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Introduction: The a6 subunit-containing GABAA receptors (a6GABAARs) are highly expressed in the trigeminal ganglia (TG), the sensory hub of the trigeminovascular system (TGVS). Hypo-GABAergic transmission in the TG was reported to contribute to migraine-related behavioral and histopathological phenotypes. Previously, we found that Compound 6, an a6GABAAR-selective positive allosteric modulator (PAM), significantly alleviated TGVS activationinduced peripheral and central sensitization in a capsaicin-induced migrainemimicking model. Methods: Here, we tested whether the deuterated analogues of Compound 6, namely DK-1-56-1 and RV-I-29, known to have longer half-lives than the parent compound, can exert a similar therapeutic effect in the same model. The activation of TGVS was triggered by intra-cisternal (i.c.) instillation of capsaicin in male Wistar rats. Centrally, i.c. capsaicin increased the quantity of c-Fosimmunoreactive (c-Fos-ir) neurons in the trigeminal cervical complex (TCC). Peripherally, it increased the calcitonin gene-related peptide immunoreactivity (CGRP-ir) in TG, and caused CGRP release, leading to CGRP depletion in the dura mater. Results: DK-I-56-1 and RV-I-29, administered intraperitoneally (i.p.), significantly ameliorated the TCC neuronal activation, TG CGRP-ir elevation, and dural CGRP depletion induced by capsaicin, with DK-I-56-1 demonstrating better efficacy. The therapeutic effects of 3 mg/kg DK-I-56-1 are comparable to that of 30 mg/kg topiramate. Notably, i.p. administered furosemide, a blood-brain-barrier impermeable a6GABAAR-selective antagonist, prevented the effects of DK-I-56-1 and RV-I-29. Lastly, orally administered DK-I-56-1 has a similar pharmacological effect. Discussion: These results suggest that DK-I-56-1 is a promising candidate for novel migraine pharmacotherapy, through positively modulating TG a6GABAARs to inhibit TGVS activation, with relatively favourable pharmacokinetic properties. [ABSTRACT FROM AUTHOR]

By maximizing the advantages of exoscopy, we developed a keyhole approach for intracranial hematoma removal. Herein, we validated the utility of this procedure, and compared it with conventional microscopic hematoma removal and endoscopic hematoma removal in our institution. We included 12 consecutive patients who underwent this procedure from June 2022 to March 2024. A 4-cm-long skin incision was made, and a keyhole craniotomy (diameter, 2.5 cm) was performed. An assistant manipulated a spatula, and an operator performed hematoma removal and hemostasis using typical microsurgical techniques under an exoscope. The dura mater was reconstructed without sutures using collagen matrix and fibrin glue. The outcomes of this series were compared with those of 12 consecutive endoscopic hematoma removals and 19 consecutive conventional microscopic hematoma removals from October 2018 to March 2024. The mean age was 72 ± 10 years, and 7 (58%) patients were men. Hematoma location was the putamen in 5 patients and subcortical in 7 patients. The mean operative time was 122 ± 34 min, the mean hematoma removal rate was 95% ± 8%, and the mortality rate was 0%. Although the preoperative hematoma volume was similar between the 3 groups, the operative time and total time in the operating room was significantly shorter in the exoscope group than in the microscope group (P < 0.0001). This procedure may be simpler and faster than conventional microscopic hematoma removal, and comparable to endoscopic hematoma removal. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to evaluate the effectiveness of the Piezosurgery® device in endoscopic-assisted correction of trigonocephaly. Trigonocephaly is a type of craniosynostosis characterized by a triangular-shaped forehead due to the premature fusion of the metopic suture. Traditional open cranial vault reconstruction, although common, is invasive and poses risks. The study explores a less invasive alternative using ultrasonic microvibrations for bone cutting, potentially reducing soft tissue damage and improving surgical outcomes. Methods: The Piezosurgery® device was employed in endoscopic trigonocephaly correction surgeries performed on patients under 4 months old at the French Referral Center for Craniosynostosis in Lyon. The technique involves making a small skin incision and performing osteotomies from the anterior fontanel to the glabella. A rigid 0° endoscope provides visibility, and the Piezosurgery® device enables precise bone cutting while preserving the dura mater. Post-surgery, patients were discharged within 3 days and required to wear a remodeling helmet for 6–8 months. Results: The use of Piezosurgery® device allowed precise osteotomies with minimal soft tissue damage. No dura mater injuries occurred in the patient series. The procedure was efficient, with an average duration of 80 min, and blood loss was minimal, reducing the need for blood transfusions. The endoscopic approach facilitated shorter surgical times and reduced postoperative infection risks. Enhanced visibility during surgery, due to cavitation effects, improved the accuracy of bone cuts. The technique demonstrated promising safety and esthetic outcomes, although it incurred higher costs compared to traditional methods. Conclusion: Piezosurgery® device provides a safe and effective method for minimally invasive endoscopic correction of trigonocephaly. The device's ability to selectively cut bone while preserving soft tissues offers significant advantages, despite longer surgical times and higher costs. This technique represents a viable alternative to traditional open surgery, promoting better clinical outcomes and reduced recovery times. [ABSTRACT FROM AUTHOR]

Purpose: Cerebrospinal fluid (CSF) leakage is a challenging complication of intradural cranial surgery, and children are particularly at risk. The use of dural sealants confers protection in adults, but pediatric studies are scarce. We evaluated the safety and efficacy of Evicel® fibrin sealant as an adjunct to primary dural suturing in children undergoing cranial surgery. Methods: A multicenter trial prospectively enrolled pediatric subjects (< 18 years) undergoing cranial neurosurgery who, upon completion of primary sutured dural repair, experienced CSF leakage. As agreed by the EMA Evicel® Pediatric Investigation Plan, 40 subjects were intra-operatively randomized 2:1 to Evicel® or additional sutures ('Sutures'). Data analysis was descriptive. The efficacy endpoint was treatment success rate, with success defined as intra-operative watertight closure after provocative Valsalva maneuver (primary endpoint). Safety endpoints were postoperative CSF leakage (incisional CSF leakage, pseudomeningocele or both) and surgical site complications (secondary endpoints). Results: Forty subjects (0.6–17 years) were randomized to Evicel® (N = 25) or Sutures (N = 15) (intention-to-treat). Intracranial tumor was the most common indication and procedures were mostly supratentorial craniotomies. Success rates were 92.0% for Evicel® and 33.3% for Sutures, with a 2.76 estimated ratio of success rates (Farrington-Manning 95% CI [1.53, 6.16]). Sensitivity analyses in per-protocol and safety sets showed similar results. Despite a higher rescue treatment rate, the frequencies of postoperative CSF leakage and wound complications were higher for Sutures than for Evicel®. Conclusion: This small-scale prospective study shows Evicel® treatment to be safe and effective as an adjunct to primary sutured dura mater closure in a pediatric population. Compared to additional sutures, Evicel® was associated with reduced postoperative CSF leakage and surgical site complications. (Trial registration: The trial was registered as NCT02309645 and EudraCT 2013-003558-26). [ABSTRACT FROM AUTHOR]

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Introduction: Toward further cerebro-spinal flow quantification in clinical practice, this study aims at assessing the variations in the cerebro spinal fluid flow pattern associated with change in the morphology of the subarachnoid space of the cervical canal of healthy humans by developing a computational fluid dynamics model. Methods: 3D T2-space MRI sequence images of the cervical spine were used to segment 11 cervical subarachnoid space. Model validation (time-step, mesh size, size and number of boundary layers, influences of parted inflow and inflow continuous velocity) was performed a 40-year-old patient-specific model. Simulations were performed using computational fluid dynamics approach simulating transient flow (Sparlart-Almaras turbulence model) with a mesh size of 0.6, 6 boundary layers of 0.05 mm, a time step of 20 ms simulated on 15 cycles. Distributions of components velocity and WSS were respectively analyzed within the subarachnoid space (intervertebral et intravertebral levels) and on dura and pia maters. Results: Mean values cerebro spinal fluid velocity in specific local slices of the canal range between 0.07 and 0.17 m.s-1 and 0.1 and 0.3 m.s-1 for maximum values. Maximum wall shear stress values vary between 0.1 and 0.5 Pa with higher value at the middle of the cervical spine on pia mater and at the lower part of the cervical spine on dura mater. Intra and inter-individual variations of the wall shear stress were highlighted significant correlation gwith compression ratio (r = 0.76), occupation ratio and cross section area of the spinal cord. Conclusion: The inter-individual variability in term of subarachnoid canal morphology and spinal cord position influence the cerebro-spinal flow pattern, highlighting the significance of canal morphology investigation before surgery. [ABSTRACT FROM AUTHOR]

