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JCI Insight May 2024Peripheral nerve injury-induced neuronal hyperactivity in the dorsal root ganglion (DRG) participates in neuropathic pain. The calcium-activated potassium channel...
Peripheral nerve injury-induced neuronal hyperactivity in the dorsal root ganglion (DRG) participates in neuropathic pain. The calcium-activated potassium channel subfamily N member 1 (KCNN1) mediates action potential afterhyperpolarization (AHP) and gates neuronal excitability. However, the specific contribution of DRG KCNN1 to neuropathic pain is not yet clear. We report that chronic constriction injury (CCI) of the unilateral sciatic nerve or unilateral ligation of the fourth lumbar nerve produced the downregulation of Kcnn1 mRNA and KCNN1 protein in the injured DRG. This downregulation was partially attributed to a decrease in DRG estrogen-related receptor gamma (ESRRG), a transcription factor, which led to reduced binding to the Kcnn1 promoter. Rescuing this downregulation prevented CCI-induced decreases in total potassium voltage currents and AHP currents, reduced excitability in the injured DRG neurons, and alleviated CCI-induced development and maintenance of nociceptive hypersensitivities, without affecting locomotor function and acute pain. Mimicking the CCI-induced DRG KCNN1 downregulation resulted in augmented responses to mechanical, heat, and cold stimuli in naive mice. Our findings indicate that ESRRG-controlled downregulation of DRG KCNN1 is likely essential for the development and maintenance of neuropathic pain. Thus, KCNN1 may serve as a potential target for managing this disorder.
Topics: Animals; Neuralgia; Ganglia, Spinal; Mice; Down-Regulation; Sensory Receptor Cells; Male; Peripheral Nerve Injuries; Mice, Inbred C57BL; Sciatic Nerve; Disease Models, Animal; Intermediate-Conductance Calcium-Activated Potassium Channels; Action Potentials
PubMed: 38912580
DOI: 10.1172/jci.insight.180085 -
Journal of Biomedical Optics Jul 2024Information about the spatial organization of fibers within a nerve is crucial to our understanding of nerve anatomy and its response to neuromodulation therapies. A...
NerveTracker: a Python-based software toolkit for visualizing and tracking groups of nerve fibers in serial block-face microscopy with ultraviolet surface excitation images.
SIGNIFICANCE
Information about the spatial organization of fibers within a nerve is crucial to our understanding of nerve anatomy and its response to neuromodulation therapies. A serial block-face microscopy method [three-dimensional microscopy with ultraviolet surface excitation (3D-MUSE)] has been developed to image nerves over extended depths . To routinely visualize and track nerve fibers in these datasets, a dedicated and customizable software tool is required.
AIM
Our objective was to develop custom software that includes image processing and visualization methods to perform microscopic tractography along the length of a peripheral nerve sample.
APPROACH
We modified common computer vision algorithms (optic flow and structure tensor) to track groups of peripheral nerve fibers along the length of the nerve. Interactive streamline visualization and manual editing tools are provided. Optionally, deep learning segmentation of fascicles (fiber bundles) can be applied to constrain the tracts from inadvertently crossing into the epineurium. As an example, we performed tractography on vagus and tibial nerve datasets and assessed accuracy by comparing the resulting nerve tracts with segmentations of fascicles as they split and merge with each other in the nerve sample stack.
RESULTS
We found that a normalized Dice overlap ( ) metric had a mean value above 0.75 across several millimeters along the nerve. We also found that the tractograms were robust to changes in certain image properties (e.g., downsampling in-plane and out-of-plane), which resulted in only a 2% to 9% change to the mean values. In a vagus nerve sample, tractography allowed us to readily identify that subsets of fibers from four distinct fascicles merge into a single fascicle as we move along the nerve's length.
CONCLUSIONS
Overall, we demonstrated the feasibility of performing automated microscopic tractography on 3D-MUSE datasets of peripheral nerves. The software should be applicable to other imaging approaches. The code is available at https://github.com/ckolluru/NerveTracker.
Topics: Software; Nerve Fibers; Imaging, Three-Dimensional; Algorithms; Animals; Image Processing, Computer-Assisted; Tibial Nerve; Vagus Nerve; Microscopy, Ultraviolet; Microscopy
PubMed: 38912214
DOI: 10.1117/1.JBO.29.7.076501 -
Cureus Jun 2024Background Postpartum peripheral nerve injuries can impact recovery. Elastic stockings are recommended for thromboembolism prevention, although concerns about entrapment...
