Search

A 23-month-old boy with poor growth, developmental delay, and hypotonia presented with acute onset of ataxia and fatigue. Magnetic resonance imaging (MRI) of the brain and spinal cord was performed as part of diagnostic work-up. MRI showed bilateral symmetrical lesions in basal ganglia, midbrain, and brainstem consistent with Leigh syndrome. Signal abnormalities were also present within the cervical cord, with enhancement of multiple cranial, spinal, and cauda equina nerve roots. Genetic testing confirmed compound heterozygosity for two pathogenic variants in SURF1 implicated in Leigh syndrome. Whilst nerve root enhancement has been described in other mitochondrial disorders, we believe this is the first published case of both cranial and spinal nerve root enhancement in Leigh syndrome. [ABSTRACT FROM AUTHOR]

Background: Current research lacks comprehensive investigation into the biomechanical changes in the spinal cord and nerve roots during scoliosis correction. This study employs finite element analysis to extensively explore these biomechanical variations across different Cobb angles, providing valuable insights for clinical treatment. Methods: A personalized finite element model, incorporating vertebrae, ligaments, spinal cord, and nerve roots, was constructed using engineering software. Forces and displacements were applied to achieve Cobb angle improvements, designating T1/2-T4/5 as the upper segment, T5/6-T8/9 as the middle segment, and T9/10-L1/2 as the lower segment. Simulations under traction, pushing, and traction + torsion conditions were conducted, and biomechanical changes in each spinal cord segment and nerve roots were analyzed. Results: Throughout the scoliosis correction process, the middle spinal cord segment consistently exhibited a risk of injury under various conditions and displacements. The lower spinal cord segment showed no significant injury changes under traction + torsion conditions. In the early correction phase, the upper spinal cord segment demonstrated a risk of injury under all conditions, and the lower spinal cord segment presented a risk of injury under pushing conditions. Traction conditions posed a risk of nerve injury on both sides in the middle and lower segments. Under pushing conditions, there was a risk of nerve injury on both sides in all segments. Traction + torsion conditions implicated a risk of injury to the right nerves in the upper segment, both sides in the middle segment, and the left side in the lower segment. In the later correction stage, there was a risk of injury to the upper spinal cord segment under traction + torsion conditions, the left nerves in the middle segment under traction conditions, and the right nerves in the upper segment under pushing conditions. Conclusion: When the correction rate reaches 61–68%, particular attention should be given to the upper-mid spinal cord. Pushing conditions also warrant attention to the lower spinal cord and the nerve roots on both sides of the main thoracic curve. Traction conditions require attention to nerve roots bilaterally in the middle and lower segments, while traction combined with torsion conditions necessitate focus on the right-side nerve roots in the upper segment, both sides in the middle segment, and the left-side nerve roots in the lower segment. [ABSTRACT FROM AUTHOR]

This study aims to discuss the identification of the C1 nerve root as an effective surgical approach to successfully locate the shunting point of craniocervical junction spinal dural arteriovenous fistula (CCJ-SDAVF) intraoperatively. This study included all patients with CCJ-SDAVF who underwent surgical treatment using the far-lateral transcondylar approach at a single institution from January 2017 to June 2023. Data on patient demographics, clinical and angiographic characteristics of CCJ-SDAVF, surgical details, and treatment outcomes were collected. Follow-up assessments were conducted for all patients until December 31, 2023. The study included a total of 7 patients, comprising 5 men(71.4%) and 2 women (28.6%), with an average age of 57.6 years. Among them, 4 patients (57.1%) developed diffuse subarachnoid hemorrhage(SAH), while 2 patients (28.6%) experienced progressive cervical myelopathy. The shunting points of all CCJ-SDAVFs, which exhibited engorged veins, were identified next to the C1 root. Complete obliteration of CCJ-SDAVFs was successfully achieved in all patients, as confirmed by postoperative angiography one month later. No recurrent CCJ-SDAVFs were observed two years after the operation. Among the patients, 5 (71.4%) experienced good functional recovery, as indicated by an mRS score ranging from 0 to 1, while the remaining 2 patients (28.6%) showed incomplete functional recovery. The surgical interruption of CCJ-SDAVFs is the preferred treatment option, given its high obliteration rate and favorable functional recovery outcomes. We advocate the identification of C1 spinal nerve root as a crucial surgical step to identify the shunting points of CCJ- SDAVFs. [ABSTRACT FROM AUTHOR]

Background Open-door laminoplasty is a classical decompression method used to treat cervical spondylotic myelopathy. However, hinge fracture displacement (HFD) is a common occurrence during this procedure. The current study aimed to investigate the safety and efficacy of a combined imbrication axle reconstruction and Z-type titanium plate fixation method for HFD during open-door laminoplasty. Methods In total, 617 patients with cervical spondylotic myelopathy who underwent C3–C7 open-door laminoplasty from March 2015 to October 2018 were included in this retrospective study. Overall, 73 patients developed HFD during surgery. Of these, 43 underwent combined imbrication axle reconstruction and Z-type titanium plate fixation (IRZF group) and 30 underwent traditional titanium plate fixation (TF group). Data such as the operative time, intraoperative blood loss volume, and distribution of fractured hinges were recorded. Both groups were compared in terms of improvement in neurologic function, cervical curvature index, hinge fusion rate, incidence of C5 palsy, severity of axial symptoms, and development of complications. Results The operative time and intraoperative blood loss were slightly higher in the IRZF group than in the TF group; however, the differences were not significant (p > 0.05). Furthermore, there was no significant difference between the groups in terms of the number of fractured segments and the distribution of fractured hinges (p > 0.05). The cervical curvature index did not decline in the two groups (p > 0.05). The IRZF group had a higher hinge fusion rate than the TF group at 3 (79.6 vs. 57.1%) and 12 (93.9 vs. 74.3%) months postoperatively (p < 0.05). There was no significant difference in the incidence of C5 palsy between the two groups (9.3 vs. 6.7%; p > 0.05). However, the TF group had more severe axial symptoms than the IRZF group (p < 0.05). The neurologic function of the two groups increased postoperatively as per the Japanese Orthopaedic Association scoring system (p < 0.05). Nevertheless, there was no significant difference in terms of neurologic function at any observational time point (p > 0.05). One patient in the TF group with hinge nonunion underwent laminectomy due to lamina displacement into the spinal canal and nerve root compression. Conclusion In patients with HFD, IRZF facilitates a more intimate contact between the lamina and the lateral mass and, therefore, achieves fractured hinge fusion without additional surgical trauma. This technical improvement can significantly promote neurologic recovery, decrease the severity of axial symptoms, and prevent the development of spinal cord or nerve root recompression. [ABSTRACT FROM AUTHOR]

Primary spinal malignant melanoma (PSMM) is a rare cancer of the central nervous system (CNS), and PSMM of the spinal nerve root is even more extraordinary. PSMM of a nerve root can mimic the radiographic appearance of benign nerve sheath tumors, thus resulting in misdiagnosis until tissue diagnosis can be made. A 53-year-old African American woman presented with pain primarily involving the left aspect of her neck and shoulder for 2 years. Magnetic resonance imaging (MRI) of the cervical spine demonstrated a T1-hyperintense, T2-hypointense, homogenously enhancing, dumbbell-shaped, intradural extramedullary mass extending out through the left C2–3 foramen. A midline incision was used to perform a C2 and C3 laminectomy, and the mass was removed from the cavity. The histopathologic profile was consistent with the diagnosis of malignant melanoma. The present case report adds to the 110 cases of PSMM and the 20 cases of PSMM of the spinal nerve root in the existing body of literature. Radiographic and clinical features resemble that of the much more common schwannoma or neurofibroma requiring immunohistochemical analysis for definitive diagnosis. The optimal treatment for PSMM has not yet been defined due to its rarity and it is therefore important to report such cases in order to share our clinical experiences and provide data to other clinicians treating this uncommon disease. [ABSTRACT FROM AUTHOR]

The article discusses the case of a Labrador Retriever dog which presented with left pelvic limb monoparesis with excessive external hip rotation. Topics discussed include the anatomic and etiologic diagnoses, the results of thoracic radiography and magnetic resonance imaging, and the presumptive diagnosis of nerve sheath neoplasm.