Postoperative adhesion (POA) has emerged as a prevalent clinical challenge in soft tissue repair, emphasizing the critical need for preventive measures. However, the complex POA development process makes POA prevention from a single aspect insufficient. Hence, a curcumin‐loaded poly‐L‐lactic acid‐poly (caprolactone) micro‐nano conjugated fibrous membrane (PAPC MCFM (cur)) is engineered to synergistically prevent POA from multiple perspectives, in which poly (caprolactone) (PCL) nanofibers (118 ± 12 nm) with low orientation traverse the oriented poly‐L‐lactic acid (PLLA) microfibers (2.0 ± 0.3 µm). The PAPC MCFM not only significantly improves the mechanical properties of the anisotropic fibrous membrane (AIFM) that the modulus of elasticity and the tensile strength in the direction vertical to microfiber orientation increase by 4.5 and 13.0 times, respectively, but also can further enhance the “contact guidance effect” of AIFM, i.e., hindering fibroblast adhesion, proliferation, and differentiation to myofibroblast through inhibiting integrin β1 activation, vinculin expression and focal adhesion (FA) formation, and the nuclear localization activation of yes‐associated protein (YAP). Except for these effects, PAPC MCFM loading with 2.5 mg mL−1 curcumin can further prevent POA by delivering anti‐inflammatory, antioxidant, and antibacterial properties, and by suppressing fibrosis through decreased transforming growth factor‐β1(TGF‐β1) expression, showing effective POA prevention in rat abdominal cavity and rabbit dura mater models. [ABSTRACT FROM AUTHOR]

Objectives Methods Results Conclusions Collagen membranes are extensively used for guided bone regeneration procedures, primarily for horizontal bone augmentation. More recently, it has been demonstrated that collagen membranes promote bone regeneration. Present study aimed at assessing if structural modifications of collagen membranes may enhance their osteoconductive capacity.Twenty‐four adult Wistar rats were used. Bilateral calvaria defects with a diameter of 5 mm were prepared and covered with prototypes of collagen membranes (P1 or P2). The P1 membrane (positive control) presented a lower onset temperature of protein denaturation and a higher solubility than the P2 membrane (test). The contralateral defects were left uncovered (NC). After 1 and 4 weeks, the animals were euthanized. A microcomputed tomography analysis of the harvested samples was performed within and above the bony defect. Undecalcified ground sections were subjected to light microscopy and morphometric analysis.Bone formation was observed starting from the circumferential borders of the defects in all groups at 1‐week of healing. The foci of ossification were observed at the periosteal and dura mater sites, with signs of collagen membrane mineralization. However, there was no statistically significant difference between the groups. At 4 weeks, remnants of the collagen fibers were embedded in the newly formed bone. In the P2 group, significantly more bone volume, more new bone, and marrow spaces compared to the NC group were observed. Furthermore, the P2 group showed more bone volume ectocranially then the P1 group.Bone formation subjacent to a P2 membrane was superior than subjacent to the P1 membrane and significantly better compared to the control. Modifications of the physico‐chemical properties may enhance the osteoconductive competence of collagen membranes, supporting bone formation outside the bony defects. [ABSTRACT FROM AUTHOR]

Hypertrophic pachymeningitis (HP) is a rare disorder marked by thickening of the dura mater due to diverse etiologies. MPO-ANCA-positive HP represents a variant of AAV confined to the central nervous system, distinguished by the presence of serum MPO antibodies. Distinguishing HP triggered by MPO-ANCA from other causes can be challenging. In this study, we present two cases of MPO-ANCA-positive HP initially misdiagnosed as intracranial infections. Case 1 underwent surgery for chronic suppurative otitis media, with histopathological findings revealing inflammatory changes without definitive suppuration. He was presumed to have a secondary intracranial infection resulting from the surgery. However, his condition deteriorated despite two weeks of antibiotic and antiviral treatment. Case 2 presented with headache and was initially suspected of having intracranial Brucellosis given his serum Brucella positivity. Despite treatment for brucellosis, his symptoms persisted, and he developed visual and hearing impairments. Both patients were ultimately diagnosed with MPO-ANCA-positive HP, exhibiting serum MPO antibody positivity. Their symptoms showed improvement with glucocorticoid and immunosuppressive therapy. Based on these observations, we propose that MPO-ANCA-positive HP may initially present as intracranial infection. For HP patients presenting with headache, mastoiditis, otitis media, and visual loss, it is imperative to conduct ANCA antibody-related tests to enhance diagnostic precision. [ABSTRACT FROM AUTHOR]

BACKGROUND: The dura mater and skull are physically and functionally related, although there have been few investigations on primary extraction of dura mater and cranial cells, as well as co-culture of the two. The use of primary cells to investigate the influence of the dura mater on the skull is novel, and it is hoped that it may give a theoretical foundation for therapeutic therapy. OBJECTIVE: Rat dura mater and cranial bone cells were retrieved in situ to observe the influence of dura mater on cranial bone proliferation and differentiation, as well as to get a basic knowledge of the involvement of Twist1 in this process. METHODS: The enzyme digestion method was used in conjunction with the tissue block method to extract dural cells and cranial osteoblasts from rats within three days of birth. Immunofluorescence staining was used to identify the extracted cells, and alizarin red staining was used to identify and evaluate cranial osteoblasts and their mineralization ability. After co-culturing dural cells and cranial osteoblasts, real-time PCR was utilized to identify the expression of genes associated to cranial osteoblast proliferation and osteogenesis, as well as Twist1. RESULTS AND CONCLUSION: (1) Morphology: The retrieved dural cells had morphological traits similar to fibroblasts, while the osteoblasts were spindle-shaped. (2) Cell identification: immunofluorescence staining revealed that extracted dural cells expressed high levels of vimentin and cranial osteoblasts expressed high levels of alkaline phosphatase; cranial osteoblasts were stained with alizarin red 28 days after osteogenic induction, and obvious mineralized nodules were observed. (3) Real time PCR detection showed that the co-culture group had higher levels of PCNA, alkaline phosphatase, and RUNX2 mRNA expression than the control group (P < 0.01); however, Twist1 mRNA expression was lower (P < 0.01). (4) The findings showed that the primary extracted cranial osteoblasts had a high mineralization capacity, and that the dura mater was a key factor in promoting cranial growth and development and osteogenic differentiation, with Twist1 playing a key role in this process. [ABSTRACT FROM AUTHOR]

This document is a letter published in the journal Acta Neuropathologica Communications. It discusses the genetic analysis of foramen magnum meningiomas (FMMs), which are rare tumors that account for approximately 1% of intracranial meningiomas. The study aims to elucidate the genetic profiles of meningiomas at the foramen magnum, a challenging task due to the difficulty in identifying their site of origin. The researchers accurately identified the main feeder of FMMs and performed a genetic analysis, revealing that the AKT1 p.Glu17Lys mutation was the most frequent driver mutation in FMMs, while TRAF7 mutations were absent. The study suggests that FMMs resemble spinal meningiomas more than common intracranial meningiomas in terms of driver mutations. [Extracted from the article]

Background and Purpose Methods Results Conclusions The optic nerve sheath diameter (ONSD) is a commonly used estimate of intracranial pressure (ICP). The rationale behind this is that pressure changes in the cerebrospinal fluid affect the optic nerve subarachnoid space (ONSAS) thickness. Still, possible effects on other compartments of the optic nerve sheath (ONS) have not been studied. This is the first study ever to analyze all measurable compartments of the ONS for associations with elevated ICP.We measured changes in ICP and changes in ONS compartments in 75 patients treated with invasive ICP monitoring at the Karolinska University Hospital. Associations between changes in ICP and changes in ONS compartments were estimated with generalized estimating equations. The potential to identify elevated ICP was assessed with the area under the receiver operating characteristic curve (AUROC) for ONS compartments associated with ICP changes.Both ONSAS and perioptic dura mater thickness were significantly associated with changes in ICP in multivariable modeling. ONSAS was the only compartment that independently predicted changes in ICP, with an AUROC of 0.69 for predicting ICP increase. Still, both the perioptic dura mater thickness and the optic nerve diameter added value in predicting ICP changes in multivariable modeling.The results from this study challenge the current understanding of the mechanism behind the association between ICP and ONSD. Contrary to the common opinion that ONSAS is the only affected compartment, this study shows a more complex picture. It suggests that all ONS compartments may add value in predicting changes in ICP. [ABSTRACT FROM AUTHOR]