Background Postpartum peripheral nerve injuries can impact recovery. Elastic stockings are recommended for thromboembolism prevention, although concerns about entrapment neuropathy exist. In this prospective observational study, we investigated the differential compressions caused by wearing elastic stockings before and after anesthesia, as well as changes in the diameters of the lower leg and ankle in parturient women undergoing spinal anesthesia for elective cesarean section (CS). Methods Eighteen pregnant women, classified by the American Society of Anesthesiologists as having physical status 2, underwent lower leg measurements taken before a CS. Elastic stockings were applied, and compression pressure was measured at pre-anesthesia, post-surgery, and six hours post-return to a hospital room. Fluid, blood loss, urine output, and neuropathy presence were recorded. For all parameters, changes at the three time points were compared for the primary analysis. For secondary analysis, participants were categorized as having intraoperative blood loss greater than (group P) or less than 1,000 g (group N), and factors were compared with pre-anesthesia and six hours post-return to a room. Data were analyzed and presented using a one-way analysis of variance with Bonferroni correction for multiple comparisons or unpaired two-tailed t-tests for pairwise comparison. Results None of the women had postoperative entrapment neuropathy. Six patients had >1,000 g of blood loss. Compression significantly increased from pre-anesthesia (left 13.6 ± 2.4, 95% CI: 12.18 to 14.52; right 13.4 ± 2.4, 95% CI: 12.41 to 14.69) to post-surgery (left, 17.4 ± 2.6, 95% CI: 15.68 to 18.12; right, 16.9 ± 2.6, 95% CI: 16.20 to 18.70) (p < 0.01). Compression pressure at post-surgery differed significantly between group P (left, 15.3 ± 1.3; right, 14.7 ± 1.8; 95% CI: -4.98 to -0.32) and group N (left, 18.1 ± 2.9; right, 17.8 ± 2.4; 95% CI: -5.38 to -0.26) (p < 0.05). The results are expressed as mean ± standard deviation, with P-values <0.05 indicating statistical significance. Conclusions In this study, no neuropathy occurred; however, over-compression risk with elastic stockings, especially when exceeding recommended pressure levels, was highlighted. Balancing thromboembolism prevention and over-compression risks is crucial for patients undergoing CSs with spinal anesthesia.
PubMed: 38912079
DOI: 10.7759/cureus.62809 -
ENeurologicalSci Jun 2024Intractable hiccups, persisting beyond 48 h, pose a clinical challenge, particularly in demyelinating diseases like Neuromyelitis Optica (NMO) and Multiple Sclerosis...
BACKGROUND
Intractable hiccups, persisting beyond 48 h, pose a clinical challenge, particularly in demyelinating diseases like Neuromyelitis Optica (NMO) and Multiple Sclerosis (MS). Understanding the complex neural pathways of the hiccup reflex and the impact of high-dose steroid therapy is crucial for managing this rare but distressing symptom. The hiccup reflex involves afferents from the vagus, phrenic, and sympathetic nerves, with the reflex center in the anterior horns at the C3 to 5 level and the medulla oblongata. The potential interplay between demyelination and corticosteroid therapy in triggering persistent hiccups requires exploration.
CASE REPORT
This case report details a 21-year-old male with undiagnosed demyelinating disorder, presenting persistent hiccups following high-dose steroid therapy for an acute disease flare. The patient's history included vertigo and progressive neurological symptoms, leading to an MS diagnosis with significant brain and spinal lesions. Persistent hiccups, initiated by steroid administration, were recurrent but responsive to metoclopramide after other measures failed.
DISCUSSION
The discussion centers on investigating the cause of hiccups in a patient with demyelination following steroid administration. Steroids' impact on neurological systems, including neurotransmitter function, and the potential disruption of neurological pathways due to demyelination may contribute to hiccups. Successful hiccup resolution with metoclopramide suggests a potential pharmacological approach for corticosteroid-induced hiccups in demyelinating diseases. This case emphasizes the need for further research into the intricate relationship between demyelination, steroid therapy, and hiccups to enhance management strategies for this uncommon yet impactful symptom.
PubMed: 38911508
DOI: 10.1016/j.ensci.2024.100509 -
Wellcome Open Research 2023Schwannoma is a nerve sheath tumour arising from differentiated Schwann cells, and melanocytic schwannoma (MS) is a rare variant where the Schwan cells produce melanin...
