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Background: Different responses in human coronary arteries (HCA) and human middle meningeal arteries (HMMA) were observed for some of the novel CGRP receptor antagonists, the gepants, for inhibiting CGRP-induced relaxation. These differences could be explained by the presence of different receptor populations in the two vascular beds. Here, we aim to elucidate which receptors are involved in the relaxation to calcitonin gene-related peptide (CGRP), adrenomedullin (AM) and adrenomedullin 2 (AM2) in HCA and HMMA. Methods: RNA was isolated from homogenized human arteries (23 HCAs; 12 F, 11 M, age 50 ± 3 years and 26 HMMAs; 14 F, 12 M, age 51 ± 3 years) and qPCR was performed for different receptor subunits. Additionally, relaxation responses to CGRP, AM or AM2 of the human arteries were quantified using a Mulvany myograph system, in the presence or absence of the adrenomedullin 1 receptor antagonist AM22-52 and/or olcegepant. Results: Calcitonin-like receptor (CLR) mRNA was expressed equally in both vascular beds, while calcitonin receptor (CTR) and receptor activity-modifying protein 3 (RAMP3) expression was low and could not be detected in all samples. RAMP1 expression was similar in HCA and HMMA, while RAMP2 expression was higher in HMMA. Moreover, receptor component protein (RCP) expression was higher in HMMA than in HCA. Functional experiments showed that olcegepant inhibits relaxation to all three agonists in both vascular beds. In HCA, antagonist AM22-52 did not inhibit relaxation to any of the agonists, while a trend for blocking relaxation to AM and AM2 could be observed in HMMA. Conclusion: Based on the combined results from receptor subunit mRNA expression and the functional responses in both vascular tissues, relaxation of HCA is mainly mediated via the canonical CGRP receptor (CLR-RAMP1), while relaxation of HMMA can be mediated via both the canonical CGRP receptor and the adrenomedullin 1 receptor (CLR-RAMP2). Future research should investigate whether RAMP2 predominance over RAMP1 in the meningeal vasculature results in altered migraine susceptibility or in a different response to anti-migraine medication in these patients. Moreover, the exact role of RCP in CGRP receptor signalling should be elucidated in future research. [ABSTRACT FROM AUTHOR]

Objective: As the prevalence of neuroendovascular interventions increases, it is critical to mitigate unnecessary radiation for patients, providers, and health care staff. Our group previously demonstrated reduced radiation dose and exposure during diagnostic angiography by reducing the default pulse and frame rates. We applied the same technique for basic neuroendovascular interventions. Methods: We performed a retrospective review of prospectively acquired data after implementing a quality improvement protocol in which pulse rate and frame rate were reduced from 15 p/s to 7.5 p/s and 7.5 f/s to 4.0 f/s respectively. We studied consecutive, unilateral middle meningeal artery embolizations treated with particles. Total radiation dose, radiation per angiographic run, total radiation exposure, and exposure per run were calculated. Multivariable log-linear regression was performed to account for patient body mass index (BMI), number of angiographic runs, and number of vessels catheterized. Results: A total of 20 consecutive, unilateral middle meningeal artery embolizations were retrospectively analyzed. The radiation reduction protocol was associated with a 39.2% decrease in the total radiation dose and a 37.1% decrease in radiation dose per run. The protocol was associated with a 41.6% decrease in the total radiation exposure and a 39.5% decrease in exposure per run. Conclusions: Radiation reduction protocols can be readily applied to neuroendovascular interventions without increasing overall fluoroscopy time and reduce radiation dose and exposure by 39.2% and 41.6% respectively. We strongly encourage all interventionalists to be cognizant of pulse rate and frame rate when performing routine interventions. [ABSTRACT FROM AUTHOR]