Introduction: The etiology of brain aneurysms remains poorly understood. Finnish research suggests that oral bacteria might contribute to the development and rupture of brain aneurysms. Previous studies by our team have not confirmed these findings, likely due to methodological differences. We aimed to replicate the Finnish study with a French population, using the same primers and comparing the results to internal controls. Methods: We used RT-qPCR to retrospectively analyze the expression of oral bacterial genes in eight patients. During surgical procedures, four tissue types were consistently sampled from each patient: the aneurysmal wall, the superficial temporal artery (STA), the middle meningeal artery (MMA), and the dura mater (DM). Results were expressed as fold differences employing the 2−∆∆Ct method, and statistical analyses were performed accordingly. Results: Our cohort included eight patients, evenly split into ruptured and unruptured groups. The sex distribution was balanced (4 females, 4 males). We observed DNA expression from oral bacteria in all sampled tissues; however, there were no significant differences between the ruptured and unruptured groups. Conclusion: We detected oral bacterial gene expression in the aneurysmal wall, STA, MMA, and DM in a sample of French patients. Although limited by the small sample size, our results suggest a potential role for bacterial involvement in vascular invasiveness related to bacteremia. These findings do not definitively link oral bacteria to the pathogenesis of aneurysm development and rupture. [ABSTRACT FROM AUTHOR]

Background: The pleiotropic effects of the melanocortin system show promise in overcoming limitations associated with large variations in opioid analgesic effectiveness observed in equine practice. Of particular interest is variation in the melanocortin-1-receptor (MC1R) gene, which dictates pigment type expression through its epistatic interaction with the agouti signalling protein (ASIP) gene. MC1R has previously been implicated in opioid efficacy in other species; however, this relationship is yet to be explored in horses. In this study, analgesic effectiveness was scored (1-3) based on noted response to dura penetration during the performance of cerebrospinal fluid centisis after sedation and tested for association with known genetic regions responsible for pigmentation variation in horses. Results: The chestnut phenotype was statistically significant (P < 0.05) in lowering analgesic effectiveness when compared to the bay base coat colour. The 11bp indel in ASIP known to cause the black base coat colour was not significant (P>0.05); however, six single nucleotide polymorphisms (SNPs) within the genomic region encoding the ASIP gene and one within MC1R were identified as being nominally significant (P<0.05) in association with opioid analgesic effectiveness. This included the location of the known e MC1R variant resulting in the chestnut coat colour. Conclusions: The current study provides promising evidence for important links between pigmentation genes and opioid effectiveness in horses. The application of an easily identifiable phenotype indicating variable sensitivity presents a promising opportunity for accessible precision medicine in the use of analgesics and warrants further investigation. [ABSTRACT FROM AUTHOR]

Objectives: Intraoperative ultrasonography (IOUS) offers the advantage of providing real-time imaging features, yet it is not generally used. This study aims to discuss the benefits of utilizing IOUS in spinal cord surgery and review related literature. Materials and methods: Patients who underwent spinal cord surgery utilizing IOUS at a single institution were retrospectively collected and analyzed to evaluate the benefits derived from the use of IOUS. Results: A total of 43 consecutive patients were analyzed. Schwannoma was the most common tumor (35%), followed by cavernous angioma (23%) and ependymoma (16%). IOUS confirmed tumor extent and location before dura opening in 42 patients (97.7%). It was particularly helpful for myelotomy in deep-seated intramedullary lesions to minimize neural injury in 13 patients (31.0% of 42 patients). IOUS also detected residual or hidden lesions in 3 patients (7.0%) and verified the absence of hematoma post-tumor removal in 23 patients (53.5%). In 3 patients (7.0%), confirming no intradural lesions after removing extradural tumors avoided additional dural incisions. IOUS identified surrounding blood vessels and detected dural defects in one patient (2.3%) respectively. Conclusions: The IOUS can be a valuable tool for spinal cord surgery in identifying the exact location of the pathologic lesions, confirming the completeness of surgery, and minimizing the risk of neural and vascular injury in a real-time fashion. [ABSTRACT FROM AUTHOR]

Classical migraine patients can experience aura, which is transient neurological deficits associated with cortical spreading depression (CSD), preceding headache attacks. It is not currently understood how a pathological event in cortex can affect peripheral sensory neurons. In this study, we show that cerebrospinal fluid (CSF) flows into the trigeminal ganglion, establishing nonsynaptic signaling between brain and trigeminal cells. After CSD, ~11% of the CSF proteome is altered, with up-regulation of proteins that directly activate receptors in the trigeminal ganglion. CSF collected from animals exposed to CSD activates trigeminal neurons in naïve mice in part by CSF-borne calcitonin gene-related peptide (CGRP). We identify a communication pathway between the central and peripheral nervous system that might explain the relationship between migrainous aura and headache. [ABSTRACT FROM AUTHOR]

There are lasting concerns on calvarial development because cranium not only accommodates the growing brain, but also safeguards it from exogenous strikes. In the past decades, most studies attributed the dynamic expansion and remodeling of cranium to the proliferation of osteoprecursors in cranial primordium, and the proliferation of osteoprogenitors at the osteogenic front of cranial suture mesenchyme. Further investigations identified series genes expressed in suture mesenchymal cells as the markers of the progenitors, precursors and postnatal stem cells in cranium. However, similar to many other organs, it is suggested that the reciprocal interactions among different tissues also play essential roles in calvarial development. Actually, there are increasing evidence indicating that dura mater (DM) is indispensable for the calvarial morphogenesis and osteogenesis by secreting multiple growth factors, cytokines and extracellular matrix (ECM). Thus, in this review, we first briefly introduce the development of cranium, suture and DM, and then, comprehensively summarize the latest studies exploring the involvement of ECM in DM and cranium development. Eventually, we discussed the reciprocal interactions between calvarium and DM in calvarial development. Actually, our review provides a novel perspective for cranium development by integrating previous classical researches with a spotlight on the mutual interplay between the developing DM and cranium. [ABSTRACT FROM AUTHOR]

Background: Technological advancements have been rapidly integrated within the neurosurgical education track since it is a high-risk specialty with little margin for error. Indeed, simulation and virtual reality during training can improve surgical performance and technical skills. Our study aims to investigate the impact of neurosurgical technology-based simulation activities on medical students. Methods and Materials: The "Suturing Mission–The Symposium" was a three-day event held at Humanitas University. Participants had access to live-streamed conferences held by worldwide experts in several fields of neurosurgery and practical simulations of dura mater sutures, microvascular anastomosis, and augmented reality neurosurgical approaches. An anonymous survey was conducted at the beginning and end of the event. Results: 141 medical students with a mean age of 21 participated. After the course, 110 participants (77.5%) showed interest in pursuing a surgical path, with a great prevalence in those who had planned to have a surgical career before the event (88.7% vs. 41.4%, p < 0.001). Participants were also asked about their comfort levels while handling surgical instruments, and a good outcome was reached in 72.7% of participants, with a significant difference between those who had previously attended a suture course (87.8% vs. 66.3%, p = 0.012). Conclusion: Training sessions on surgical simulators were effective in increasing participants' interest in pursuing a surgical path, improving their understanding of postgraduate orientation, and boosting their confidence with surgical instruments. [ABSTRACT FROM AUTHOR]