Schwannoma is a nerve sheath tumour arising from differentiated Schwann cells, and melanocytic schwannoma (MS) is a rare variant where the Schwan cells produce melanin pigment. MS is typically associated with spinal nerve roots and there have been only ~20 reports of cutaneous or subcutaneous MS to-date in humans. In canines, there have only been two reports of MS, both associated with spinal root nerves. In this report, we describe a 7-year-old Weimaraner cross breed dog that presented with two pigmented lesions on the eyelids. The lesions were surgically removed and histological analysis revealed well-circumscribed, non-encapsulated, expansile, neoplasms that were displacing most of the dermis and adnexa. The first lesion was composed of spindloid cells arranged in short interlacing streams with large amounts of pale eosinophilic cytoplasm that sometimes contained fine melanin granules. In areas there were spindle cells arranged in verocay bodies which led to a diagnosis of MS. In contrast, the second lesion was composed of polygonal cells arranged in thick sheets with large amounts of pale eosinophilic cytoplasm that sometimes contained fine melanin granules. The diagnosis was melanocytoma (which is one of the macroscopic differential diagnoses for MS). Whilst melanocytoma is a commonly occurring cutaneous lesion in canines and surgical removal is considered curative, due to little being known about MS in dogs, the outcome remained guarded, as MS in humans has an unpredictable nature, and recurrence and metastasis have been reported.
PubMed: 38911282
DOI: 10.12688/wellcomeopenres.19694.2 -
Journal of Orthopaedic Case Reports Jun 2024Thromboangiitis obliterans (TAO) or Buerger's disease (BD) is a small and medium-sized arteriovenous segmental occlusive inflammatory disease frequently occurring in men...
INTRODUCTION
Thromboangiitis obliterans (TAO) or Buerger's disease (BD) is a small and medium-sized arteriovenous segmental occlusive inflammatory disease frequently occurring in men as compared to women. Although a common etiological agent is smoking or tobacco consumption, it has also been reported infrequently in non-smokers. Except for smoking other etiological agents, HLA, autoimmune diseases like systemic lupus erythematosus, and periodontitis have also been suggested. Minimally invasive pain and spine intervention (MIPSI) like stellate ganglion neurolysis with 8% phenol, 10 days apart in patients suffering from bilateral digital ischemia of both hands is a safe and effective treatment.
CASE REPORT
Fifty-five-year-old female with chief complaints of burning pain, swelling, and blackening of all five fingers of the right and four fingers of the left hands excluding the thumb for the past 3 months. On examination, pulse was almost absent at the wrist in both hands. There was no history of smoking. Under aseptic precautions, fluoroscopy and radiocontrast guidance stellate ganglion neurolysis with a 22G spinal needle, 2 ml of 8% phenol, 2 ml of 0.25% bupivacaine and 4 mg of dexamethasone were given at C7 vertebral level 10 days apart on both sides. After 3-4 months of stellate ganglion phenol chemical neurolysis, involved fingers were saved except the gangrenous part which was autoamputated itself in due course of time.
CONCLUSION
Bilateral interval (10 days apart) chemical neurolysis of stellate ganglion in Buerger's disease involving both hands is a safe and effective technique in terms of control of disease progression, pain, cardiac complications, and recurrent laryngeal nerve-related complications.
PubMed: 38910976
DOI: 10.13107/jocr.2024.v14.i06.4496 -
Cureus May 2024Adductor canal block is a widely used regional anesthesia technique for total knee arthroplasty that helps in reducing post-surgical pain and opioid use. Anatomically,...
Adductor canal block is a widely used regional anesthesia technique for total knee arthroplasty that helps in reducing post-surgical pain and opioid use. Anatomically, the adductor canal extends from the apex of the femoral triangle proximally to the adductor hiatus distally and is roofed by the sartorius and vasto-adductor fascia. All these serve as a potential path for the spread of the local anesthetic when it is injected inside the adductor canal during the block. Subsartorial space is of unique interest as it lies between the sartorius and vasto-adductor fascia, carrying the subsartorial plexus that can provide additional analgesia to the knee when the adductor canal block injectate spreads into it. While the spread can be variable, ultrasound can be a useful tool to evaluate this spread. This is a case series of patients who underwent total knee arthroplasty under spinal anesthesia and adductor canal blocks. We present the findings of ultrasound evaluation of the injectate spread following adductor canal blocks and evaluation of their analgesia effects.
PubMed: 38910653
DOI: 10.7759/cureus.60849 -
International Immunopharmacology Jun 2024Blood always shows coagulation changes after spinal cord injury (SCI), and identifying these blood changes may be helpful for diagnosis and treatment of SCI....
BACKGROUND
Blood always shows coagulation changes after spinal cord injury (SCI), and identifying these blood changes may be helpful for diagnosis and treatment of SCI. Nevertheless, studies to date on blood coagulation changes after SCI in humans are not comprehensive. Therefore, this study aims to identify blood coagulation diagnostic biomarkers and immune changes related to SCI and its severity levels.