Background: Orally administered second-generation gepants are effective for the treatment of migraine. The intranasal administration of the third-generation gepant zavegepant might have additional benefits including a rapid onset of action, but it is not clear yet to which extent this has clinical relevance. Methods: We examined the effect of zavegepant on the relaxations induced by calcitonin gene-related peptide (CGRP) in human isolated middle meningeal arteries. Furthermore, we connected the pharmacodynamics and pharmacokinetics of gepants by combining data from clinical and basic research. Results: We showed that 10 nM zavegepant potently antagonized the functional response to CGRP. We also showed that all gepants are effective at inhibiting functional responses to CGRP at their therapeutic plasma concentrations. Conclusions: The relatively low predicted potency of zavegepant to inhibit CGRP-induced relaxation at therapeutic systemic plasma concentrations may point to the relevance of local delivery to the trigeminovascular system through intranasal administration. This approach may have additional benefits for various groups of patients, including overweight patients. [ABSTRACT FROM AUTHOR]

Background Clip ligation of anterior cranial fossa (ACF) dural arteriovenous fistulas (DAVFs) is the traditionally accepted first- line treatment. Endovascular treatment for ACF DAVFs may achieve good outcomes as endovascular techniques advance. Here we report the clinical and angiographic outcomes in patients with ACF DAVFs who underwent transarterial embolization (TAE) as first-line treatment. Methods Over a 20- year period, 87.0% (40/46) of patients received TAE as first-line treatment. The clinical presentation, angiographic features, treatment strategy, and clinical and angiographic outcomes are described in this article. Results Forty patients underwent TAE as first-line treatment. There were 36 men and 4 women, with a mean age of 55.6 (55.6±7.4) years. A total of 64 embolization attempts were performed. The middle meningeal artery (66.7%, 12/18) and the ophthalmic artery (54.2%, 13/24) were the most frequently used arterial access routes for complete embolization. The second option was the sphenopalatine artery (46.7%, 7/15). Complications, that is, retinal ischemia, occurred in one patient (2.5%). The total immediate complete occlusion rate for TAE was 82.5% (33/40). Two patients needed surgery for incomplete embolization. When followed up (90%, 36/40), one patient (2.8%, 1/36) reported worsening symptoms due to retinal ischemia following TAE. Although fewer than 50% of the patients received digital subtraction angiography follow- up, there were no recurrences. Conclusions We show that TAE is safe and effective in the treatment of ACF DAVFs in this study of 40 patients, making it a viable alternative to surgical ligation and transvenous embolization. More research is needed to compare these various treatment modalities. [ABSTRACT FROM AUTHOR]

Background: Endovascular surgery is rapidly advancing and is widely used for the management of various cerebrovascular diseases. Usually, chronic subdural hematomas are treated surgically; however, endovascular surgery is recently being attempted as a new treatment option based on the pathophysiology of this condition. Current Concepts: Chronic subdural hematomas have an outer membrane derived from the dura mater. Sinusoidal capillaries in the outer membrane are a source of bleeding, which leads to hematoma growth and postoperative recurrence. Theoretically, embolization of the middle meningeal artery using endovascular procedures can prevent bleeding from the outer membrane and promote spontaneous resolution of a hematoma. Clinical studies, including recent prospective trials, have demonstrated the superior efficacy and safety of middle meningeal artery embolization over conventional treatment. Discussion and Conclusion: More clinical trials on endovascular surgery for chronic subdural hematomas are forthcoming. We expect that the results of future studies will strengthen the findings of recent prospective trials and contribute to a major shift in the management of chronic subdural hematomas. [ABSTRACT FROM AUTHOR]

Background Middle meningeal artery (MMA) embolization for endovascular treatment of chronic subdural hematoma (cSDH) is growing in popularity. cSDH volume and midline shift were analyzed in the immediate postoperative window after MMA embolization. Methods A retrospective analysis of cSDHs managed via MMA embolization from January 1, 2018 to March 30, 2021 was performed at a large quaternary center. Pre- and postoperative cSDH volume and midline shift were quantified with CT. Postoperative CT was obtained 12 to 36 hours after embolization. Paired t-tests were used to determine significant reduction. Multivariate analysis was performed using logistic and linear regression for percent improvement from baseline volume. Results In total, 80 patients underwent MMA embolization for 98 cSDHs during the study period. The mean (SD) initial cSDH volume was 66.54 (34.67) mL, and the mean midline shift was 3.79 (2.85) mm. There were significant reductions in mean cSDH volume (12.1 mL, 95% CI 9.32 to 14.27 mL, P<0.001) and midline shift (0.80 mm, 95% CI 0.24 to 1.36 mm, P<0.001). In the immediate postoperative period, 22% (14/65) of patients had a>30% reduction in cSDH volume. A multivariate analysis of 36 patients found that preoperative antiplatelet and anticoagulation use was significantly associated with an expansion in volume (OR 0.028, 95% CI 0.000 to 0.405, P=0.03). Conclusion MMA embolization is safe and effective for the management of cSDH and is associated with significant reductions in hematoma volume and midline shift in the immediate postoperative period. [ABSTRACT FROM AUTHOR]