Central nervous system (CNS) dural arteriovenous fistulas (DAVF) have been reported in PTEN‐related hamartoma tumor syndrome (PHTS). However, PHTS‐associated DAVF remain an underexplored field of the PHTS clinical landscape. Here, we studied cases with a PTEN pathogenic variant identified between 2007 and 2020 in our laboratory (n = 58), and for whom brain imaging was available. Two patients had DAVF (2/58, 3.4%), both presenting at advanced stages: a 34‐year‐old man with a left lateral sinus DAVF at immediate risk of hemorrhage, and a 21‐year‐old woman with acute intracranial hypertension due to a torcular DAVF. Interestingly, not all patients had 3D TOF/MRA, the optimal sequences to detect DAVF. Early diagnosis of DAVF can be lifesaving, and is easier to treat compared to developed, proliferative, or complex lesions. As a result, one should consider brain MRI with 3D TOF/MRA in PHTS patients at genetic diagnosis, with subsequent surveillance on a case‐by‐case basis. [ABSTRACT FROM AUTHOR]

Endoscopic lumbar discectomy (ELD) is a key advancement in minimally invasive spinal surgery, particularly for lumbar disc herniation. Interlaminar endoscopic lumbar discectomy (IELD) and transforaminal endoscopic lumbar discectomy (TELD) are the two major methods used for FED. TELD, while less familiar to spine surgeons inexperienced in endoscopic surgery, presents challenges in visualizing the dura mater, a crucial aspect for reducing surgical complications. The hand down outside-in (HDOI) technique introduced by Dezawa enhances this visualization by positioning the cannula tip dorsally on the intervertebral disc and maneuvering it between the dura mater and disc to the spinal canal's midpoint. The cannula is then flipped to directly visualize the dura mater, enabling safe removal of the prolapsed disc material. A comparative study involving 20 patients treated from April 2020 to April 2022 examined the efficacy of the HDOI technique against conventional TELD. Each group, comprising ten patients, underwent ELD for lumbar disc herniation. While both groups showed similar improvements in clinical outcomes, as assessed using the Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) for pain, the HDOI group exhibited a 100% success rate for dura mater visualization, and this rate is significantly higher than the 60% observed in the conventional TELD group. Additionally, the time required for dura mater visualization was notably shorter for the HDOI technique. These results indicate that the HDOI technique not only enhances the safety and efficacy of TELD but may also encourage its wider use in clinical settings. [ABSTRACT FROM AUTHOR]

Purpose: The chordae Willisii (CWs), trabecular projections into the lumen of the dural sinuses, are not well understood. We aimed to explore them using magnetic resonance imaging (MRI). Methods: Eighty-five patients underwent volumetric contrast-enhanced MRI, while another 30 underwent a fluid-attenuated inversion recovery (FLAIR) sequence in the coronal section. Results: The CWs were detected as linear filling defects lying in the dural sinuses, adjacent to the surrounding dura mater. They were found in the superior sagittal sinus (SSS) in 68.2% of the patients, most frequently in the middle third, with laminar appearance. In 27.1% of the patients, the CWs divided the SSS lumen into separate channels. The CWs were identified in the transverse sinus, transverse-sigmoid sinus junctional area and sigmoid sinus, and straight sinus in 54.1, 47.1, and 8.2%, respectively. On the FLAIR images, dural septi partially dividing the SSS lumen were identified in all patients. In addition, in 73.3% of the patients, fine linear structures were observed in the lumen with inconstant arrangements. Conclusions: The CWs may be constant structures distributed over the lumen of the intracranial dural sinuses. Contrast-enhanced MRI may be useful for detecting laminar CWs. The FLAIR sequence may be advantageous for delineating the dural septi projecting into the lumen of the dural sinuses. [ABSTRACT FROM AUTHOR]

Purpose: To introduce a method of cranial bone reconstruction for cranial burst fractures and early-stage growing skull fractures, named bone flap binding and transposition. Methods: Cranial burst fractures, severe head injuries predominantly observed in infants, are characterized by widely diastatic skull fractures coupled with acute extracranial cerebral herniation beneath an intact scalp through ruptured dura mater. These injuries can develop into growing skull fractures. This study included two cases to illustrate the procedure, with a particular focus on the bone steps in managing these conditions. The medical history, clinical presentation, surgical procedures, and postoperative follow-up were retrospectively studied. The details of the surgical procedure were described. Results: The method of bone reconstruction, named bone flap binding and transposition, was applied after the lacerated dural repair. Two bone pieces were combined to eliminate the diastatic bone defect and then fixed by an absorbable cranial fixation clip and bound by sutures. The combined bone flap was repositioned into the bone window, completely covering the area of the original dural laceration. Subsequently, the bone defect was transferred to the area of normal dura. The postoperative courses for the two infants were uneventful. Follow-up CT scans revealed new bone formation at the previous bone defect and no progressive growing skull fracture. The major cranial defects had disappeared, leaving only small residual defects at the corners of the skull bone window, which required further recovery and did not affect the solidity of the skull. Conclusion: Bone flap binding and transposition provide a straightforward, cost-effective, and reliable method for cranial bone reconstruction of cranial burst fractures and early-stage growing skull fractures. This method has taken full advantage of the small infant's dura osteogenic potential without the need for artificial or metallic bone repair materials. The effectiveness of the method needs further validation with more cases in the future. [ABSTRACT FROM AUTHOR]

The most common method of inducing brain death in rats is inflating an intracranially placed balloon of a Fogarty catheter inserted through a burr hole. However, because of the poor controllability of balloon position, the standardization and stability of the model are compromised. This study examined an improved technique in which the balloon is placed and fixed through double holes. Forty adult male Sprague-Dawley (SD) rats were randomly and equally assigned into the single-hole (SH) group and the double-hole (DH) group. In each rat in the DH group, 2 holes were made, at the left frontal bone and parietal bone. A Fogarty catheter was inserted outside of the dura mater through the frontal hole, and its tip was guided out through the parietal hole using an arc-shaped needle. The SH group served as a control. In both groups, normal saline was injected into the balloon at 40 μL/minute until breathing stopped. Mechanical ventilation was instituted immediately and provided for another 6 hours after the determination of brain death. Typical blood pressure patterns were observed in both groups during the brain death induction period, whereas the fluctuation seemed relatively mild in the DH group. Stable brain death with normotension for 6 hours was induced successfully in 18 rats (90%) in the DH group and in 9 rats (45%) in the SH group (P =.002). The mean arterial pressure at 3 hours and thereafter was significantly higher in the DH group compared to the SH group (P <.05). Our results demonstrate that the DH method is a simple and effective technique to make the brain death model more stable and standardized, possibly due to precise control of the direction of the cannulation and the position of the balloon. [ABSTRACT FROM AUTHOR]

Benign fibrous histiocytoma (BFH) within the intracerebral region is remarkably rare. Our report details 2 cases of unusual BFH instances that exhibit no adhesion to the dura mater or cerebral falx, accompanied by a comprehensive literature review. While magnetic resonance imaging demonstrates specific characteristics for BFH, it does not readily differentiate BFH from more common brain neoplasms like gliomas and metastatic tumors. The definitive diagnosis of BFH depends primarily on histopathological and immunohistochemical examinations. Total surgical resection is considered an efficacious therapeutic approach, emphasizing the necessity for prolonged postoperative surveillance to detect any potential tumor recurrence or metastasis. [ABSTRACT FROM AUTHOR]

Leptomeninges, consisting of the pia mater and arachnoid, form a connective tissue investment and barrier enclosure of the brain. The exact nature of leptomeningeal cells has long been debated. In this study, we identify five molecularly distinct fibroblast-like transcriptomes in cerebral leptomeninges; link them to anatomically distinct cell types of the pia, inner arachnoid, outer arachnoid barrier, and dural border layer; and contrast them to a sixth fibroblast-like transcriptome present in the choroid plexus and median eminence. Newly identified transcriptional markers enabled molecular characterization of cell types responsible for adherence of arachnoid layers to one another and for the arachnoid barrier. These markers also proved useful in identifying the molecular features of leptomeningeal development, injury, and repair that were preserved or changed after traumatic brain injury. Together, the findings highlight the value of identifying fibroblast transcriptional subsets and their cellular locations toward advancing the understanding of leptomeningeal physiology and pathology.