Intervertebral disc degeneration is common and may play an important role in low back pain, but it is not well-understood. Previous studies have shown that the outer layer of the annulus fibrosus of a healthy disc is innervated by nociceptive nerve fibers. In the process of disc degeneration, it can grow into the inner annulus fibrosus or nucleus pulposus and release neuropeptides. Disc degeneration is associated with inflammation that produces inflammatory factors and potentiates nociceptor sensitization. Subsequently neurogenic inflammation is induced by neuropeptide release from activated primary afferent terminals. Because the innervation of a lumbar disc comes from multisegmental dorsal root ganglion neurons, does neurogenic inflammation in a degenerative disc initiate neurogenic inflammation in neighboring healthy discs by antidromic activity? This study was based on animal experiments in Sprague-Dawley rats to investigate the role of neurogenic inflammation in adjacent healthy disc degeneration induced by disc injury. This was an experimental study. Seventy-five 12-week-old, male Sprague-Dawley rats were allocated to 3 groups (sham group, disc injury group and disc injury+TrkA antagonist group). The disc injury group was punctured in the tail disc between the eighth and ninth coccygeal vertebrae (Co8–9) to establish an animal model of tail intervertebral disc degeneration. The sham group underwent only skin puncture and the disc injury+TrkA antagonist group was intraperitoneally injected with GW441756 two days before disc puncture. The outcome measure included quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Disc injury induced an increase in aggrecan, NGF, TrkA, CGRP, SP, IL-1β, and IL-6 mRNA levels in the injured (Co8–9) and adjacent discs (Co7–8), which reached a peak on day 1, then gradually decreased, and returned to normal on day 14. After intraperitoneal injection of GW441756 prior to puncture, the mRNA levels of the above indicators were down-regulated in Co7–8 and Co8–9 intervertebral discs on the 1st and 7th days. The protein content of the above indicators in Co7–8 and Co8–9 intervertebral discs showed roughly the same trend as mRNA levels. Degeneration of one disc can induce neurogenic inflammation of adjacent healthy discs in a rat model. This model supports a key role of neurogenic inflammation in disc degeneration, and may play a role in the experience of low back pain. [ABSTRACT FROM AUTHOR]

Transient Receptor Potential Vanilloid 1 (TRPV1) is a nonselective cation channel expressed by pain-sensing neurons and has been an attractive target for the development of drugs to treat pain. Recently, Src homology region two domain-containing phosphatase-1 (SHP-1, encoded by Ptpn6) was shown to dephosphorylate TRPV1 in dorsal root ganglia (DRG) neurons, which was linked with alleviating different pain phenotypes. These previous studies were performed in male rodents only and did not directly investigate the role of SHP-1 in TRPV-1 mediated sensitization. Therefore, our goal was to determine the impact of Ptpn6 overexpression on TRPV1-mediated neuronal responses and capsaicin-induced pain behavior in mice of both sexes. Twelve-week-old male and female mice overexpressing Ptpn6 (Shp1-Tg) and their wild type (WT) littermates were used. Ptpn6 overexpression was confirmed in the DRG of Shp1-Tg mice by RNA in situ hybridization and RT-qPCR. Trpv1 and Ptpn6 were found to be co-expressed in DRG sensory neurons in both genotypes. Functionally, this overexpression resulted in lower magnitude intracellular calcium responses to 200 nM capsaicin stimulation in DRG cultures from Shp1-Tg mice compared to WTs. In vivo, we tested the effects of Ptpn6 overexpression on capsaicin-induced pain through a model of capsaicin footpad injection. While capsaicin injection evoked nocifensive behavior (paw licking) and paw swelling in both genotypes and sexes, only WT mice developed mechanical allodynia after capsaicin injection. We observed similar level of TRPV1 protein expression in the DRG of both genotypes, however, a higher amount of tyrosine phosphorylated TRPV1 was detected in WT DRG. These experiments suggest that, while SHP-1 does not mediate the acute swelling and nocifensive behavior induced by capsaicin, it does mediate a protective effect against capsaicin-induced mechanical allodynia in both sexes. The protective effect of SHP-1 might be mediated by TRPV1 dephosphorylation in capsaicin-sensitive sensory neurons of the DRG. [ABSTRACT FROM AUTHOR]

Background: Neurosarcoidosis is rare, and among its manifestations, nerve root involvement has been reported in only a few cases. Therefore, magnetic resonance imaging (MRI) findings of neurosarcoidosis, particularly those involving nerve roots, are scarce in the literature. Methods: We presented the case of neurosarcoidosis involving cervical nerve roots and cranial nerves, alongside a systematic literature review. Results: A 28-year-old female suddenly developed right facial numbness as well as left upper extremity and left hand pain. Initial brain and spine MRI showed a bulging mass of T2 iso-to-high signal intensity in the left Meckel's cave/trigeminal nerve, as well as diffuse enlargement of the right C6 and C7 nerve roots. Follow-up MRI at 2 months revealed a reduction in the size of the initial lesion and the appearance of new similar lesions on the contralateral side (right Meckel's cave, left C3–C8 nerve roots). In particular, the lesions involving the nerve roots demonstrated central enlargement along the nerve roots, without involvement of the adjacent spinal cord. All these lesions exhibited enhancement, leading to the differentiation between sarcoidosis and lymphoma. Sarcoidosis was subsequently confirmed through biopsy of a hilar lymph node. Conclusions: This report presents a distinctive MRI feature of neurosarcoidosis involving spinal nerve roots, representing the first of its kind, and describes the evolution of MRI findings throughout the clinical course. [ABSTRACT FROM AUTHOR]

Background: Endoscopic spine lumbar interbody fusion (Endo-LIF) is well-regarded within the academic community. However, it presents challenges such as intraoperative disorientation, high rates of nerve damage, a steep learning curve, and prolonged surgical times, often occurring during the creation of the operative channel. Furthermore, the undefined safe operational zones under endoscopy continue to pose risks to surgical safety. We aimed to analyse the anatomical data of Kambin's triangle via CT imaging to define the parameters of the safe operating area for transforaminal posterior lumbar interbody fusion (TPLIF), providing crucial insights for clinical practice. Methods: We selected the L4–L5 intervertebral space. Using three-dimensional (3D), we identified Kambin's triangle and the endocircle within it, and recorded the position of point 'J' on the adjacent facet joint as the centre 'O' of the circle shifts by angle 'β.' The diameter of the inscribed circle 'd,' the abduction angle 'β,' and the distances 'L1' and 'L2' were measured from the trephine's edge to the exiting and traversing nerve roots, respectively. Results: Using a trephine with a diameter of 8 mm in TPLIF has a significant safety distance. The safe operating area under the TPLIF microscope was also clarified. Conclusions: Through CT imaging research, combined with 3D simulation, we identified the anatomical data of the L4–L5 segment Kambin's triangle, to clarify the safe operation area under TPLIF. We propose a simple and easy positioning method and provide a novel surgical technique to establish working channels faster and reduce nerve damage rates. At the same time, according to this method, the Kambin's triangle anatomical data of the patient's lumbar spine diseased segments can be measured through CT 3D reconstruction of the lumbar spine, and individualised preoperative design can be conducted to select the appropriate specifications of visible trephine and supporting tools. This may effectively reduce the learning curve, shorten the time operation time, and improve surgical safety. [ABSTRACT FROM AUTHOR]

Primary neurolymphomatosis is the direct infiltration of lymphomatous neoplastic cells into nerve roots and/or peripheral nerves. A 67-year- old man had a 24-month history of progressive and severe left lower limb neuropathic pain, ipsilateral ankle dorsiflexion weakness and gait disturbance. Gadolinium-enhanced MRI showed thickening and enhancement of the cauda equina, L5, S1 and S2 nerve roots. 18Fluorodeoxyglucose positron emission tomography showed concordant hypermetabolism. L5 nerve root biopsy confirmed diffuse large B- cell lymphoma. One cycle of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) chemotherapy resulted in remission, but this was not sustained. Primary neurolymphomatosis is rare and diagnostically challenging, and often the diagnosis is delayed. While biopsy is the gold standard for diagnosis, neuroimaging helps to characterise lesions and to determine the feasibility of biopsy. [ABSTRACT FROM AUTHOR]

Background: Pulsed radiofrequency (PRF) of the lumbar dorsal root ganglion (DRG) has been widely used as a method to relieve lumbar radicular pain (LRP). However, the value of PRF application in LRP patients remains uncertain. This systematic review aimed to compare the effects of PRF of lumbar DRG and LEI in patients with LRP. Methods: A literature search was performed using well‐known databases for articles published up to May 2023. We included randomized controlled trials (RCTs) that evaluated the effects of PRF compared to LEI with or without steroids. We screened articles, extracted data, and assessed risk of bias in duplicate. The pain scores and Oswestry Disability Index (ODI) scores at 1, 3, and 6 months after procedures were obtained. A random‐effects meta‐analysis model was applied for outcomes. We evaluated evidence certainty for each outcome using the GRADE scoring system. This review was registered in the PROSPERO (ID: CRD42021253628). Results: A total of 10 RCTs were included and data of 613 patients were retrieved. We assessed the overall quality of the evidence as very low to moderate. PRF showed no difference in pain scores at 1 (mean difference [MD] −0.80, 95% confidence interval [CI] –1.59 to 0.00, low certainty) and 6 months (MD –2.37, 95% CI –4.79 to 0.05, very low certainty), and significantly improved pain scores at 3 months (MD –1.31, 95% CI –2.29 to −0.33, low certainty). There was no significant difference in ODI score at any interval (very low to low certainty). In the subgroup who underwent a diagnostic block, did not use steroids, and PRF duration greater than 360 s, PRF significantly reduced pain scores at 3 months after procedures. Conclusions: We found low quality of the evidence supporting adjuvant PRF to the lumbar DRG has a greater analgesic effect at 3 months after procedures in patients with LRP than LEI. We identified no convincing evidence to show that this treatment improves function. High‐quality evidence is lacking, and data were largely derived from short‐term effects. Given these limitations, high‐quality trials with data on long‐term effects are needed. [ABSTRACT FROM AUTHOR]