Background Liquid embolic agents and polyvinyl alcohol (PVA) particles have been used for the embolization of the middle meningeal artery (MMA) for the treatment of chronic subdural hematomas. However, the vascular penetration and distribution of these embolic agents have not yet been compared. The current study compares distribution of a liquid embolic agent (Squid) to PVA particles (Contour) in an in vitro model of the MMA. Methods MMA models were embolized with Contour PVA particles 45-150 µm, Contour PVA particles 150-250 µm, and Squid-18 liquid embolic agent (n=5 each). The models were scanned and every vascular segment with embolic agent was manually marked on the images. Embolized vascular length as a percentage of control, average embolized vascular diameter, and embolization time were compared between the groups. Results The 150-250 µm Contour particles primarily accumulated close to the microcatheter tip, yielding proximal branch occlusions. The 45-150 µm Contour particles achieved a more distal distribution, but in a patchy segmental pattern. However, the models embolized with Squid-18 had a consistently distal, near-complete and homogenous distribution. Embolized vascular length was significantly higher (76±13% vs 5±3%, P=0.0007) and average embolized vessel diameter was significantly smaller (405±25 µm vs 775±225 µm, P=0.0006) with Squid than with Contour. Embolization time with Squid was also lower (2.8±2.4 min vs 6.4±2.7 min, P=0.09). Conclusions Squid-18 liquid results in a considerably more consistent, distal and homogeneous pattern of embolysate distribution than Contour PVA particles in an anatomical model of the MMA tree. [ABSTRACT FROM AUTHOR]

Objective: We describe a patient with leukemia-related chronic subdural hematoma (CSDH) who was successfully treated using the combination of surgical evacuation and middle meningeal artery (MMA) embolization. Case Presentation: A 73-year-old man without apparent head trauma history was admitted to our hospital because of acute myeloid leukemia (AML). Head CT on admission revealed mild CSDH on both sides. Medical treatment options, including chemotherapy, were started. Since a decrease in platelet count and disseminated intravascular coagulation were observed on day 4, recombinant thrombomodulin was administered. As the patient exhibited signs of altered consciousness due to the enlargement of the right CSDH on day 10, we performed surgical drainage. Despite subsequent platelet transfusion and administration of goreisan, the right CSDH recurred within a short period. On day 17, we performed the second surgery and MMA embolization in one stage. The postoperative clinical course was favorable without recurrence of the hematoma. The patient eventually died on day 123 from a deterioration of his general condition. Conclusion: Although MMA embolization has recently been recognized as an effective treatment option for recurrent CSDH, there are no published reports addressing the efficacy of MMA embolization for refractory CSDH associated with hematological malignancies. Findings from the management of this case suggest that MMA embolization can be the effective treatment option for CSDH in patients with severe hemorrhagic diathesis due to AML. [ABSTRACT FROM AUTHOR]

Hematomas caused by the rupture of a pseudoaneurysm in the middle meningeal artery (MMA) after trauma usually present as epidural hematomas. Intracerebral hemorrhage (ICH) is extremely rare. We reviewed ICH due to the rupture of MMA pseudoaneurysms. We found that in cases of acute ICH, a pseudoaneurysm was attached to the outer surface of the dura mater and associated with dura tear. In patients with acute ICH, the intraoperative rupture of a pseudoaneurysm developed just after bone flap removal. In cases of delayed ICH, pseudoaneurysms adhered to the inner surface of the dura mater. In patients with delayed ICH, the intraoperative rupture of a pseudoaneurysm developed during dura opening and hematoma removal. In situations of dura tear after trauma, the rupture of pseudoaneurysms might lead to ICH via a dura tear. Pseudoaneurysms that develop in the MMA after trauma may exert pressure and result in the thinning of the dura mater. In this case, pseudoaneurysms will adhere to the inner surface of the dura mater after several days or weeks. ICH might develop through both acute and delayed mechanisms following the development of pseudoaneurysms in the MMA. Clinicians should pay attention to the timing of such ruptures during operations for both acute and delayed ICH. [ABSTRACT FROM AUTHOR]