BACKGROUND: DuraMatrix-Onlay® Plus is a collagen dura membrane derived from purified bovine Achilles tendon. The matrix provides a scaffold for collagen synthesis and is intended to be used as an onlay without the need for dural sutures. The study aims to describe our experience with 33 consecutive patients who underwent a duraplasty procedure using the novel DuraMatrix-Onlay® Plus collagen dura membrane. METHODS: This is a retrospective case series of 33 patients who underwent a duraplasty procedure at a single academic hospital in Los Angeles, CA, USA between May 2016 and March 2017. The primary outcome was the incidence rate of cerebrospinal fluid (CSF) leak. Secondary outcomes included rates of patient infection, dural substitute complication, and removal. RESULTS: Thirty-three patients underwent a duraplasty procedure using the DuraMatrix-Onlay® Plus material. The average age of the patients was 41.12±7.34 years (range 2-75 years). There were 18 (54.5%) females and 15 (45.5%) males. The majority of procedures were elective operations for the resection of a lesion (n=19, 58%), and the average graft size was 17.69±4.73 cm². At an average follow-up of 3 months, there were no postoperative CSF leaks. The rates of patient infection, dural substitute complication, and removal were 6%, 6%, and 3%, respectively. CONCLUSION: DuraMatrix-Onlay® Plus is associated with a low rate of postoperative CSF leakage and an acceptable complication profile. This result supports the use of collagen matrices for dural closure in general neurosurgical procedures.

Introduction Methods Results Conclusions In high‐frequency spinal cord stimulation anatomic placement targeting of the T9‐10 disc space is based on “empiric” results that are best replicated with coverage broadly from T8 to T10. This study contains the largest cohort of patients evaluating low thoracic morphology and seeks to address the lack of MRI morphological analysis in literature.This study was a retrospective review of a database of 101 consecutive patients undergoing permanent implant of thoracic SCS for chronic pain. Measurements were carried out on preoperative MRI imaging. Anteroposterior (AP) and lateral dimensions of the spinal cord as well as dural sac were measured. In addition, dorsal cerebrospinal fluid thickness and paddle depression distance were also measured.When comparing morphological dimensions by level, dorsal CSF thickness was smaller at T9‐10 than T7‐8 (p = 0.018). In addition, lateral dural and spinal cord diameters were larger at T10‐11 than T9‐10, contributing to larger dural surface area at T10‐11 (p = 0.028). While trends of dorsal CSF thickness tend to decrease with lower thoracic levels, the ratio of surface area of spinal cord to dural sac appeared to remain relatively constant.Dorsal CSF thickness is smaller at T9‐10 than T7‐8 in chronic pain patients in this cohort. More ellipsoid, cord, and spinal canal diameter measurements were noted at lower levels of the thoracic spinal cord, particularly at T10‐11. This may correlate with anatomical SCS placement. Future studies should evaluate efficacy of SCS therapy for pain based on these anatomical considerations. [ABSTRACT FROM AUTHOR]

B cells and T cells collaborate in multiple sclerosis (MS) pathogenesis. IgH[MOG] mice possess a B cell repertoire skewed to recognize myelin oligodendrocyte glycoprotein (MOG). Here, we show that upon immunization with the T cell-obligate autoantigen, MOG[35-55], IgH[MOG] mice develop rapid and exacerbated experimental autoimmune encephalomyelitis (EAE) relative to wildtype (WT) counterparts, characterized by aggregation of T and B cells in the IgH[MOG] meninges and by CD4+ T helper 17 (Th17) cells in the CNS. Production of the Th17 maintenance factor IL-23 is observed from IgH[MOG] CNS-infiltrating and meningeal B cells, and in vivo blockade of IL-23p19 attenuates disease severity in IgH[MOG] mice. In the CNS parenchyma and dura mater of IgH[MOG] mice, we observe an increased frequency of CD4+PD-1+CXCR5- T cells that share numerous characteristics with the recently described T peripheral helper (Tph) cell subset. Further, CNS-infiltrating B and Tph cells from IgH[MOG] mice show increased reactive oxygen species (ROS) production. Meningeal inflammation, Tph-like cell accumulation in the CNS and B/Tph cell production of ROS were all reduced upon p19 blockade. Altogether, MOG-specific B cells promote autoimmune inflammation of the CNS parenchyma and meninges in an IL-23-dependent manner. B cells are crucial in multiple sclerosis (MS) pathology but the mechanisms are incompletely understood. In a mouse model of MS, the authors show that B cells make IL-23, and that IL-23 invokes meningeal inflammation and CNS presence of T peripheral helper cells. [ABSTRACT FROM AUTHOR]

Background: Myelocele is a rare form of open spina bifida. Surgical repair is recommended prenatally or in the first 48 h. In some cases, the repair may be delayed, and specific surgical factors need to be considered. Method: We give a brief overview of the surgical anatomy, followed by a description of the surgical repair of a thoracolumbar Myelocele in an 11-month-old child. Conclusion: Surgical repair of the Myelocele stabilizes the neurological status, prevents local and central nervous system infections. The understanding of Myelocele anatomy enables its removal while preserving as much healthy tissue as possible and restoring normal anatomy. Key points: 1. In the absence of life-threatening condition, any spinal dysraphism repair should be undertaken as soon as possible, ideally within the first 48 hours of life. However, circumstances may lead to a delayed repair, as in our case. 2. Each child should undergo a preoperative MRI of the spinal cord and imaging of the brain to look for signs of hydrocephalus (present in approximately 90% of cases). 3. A good anatomical understanding is fundamental. 4. The aim of the surgery is to restore the normal anatomical pattern, stabilize the neurological and clinical status of the child and prevent complications such as local infection or meningitis. 5. Microscopic magnification is crucial for identification of structures such as the opening of the normal dura into the skin, fusion of the spinal cord into the placode and the emergence of roots in epidural space. 6. Removal of the epithelium covering the placode is mandatory to prevent the formation of inclusion dermoid cysts. 7. Watertight closure of the dura mater is imperative to prevent CSF leakage. 8. Maximum effort should be made to facilitate primary closure of the soft tissue. Incision at the border of the dystrophic skin covering the MC and horizontal incision allows efficient skin transposition and closure. 9. Blunt dissection between the subcutaneous fat and the thoracolumbar fascia allows for the preservation of the perforating arteries. 10. Early signs of complications such as wound dehiscence, CSF leakage and infection of the operative site should be carefully monitored. [ABSTRACT FROM AUTHOR]

This Article provides a concise summary of the comprehensive exploration into the dura mater, dural tears, and the groundbreaking medical device, ArtiFascia® Dura Substitute. The neuroanatomy of the dura mater is elucidated, emphasizing its resilience and susceptibility to tears during spinal surgery. Dural repair methods are scrutinized, with research findings revealing the efficacy of primary closure with or without a patch. The introduction of ArtiFascia®, a nanofiber-based resorbable dural repair graft, represents a pivotal moment in neurosurgery. Obtaining 510(k) clearance from the FDA, ArtiFascia® demonstrates exceptional biological benefits, including enhanced cellular adhesion and tissue regeneration. The device's safety is affirmed through chemical analysis and toxicological risk assessment. The NEOART study, a randomized clinical trial involving 85 subjects across prominent European medical centers, validates ArtiFascia®'s superiority over existing dural substitutes. Noteworthy findings include exceptional graft strength, durability, and its ability to withstand physiological pressures. In conclusion, ArtiFascia® marks a revolutionary era in neurosurgery, promising safer and more effective solutions. This innovative device has the potential to elevate standards of care, offering both patients and surgeons an improved experience in navigating the complexities of neurosurgical procedures. The abstract encapsulates the key elements of the research, emphasizing the transformative impact of ArtiFascia® in the field. [ABSTRACT FROM AUTHOR]