Introduction: Guillain–Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) are inflammatory polyneuropathies with an autoimmune etiology. These diseases differ mainly in the timing of their course but also in certain clinical differences. Electroneurography and electromyography are crucial for fulfilling the primary (for CIDP) and secondary (for GBS) diagnostic criteria. High-resolution ultrasound (HRUS) is recognized as a complementary method in the diagnosis of CIDP and GBS. Aim: The aim of this study was to present the neurophysiological and ultrasound findings of patients with clinically diagnosed inflammatory neuropathies (GBS and CIDP). Material and Methods: We collected data from clinically confirmed patients with GBS (3 persons) and CIDP (6 persons). The neurography and high-resolution ultrasound examinations according to the UPSS scale were performed. Results: The neurography tests of GBS and CIDP patients showed mainly demyelinating lesions of the examined nerves, often with abnormal F-wave recordings. Examination using HRUS in GBS patients showed mild and regional nerve swelling with hypoechoic bundles with a predilection for proximal segments and cervical spinal nerve roots. In contrast, CIDP patients had diffused nerve swelling with hypoechoic bundles of greater severity and extent than those with GBS. Conclusion: Neurophysiological tests and HRUS of peripheral nerves, plexi, and roots performed together can be very valuable, complementary diagnostic methods for the early diagnosis and effective treatment of inflammatory polyneuropathies. [ABSTRACT FROM AUTHOR]

Background and Objectives: Cervical radiculopathy (CR) manifests as pain and sensorimotor disturbances in the upper extremities, often resulting from nerve root compression due to intervertebral disc herniation, degenerative changes, or trauma. While conservative treatments are initially preferred, persistent or severe cases may require surgical intervention. Ultrasound-guided selective nerve root block (SNRB) has emerged as a promising intervention for alleviating symptoms and potentially obviating the need for surgery. This study evaluates the therapeutic efficacy of ultrasound-guided SNRB in managing chronic CR, aiming to determine its potential in symptom relief and delaying or avoiding surgical procedures. Materials and Methods: A retrospective analysis was conducted on 720 outpatients treated for CR between October 2019 and March 2022. After excluding patients with traumatic CR, previous surgeries, malignancies, progressive neurological symptoms requiring immediate surgery, or inadequate conservative treatment, 92 patients who had experienced cervical radicular pain for more than three months and had failed to improve after more than six weeks of conservative treatment with VAS scores ≥ 5 were included. The patients underwent single or multiple ultrasound-guided SNRB procedures, involving the injection of dexamethasone and lidocaine under real-time ultrasound guidance. Symptom severity was assessed at the baseline, and at 4, 8, and 12 weeks post-procedure using the Visual Analog Scale (VAS). The data collected included age, sex, presence of neck and/or radicular pain, physical examination findings, recurrence of symptoms, improvement in symptoms, and whether surgical intervention was ultimately required. Statistical analyses were performed to identify the factors associated with symptom improvement or recurrence. Results: Significant symptom improvement was observed in 69 (75.0%) participants post-SNRB, with 55 (79.7%) showing improvement at 4 weeks, 11 (15.9%) at 8 weeks, and 3 (4.4%) at 12 weeks. Symptom recurrence, defined by an increase in VAS score accompanied by a pain flare lasting at least 24 h after a pain-free interval of at least one month, was noted in 48 (52.2%) patients. The presence of combined neck and radicular pain was a significant predictor of recurrence (p = 0.008). No significant associations were found between symptom relief and factors such as age, gender, initial pain severity, or MRI findings. Conclusions: Ultrasound-guided SNRB effectively manages chronic CR, providing substantial symptom relief and potentially reducing the need for surgical intervention. This technique offers a promising conservative treatment option, especially given its real-time visualization advantages and minimal radiation exposure. [ABSTRACT FROM AUTHOR]

The mini-hemilaminectomy is a frequently used surgical technique for decompressive disk surgery on dogs. The aim of the study was to assess landmarks in the canine thoracolumbar spine to perform a mini-hemilaminectomy, with the aim of achieving optimal exposure of the ventral aspect of the vertebral canal. We hypothesized that the accessory process is a useful landmark for the identification of the level of the vertebral canal floor (VCF) and for decreasing surgical time. To define the level of the VCF, different landmarks and their distance to the VCF from computed tomography images of 40 mature chondrodystrophic dogs were evaluated in the first part of the study. To test the predefined landmarks, a cadaveric experiment was subsequently performed in the second part of the study. An experienced surgeon and a second-year surgical resident performed minihemilaminectomies as precisely as possible, with and without using the landmark values. Surgery time, precision of the mini-hemilaminectomy, and iatrogenic damage of the spinal nerve roots were compared between the two groups. Based on the results in the first part of the study, the distance from the dorsal border of the accessory process to the VCF (DBAP-VCF) was chosen as a landmark due to the good intra-(0.96) and interobserver (0.83) agreement. However, the distance is highly variable between breeds. In the second part of the study, using the DBAPVCF landmark value did not influence the surgery time in both surgeons (p = 0.467, p > 0.99). An improved accuracy of the VCF was seen for the surgical resident with limited experience (p = 0.014), but not for the experienced surgeon (p = 0.926). For both surgeons, the spinal nerve roots were injured in 20% of the cases unrelated to the use of landmark values. In conclusion, this study suggests that the DBAPVCF has been described as a breed-specific landmark that can be determined in CT with good agreement. Using the previously evaluated landmark values can help improve precision in decompressive spinal surgery for a surgeon with limited experience without prolonging surgical time. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of proanthocyanidins (PC) on the neurite outgrowth of rat dorsal root ganglion (DRG) neurons. Methods In vitro, primary rat DRG neurons were cultured with a series of concentration of PC to assess the effect of PC on the number and length of neurites as well as the morphology of growth cone. In vivo, the expression of growth associated protein 43 (GAP43) in the early stage of injury was detected using the sciatic nerve crush model. Finally, the impact of PC on nerve growth factor (NG)) expression in DRG neurons was evaluated in vitro using immunofluorescence and ELISA. Results PC significantly increased the number and length of neurites and the number of pseudopodium in growth cones of DRG neurons. PC also promoted the expression of GAP43 in the early stage of sciatic nerve injury in rats and enhanced the expression of NGF in DRG neurons. Conclusion PC may promote the neurite outgrowth by increasing the expression of NGF in DRG neurons. [ABSTRACT FROM AUTHOR]

The brachial plexus is a set of nerves that innervate the upper extremity and may become injured during the birthing process through an injury known as Neonatal Brachial Plexus Palsy. Studying the mechanisms of these injuries on infant cadavers is challenging due to the justifiable sensitivity surrounding testing. Thus, these specimens are generally unavailable to be used to investigate variations in brachial plexus injury mechanisms. Finite Element Models are an alternative way to investigate the response of the neonatal brachial plexus to loading. Finite Element Models allow a virtual representation of the neonatal brachial plexus to be developed and analyzed with dimensions and mechanical properties determined from experimental studies. Using ABAQUS software, a two-dimensional brachial plexus model was created to analyze how stresses and strains develop within the brachial plexus. The main objectives of this study were (1) to develop a model of the brachial plexus and validate it against previous literature, and (2) to analyze the effect of stress on the nerve roots based on variations in the angles between the nerve roots and the spinal cord. The predicted stress for C5 and C6 was calculated as 0.246 MPa and 0.250 MPa, respectively. C5 and C6 nerve roots experience the highest stress and the largest displacement in comparison to the lower nerve roots, which correlates with clinical patterns of injury. Even small (+/- 3 and 6 degrees) variations in nerve root angle significantly impacted the stress at the proximal nerve root. This model is the first step towards developing a complete three-dimensional model of the neonatal brachial plexus to provide the opportunity to more accurately assess the effect of the birth process on the stretch within the brachial plexus and the impact of biological variations in structure and properties on the risk of Neonatal Brachial Plexus Palsy. [ABSTRACT FROM AUTHOR]

Purpose Recent studies have demonstrated the usefulness of diffusion-weighted MR neurography (DW MRN) for assessing nerve roots. This study aimed to evaluate the utility of DW MRN with a unidirectional motion-probing gradient (MPG) for the lumbar nerve roots at 1.5T MR. Materials and Methods Sixty-four lumbar spine MRI scans with DW MRN using anteroposterior unidirectional MPG were retrospectively analyzed. Any changes in the 512 lumbar spinal nerve roots from L3 to S1 were evaluated using T2-weighted imaging (T2WI), contrast-enhanced T1-weighted imaging (CE T1WI), and DW MRN, with agreement and correlation analysis. Results T2WI revealed compression of 78 nerve roots, and CE T1WI revealed 52 instances of nerve root enhancement. Sixty-seven nerve roots showed swelling and hyperintensity on DW MRN. A total of 42 nerve roots showed changes in the CE T1WI and DW MRN sequences. Moderate to substantial agreement and moderate positive correlation were observed between DW MRN and CE T1WI, as well as DW MRN and T2WI (κ = 0.59-0.65, ρ = 0.600-0.653). Conclusion DW MRN with unidirectional anteroposterior MPG can help evaluate neuritisrelated changes in spinal nerve roots and could serve as a sequence capable of complementing or substituting gadolinium CE imaging. [ABSTRACT FROM AUTHOR]