Background Embolization of the middle meningeal artery (MMA) is a promising minimally invasive technique that is gaining traction in the treatment of chronic subdural hematoma. Unfortunately, the human meninges and associated arteries are significantly larger than those of conventional laboratory animals, making the development of a clinically relevant animal model for testing of embolization agents elusive. Objective To introduce the posterior intercostal artery (PIA) model in swine and provide anatomical, angiographic, histological, and procedural data to validate its relevance in modeling the human MMA. Methods In human cadaveric specimens, 3D angiograms of the internal maxillary arteries (n=6) were obtained and the dura with MMA were harvested and histologically processed. Angiographic and histologic data of the human MMA were compared with the swine PIA (three animals). Then, embolization of the PIA (n=48 arteries) was conducted with liquid embolization agent (Onyx, Medtronic), and angiographic and histological results were assessed acutely (four animals) and after 30 days (two animals). Results The human MMA has equivalent diameter, length, branching pattern, 3D trajectory, and wall structure to those of swine PIAs. Each swine has 12 to 14 PIAs (6-7 per side) suitable for acute or chronic embolization, which can be performed with high fidelity using the same devices, agents, and techniques currently used to embolize the MMA. The arterial wall structure and the acute and chronic histological findings in PIAs after embolization are comparable to those of humans. Conclusions This PIA model in swine could be used for research and development; objective benchmarking of agents, devices, and techniques; and in the training of neurointerventionalists. [ABSTRACT FROM AUTHOR]

Resumen: Introducción: Dadas las altas tasas de recurrencia, el hematoma subdural crónico (HSDC) es una condición que supone un reto para el clínico. La embolización endovascular de la arteria meníngea media (EeAMM) ha surgido como una alternativa para aquellos pacientes con problemas de salud o con varias recurrencias de su HSDC. A pesar de la publicación de algunos artículos prometedores referentes a esta técnica, el perfil de seguridad, las indicaciones y las limitaciones no están claramente establecidas. Desarrollo: Nuestro objetivo es evaluar la evidencia actual sobre la EeAMM en el HSDC. Se realizó una revisión sistemática de la literatura según las guías PRISMA. Nuestra búsqueda arrojó un total de 6 estudios, en los que 164 pacientes con HSDC se sometieron a EeAMM. La tasa de recurrencia entre todos los estudios fue del 6,7% y se produjeron complicaciones en hasta el 6% de los pacientes. Conclusión: La EeAMM es una técnica factible en el tratamiento del HSDC con una tasa de recurrencia relativamente baja y tasas aceptables de complicaciones. Se necesitan más estudios prospectivos y aleatorizados para establecer formalmente un perfil de seguridad claro y su efectividad. Abstract: Introduction: Chronic subdural haematoma (CSDH) represents a clinical challenge due to its high recurrence rate. Endovascular middle meningeal artery embolisation (eMMAE) has emerged as an alternative for those patients presenting health problems or multiple recurrences of CSDH. Despite several encouraging reports, the safety profile, indications, and limitations of the technique are not clearly established. Development: This study aimed to evaluate the current evidence on eMMAE in patients with CSDH. We performed a systematic review of the literature, following the PRISMA guidelines. Our search yielded a total of 6 studies, in which a total of 164 patients with CSDH underwent eMMAE. The recurrence rate across all studies was 6.7%, and complications occurred in up to 6% of patients. Conclusions: eMMAE is a feasible technique for treating CSDH, with a relatively low recurrence rate and an acceptable rate of complications. Further prospective and randomised studies are needed to formally establish a clear profile of the safety and effectiveness of the technique.