A novel posteriolateral surgical approach is described that will provide safe access to intradural and extradural lesions located in the anterior part of the spinal cord (SC) at the C1-2 level and to the odontoid in single session. A total of five cadavers and two dry C1 vertebrae were used in this study. The study involved obtaining computed tomography magnetic resonance imaging scans and magnetic resonance imaging of all cadaver groups before and after the procedures. Group 1: Control; Group 2: Unilateral C1 posterior arch was removed, the inferomedial part of C1 lateral mass was removed, and access the anterior and lateral aspects of the SC. Group 3: In addition, odontoid was removed, Group 4: In addition, unilateral C1- C2 screw was placed. Group 5: In addition, bilateral C1-C2 screw was placed. The median distance from the midpoint of C1 posterior tubercle to vertebral groove which was removed in groups is 21.4 ± 2.88 mm. The average width of C1 lateral mass was 13.4 ± 2.4 mm. After the lateral mass was drilled, its width decreased to 10,2 mm.This area was sufficient to open a surgical corridor and reach the anterior of SC and odontoid. After the procedure, no instability was found in group 2 without instrumentation on computed tomography and magnetic resonance imaging scans. It is possible to access the anterior C1–C2 via a posterolateral paramass approach by drilling 20%–30% of the lateral mass, providing an open pathway for easy intervention in C1–C2 intradural lesions. It is also possible to perform odontoid resection using this approach. [ABSTRACT FROM AUTHOR]

Introduction: Idiopathic hypertrophic pachymeningitis (IHP) is a rare disorder presenting with headache, cranial and spinal neuropathy. This study is to explore the clinical, laboratory and imaging changes; treatment; and clinical outcomes of idiopathic hypertrophic pachymeningitis (IHP). Methods: This was a retrospective evaluation of 9 patients (5 men and 4 women; mean age: 53.6 years), their clinical features, laboratory tests, cerebral spinal fluid (CSF) analysis, MRI results, pathological features, treatment and clinical outcomes from a tertiary centre in Qingdao, North East China. The serum IgG4 was negative for all the cases. Results: Headache was the most common symptom (7/9), followed by oculomotor, trigeminal, abducens and facial nerve neuropathies, and limb numbness in one case. Two cases showed increased ESR and CRP, and four were positive for ANA or anti-SSA antibodies. On CSF analysis, 2/7 had increased pressure, and 4/7 showed lymphocytosis and high protein levels. MRI revealed a thickening and enhancement of the dura, mainly involving bilateral tentorium (85%), falx cerebri (57%), and cerebellar hemisphere (57%). The tissue biopsy of dura mater in three cases showed thickened collagen fibers, lymphocytosis and focal necrosis, with similar but not identical features to IgG4-related sclerosing disease. Most patients were treated with corticosteroids, and 79% showed improvement. The abnormal thickness and enhancement of the dura mater disappeared in one case. Conclusion: Gadolinium-enhanced MRI serves as the key preliminary investigation for the diagnosis and evaluation of the clinical course for IHP. Majority of patients have good respond to steroid. [ABSTRACT FROM AUTHOR]

This article examines the research trends in optic nerve sheath diameter (ONSD) monitoring through a bibliometric study. The study reveals a consistent increase in the number of articles on ONSD, with the highest number of publications in 2023. The analysis of keywords indicates that ONSD monitoring is widely used for predicting neurological outcomes and has gained significance in non-neurological intensive care settings. The article also highlights the potential of ONSD monitoring for non-invasive intracranial pressure measurement in neurosurgery. However, the study's inclusion of all PubMed titles may have led to the repetition of keywords, limiting its findings. Nonetheless, the article offers valuable insights into the current state of research in ONSD monitoring. [Extracted from the article]

Background and purpose: An increasing number of cases of iatrogenic cerebral amyloid angiopathy (CAA) have now been reported worldwide. Proposed diagnostic criteria require a history of medical intervention with potential for amyloid‐β transmission, for example those using cadaveric dura mater or requiring instrumentation of the brain or spinal cord. Clinical presentation occurs after an appropriate latency (usually three or four decades); to date, most patients with iatrogenic CAA have had 'early‐onset' disease (compared to sporadic, age‐related, CAA), as a consequence of childhood procedures. Results: We describe five cases of possible iatrogenic CAA in adults presenting in later life (aged 65 years and older); all had prior neurosurgical interventions and presented after a latency suggestive of iatrogenic disease (range 30–39 years). Use of cadaveric dura mater was confirmed in one case, and highly likely in the remainder. Conclusion: The presentation of iatrogenic CAA in older adults widens the known potential spectrum of this disease and highlights the difficulties of making the diagnosis in this age group, and particularly in differentiating iatrogenic from sporadic CAA. Increased vigilance for cases presenting at an older age is essential for furthering our understanding of the clinical phenotype and broader implications of iatrogenic CAA. [ABSTRACT FROM AUTHOR]

Background: Post-dural puncture headache (PDPH) is a debilitating condition that appears after puncturing the dura mater. The headache is severe, throbbing, frontal, radiates to the occiput; increases by standing, and decreases by lying down. Objectives: This study aimed to compare the effect of ondansetron compared to neostigmine on reducing the incidence of PDPH in parturients undergoing spinal anesthesia for elective cesarean section. Methods: Fifty-one parturients undergoing spinal anesthesia for elective cesarean section were allocated randomly into three equal groups; Group (n = 17) parturients received intravenous injection of 0.9% normal saline after delivery of the fetus as controls, Group (n = 17) parturients received intravenous injection of neostigmine and atropine after delivery of the fetus, Group (n = 17) parturients received intravenous injection of ondansetron after delivery of the fetus. Results: The incidence of headache, and median of VAS was higher among controls as compared to the neostigmine and the ondansetron group. Also, were higher in the neostigmine group compared to the ondansetron group. The control group (47.1%) required significantly more post-operative analgesia than the ondansetron group (11.8%; p=0.01). The patient's heart rate increased during spinal anesthesia, but it reduced throughout delivery and after drug infusion. The occurrence of headache and median visual analogue scale score at 48 and 7 days were postpartum differed significantly among the three groups. Conclusions: Intravenous injection of 0.08 mg/kg ondansetron is more effective in lowering the incidence and severity of post-dural puncture headache compared to 20g/kg neostigmine plus 10g/kg atropine intravenous injection in parturients undergoing spinal anesthesia for elective cesarean section. [ABSTRACT FROM AUTHOR]

Chronic subdural hematoma (CSDH) development involves inflammatory, angiogenetic, and fibrinolytic mechanisms, several components of which are now unraveled through intensive research. The urokinase plasminogen activator receptor (uPAR) is part of the plasminogen activator system and possesses inflammatory, angiogenetic, and fibrinolytic capabilities. As a first, this study aims to identify uPAR in the hematoma fluid, hematoma membrane, dura mater, and systemic blood from patients with CSDH and, if present, to investigate if the uPAR level at the time of surgery may be a predictor for later developing recurrent CSDH. uPAR expression in the hematoma membrane and dura mater was analyzed using immunohistochemistry and presented as the H-score of the positive immunostaining. The uPAR levels in the hematoma fluid and systemic blood were determined using a multiplex antibody bead kit (Luminex). Samples were collected at the time of the first CSDH surgery, and in the case of recurrent CSDH within 90 days, the samples were again collected at reoperation. A comparison of uPAR expression between the hematoma membrane and dura mater, as well as uPAR levels in systemic blood and hematoma fluid, was performed using the Wilcoxon rank sum test. We included 112 patients, 26 of whom had recurrent CSDH. The median hematoma uPAR level was 22,125 (14,845–33,237) and significantly higher than the median systemic blood level of 789 pg/L (465–2,088) (p < 0.001). Similarly, the uPAR level of the hematoma membrane was 14.3 (7.54–44.8) and significantly higher than the dural uPAR level of 0.81 (0.3–1.98) (p < 0.001). For the first time, we identified uPAR in the subdural fluid, hematoma membrane, dura mater, and systemic blood from patients with CSDH. The high expression of uPAR in the subdural fluid and hematoma membrane indicates that the mechanisms of CSDH are predominantly in the subdural fluid collection and surrounding hematoma membrane. [ABSTRACT FROM AUTHOR]

Cranial dura mater is a dense interwoven vascularized connective tissue that helps regulate neurocranial remodeling by responding to strains from the growing brain. Previous ex vivo experimentation has failed to account for the role of prestretch in the mechanical behavior of the dura. Here we aim to estimate the prestretch in mouse cranial dura mater and determine its dependency on direction and age. We performed transverse and longitudinal incisions in parietal dura excised from newborn (day ∼ 4) and mature (12 weeks) mice and calculated the ex vivo normalized incision opening (measured width over length). Then, similar incisions were simulated under isotropic stretching within Abaqus/Standard. Finally, prestretch was estimated by comparing the ex vivo and in silico normalized openings. There were no significant differences between the neonatal and adult mice when comparing cuts in the same direction, but adult mice were found to have significantly greater stretch in the anterior–posterior direction than in the medial–lateral direction, while neonatal dura was essentially isotropic. Additionally, our simulations show that increasing curvature impacts the incision opening, indicating that flat in silico models may overestimate prestretch. [ABSTRACT FROM AUTHOR]