Backgroud: Neurofibromatosis type 1 (NF1) is a heterogeneous neurocutaneous disorder. Spinal neurofibromatosis (SNF) is a distinct clinical entity of NF1, characterized by bilateral neurofibromas involving all spinal nerve roots. Although both forms are caused by intragenic heterozygous variants of NF1, missense variants have been associated with SNF, according to a dominant inheritance model causing haploinsufficiency. Most patients carry pathogenic variants in one of the NF1 alleles; nevertheless, patients with both NF1‐mutated copies have been described. Interestingly, all NF1 variants carried by the known SNF compound heterozygotes were missense/splicing variants or in‐frame insertion‐deletions. Aims: To investigate whether there is a differential expression of NF1 variant alleles in an NF1 compound heterozygous SNF patient possibly contributing to clinical phenotype. Materials & methods: We performed an allele‐specific expression study, by chip‐based digital PCR, in an SNF family carrying two NF1 missense variants. We evaluated the expression levels of the two NF1‐mutated alleles both carried by the compound heterozygous SNF patient and his relatives. Results: Both alleles were expressed at comparable levels in the patient and hyper‐expressed compared to the wild‐type alleles of healthy controls. Discussion: Here we provide new insights into expression studies of NF1‐mutated transcripts suggesting that a novel pathogenetic mechanism, caused by gain‐of‐function variants, could be associated with SNF. Conclusions: Further studies should be performed in larger cohorts, opening new perspectives in the NF1 pathogenesis comprehension. [ABSTRACT FROM AUTHOR]

When contracting muscles are freely perfused, the acid-sensing ion channel 3 (ASIC3) on group IV afferents plays a minor role in evoking the exercise pressor reflex. We recently showed in isolated dorsal root ganglion neurons innervating the gastrocnemius muscles that two mu opioid receptor agonists, namely endomorphin 2 and oxycodone, potentiated the sustained inward ASIC3 current evoked by acidic solutions. This in vitro finding prompted us to determine whether endomorphin 2 and oxycodone, when infused into the arterial supply of freely perfused contracting hindlimb muscles, potentiated the exercise pressor reflex. We found that infusion of endomorphin 2 and naloxone in decerebrated rats potentiated the pressor responses to contraction of the triceps surae muscles. The endomorphin 2-induced potentiation of the pressor responses to contraction was prevented by infusion of APETx2, an ASIC3 antagonist. Specifically, the peak pressor response to contraction averaged 19.3 ± 5.6 mmHg for control (n = 10), 27.2 ± 8.1 mmHg after naloxone and endomorphin 2 infusion (n = 10), and 20 ± 8 mmHg after APETx2 and endomorphin 2 infusion (n = 10). Infusion of endomorphin 2 and naloxone did not potentiate the pressor responses to contraction in ASIC3 knockout rats (n = 6). Partly similar findings were observed when oxycodone was substituted for endomorphin 2. Oxycodone infusion significantly increased the exercise pressor reflex over its control level, but subsequent APETx2 infusion failed to restore the increase to its control level (n = 9). The peak pressor response averaged 23.1 ± 8.6 mmHg for control (n = 9), 33.2 ± 11 mmHg after naloxone and oxycodone were infused (n = 9), and 27 ± 8.6 mmHg after APETx2 and oxycodone were infused (n = 9). Our data suggest that after opioid receptor blockade, ASIC3 stimulation by the endogenous mu opioid, endomorphin 2, potentiated the exercise pressor reflex. NEW & NOTEWORTHY: This paper provides the first in vivo evidence that endomorphin 2, an endogenous opioid peptide, can paradoxically increase the magnitude of the exercise pressor reflex by an ASIC3-dependent mechanism even when the contracting muscles are freely perfused. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to compare the clinical outcomes of spinal cord stimulation (SCS) and dorsal root ganglion stimulation (DRG-S) in the treatment of painful diabetic peripheral neuropathy (PDPN). Methods: In this prospective cohort study, 55 patients received dorsal column spinal cord stimulation (SCS group) and 51 patients received dorsal root spinal cord stimulation (DRG-S group). The primary outcome was a Numerical Rating Scale (NRS) remission rate of =50%, and secondary outcomes included the effects of SCS and DRG-S on quality of life scores (EQ-5D-3L), nerve conduction velocity, and HbA1c, respectively. Results: The percentage of NRS remission rate = 50% at 6 months was 80.43 vs. 79.55%, OR (95% CI): 1.06 (0.38-2.97) in the SCS and DRG-S groups, respectively, and the percentage of VAS remission rate = 50% at 12 months was 79.07 vs. 80.95%, OR (95% CI): 0.89 (0.31-2.58). Compared with baseline, there were significant improvements in EQ-5D and EQ-VAS at 6 and 12 months (p < 0.05), but there was no difference in improvement between the SCS and DRG-S groups (p > 0.05). Nerve conduction velocities of the common peroneal, peroneal, superficial peroneal, and tibial nerves were significantly improved at 6 and 12 months compared with the preoperative period in both the SCS and PND groups (p < 0.05). However, at 6 and 12 months, there was no difference in HbA1c between the two groups (p > 0.05). Conclusion: Both SCS and DRG-S significantly improved pain, quality of life, and lower extremity nerve conduction velocity in patients with PDPN, and there was no difference between the two treatments at 12 months. [ABSTRACT FROM AUTHOR]

We have demonstrated in canines that somatic nerve transfer to vesical branches of the inferior hypogastric plexus (IHP) can be used for bladder reinnervation after spinal root injury. Yet, the complex anatomy of the IHP hinders the clinical application of this repair strategy. Here, using human cadavers, we clarify the spatial relationships of the vesical branches of the IHP and nearby pelvic ganglia, with the ureteral orifice of the bladder. Forty-four pelvic regions were examined in 30 human cadavers. Gross post-mortem and intra-operative approaches (open anterior abdominal, manual laparoscopic, and robot-assisted) were used. Nerve branch distances and diameters were measured after thorough visual inspection and gentle dissection, so as to not distort tissue. The IHP had between 1 to 4 vesical branches (2.33 ± 0.72, mean ± SD) with average diameters of 0.51 ± 0.06 mm. Vesical branches from the IHP arose from a grossly visible pelvic ganglion in 93% of cases (confirmed histologically). The pelvic ganglion was typically located 7.11 ± 6.11 mm posterolateral to the ureteral orifice in 69% of specimens. With this in-depth characterization, vesical branches from the IHP can be safely located both posterolateral to the ureteral orifice and emanating from a more proximal ganglionic enlargement during surgical procedures. [ABSTRACT FROM AUTHOR]

Radicular pain, a common and complex form of neuropathic pain, presents significant challenges in treatment. Acupuncture, a therapy originating from ancient traditional Chinese medicine and widely utilized for various pain types, including radicular pain, has shown promising outcomes in the management of lumbar radicular pain, cervical radicular pain, and radicular pain due to spinal stenosis. Despite its efficacy, the exact mechanisms through which acupuncture achieves analgesia are not fully elucidated and are the subject of ongoing research. This review sheds light on the current understanding of the analgesic mechanisms of acupuncture for radicular pain, offering valuable perspectives for both clinical application and basic scientific research. Acupuncture is postulated to relieve radicular pain by several mechanisms: peripherally, it reduces muscle spasms, lessens mechanical pressure on nerve roots, and improves microcirculation; at the molecular level, it inhibits the HMGB1/RAGE and TLR4/NF-kB signaling pathways, thereby decreasing the release of proinflammatory cytokines; within the spinal cord, it influences synaptic plasticity; and centrally, it modulates brain function, particularly affecting the medial prefrontal cortex, anterior cingulate cortex, and thalamus within the default mode network. By acting across these diverse biological domains, acupuncture presents an effective treatment modality for radicular pain, and deepening our understanding of the underlying mechanisms regarding analgesia for radicular pain is crucial for enhancing its clinical efficacy and advancement in pain management. [ABSTRACT FROM AUTHOR]

Sacral Tarlov cysts (TCs), often asymptomatic, can cause significant pain and severe neurological dysfunction. Conventional treatments are generally associated with high recurrence and complication rates. Specifically, the substantial recurrence rates, which can reach as high as 50%, significantly impact long-term outcomes. Recent evidence increasingly supports the hypothesis that the formation of Tarlov cysts (TCs) may be associated with inflammatory processes within the nerve root sheath, further exacerbated by elevated cerebrospinal fluid (CSF) pressure. This retrospective study explores thecaloscopy, combined with surgical techniques, as a more effective alternative. We observed a total of 78 patients, 48 of whom underwent endoscopic fenestration of the arachnoid sheath in addition to microsurgical resection of the TC. We found that the fenestration of the arachnoid sheath at the level of lumbosacral spinal nerve root entry led to a significantly decreased risk of developing recurrent TCs (5/48 vs. 9/30). Only one of the patients suffered from a persistent new bladder dysfunction after microsurgical resection. This presented technique provides a promising treatment path for the future management of TCs, offering a safe and more effective treatment option compared to previous methods. Additionally, the advantages of the thecaloscopy provide pathophysiological implications regarding the development of perineural cysts. [ABSTRACT FROM AUTHOR]