Purpose: To identify prognostic factors with emphasis on chronic subdural hematoma (CSDH) architecture that determines short-term outcome of middle meningeal artery embolization (MMAE). Methods: Consecutive CSDH patients treated by MMAE (November 2019 and March 2022) were retrospectively analyzed. Four architectures were analyzed: homogeneous, laminar, separated, and trabecular types. Predictor variables from baseline CT were correlated with radiological endpoint (≥ 50% of hematoma volume reduction), time to reach the endpoint, and rate of volume reduction. Results: Study included 50 patients with 56 CSDHs (median age [first quartile, Q1; third quartile, Q3] 70.5 [60, 78.3] years; 36 were men). Separated type reached the endpoint at a lower rate on both bivariate (p = 0.02) and multivariate Cox model (0.034). Kaplan–Meier curves demonstrated that the median [Q1, Q3] time for 50% of the hematomas to reach the endpoint was 5 [4, 8], 4 [3, 5], 15 [15, 15], and 11 [4, 19] weeks for homogeneous, laminar, separated, and trabecular types, respectively. Linear mixed-effect model demonstrated a significant variation in the slope of hematoma volume reduction that was − 4.16 (95% confidence interval [CI] − 5.4, − 2.9), − 6.7 (95% CI − 8.35, − 5.1), − 2.03 (95% CI − 4.14, 0.08), and − 5.06 (95% CI − 6.8, − 3.32) ml per week for homogeneous, laminar, separated, and trabecular subtypes, respectively. Conclusion: Separated CSDH is a poor prognostic type in achieving radiological endpoint and a slower rate of volume reduction. While, homogeneous and laminar types reached the endpoint faster than separated and trabecular types on short-term follow-up. [ABSTRACT FROM AUTHOR]

Abstract Background Despite the pervasiveness of migraine, the underlying pathophysiological mechanisms initiating migraine attacks are far from well understood and are matter of scientific debate. Objective In this narrative review, we discuss key evidence for that suggest a peripheral origin or central origin and provide directions for future studies that may provide further clarification. Discussion Migraine pathogenesis is considered to involve the trigeminovascular system, a term that encompasses the trigeminal nerve and its axonal projections to the intracranial blood vessels. Beyond any doubt both peripheral and central mechanisms are involved in migraine pathogenesis, but an unresolved question is the how the initial activation occurs in a migraine attack. Evidence favoring a peripheral origin of migraine attacks, i.e., initial events occur outside of the blood–brain barrier, include the importance of sensitization of perivascular sensory afferents early on in a migraine attack. Evidence favoring a central origin include the occurrence of prodromal symptoms, migraine aura, and activation of structures within the central nervous system early in and during a migraine attack. Conclusions Both peripheral and central mechanisms are likely involved in a migraine attack, e.g., peripheral nociceptive input is necessary for pain transmission and cortical activity is necessary for pain perception. Yet, the debate of whether migraine attacks are initiated a peripheral or central site remains unresolved. The increased focus on prodromal symptoms and on the development of a human model of migraine aura will possibly provide key arguments needed to answer this question in the near future. Until then, we cannot draw firm conclusions and the debate goes on. Video link Video recording of the debate held at the 1st International Conference on Advances in Migraine Sciences (ICAMS 2022, Copenhagen, Denmark) is available at: https://www.youtube.com/watch?v=NC0nlcKohz0 . Graphical Abstract

To describe a case of persistent facial nerve palsy after middle meningeal artery (MMA) embolization for chronic subdural hematoma (cSDH). A literature search was conducted for publications within the last 10 years of facial nerve palsy following cerebral circulation embolization procedures. With inconsistencies between previously believed pathophysiology and clinical features, other mechanisms causing cSDH such as angiogenesis and capillary formation have been proposed. MMA embolization has evolved as a therapeutic approach to reduce recurrence of subdural hematoma; however, postoperative neural complications such as cranial nerve palsies are poorly described in the literature. cSDH is increasingly more common and is on trajectory to become the most prevalent cranial neurosurgical condition. MMA embolization is described as a safe and minimally invasive procedure; however, as a relatively new procedure further research is needed to elucidate associated complications. [ABSTRACT FROM AUTHOR]