METHODS
Human blood sequencing datasets were obtained from public databases. Differentially expressed coagulation-related genes were analyzed (DECRGs). Enrichment analysis and assessment of immune changes were conducted. Weighted gene co-expression network analysis, least absolute shrinkage and selection operator logistic regression were used to identify biomarkers. Validation for these biomarkers was performed. The correlation between biomarkers and immune cells was evaluated. Transcription factors, miRNA, lncRNA, and drugs that can regulate biomarkers were analyzed.
RESULTS
DECRGs associated with SCI and its different grades were identified, showing enrichment in altered coagulation and immune-related signaling pathways. ADAM9, CD55, and STAT4 were identified as coagulation diagnostic biomarkers for SCI. IRF4 and PABPC4 were identified as coagulation diagnostic biomarkers for American Spinal Injury Association Impairment Scale (AIS) A grade of SCI. GP9 was designated as a diagnostic biomarker for AIS D grade of SCI. Immune changes in blood of SCI and its different grades were observed. Correlation between diagnostic biomarkers and immune cells were identified. Transcription factors, miRNA, lncRNA, and drugs that can regulate diagnostic biomarker expression were discovered.
CONCLUSION
Therefore, detecting the expression of these putative diagnostic biomarkers and related immune changes may be helpful for predicting the severity of SCI. Uncovering potential regulatory mechanisms for biomarkers may be beneficial for further research.
PubMed: 38908081
DOI: 10.1016/j.intimp.2024.112505 -
Journal of Cardiothoracic Surgery Jun 2024The incidence of minimally invasive heart surgery via mini-thoracotomy (MT; right anterior thoracotomy) is on the rise, accompanied by an increase in post-MT intercostal...
BACKGROUND
The incidence of minimally invasive heart surgery via mini-thoracotomy (MT; right anterior thoracotomy) is on the rise, accompanied by an increase in post-MT intercostal nerve neuralgia and the risk of lung herniation through the incision site. While various methods have been proposed to address these issues, none have been commonly effective. In this case report, we attempted to simultaneously address these problems by performing intercostal cryoablation (IC) and mesh repair.
CASE PRESENTATION
A 43-year-old male was referred to our hospital for chronic post-thoracotomy neuralgia following heart surgery via MT, involving patch closure of an atrial septal defect and tricuspid annuloplasty. He presented with intercostal nerve neuralgia and lung herniation accompanied by severe pain. Despite medication and lidocaine injections, there was no relief. Consequently, he underwent surgical treatment with IC for chronic MT wound pain and simultaneously underwent mesh repair for a lung hernia. He was discharged from hospital free of complications. Subsequently, he no longer required further pain medication and experienced a favorable recovery.
CONCLUSION
Our findings suggest that concurrent IC and mesh repair can effectively relieve chronic post-MT intercostal nerve neuralgia and severe lung herniation pain in patients who underwent MT surgery, leading to a decrease in opioid medication usage.
Topics: Humans; Male; Adult; Cryosurgery; Thoracotomy; Surgical Mesh; Herniorrhaphy; Intercostal Nerves; Pain, Postoperative; Lung Diseases; Neuralgia; Hernia; Chronic Pain
PubMed: 38907312
DOI: 10.1186/s13019-024-02864-y -
Scientific Reports Jun 2024Despite a 15% misplacement rate of screws in idiopathic scoliosis surgery, little is known about the relationship between pedicles and nerve structures in the entire...
Despite a 15% misplacement rate of screws in idiopathic scoliosis surgery, little is known about the relationship between pedicles and nerve structures in the entire thoracic curve. This study aimed to explore the spinal cord's proximity to the pedicle wall at each thoracic vertebra in the entire thoracic curve, while considering different anatomical changes. Spinal cord to medial pedicle distances were measured on magnetic resonance imaging in 73 patients who underwent posterior spinal fusion with pedicle screw instrumentation. Associations with different variables were examined. A total of 51 patients (69.9%) showed a distance within 2 mm at the apex vertebra on the concave side, more than 50% had a distance within 2 mm in the next thoracic vertebra level above and below, and more than 25% two levels above and below. Weak correlations were found between proximity of the spinal cord at the apex vertebra and vertebra's level and Cobb angle on the concave side (r = - 0.310, P = 0.008, r = 0.380, P = 0.001, respectively). These results emphasize the importance of thorough assessment when placing thoracic pedicle screws in idiopathic scoliosis patients. Further research is warranted to develop surgical strategies aimed at preventing potentially neurological complications resulting from screw misplacement.
Topics: Humans; Scoliosis; Female; Thoracic Vertebrae; Male; Pedicle Screws; Adolescent; Spinal Cord; Spinal Fusion; Magnetic Resonance Imaging; Child; Young Adult; Adult; Retrospective Studies
PubMed: 38906927
DOI: 10.1038/s41598-024-64971-z