Hindlimb ischaemia–reperfusion (IR) is among the most prominent pathophysiological conditions observed in peripheral artery disease (PAD). An exaggerated arterial blood pressure (BP) response during exercise is associated with an elevated risk of cardiovascular events in individuals with PAD. However, the precise mechanisms leading to this exaggerated BP response are poorly elucidated. The P2X3 signalling pathway, which plays a key role in modifying the exercise pressor reflex (EPR), is the focus of the present study. We determined the regulatory role of P2X3 on the EPR in a rat model of hindlimb IR. In vivo and in vitro approaches were used to determine the expression and functions of P2X3 in muscle afferent nerves and EPR in IR rats. We found that in IR rats there was (1) upregulation of P2X3 protein expression in the L4–6 dorsal root ganglia (DRG); (2) amplified P2X currents in isolated isolectin B4 (IB4)‐positive muscle DRG neurons; and (3) amplification of the P2X‐mediated BP response. We further verified that both A‐317491 and siRNA knockdown of P2X3 significantly decreased the activity of P2X currents in isolated muscle DRG neurons. Moreover, inhibition of muscle afferents' P2X3 receptor using A‐317491 was observed to alleviate the exaggerated BP response induced by static muscle contraction and P2X‐induced BP response by α,β‐methylene ATP injection. P2X3 signalling pathway activity is amplified in muscle afferent DRG neurons in regulating the EPR following hindlimb IR. What is the central question of this study?Is the P2X3 signal pathway engaged in the exaggerated exercise pressor reflex (EPR) response in the ischaemia–reperfusion (IR) injury of peripheral artery disease (PAD)?What is the main finding and its importance?IR upregulates expression of the P2X3 receptor and increases the P2X currents in muscle afferent DRG neurons. Pharmacological inhibition using A‐317491 (P2X3 antagonist) and the genetic knockdown of P2X3 reduce the P2X currents in the muscle afferent DRG neurons. A‐317491 also attenuates the exacerbated EPR response following IR.The findings provide evidence that interventions attenuating the P2X3 signalling pathway may enhance tolerance of and adherence to exercise rehabilitation for PAD patients. [ABSTRACT FROM AUTHOR]

Cervical spondylosis is the most common progressive disease of the cervical spine. As a disease that directly affects the function and morphology of the spinal cord and nerve roots, it is of particular interest to neurologists and neurosurgeons. However, due to its prevalence, physicians of all specialties encounter this disease. This article summarizes the current knowledge of the patho-mechanism, diagnostics, and treatment of cervical spondylosis. [ABSTRACT FROM AUTHOR]

Narrative: This report discusses possible factors thought to alter nerve transmission as influenced by segmental mechanical disruption being one of the elements in a Vertebral Subluxation Complex (VSC). In addition to noxious sensory input, this discussion raises the possibility of the following physical modifier under the influence of segmental biomechanical disturbance. We hypothesise on what potential influence an intersegmental functional fixation may have on vascular and Cerebrospinal Fluid (CSF) circulation due to disturbed neural function within the Intervertebral Foramen (IVF). As the adjacent lips of articular facets form a part of the IVF margin, it is proposed here that the intersegmental articular fixation element of a VSC has the potential to also limit motion within the foramen, and potentially modify the flow of CSF within the neural sleeves which bathe the spinal nerve roots. We speculate that the effect of the fixation may lead to CSF stasis, or at least reduced CSF circulation within that radicular setting. In turn, that this may effect the spinal nerve root neurons and nerve transmission. Telano & Baker (2022) and Whedon and Glassey (2009) state that CSF 'appears to be particularly prone to stasis due to the relatively high capacitance of the lumbar cistern and lower intrathecal pressures in the distal spinal canal.' [ABSTRACT FROM AUTHOR]

This summary discusses the use of an epidural blood patch as a treatment for atypical headaches caused by spontaneous intracranial hypotension associated with meningeal diverticulum. The article presents a case study of a 33-year-old female who experienced various symptoms, including throbbing headaches, nausea, vomiting, and neck pain. After conservative treatment failed to improve her condition, two epidural blood patches were administered, resulting in significant relief of symptoms. The article emphasizes the successful treatment approach and the difficulties in diagnosing and treating intracranial hypotension associated with meningeal diverticulum. The document is available for download from the website http://journals.lww.com/mjdy and is an issue of the Patil Vidyapeeth journal, specifically Volume 17, Issue 4, published in July-August 2024. [Extracted from the article]

This study aims to determine the cutoff values for the compound muscle action potential (CMAP) stimulus in anatomically identified anterior (motor nerve) and posterior roots (sensory nerve) during cervical intradural extramedullary tumor surgery. The connection between CMAP data from nerve roots and postoperative neurological symptoms in thoracolumbar tumors was compared with data from cervical lesions. The participants of the study included 22 patients with intradural extramedullary spinal tumors (116 nerve roots). The lowest stimulation intensity to the nerve root at which muscle contraction occurs was defined as the minimal activation intensity (MAI) in the CMAP. In cervical tumors, the MAI was measured after differentiating between the anterior and posterior roots based on the anatomical placement of the dentate ligament and nerve roots. The MAIs for 20 anterior roots in eight cervical tumors were between 0.1 and 0.3 mA, whereas those for 19 posterior roots were between 0.4 and 2.0 mA. The cutoff was

Background: Loss of Cholinergic Receptor Muscarinic 1 (CHRM1) has been linked to the pathogenesis of Alzheimer's disease (AD). Our recent study found significantly lower CHRM1 protein levels in AD patient cortices, linked to reduced survival. Furthermore, using knockout mice (Chrm1−/−) we demonstrated that deletion of Chrm1 alters cortical mitochondrial structure and function, directly establishing a connection between its loss and mitochondrial dysfunction in the context of AD. While CHRM1's role in the brain has been extensively investigated, its impact on peripheral neurons in AD remains a crucial area of research, especially considering reported declines in peripheral nerve conduction among AD patients. Objective: The objective was to characterize Chrm1 localization and mitochondrial deficits in Chrm1−/− dorsal root ganglion (DRG) neurons. Methods: Recombinant proteins tagged with Green or Red Fluorescent Protein (GFP/RFP) were transiently expressed to investigate the localization of Chrm1 and mitochondria, as well as mitochondrial movement in the neurites of cultured primary mouse DRG neurons, using confocal time-lapse live cell imaging. Transmission electron microscopy was performed to examine the ultrastructure of mitochondria in both wild-type and Chrm1−/− DRGs. Results: Fluorescence imaging revealed colocalization and comigration of N-terminal GFP-tagged Chrm1 and mitochondrial localization signal peptide-tagged RFP-labelled mitochondria in the DRGs neurons. A spectrum of mitochondrial structural abnormalities, including disruption and loss of cristae was observed in 87% neurons in Chrm1−/− DRGs. Conclusions: This study suggests that Chrm1 may be localized in the neuronal mitochondria and loss of Chrm1 in peripheral neurons causes sever mitochondrial structural aberrations resembling AD pathology. [ABSTRACT FROM AUTHOR]

Background: Post herpetic neuralgia (PHN) is a chronic neuropathic pain syndrome which presents after an episode of herpes zoster caused by the reactivation of varicella zoster virus. Conservative treatment starts with pharmacological measures using Anti‐epileptics and Antidepressants. Some patients also respond well to epidural steroid injections too, but the effect is usually short lasting. Dorsal Root Ganglion Stimulator (DRG‐S) has recently been suggested as a new treatment modality for PHN due to its selective targeting of the pathophysiologic focus. Case Series: We are reporting three cases, who were suffering from neuropathic pain after an episode of herpes zoster. Pain and pain related suffering scores were high, even with multiple antiepileptics and opioid medications. They underwent DRG‐S implant and appreciated more than 50% reduction of their pain score, meaningful reduction in the dose of medications along with significant improvement of their general well being measured using Generalized Anxiety Disorder Questionnaire (GAD‐7), pain disability index (PDI), and 9 Question Patient Health Questionnaire (PHQ‐9). To our knowledge this is the first report on DRG stimulator from the Middle East Region. Conclusion: DRG‐S has potential to be a preferable treatment option in patients with refractory PHN and acts as a specific targeted therapy in the treatment of these patients. [ABSTRACT FROM AUTHOR]

Introduction: Patients suffering lumbosacral radicular pain report radiating pain in one or more lumbar or sacral dermatomes. In the general population, low back pain with leg pain extending below the knee has an annual prevalence that varies from 9.9% to 25%. Methods: The literature on the diagnosis and treatment of lumbosacral radicular pain was reviewed and summarized. Results: Although a patient's history, the pain distribution pattern, and clinical examination may yield a presumptive diagnosis of lumbosacral radicular pain, additional clinical tests may be required. Medical imaging studies can demonstrate or exclude specific underlying pathologies and identify nerve root irritation, while selective diagnostic nerve root blocks can be used to confirm the affected level(s). In subacute lumbosacral radicular pain, transforaminal corticosteroid administration provides short‐term pain relief and improves mobility. In chronic lumbosacral radicular pain, pulsed radiofrequency (PRF) treatment adjacent to the spinal ganglion (DRG) can provide pain relief for a longer period in well‐selected patients. In cases of refractory pain, epidural adhesiolysis and spinal cord stimulation can be considered in experienced centers. Conclusions: The diagnosis of lumbosacral radicular pain is based on a combination of history, clinical examination, and additional investigations. Epidural steroids can be considered for subacute lumbosacral radicular pain. In chronic lumbosacral radicular pain, PRF adjacent to the DRG is recommended. SCS and epidural adhesiolysis can be considered for cases of refractory pain in specialized centers. [ABSTRACT FROM AUTHOR]