Background: Despite the pervasiveness of migraine, the underlying pathophysiological mechanisms initiating migraine attacks are far from well understood and are matter of scientific debate. Objective: In this narrative review, we discuss key evidence for that suggest a peripheral origin or central origin and provide directions for future studies that may provide further clarification. Discussion: Migraine pathogenesis is considered to involve the trigeminovascular system, a term that encompasses the trigeminal nerve and its axonal projections to the intracranial blood vessels. Beyond any doubt both peripheral and central mechanisms are involved in migraine pathogenesis, but an unresolved question is the how the initial activation occurs in a migraine attack. Evidence favoring a peripheral origin of migraine attacks, i.e., initial events occur outside of the blood–brain barrier, include the importance of sensitization of perivascular sensory afferents early on in a migraine attack. Evidence favoring a central origin include the occurrence of prodromal symptoms, migraine aura, and activation of structures within the central nervous system early in and during a migraine attack. Conclusions: Both peripheral and central mechanisms are likely involved in a migraine attack, e.g., peripheral nociceptive input is necessary for pain transmission and cortical activity is necessary for pain perception. Yet, the debate of whether migraine attacks are initiated a peripheral or central site remains unresolved. The increased focus on prodromal symptoms and on the development of a human model of migraine aura will possibly provide key arguments needed to answer this question in the near future. Until then, we cannot draw firm conclusions and the debate goes on. Video link: Video recording of the debate held at the 1st International Conference on Advances in Migraine Sciences (ICAMS 2022, Copenhagen, Denmark) is available at: https://www.youtube.com/watch?v=NC0nlcKohz0. [ABSTRACT FROM AUTHOR]

Background Few reports discuss variables associated with improved outcomes after middle meningeal artery (MMA) embolization for chronic subdural hematomas (cSDHs). We analyzed radiographic evidence of cSDH clearance after MMA embolization to elucidate optimal techniques, hematoma clearance rates, and suitable length of follow-up. Methods Patients who underwent MMA embolization for cSDH from January 1, 2018 through December 31, 2020 were analyzed. Patient characteristics, demographics, and technical procedural details were examined. Outcomes for cSDHs analyzed included complete or near-complete resolution at 30, 90, and 180 days following embolization. A multivariable logistic regression analysis identified variables predictive of rapid clearance and resolution of hematomas at 90 days. Results The study cohort comprised 66 patients with 84 treated cSDHs. The mean (SD) cSDH size differed significantly at 30-day (8.8 (4.3) mm), 90-day (3.4 (3.0) mm), and 180-day (1.0 (1.7) mm) follow-up (p<0.001). More cSDHs had complete or near-complete resolution at 180 days (92%, 67/73) than at 90 (63%, 45/72) and 30 days (18%, 15/84) post-embolization (p<0.001). Only distal embolysate penetration was independently associated with rapid clearance (OR 3.9, 95% CI 1.4 to 11.1; p=0.01) and resolution of cSDHs at 90 days (OR 5.0, 95% CI 1.7 to 14.6; p=0.003). Conclusion Although 63% of cSDHs with MMA embolization had complete or near-complete resolution by 90 days post-procedure, 92% reached this stage by 180 days. Therefore, 90-day follow-up may be insufficient to determine the effectiveness of MMA embolization for cSDHs, particularly compared with surgical evacuation alone. Also, distal MMA penetration may be associated with more rapid hematoma clearance. [ABSTRACT FROM AUTHOR]

Background: Chronic subdural hematoma (cSDH) is one of the most common neurosurgical disorders and the incidence is rising. The routine treatment is neurosurgical hematoma evacuation, which is associated with recurrence rates up to 10-25%. In recent years, endovascular embolization of the middle meningeal artery (eMMA) has garnered much attention due to recurrence rates as low as < 5%. Several randomized controlled trials are planned or ongoing. In most of these trials, conventional neurosurgical treatment with or without adjunctive endovascular embolization is compared. The proposed trial aims to conduct a head-to-head comparison between neurosurgical and endovascular treatment as stand-alone treatments.Methods: The trial is academically driven and funded within existing public healthcare systems and infrastructure. Patients with uni- or bilateral cSDH, presenting with mild-to moderate symptoms, and admitted to neurosurgery on clinical grounds will be offered participation. Subjects are randomized 1:1 between conventional neurosurgical treatment (control) and endovascular embolization of the middle meningeal artery (intervention). Primary endpoint is reoperation due to clinically and/or radiologically significant recurrence within 3 months. Secondary endpoints include safety, technical success rate, neurological disability, and quality of life.Discussion: There are mounting retrospective data suggesting eMMA, as sole treatment or as an adjunctive to neurosurgery for cSDH, is safe and effective with a reoperation rate lower than neurosurgical hematoma evacuation alone. If randomized controlled trials confirm these findings, there is a potential for a paradigm shift in the treatment of cSDH where a minimally invasive procedure can replace open surgery in a large and oftentimes old and fragile patient cohort.Trial Registration: ClinicalTrials.gov, ClinicalTrials.gov Identifier NCT05267184 . Registered March 4, 2022. [ABSTRACT FROM AUTHOR]

