative effects of QCN, we applied QCN on the H2O2-induced BV-2 cells in vitro, and the results attested that QCN significantly ameliorated the H2O2-induced ROS production in BV-2 cells, inhibited the H2O2-induced activation of PKC/MAPK/NOX pathway. Our study for the first time provided evidence that QCN was able to attenuate pain hypersensitivity following the C7 spinal root avulsion in rats, and the molecular mechanisms involve the reduction of both neuro-inflammatory infiltration and oxidative stress via suppression of P2X receptors and inhibition of the activation of PKC/MAPK/NOX pathway. The results indicate that QCN is a natural compound with great promise worthy of further development into a novel therapeutic method for the treatment of BPA-induced neuropathic pain.

A Case Report of Reversible Iatrogenic Compressive Myelopathy

Physical rehabilitation is a proven method of non-specific lower back pain treatment in contrast to manual therapy which has no evidence of clinical effectiveness. But sometimes, in the search for relief, patients develop complications resulting from the actions of unscrupulous healthcare providers in this field. A 35-year-old patient developed unbearable pain, impaired sensitivity, decreased muscle strength, stiffness in both legs, and urinary retention after rough manual-barefoot manipulation. Computed tomography scans of the cervical, thoracic, and lumbar spine regions revealed signs of hematomyelia involving the Th9-Th10, Th10-Th11, and L1-L2 spinal cord segments. After undergoing therapy with nonsteroidal anti-inflammatory drugs and glucocorticosteroids, the patient reported a significant improvement in his condition. The description of this clinical case demonstrates a complication of the manual-barefoot manipulation presenting as compressive myelopathy.

Diagnostic value of magnetic resonance diffusion tensor imaging in evaluation of cervical spondylotic myelopathy

BackgroundRadiological diagnosis of cervical spondylotic myelopathy should be made as early as possible to obtain favourable clinical outcomes when compared with later stages. Diffusion tensor imaging can reveal early structural changes of the cord in patients with cervical compressive myelopathy.AimThis study aimed to assess the role of magnetic resonance diffusion tensor imaging in the accurate evaluation of cervical spondylotic myelopathy.Patients and methodsThis prospective study included a group of 60 patients with neurological symptoms suggestive for cervical spondylotic myelopathy and a control group of 30 healthy subjects. The clinical severity of compressive myelopathy was assessed based on the European myelopathy score. Magnetic resonance diffusion tensor imaging and tractography were done for all patients and controls.ResultsFractional anisotropy values at the most compressed segments of spinal cord are lower while apparent diffusion coefficient values of the same segments are higher than healthy segments in controls. Fractional anisotropy and apparent diffusion coefficient parameters had higher sensitivity (97.0% and 88.1%, respectively) than conventional T2 WIs (13.4%) and fibre tractography (10%) for the detection of early compressive myelopathy with cutoff values ≤ 0.56 and > 1.23, respectively, in differentiating between patients and control groups.ConclusionDiffusion tensor imaging indices are valuable tools for quantitative assessment of degenerative cervical spondylotic myelopathy in addition to routine cervical spine magnetic resonance.

Relationship between acupoint sensitization and changes in dorsal root ganglion neuron excitability in myocardial ischemia mice

To investigate the relationship between the sensitization state of acupoints on the surface of the myocardial ischemia (MI) model mice and the changes in the electrophysiological properties of the dorsal root ganglion (DRG) neurons in the corresponding spinal cord segment, and its underlying mechanism. Sixty-eight male C57BL/6J mice were randomly divided into control and model groups (34 mice in each group). The model group received an intraperitoneal injection of 160 mg/kg isoproterenol (ISO) to establish the MI model, and the control group received an injection of the same dose of normal saline as the model group. After modeling for about 6 days, MI proportion was measured by HE staining to verify the pathological changes in the heart tissue. Evans blue (EB) dye was injected into the tail vein of mice to reflect the size, location, distribution, and number of exudates on the body surface. Then, whole-cell membrane currents, intrinsic excitability and membrane properties of different types of DRG neurons were evaluated by electrophysiological experiment in vitro. Compared with the control group, the heart size was larger, with pathological outcomes showing enlarged myocardial hypertrophy, destroyed structure of cardiomyocytes, with mononuclear cell infiltration among the cardiomyocytes in the model group. Compared with the control group, the number of EB exudation points was significantly increased (P<0.01), which were mainly concentrated in the epidermis near the T1-T5 segment of the spinal cord, "Feishu" (BL13), "Jueyinshu" (BL14) and "Xinshu" (BL15) in the model group. Compared with the control group, the rheobase and action potential amplitude (APA) of DRG medium-sized neurons were obviously decreased (P<0.01, P<0.05), while the whole-cell membrane currents, the spike numbers, the average instantaneous frequency, and the average discharge frequency were markedly increased (P<0.01). There were no significant alterations in the membrane properties and intrinsic excitability induced by depolarized currents of small-sized neurons between groups. Compared with the control group, the whole-cell membrane currents, spike numbers, and the average instantaneous frequency were significantly increased in the model group(P<0.05, P<0.01) while rheobase was significantly decreased (P<0.05) in DRG medium-sized neurons labeled with biotin and CGRP. After the mice were modeled by ISO, the DRG medium-size neurons in the T1-T5 segment of the spinal cord may mediate the sensitization of acupoints on the body surface through their different neuronal membrane properties and intrinsic excitabilities.