We report a case where neuromonitoring, using motor evoked potentials (MEP), detected an intraoperative L5 nerve root deficit during a lumbosacral decompression and instrumented fusion procedure. Critically, the MEP changes were not preceded nor accompanied by any significant spontaneous electromyography (sEMG) activity. Presumptive L5 innervated muscles, including tibialis anterior (TA), extensor hallucis longus (EHL) and gluteus maximus, were targets for nerve root surveillance using combined MEP and sEMG techniques. During a high-grade spondylolisthesis correction procedure, attempts to align a left-sided rod resulted in repeated loss and recovery cycles of MEP from the TA and EHL. No accompanying EMG alerts were associated with any of the MEP changes nor were MEP variations seen from muscles innervated above and below L5. After several attempts, the rod alignment was achieved, but significant MEP signal decrement (72% decrease) remained from the EHL. Postoperatively, the patient experienced significant foot drop on the left side that recovered over a period of 3 months. This case contributes to a growing body of evidence that exclusive reliance on sEMG for spinal nerve root scrutiny can be unreliable and MEP may provide more dependable data on nerve root patency. [ABSTRACT FROM AUTHOR]

Study design: This is a cross-sectional survey. Objective: The aim was to assess the reliability of a proposed novel classification system for thoracic disc herniations (TDHs). Summary of background data: TDHs are complex entities varying substantially in many factors, including size, location, and calcification. To date, no comprehensive system exists to categorize these lesions. Methods: Our proposed system classifies 5 types of TDHs using anatomic and clinical characteristics, with subtypes for calcification. Type 0 herniations are small (≤40% of spinal canal) TDHs without significant spinal cord or nerve root effacement; type 1 are small and paracentral; type 2 are small and central; type 3 are giant (>40% of spinal canal) and paracentral; and type 4 are giant and central. Patients with types 1 to 4 TDHs have correlative clinical and radiographic evidence of spinal cord compression. Twenty-one US spine surgeons with substantial TDH experience rated 10 illustrative cases to determine the system's reliability. Interobserver and intraobserver reliability were determined using the Fleiss kappa coefficient. Surgeons were also surveyed to obtain consensus on surgical approaches for the various TDH types. Results: High agreement was found for the classification system, with 80% (range 62% to 95%) overall agreement and high interrater and intrarater reliability (kappa 0.604 [moderate to substantial agreement] and kappa 0.630 [substantial agreement], respectively). All surgeons reported nonoperative management of type 0 TDHs. For type 1 TDHs, most respondents (71%) preferred posterior approaches. For type 2 TDHs, responses were roughly equivalent for anterolateral and posterior options. For types 3 and 4 TDHs, most respondents (72% and 68%, respectively) preferred anterolateral approaches. Conclusions: This novel classification system can be used to reliably categorize TDHs, standardize description, and potentially guide the selection of surgical approach. Validation of this system with regard to treatment and clinical outcomes represents a line of future study. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to develop an arbitrary-dimensional nerve root reconstruction magnetic resonance imaging (ANRR-MRI) technique for identifying the leakage orificium of sacral meningeal cysts (SMCs) without spinal nerve root fibres (SNRFs). Methods: This prospective study enrolled 40 consecutive patients with SMCs without SNRFs between March 2021 and March 2022. Magnetic resonance neural reconstruction sequences were performed for preoperative evaluation. The cyst and the cyst-dura intersection planes were initially identified based on the original thin-slice axial T2-weighted images. Sagittal and coronal images were then reconstructed by setting each intersecting plane as the centre. Then, three-dimensional reconstruction was performed, focusing on the suspected leakage point of the cyst. Based on the identified leakage location and size of the SMC, individual surgical plans were formulated. Results: This cohort included 30 females and 10 males, with an average age of 42.6 ± 12.2 years (range, 17-66 years). The leakage orificium was located at the rostral pole of the cyst in 23 patients, at the body region of the cyst in 12 patients, and at the caudal pole in 5 patients. The maximum diameter of the cysts ranged from 2 cm to 11 cm (average, 5.2 ± 1.9 cm). The leakage orificium was clearly identified in all patients and was ligated microscopically through a 4 cm minimally invasive incision. Postoperative imaging showed that the cysts had disappeared. Conclusion: ANRR-MRI is an accurate and efficient approach for identifying leakage orificium, facilitating the precise diagnosis and surgical treatment of SMCs without SNRFs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Retrospective Observational Study. Lumbar radicular pain has a prevalence of 3–5%. Level 1 evidence has demonstrated equivalence between surgical and injection treatment. We assess the outcomes from a transforaminal epidural steroid injection clinic in a tertiary neuroscience referral centre. We performed an analysis of data from consecutive patients entered into a new internal referral database between August 2018 to May 2021. Radicular pain was classified as one of "first presentation" or "recurrence". Outcomes were obtained from follow up clinic letters and recorded in a binary manner of "positive result" or "negative result". Spinal pathology was documented from radiology reports and MRI images. We analysed 208 patients referred to the clinic. Excluding those who improved to a point of not requiring treatment, and those who underwent surgical intervention, 119 patients undergoing injection were included, of which 14 were lost to follow-up. 68 % of patients had a positive result from injection. Subgroup analysis demonstrated good outcomes for both hyperacute (<6 weeks) and chronic (>12 months). Contained disk pathologies had better outcomes than uncontained. There was no difference in outcomes across grades of compression, but previous same level surgery was associated with poorer response rates. There is a high rate of natural resolution of symptoms in patients with LSRP. In those where pain persists, TFESI is a valuable first line treatment modality. This study suggests the efficacy of TFESI is potentially independent of grade of stenosis and chronicity of symptoms. Contained disc pathologies respond better than uncontained. • Injection therapy is a cost effective modality in managing lumbosacral radicular pain. • 68 % of patients reported a positive outcome. • Those with a contained disc pathology where more likely to have better outcomes. • There was no correlation between severity of stenosis and outcome from injection. [ABSTRACT FROM AUTHOR]

Peripheral nerve injuries lead to significant changes in the dorsal root ganglia, where the cell bodies of the damaged axons are located. The sensory neurons and the surrounding satellite cells rearrange the composition of the intracellular organelles to enhance their plasticity for adaptation to changing conditions and response to injury. Meanwhile, satellite cells acquire phagocytic properties and work with macrophages to eliminate degenerated neurons. These structural and functional changes are not identical in all injury types. Understanding the cellular response, which varies according to the type of injury involved, is essential in determining the optimal method of treatment. In this research, we investigated the numerical and morphological changes in primary sensory neurons and satellite cells in the dorsal root ganglion 30 days following chronic compression, crush, and transection injuries using stereology, high-resolution light microscopy, immunohistochemistry, and behavioral analysis techniques. Electron microscopic methods were employed to evaluate fine structural alterations in cells. Stereological evaluations revealed no statistically significant difference in terms of mean sensory neuron numbers (p > 0.05), although a significant decrease was observed in sensory neuron volumes in the transection and crush injury groups (p < 0.05). Active caspase-3 immunopositivity increased in the injury groups compared to the sham group (p < 0.05). While crush injury led to desensitization, chronic compression injury caused thermal hyperalgesia. Macrophage infiltrations were observed in all injury types. Electron microscopic results revealed that the chromatolysis response was triggered in the sensory neuron bodies from the transection injury group. An increase in organelle density was observed in the perikaryon of sensory neurons after crush-type injury. This indicates the presence of a more active regeneration process in crush-type injury than in other types. The effect of chronic compression injury is more devastating than that of crush-type injury, and the edema caused by compression significantly inhibits the regeneration process. [ABSTRACT FROM AUTHOR]

A feature of peripheral artery diseases (PAD) includes limb ischemia/reperfusion (I/R) and ischemia. Both I/R and ischemia amplify muscle afferent nerve‐activated reflex sympathetic nervous and blood pressure responses (termed as exercise pressor reflex). Nevertheless, the underlying mechanisms responsible for the exaggerated autonomic responses in PAD are undetermined. Previous studies suggest that acid‐sensing ion channels (ASICs) in muscle dorsal root ganglion (DRG) play a leading role in regulating the exercise pressor reflex in PAD. Thus, we determined if signaling pathways of nerve growth factor (NGF) contribute to the activities of ASICs in muscle DRG neurons of PAD. In particular, we examined ASIC1a and ASIC3 currents in isolectin B4‐negative muscle DRG neurons, a distinct subpopulation depending on NGF for survival. Hindlimb I/R and ischemia were obtained in male rats. In results, femoral artery occlusion increased the levels of NGF and NGF‐stimulated TrkA receptor in DRGs, whereas they led to upregulation of ASIC3 but not ASIC1a. In addition, application of NGF onto DRG neurons increased the density of ASIC3 currents and the effect of NGF was significantly attenuated by TrkA antagonist GW441756. Moreover, the enhancing effect of NGF on the density of ASIC3‐like currents was decreased by the respective inhibition of intracellular signaling pathways, namely JNK and NF‐κB, by antagonists SP600125 and PDTC. Our results suggest contribution of NGF to the activities of ASIC3 currents via JNK and NF‐κB signaling pathways in association with the exercise pressor reflex in experimental PAD. [ABSTRACT FROM AUTHOR]