Migraine is a prevalent and debilitating neurologic disorder. Advancements in understanding the underlying pathophysiological mechanisms are spearheading the effort to introduce disease-specific treatment options. In recent years this effort has largely focused on alteration of endogenous neuropeptide signaling, namely the peptides calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP). Human studies into the pathophysiological underpinnings of CGRP and PACAP in migraine are manifold and here we review the works investigating these neuropeptides in patients suffering from migraine in order to elucidate the background for developing new treatment options for this vastly disabling disorder. [ABSTRACT FROM AUTHOR]

Cross study heterogeneity has limited the evidence based evaluation of middle meningeal artery embolization (MMAE) as a treatment for chronic subdural hematoma (CSDH). Ongoing trials and prospective studies suggest that heterogeneity in upcoming publications may detract from subsequent meta-analyses and systemic reviews. This study aims to describe this data heterogeneity to promote harmonization with common data elements (CDEs) in publications. ClinicalTrials.gov and PubMed were searched for published or ongoing prospective trials of MMAE. The Nested Knowledge AutoLit living review platform was utilized to classify endpoints from randomized control trials (RCTs) and prospective cohort studies comparing MMAE with other treatments. The qualitative synthesis feature was used to determine cross study overlap of outcome related data elements. Eighteen studies were included: 12 RCTs, two nonrandomized controlled studies, two prospective single arm trials, one combined prospective and retrospective controlled study, and one prospective cohort study. The most commonly reported data element was recurrence (15/18), but seven heterogenous (non-comparable) definitions were used for 'recurrence'. Mortality was reported in 10/18 studies, but no common timepoint was reported in more than four studies. Re-intervention and CSDH volume were reported in eight studies, CSDH width in seven, and no other outcome was common across more than five studies. There was significant heterogeneity in data element collection even among prospective registered trials of MMAE. Even among CDEs, variation in definition and timepoints prevented harmonization. A standardized approach based on CDEs may be necessary to facilitate future meta-analyses and evidence driven evaluation of MMAE treatment of CSDH. [ABSTRACT FROM AUTHOR]

Objective: Transarterial Onyx embolization is the mainstay of intracranial non-cavernous dural arteriovenous fistulas (dAVFs) treatment. Although the dural arterial supply varies depending on the location, the impact of arterial access on treatment outcomes has remained unclear. The aim of this study was to characterize factors as sociated with complete obliteration following transarterial Onyx embolization, with a special focus on arterial access routes and dAVF location. Methods: A retrospective analysis of the patients who underwent transarterial Onyx embolization for intracranial dAVFs at two academic institutions was performed. Patients with angiographic follow-up were considered eligible to investigate the impact of the arterial access on achieving complete obliteration. Results: Sixty-eight patients underwent transarterial Onyx embolization of intracranial dAVFs. Complete obliteration was achieved in 65% of all treated patients and in 75% of those with cortical venous reflux. Multivariable analysis identified middle meningeal artery (MMA) access to be a significant independent predictive factor for complete obliteration (OR, 2.32; 95% CI, 1.06-5.06; p=0.034). Subgroup analysis showed that supratentorial and lateral cerebellar convexity dAVFs (OR, 5.72, 95% CI, 1.89-17.33, p=0.002), and Borden type III classification at pre-treatment (OR, 3.13, 95% CI, 1.05- 9.35, p=0.041), were independent predictive factors for complete obliteration following embolization through the MMA. Conclusions: MMA access is an independent predictive factor for complete oblitera)tion following transarterial Onyx embolization for intracranial non-cavernous dAVFs. It is particularly effective for supratentorial and lateral cerebellar convexity dAVFs and those that are Borden type III. [ABSTRACT FROM AUTHOR]