Spinal surgery can be associated with significant intraoperative blood loss which may lead to various complications. As the number of patients undergoing spinal surgery increases over time, accurate and effective hemostasis becomes critically important. Despite various surgical hemostatic techniques, conventional interventions such as compression, suture, ligation, and heat-generating cautery, are not suitable for osseous and epidural venous plexus bleeding during spinal procedures. Therefore, a variety of hemostatic agents have been developed to promote hemostasis. As they differ in terms of mechanism, form, application and potential adverse reactions, it is important to understand the natural features of existing agents. Here we comprehensively review currently available topical hemostatic agents from different sources and summarize their mechanisms of action, applications, and current or potential utilization in spinal surgery. We found hemostatic agents from different sources exert hemostatic actions through different mechanisms. In addition, topical hemostatic agents play various roles in spinal surgery including as hemostatic agent, dura mater repair, drug-carrier, skin closure, and fibrosis prevention. Compressive neurological complications are the most common complications of these hemostatic agents. Therefore, optimal use in spinal environments should match their features, indications, and efficacy with clinical conditions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ankara University Faculty of Medicine / Ankara Üniversitesi Tip Fakültesi Mecmuasi is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Spatial accuracy in electrophysiological investigations is paramount, as precise localization and reliable access to specific brain regions help the advancement of our understanding of the brain's complex neural activity. Here, we introduce a novel, multi camera-based, frameless neuronavigation technique for precise, 3-dimensional electrode positioning in awake monkeys. The investigation of neural functions in awake primates often requires stable access to the brain with thin and delicate recording electrodes. This is usually realized by implanting a chronic recording chamber onto the skull of the animal that allows direct access to the dura. Most recording and positioning techniques utilize this implanted recording chamber as a holder of the microdrive or to hold a grid. This in turn reduces the degrees of freedom in positioning. To solve this problem, we require innovative, flexible, but precise tools for neuronal recordings. We instead mount the electrode microdrive above the animal on an arch, equipped with a series of translational and rotational micromanipulators, allowing movements in all axes. Here, the positioning is controlled by infrared cameras tracking the location of the microdrive and the monkey, allowing precise and flexible trajectories. To verify the accuracy of this technique, we created iron deposits in the tissue that could be detected by MRI. Our results demonstrate a remarkable precision with the confirmed physical location of these deposits averaging less than 0.5 mm from their planned position. Pilot electrophysiological recordings additionally demonstrate the accuracy and flexibility of this method. Our innovative approach could significantly enhance the accuracy and flexibility of neural recordings, potentially catalyzing further advancements in neuroscientific research. [ABSTRACT FROM AUTHOR]

Purpose: To compare the efficacy and complications of Tenon duplication with dura mater covering technique for Ahmed glaucoma valve (AGV) implantation. Methods: This retrospective study included 44 refractory glaucoma patients (44 eyes) who underwent AGV implantation from 2017 to 2020 in the Ophthalmology Clinic of Eskişehir Osmangazi University Hospital and attended regular postoperative follow-ups. The patients were divided based on whether they underwent Tenon duplication technique (group 1: n = 20) or dura mater covering technique (group 2: n = 24) during surgery. The patients' age, gender, systemic diseases, glaucoma type, pre-op intraocular pressure (IOP), and ocular surgeries were recorded. The groups were compared for IOP level control, early and late complications, postoperative antiglaucomatous medication requirements, glaucoma surgery requirements, presence of postoperative hypertensive phase (HP), and surgical success which was defined as an IOP ≥5 and ≤21 mmHg, with or without antiglaucoma medication. Results: By the end of the mean follow-up (22.6 ± 10.6 months), the success rates were 95% (group 1) and 96% (group 2). The groups showed no differences in postoperative complications, postoperative antiglaucomatous drugs' onset time, additional glaucoma surgery, need for needling, presence of HP at 6 months postoperatively, and relationship between the glaucoma type and success rates (P values: 0.86, 0.9, 0.48, 0.12, 0.36, and 0.8, respectively). The IOP values at the last follow-up were 15.2 ± 4.1 in group 1 and 14.7 ± 4.8 in group 2. The IOP reduction rates showed no significant differences. Conclusion: Since success and complications are similar in both Tenon duplication and dura mater covering technique, unique grafting materials may not be needed in AGV implantation surgery, except in special cases. [ABSTRACT FROM AUTHOR]

The meningeal lymphatics (MLVs) play an important role in immunity and maintaining homeostasis of the central nervous system. Sleep is a natural state when lymphatic drainage becomes maximally active and, along with the flow of fluids, toxins and metabolites are removed from the brain. A decrease in function of MLVs is a key mechanism in the development of glioblastoma (GBM), which leads to the accumulation of excess fluid in the brain and an increase in intracranial pressure. Recently, promising methods of transcranial photostimulation (tPBM) of MLVs have been developed. It is interesting to note that tPBM of MLVs during sleep vs. wakefulness stimulates lymphatic drainage of brain tissues much more effectively. It is logical to expect that tPBM of MLVs during sleep will significantly increase the effectiveness of the GBM therapy. This review highlights new trends in the treatment of GBM, including tPBM of MLVs during sleep as a promising strategy in suppression of tumor progression. [ABSTRACT FROM AUTHOR]

To compare the perioperative cumulative opioid consumption and the incidence of cardiovascular complications in dogs undergoing hemilaminectomy in which either an erector spinae plane (ESP) block or systemic opioids were administered. Prospective randomized clinical trial. A total of 60 client-owned dogs. Dogs were randomized to one of three groups: an ESP block (group ESP), a constant rate infusion of fentanyl (group FNT, positive control) or a single dose of methadone as premedication (group MTD, negative control). Intraoperative nociceptive response was treated with fentanyl [1 μg kg–1, intravenously (IV)] boli. Before closure of the surgical site, morphine (0.1 mg kg–1) was applied to the dura mater. The cumulative dose of opioids was recorded and compared between groups. The incidence of intraoperative bradycardia and/or hypotension and the time to extubation were compared between groups. The short form of the Glasgow Composite Pain Scale (SF-GCPS) was used to score nociception before anaesthetic induction and 1, 2, 6, 12,18 and 24 hours postoperatively. Methadone 0.2 mg kg–1 was administered IV if the SF-GCPS score was ≥ 5. Group MTD required more intraoperative rescue analgesia than groups ESP (p = 0.008) and FNT (p = 0.001). The total cumulative intraoperative dose of fentanyl was higher in groups FNT (p < 0.0001) and MTD (p = 0.002) than in group ESP. The incidence of cardiovascular complications was similar between groups. Extubation time was longer in group MTD (p = 0.03). Postoperatively, the time to first rescue analgesia was longer in group ESP than in group MTD (p = 0.03). The cumulative postoperative opioid consumption and pain scores were similar between groups. The ESP block resulted in a reduced intraoperative opioid consumption compared with the control positive and negative groups. [ABSTRACT FROM AUTHOR]