Objective This case series retrospectively reviewed the outcomes in patients implanted with combined, synchronous dorsal root ganglion stimulation (DRGS) and spinal cord stimulation (SCS) connected to a single implantable pulse generator (IPG) in a tertiary referral neuromodulation centre in the United Kingdom. Methods Twenty-six patients underwent a trial of DRGS+SCS for treating focal neuropathic pain between January 2016 and December 2019, with a follow-up in February 2022. A Transgrade approach was employed for DRGS. Patients were provided with 3 possible stimulation programs: DRGS-only, SCS-only, or DRGS+SCS. Patients were assessed for pain intensity, patients' global impression of change (PGIC), preferred lead(s) and complications. Results Twenty patients were successful and went on for full implantation. The most common diagnosis was Complex Regional Pain Syndrome. After an average of 3.1 years follow-up, 1 patient was lost to follow-up, and 2 were non-responders. Of the remaining 17 patients, 16 (94%) continued to report a PGIC of 7. The average pain intensity at Baseline was 8.5 on an NRS scale of 0–10. At the last follow-up, the average NRS reduction overall was 78.9% with no statistical difference between those preferring DRGS+SCS (n  = 9), SCS-only (n  = 3) and DRGS-only (n  = 5). The combination of DRGS+SCS was preferred by 53% at the last follow-up. There were no serious neurological complications. Conclusions This retrospective case series demonstrates the potential effectiveness of combined DRGS+SCS with sustained analgesia observed at an average follow-up of over 3 years. Implanting combined DRGS+SCS may provide programming flexibility and therapeutic alternatives. [ABSTRACT FROM AUTHOR]

Chronic painful intervertebral disc (IVD) degeneration (i.e., discogenic pain) is a major source of global disability needing improved knowledge on multiple-tissue interactions and how they progress in order improve treatment strategies. This study used an in vivo rat annulus fibrosus (AF) injury-driven discogenic pain model to investigate the acute and chronic changes in IVD degeneration and spinal inflammation, as well as sensitization, inflammation, and remodeling in dorsal root ganglion (DRG) and spinal cord (SC) dorsal horn. AF injury induced moderate IVD degeneration with acute and broad spinal inflammation that progressed to DRG to SC changes within days and weeks, respectively. Specifically, AF injury elevated macrophages in the spine (CD68) and DRGs (Iba1) that peaked at 3 days post-injury, and increased microglia (Iba1) in SC that peaked at 2 weeks post-injury. AF injury also triggered glial responses with elevated GFAP in DRGs and SC at least 8 weeks post-injury. Spinal CD68 and SC neuropeptide Substance P both remained elevated at 8 weeks, suggesting that slow and incomplete IVD healing provides a chronic source of inflammation with continued SC sensitization. We conclude that AF injury-driven IVD degeneration induces acute spinal, DRG, and SC inflammatory crosstalk with sustained glial responses in both DRGs and SC, leading to chronic SC sensitization and neural plasticity. The known association of these markers with neuropathic pain suggests that therapeutic strategies for discogenic pain need to target both spinal and nervous systems, with early strategies managing acute inflammatory processes, and late strategies targeting chronic IVD inflammation, SC sensitization, and remodeling. [ABSTRACT FROM AUTHOR]

Microelectrodes serve as a fundamental tool in electrophysiology research throughout the nervous system, providing a means of exploring neural function with a high resolution of neural firing information. We constructed a hybrid computational model using the finite element method and multicompartment cable models to explore factors that contribute to extracellular voltage waveforms that are produced by sensory pseudounipolar neurons, specifically smaller A-type neurons, and that are recorded by microelectrodes in dorsal root ganglia. The finite element method model included a dorsal root ganglion, surrounding tissues, and a planar microelectrode array. We built a multicompartment neuron model with multiple trajectories of the glomerular initial segment found in many A-type sensory neurons. Our model replicated both the somatic intracellular voltage profile of Ad lowthreshold mechanoreceptor neurons and the unique extracellular voltage waveform shapes that are observed in experimental settings. Results from this model indicated that tortuous glomerular initial segment geometries can introduce distinct multiphasic properties into a neuron's recorded waveform. Our model also demonstrated how recording location relative to specific microanatomical components of these neurons, and recording distance from these components, can contribute to additional changes in the multiphasic characteristics and peak-to-peak voltage amplitude of the waveform. This knowledge may provide context for research employing microelectrode recordings of pseudounipolar neurons in sensory ganglia, including functional mapping and closed-loop neuromodulation. Furthermore, our simulations gave insight into the neurophysiology of pseudounipolar neurons by demonstrating how the glomerular initial segment aids in increasing the resistance of the stem axon and mitigating rebounding somatic action potentials. [ABSTRACT FROM AUTHOR]

Intraneural perineurioma is an exceptionally rare neoplasm in animals. This case study comprises a series of three cases and a brief literature review focusing on canine intraneural perineurioma. The pathological and immunohistochemical findings are documented, revealing that canine intraneural perineurioma frequently a ects adult dogs aged between 3 and 10 years old, with a male predominance. Clinical signs associated with intraneural perineurioma in dogs include spinal pain, lameness, and paresis, resulting from the involvement of spinal nerve roots of the pelvic limbs, brachial plexus, or distal part of the median nerve. Most neoplasms had characteristic pseudo-onion bulb patterns on histopathology. Neoplastic perineurial cells, inmost cases, expressed laminin and claudin-1, and NF200 consistently highlighted the central axon. While the immunohistochemical (IHC) profile of intraneural perineurioma in veterinary medicine remains incompletely characterized, the available IHC data from all reported cases suggest that a combination of laminin and claudin- 1 immunomarkers, along with distinctive histological features, can assist in establishing a definitive diagnosis of intraneural perineurioma. [ABSTRACT FROM AUTHOR]

Spinal dural arteriovenous fistulas account for the majority of spinal vascular malformations. They are typically located in the thoracolumbar region and are diagnosed in the middle-aged and elderly populations. Although spinal dural arteriovenous fistulas have been postulated to be acquired, their exact development remains uncertain. Typically, the arteriovenous shunt is situated close to the spinal nerve root, inside the dura mater, where the blood from the radiculomeningeal artery and radicular vein intermix. Throughout history, there have been multiple classification systems of spinal arteriovenous shunts since 1967. Those were mainly based on the evolution of diagnostic studies as well as the treatment of these lesions. Such classification systems have undergone significant changes over the years. Unlike intracranial dural arteriovenous fistula, spinal dural arteriovenous fistula is progressive in nature. The neurological manifestations, due to venous congestion, tend to be insidious as well as non-specific. These include sensory deficits, such as paresthesia, bilateral and/or unilateral radicular pain affecting the lower limbs, and gait disturbances. Spinal dural arteriovenous fistulas can be suspected on magnetic resonance imaging/magnetic resonance angiography and confirmed by digital subtraction angiography (DSA). The management includes surgery, endovascular therapy, and in selected cases, radiotherapy. The treatment goal of spinal dural arteriovenous fistula is to halt the progression of the disease. The prognosis depends on both the duration of symptoms as well as the clinical condition prior to therapy. The present article comprehensively reviews the pathophysiology, changes in classification systems, natural history, clinical manifestations, radiological features, management, and prognosis. [ABSTRACT FROM AUTHOR]

Objectives To describe the MRI features of histologically proven hybrid peripheral nerve sheath tumours (HPNST). Methods A retrospective analysis of the MRI features of 24 histologically proven cases of HPNST over 7 years. Demographic data obtained from clinical records included age, gender, and date of diagnosis. Two readers independently assessed MRI studies and assessed the following features: involvement of a major nerve, intramuscular location, lesion morphology, entering nerve sign, exiting nerve sign, target sign, fascicular sign, split fat sign, and ancient change (cystic change). Inter-observer agreement was assessed with Cohen's kappa coefficient. Histological diagnosis was based on either image-guided needle biopsy or resection histology. Results The study included 9 males and 15 females with mean age 50 years (range: 24-78 years). Nine tumours (35%) involved a major nerve including spinal roots (5), radial (1), median (1), tibial (1), and axillary (1), while 5 (21%) tumours were intramuscular. The mean tumour size was 4.2 cm (standard deviation of 2.4 cm). The frequency of MRI features was as follows: lobular contour (71%; 17/24), ancient change (38%; 9/24), fascicular sign (17%; 4/24), entering nerve sign (21%; 5/24), exiting nerve sign (13%; 3/24), target sign (13%; 3/24), and split fat sign (8%; 2/24). Inter-observer agreement was high, ranging from 0.7 to 0.83. Conclusions HPNST infrequently demonstrate the classical MRI signs of benign peripheral nerve sheath tumours, but commonly have a lobular morphology and can show ancient/cystic change. Advances in knowledge This is the first study in the literature analysing the MRI features of histologically proven HPNST. HPNST infrequently shows the classical MRI signs that would be expected with benign peripheral nerve sheath tumours although commonly have a lobular morphology and show cystic change. [ABSTRACT FROM AUTHOR]