Longitudinal optogenetic mapping reveals enhanced motor control by the contralesional cortex after traumatic brain injury in mice

Traumatic brain injury (TBI) is a significant cause of human disability, and understanding its spontaneous recovery pattern after injury is critical for potential treatments. However, studies on the function of the contralesional cortex after TBI have mostly focused on acute-phase changes, and long-term dynamic changes in the control of the affected limb by the contralesional cortex are less understood. To unravel long-term adaptations in the contralesional cortex, we developed a mouse model of TBI and used longitudinal optogenetic motor mapping to observe the function of contralesional corticospinal neurons (CSNs) projecting to the unilateral seventh cervical (C7) segment of the spinal cord. We injected a retrograde adeno-associated virus (AAV) expressing channelrhodopsin-2 to optogenetically stimulate and map the functional connections of the motor-sensory cortex. We validated the effectiveness of transcranial optogenetic stimulation for functional mapping and observed a general increase in the control of the affected limb by the contralesional cortex over time. Using retrograde labeling techniques, we showed that TBI does not affect the distribution of C7-CSNs but alters their function, and the labeled CSNs are concentrated in the caudal and rostral forelimb areas. Our findings provide new insights into harnessing contralesional cortical plasticity to improve treatment for affected limbs. This study sheds light on the long-term adaptations in the contralesional cortex after TBI, paving the way for potential clinical applications of optogenetic stimulation to improve motor control and rehabilitation outcomes.

Attention-gated U-Net networks for simultaneous axial/sagittal planes segmentation of injured spinal cords.

Magnetic resonance imaging is currently the gold standard for the evaluation of spinal cord injuries. Automatic analysis of these injuries is however challenging, as MRI resolutions vary for different planes of analysis and physiological features are often distorted around these injuries. This study proposes a new CNN-based segmentation method in which information is exchanged between two networks analyzing the scans from different planes. Our aim was to develop a robust method for automatic segmentation of the spinal cord in patients having suffered traumatic injuries. The database consisted of 106 sagittal MRI scans from 94 patients with traumatic spinal cord injuries. Our method used an innovative approach where the scans were analyzed in series under the axial and sagittal plane by two different convolutional networks. The results were compared with those of Deepseg 2D from the Spinal Cord Toolbox (SCT), which was taken as state-of-the-art. Comparisons were evaluated using K-Fold cross-validation combined with statistical t-test results on separate test data. Our method achieved significantly better results than Deepseg 2D, with an average Dice coefficient of 0.95 against 0.88 for Deepseg 2D (p <0.001). Other metrics were also used to compare the segmentations, all of which showed significantly better results for our approach. In this study, we introduce a robust method for spinal cord segmentation which is capable of adequately segmenting spinal cords affected by traumatic injuries, improving upon the methods contained in SCT.

The anesthetic efficacy of ultrasound-guided lumbar plexus combined with quadratus lumborum block with Shamrock approach in total hip arthroplasty: study protocol for a randomized controlled trial

IntroductionThe lumbar plexus originates from multiple segments of the spinal cord. Both single-level lumbar plexus block (LPB) and transmuscular quadratus lumborum block (TQLB) are commonly used to provide analgesia for the patients undergoing total hip arthroplasty (THA). However, neither of them can completely cover the lumbar plexus. Multiple-level LPB is also not recommended since this expert technique involves more potential risks. To achieve a better anesthetic effect and avoid risks, we propose to combine ultrasound-guided LPB with TQLB with Shamrock approach. We aim to assess the anesthetic efficacy of this combination technique and expect it will be an ideal alternative for conventional LPBs in THA.Methods and analysisIn this prospective randomized controlled trial, 84 patients schedule for THA will be enrolled. The patients will be randomly assigned at a 1:1:1 ratio to receive LPB at L3 level (P group), T12 paravertebral block combined with LPB at L3 and L4 levels (TP group), or LPB combined with TQLB at L3 level (PQ group). Each method will be evaluated in terms of the successful rate of sensory blockade, postoperative pain, performance time of block, requirement for intraoperative sufentanil, cumulative doses of intraoperative vasoactive medications, and adverse events.Ethics and disseminationThe study protocol has been approved by the institutional review board (IRB) at Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, China (No.2020–031). The results will be disseminated in a peer-reviewed journal and the ClinicalTrials.gov registry.Trial registrationClinicalTrials.gov, NCT04266236. Registered on 10 February 2020. ClinicalTrials.gov PRS: Record Summary NCT04266236.

A novel method to quantify perivascular space enlargement near the syrinx in a rodent model of post-traumatic syringomyelia

Posttraumatic syringomyelia (PTS) is an enigmatic condition characterized by the development of fluid-filled cysts (syrinxes) within the spinal cord. Perivascular spaces (PVS) are a critical component of fluid transport within the central nervous system (CNS), with dilated PVSs variably implicated in the pathogenesis of syringomyelia. The extent and spatial distribution of dilated PVSs in syringomyelia, however, remains unclear. This study aims to develop a method to assess PVS dimensions across multiple spinal cord segments in rats with PTS. Syrinxes were induced in two Sprague–Dawley rats at C6/7 with computer-controlled motorized spinal cord impaction; two control rats underwent sham laminectomies. Spinal cord segments were obtained at C4, C6 and C8, cleared via tissue clearing protocols, stained with immunofluorescent antibodies and imaged under confocal microscopy. Qualitative and quantitative analyses of PVS size were performed. Arteriolar PVSs were enlarged in the perisyringeal region of the spinal cord, compared to the control cord. No PVS enlargement was observed above or below the syrinx. These results confirm previous incidental findings of enlarged PVSs in the perisyringeal region, providing new insights into PVS dimensions across multiple spinal segments, and providing a novel method for quantifying spinal cord perivascular space size distributions.