Aims: A bone‐invasive pituitary adenoma exhibits aggressive behavior, leading to a worse prognosis. We have found that TNF‐α promotes bone invasion by facilitating the differentiation of osteoclasts, however, before bone‐invasive pituitary adenoma invades bone tissue, it needs to penetrate the dura mater, and this mechanism is not yet clear. Methods: We performed transcriptome microarrays on specimens of bone‐invasive pituitary adenomas (BIPAs) and noninvasive pituitary adenomas (NIPAs) and conducted differential expressed gene analysis and enrichment analysis. We altered the expression of TNF‐α through plasmids, then validated the effects of TNF‐α on GH3 cells and verified the efficacy of the TNF‐α inhibitor SPD304. Finally, the effects of TNF‐α were validated in in vivo experiments. Results: Pathway act work showed that the MAPK pathway was significantly implicated in the pathway network. The expression of TNF‐α, MMP9, and p‐p38 is higher in BIPAs than in NIPAs. Overexpression of TNF‐α elevated the expression of MAPK pathway proteins and MMP9 in GH3 cells, as well as promoted proliferation, migration, and invasion of GH3 cells. Flow cytometry indicated that TNF‐α overexpression increased the G2 phase ratio in GH3 cells and inhibited apoptosis. The expression of MMP9 was reduced after blocking the P38 MAPK pathway; overexpression of MMP9 promoted invasion of GH3 cells. In vivo experiments confirm that the TNF‐α overexpression group has larger tumor volumes. SPD304 was able to suppress the effects caused by TNF‐α overexpression. Conclusion: Bone‐invasive pituitary adenoma secretes higher levels of TNF‐α, which then acts on itself in an autocrine manner, activating the MAPK pathway and promoting the expression of MMP9, thereby accelerating the membrane invasion process. SPD304 significantly inhibits the effect of TNF‐α and may be applied in the clinical treatment of bone‐invasive pituitary adenoma. [ABSTRACT FROM AUTHOR]

Background: Activation of the trigeminal vascular system in migraine releases vasoactive neurotransmitters, causing abnormal vasoconstriction, which may affect the ocular system, leading to retinal damage. The purpose of our study was to determine whether there are differences in each retinal layer between migraine patients and healthy subjects. Methods: A case-control study recruited 38 migraine patients and 38 age- and sex-matched controls. Optical coherence tomography was used to measure the thickness of the peripapillary and macular retinal nerve fiber layer (pRNFL and mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), and inner nuclear layer (INL). Results: The mean ages of the migraine patients and controls were 36.29 ± 9.45 and 36.45 ± 9.27 years, respectively. Thirty-four patients (89.48%) in both groups were female. The mean disability score was 19.63 ± 20.44 (indicating severe disability). The superior-outer INL of migraine patients were thicker than controls. Thickness of the GCL at temporal-outer sector and mRNFL at the superior-outer sector of the headache-side eyes was reduced. However, the INL of the headache-side-eye showed negative correlation with the disability score. This is the first study having found thinning of the GCL and mRNFL of the headache-side eyes. The INL was also thickened in migraines but showed negative correlation with the disability score. Conclusions: Increased INL thickness in migraine patients may result from inflammation. The more severe cases with a high disability score might suffered progressive retinal neuronal loss, resulting in thinner INL than less severe cases. [ABSTRACT FROM AUTHOR]

Copyright of Neurosciences is the property of Neurosciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Subarachnoid hemorrhage (SAH) remains a major cause of cerebrovascular morbidity, eliciting severe headaches and vasospasms that have been shown to inversely correlate with vasodilator calcitonin gene-related peptide (CGRP) levels. Although dura mater trigeminal afferents are an important source of intracranial CGRP, little is known about the effects of SAH on these neurons in preclinical models. The present study evaluated changes in CGRP levels and expression in trigeminal primary afferents innervating the dura mater 72 h after experimentally induced SAH in adult rats. SAH, eliciting marked damage revealed by neurological examination, significantly reduced the density of CGRP-immunoreactive nerve fibers both in the dura mater and the trigeminal caudal nucleus in the medulla but did not affect the total dural nerve fiber density. SAH attenuated ex vivo dural CGRP release by ~40% and in the trigeminal ganglion, reduced both CGRP mRNA levels and the number of highly CGRP-immunoreactive cell bodies. In summary, we provide novel complementary evidence that SAH negatively affects the integrity of the CGRP-expressing rat trigeminal neurons. Reduced CGRP levels suggest likely impaired meningeal neurovascular functions contributing to SAH complications. Further studies are to be performed to reveal the importance of impaired CGRP synthesis and its consequences in central sensory processing. [ABSTRACT FROM AUTHOR]

BACKGROUND: Currently, the dura mater is clinically repaired using autologous tissue or materials such as gelatin sponge, but all of them have their inherent defects. Therefore, there is an urgent need for a biomaterial that can promote dural repair. OBJECTIVE: The two-sided anisotropic electrospun membrane was constructed by using directional electrospinning technology and collagen self-assembly technology, and was used as a carrier for bone marrow mesenchymal stem cells to investigate various physicochemical properties and biological characteristics of the artificial dura mater. METHODS: Ordered polylactic acid electrospun fibers with double-sided (collagen protein on one side and polylactic acid on the other side) anisotropic electrospun membranes (collagen group), disordered polylactic acid electrospun membranes (disordered fiber group), and ordered oriented polylactic acid electrospun membranes (ordered fiber group) were prepared by electrospinning technique as well as collagen self-assembly technique. Scanning electron microscopy, mechanical stretching, water contact angle testing, and degradation experiments were used to characterize the physicochemical properties of the electrospun membranes. Electrospun membranes in the collagen group (bone marrow mesenchymal stem cells were inoculated on the collagen surface to obtain the stem cell-engineered electrospun membranes), disordered fiber group and ordered fiber group were cocultured with bone marrow mesenchymal stem cells. The biocompatibility of electrospun membranes was evaluated using CCK-8 assay and live/dead staining. Integrin β1 immunofluorescence staining was used to evaluate the adhesion characteristics of electrospun membranes. The stem cell-engineered electrospun membrane and the electrospun membrane in the collagen group were cocultured with bone marrow macrophages respectively. Immunomodulatory properties were assessed by detecting the expression of inflammation-related genes using inducible nitric oxide synthase (M1 type), CD206 (M2 type) immunofluorescence staining, and qRT-PCR. RESULTS AND CONCLUSION: (1) The oriented electrospun fiber membrane could mimic the structure of the longitudinally aligned natural dura mater, and the addition of collagen increased the hydrophilicity of the fiber membrane by about 2-fold and the mechanical properties by 1.2-fold. (2) When cocultured with bone marrow mesenchymal stem cells, CCK-8 assay and live/dead staining suggested that the cellular bioactivity in the collagen group was significantly higher than that in the disordered fiber group and ordered fiber group. Immunofluorescence staining revealed that the expression of integrin β1 in the collagen group was about 2.6 times higher than that of the disordered and ordered fiber groups, and the cell spreading morphology was good. (3) When cocultured with bone marrow macrophages, immunofluorescence staining exhibited that the fluorescence intensity of M1 type macrophages in the stem cell-engineered electrospun membrane group was lower than that in the collagen group (P < 0.01), and the fluorescence intensity of M2 type macrophages was higher than that in the collagen group (P < 0.01). qRT-PCR demonstrated that proinflammatory gene tumor necrosis factor α and interleukin-1β mRNA expression in the stem cell-engineered electrospun membrane group was lower than that of the collagen group (P < 0.001); anti-inflammatory genes such as interleukin-10 and transforming growth factor β mRNA expressions were higher than those in the collagen group (P < 0.001). (4) The above results suggest that the stem cellengineered amphipathic artificial dura mimics the directional structure of normal dura, with the inner surface facilitating cell growth and adhesion and the outer edge avoiding tissue adhesion, while the polarization of macrophages to the M2 subtype is promoted and the local inflammatory microenvironment is regulated through the mesenchymal stem cell paracrine component. [ABSTRACT FROM AUTHOR]

Migraine, recognized as a severe headache disorder, is widely prevalent, significantly impacting the quality of life for those affected. This article aims to provide a comprehensive review of the application of animal model technologies in unraveling the pathomechanism of migraine and developing more effective therapies. It introduces a variety of animal experimental models used in migraine research, emphasizing their versatility and importance in simulating various aspects of the condition. It details the benefits arising from the utilization of these models, emphasizing their role in elucidating pain mechanisms, clarifying trigeminal activation, as well as replicating migraine symptoms and histological changes. In addition, the article consciously acknowledges the inherent limitations and challenges associated with the application of animal experimental models. Recognizing these constraints is a fundamental step toward fine-tuning and optimizing the models for a more accurate reflection of and translatability to the human environment. Overall, a detailed and comprehensive understanding of migraine animal models is crucial for navigating the complexity of the disease. These findings not only provide a deeper insight into the multifaceted nature of migraine but also serve as a foundation for developing effective therapeutic strategies that specifically address the unique challenges arising from migraine pathology. [ABSTRACT FROM AUTHOR]