Background Cervical radiculopathy is defined as a pathological process affecting the cervical nerve root(s). Electromyography (EMG), nerve conduction studies (NCS), and somatosensory evoked potentials (SEPs) are frequently used to evaluate spinal cord and nerve root function. Objective To evaluate the sensitivity of different SEP components in detecting cervical nerve root lesions, as well as to test the NCS, and EMG, in patients with cervical radiculopathy. Methods In this case control study, 41 patients with cervical radiculopathy and 40 healthy volunteers took part. Sensory and motor NCS of the ulnar and median nerves, EMG of the deltoid, biceps brachii, and abductor brevis, and SSEP of the median nerve were performed on each participant. Results There was no difference in the motor and sensory NCS data between the study groups. The EMG of the muscles under investigation differed significantly between the two groups in terms of both duration and amplitude, with the exception of the abductor brevis muscle, which did not exhibit any differences. SEP data indicates that the patient's N9, N13, P14, and N20 latencies were all increased, as well as the patient's N13-N9, N20-N13, and N20-N9 interpeak latencies. The N13 and P14 latencies exhibited the highest sensitivity and specificity. Conclusion SEPs are more sensitive in identifying mild posterior column dysfunction in patients with cervical radiculopathy, which is at least imperceptible on routine NCS. SEP testing is an essential adjunctive diagnostic method for evaluating the spinal cord and nerve roots electrophysiologically. The N13 and P14 components have the highest sensitivity and specificity when comparing the patient and control groups. [ABSTRACT FROM AUTHOR]

Myelin protein zero (MPZ/P0) is a major structural protein of peripheral nerve myelin. Disease‐associated variants in the MPZ gene cause a wide phenotypic spectrum of inherited peripheral neuropathies. Previous nerve biopsy studies showed evidence for subtype‐specific morphological features. Here, we aimed at enhancing the understanding of these subtype‐specific features and pathophysiological aspects of MPZ neuropathies. We examined archival material from two Central European centers and systematically determined genetic, clinical, and neuropathological features of 21 patients with MPZ mutations compared to 16 controls. Cases were grouped based on nerve conduction data into congenital hypomyelinating neuropathy (CHN; n = 2), demyelinating Charcot–Marie‐Tooth (CMT type 1; n = 11), intermediate (CMTi; n = 3), and axonal CMT (type 2; n = 5). Six cases had combined muscle and nerve biopsies and one underwent autopsy. We detected four MPZ gene variants not previously described in patients with neuropathy. Light and electron microscopy of nerve biopsies confirmed fewer myelinated fibers, more onion bulbs and reduced regeneration in demyelinating CMT1 compared to CMT2/CMTi. In addition, we observed significantly more denervated Schwann cells, more collagen pockets, fewer unmyelinated axons per Schwann cell unit and a higher density of Schwann cell nuclei in CMT1 compared to CMT2/CMTi. CHN was characterized by basal lamina onion bulb formation, a further increase in Schwann cell density and hypomyelination. Most late onset axonal neuropathy patients showed microangiopathy. In the autopsy case, we observed prominent neuromatous hyperinnervation of the spinal meninges. In four of the six muscle biopsies, we found marked structural mitochondrial abnormalities. These results show that MPZ alterations not only affect myelinated nerve fibers, leading to either primarily demyelinating or axonal changes, but also affect non‐myelinated nerve fibers. The autopsy case offers insight into spinal nerve root pathology in MPZ neuropathy. Finally, our data suggest a peculiar association of MPZ mutations with mitochondrial alterations in muscle. [ABSTRACT FROM AUTHOR]

Purpose: It is known that contact of nucleus pulposus with the dorsal root ganglion may induce changes in nerve conduction and pain behavior. It has also been suggested that the behavioristic changes are caused by changes in voltage-gated ion channels, which in turn have been upregulated by TNF. Such upregulations have previously been shown for NaV 1.8 and NaV 1.9. In this investigation, we expanded the number of studied ion channels after the application of nucleus pulposus or TNF. Methods: Following removal of the left L4-5 fact joint, a disc puncture was performed and the dorsal root ganglion was exposed to nucleus pulposus (n = 5) and TNF (n = 5). Operated rats without disc puncture served as sham (n = 5) and 5 non-operated (naïve) rats were included. After 24 h, the DRGs were harvested and analyzed by quantitative PCR on validated pre-spotted primer plates displaying genes for 90 voltage-gated ion channels. Results: It was evident that the changes in operated animals were separate from the naïve rats. It was also apparent that gene expression changes in rats with nucleus pulposus or TNF application showed similar trends and were also separated from sham-operated animals. Conclusion: The application of nucleus pulposus and TNF onto the DRG in rats induces comparable changes in gene expression of several ion channels. Since the changes induced by TNF and NP are similar, one might also suspect that TNF mediates the NP-induced changes. However, such a mechanism needs further investigation. [ABSTRACT FROM AUTHOR]

Macroautophagy/autophagy, a lysosome-dependent self-degradative process, is a critical mechanism for the clearance of misfolded proteins and dysfunctional organelles in neurons. In the peripheral nervous system, autophagic stress is associated with the development of peripheral neuropathy. However, the molecular mechanism of axonal neuropathy induced by autophagic stress due to dysfunction of autophagy in peripheral neurons in vivo is still unclear. We found that dorsal root ganglion (DRG) neuron-specific atg7 (autophagy related 7) knockout (atg7-cKO) mice employing two different Cre recombinase systems exhibited sensory neuropathy approximately 2 months after birth. In electron microscopy analysis, axon degeneration was clearly observed in the myelinated fibers of the sciatic nerve before the appearance of neuronal cell death. Dystrophic axons filled with abnormal vesicular accumulations and amorphous inclusions were specifically localized in the myelinated axons within the DRG in atg7-cKO mice, indicating the presence of autophagic stress in proximal axons. In line with the EM findings, the mutant mice showed preferential induction of axonal injury-associated genes, including ATF3 (activating transcription factor 3), in large-size DRG neurons that constitute myelinated fibers without axotomy. SARM1 (sterile alpha and HEAT/Armadillo motif containing 1), the central executioner of Wallerian degeneration, was activated in the sciatic nerves of atg7-cKO mice, and axonal degeneration and sensory neuropathy in atg7-cKO mice were prevented via expression of a dominant-negative Sarm1 transgene. Our findings demonstrate the importance of SARM1-dependent axon degeneration in the development of peripheral sensory neuropathy induced by impairment of autophagy. AAV: adeno-associated virus; ATF3: activating transcription factor 3; ATG7: autophagy related 7; AVIL: advillin; cADPR: cyclic ADP ribose; CALC: calcitonin/calcitonin-related polypeptide; CMT: Charcot-Marie-Tooth disease; cKO: conditional knockout; DEG: differentially expressed gene; DRG: dorsal root ganglion; FE-SEM: field emission scanning electron microscopy; IF: immunofluorescence; NCV: nerve conduction velocity; PVALB: parvalbumin; RAG: regeneration-associated gene; ROS: reactive oxygen species; SARM1: sterile alpha and HEAT/Armadillo motif containing 1; SYN1: synapsin I [ABSTRACT FROM AUTHOR]

Objectives: To characterise head tilt as a rare clinical sign of cervical spinal or paraspinal disease in dogs. Materials and Methods: Retrospective single‐centre case‐series study of dogs with head tilt and cervical spinal or paraspinal disease in the absence of intracranial abnormalities. Descriptive statistics were used. Results: Fifteen dogs met the inclusion criteria of this study. Median age at onset was 6 years (range 2.5 to 12 years). Onset of neurological signs was mainly chronic (9/15, 60%). Most common presenting complaints included head tilt (9/15, 60%) and cervical hyperaesthesia (8/15, 53%). Most common neurological findings included head tilt (15/15, 100%), generalised proprioceptive ataxia and tetraparesis (6/15, 40%) and cervical hyperaesthesia (8/15, 53%). Diagnoses included post‐operative complication of C2 spinal nerve root mass removal (2/15, 13%), C3‐C4 intervertebral disc extrusion (2/15, 13%), cervical paraspinal myositis (2/15, 13%) and one of each: C2 vertebral malformation, C2 spinal nerve root mass, C1‐C2 meningioma, C2 vertebral fracture, C4‐C5 intervertebral disc extrusion, C4 vertebral body mass, C5‐C7 osseous‐associated cervical spondylomyelopathy, and concurrent C5‐C6 and C6‐C7 intervertebral disc protrusions. Two dogs were euthanased shortly after diagnosis and two of 15 were dogs lost to follow‐up. No post‐mortem examination was performed for these cases. For the 11 of 15 remaining dogs, head tilt resolved in eight of 15 (53%) dogs after treatment of the underlying condition and in three of 15 (20%) dogs, it remained static. Clinical Significance: Head tilt can be a rare clinical sign of cervical spinal or paraspinal disease in dogs. [ABSTRACT FROM AUTHOR]