Subdural hematoma is an encapsulated collection of blood under the dura matter. This commonly encountered neurosurgical disorder is best managed by surgical evacuation; however, contemporary neurosurgery lacks a consensus regarding surgical technique of choice. Due to high incidence of the condition and associated complications, vast amount of literature is available on the subject; including studies comparing efficacy of various available treatment modalities. Herein, literature on surgical techniques employed for management of Chronic Subdural Hematoma (CSDH) has been reviewed to provide an evidence-based review on best surgical practices. Following conclusions can be made on basis of evidence of various levels provided in the studied literature: (1) Twist-drill craniostomy is a relatively safe technique that can be employed under local anaesthesia, thus can be considered as first line treatment in high risk surgical candidates. (2) Single and double burr-hole craniostomies have shown comparable results. (3) Intraoperative irrigation during burr-hole craniostomy doesn't affect outcome. (4) Drain insertion after hematoma evacuation lowers recurrence risk. (5) Position of drain is not significant but early drain removal is associated with higher recurrence rates. (6) Craniotomy is associated with high morbidity and mortality, hence should be reserved for recurrent and large septate hematoma cases. (7) Head elevation in postoperative period reduces recurrence. (8) Embolization of middle meningeal artery (EMMA): A novel treatment modality, is promising but requires further approval in terms of large sample sized multicenter randomized control trials. In conclusion further research is required on the subject to formulate guidelines regarding management of this common neurosurgical emergency. [ABSTRACT FROM AUTHOR]

A man in his 50s presented 1 month after an automobile accident with worsening headaches and an enlarging chronic left subdural haematoma (SDH). He underwent left middle meningeal artery (MMA) embolisation. Due to tortuosity at its origin, we were unable to catheterise the MMA distally. Only proximal coil occlusion at the origin was performed. Follow-up interval head CT showed an increase in the size of the SDH with new haemorrhage, worsening mass effect and midline shift. However, he remained neurologically intact. Contralateral embolisation of the right MMA was performed with a liquid embolic agent. His headaches improved, and a follow-up head CT 3 months later showed near-complete resolution of the SDH. [ABSTRACT FROM AUTHOR]

Purpose: The pterygomeningeal (accessory meningeal) artery arises from the middle meningeal or maxillary artery. Although there is the potential that this artery may be wounded by the surgery for the temporomandibular joint disorder, the current state of anatomical knowledge is insufficient. This study investigated the appearance and the branching pattern of this artery as a means to its characterization. Methods: The pterygomeningeal artery was dissected in 14 cadavers and its branches and their distributions to the muscles inside the mandible were examined. Results: The maxillary artery passed lateral to the lateral pterygoid muscle. The pterygomeningeal artery arose from the middle meningeal or maxillary artery. It ascended anteriorly and coursed medial or lateral to the mandibular nerve. It passed above the pterygospinous ligament and then descended. The ascending trunk gave some lateral branches to the lateral pterygoid muscle. The branches sometimes passed lateral to the mandibular nerve even if the pterygomeningeal artery coursed medial. The descending trunk was divided into middle and medial branches, which supplied the medial pterygoid muscle and the tensor veli palatini, respectively. The pterygomeningeal artery was sometimes equally bifurcate near the origin, and the counterparts passed lateral and medial to the mandibular nerve. The distributions of the medial and lateral counterparts were equivalent to those of the descending trunk and the lateral branches, respectively. Conclusion: The pterygomeningeal artery contains three groups of muscular branches, which sometimes appear in a bifurcate form. Their positions relative to the mandibular nerve and the pterygospinous ligament characterize the artery; this information may help to avoid iatrogenic injury. [ABSTRACT FROM AUTHOR]

Purpose: Due to the increase in accessibility of computed tomography (CT), repeat head CT scans are routinely ordered for patients with minor head injuries. The aim of this study is to evaluate the necessity and outcomes of routine repeat head CT in patients with GCS score of 13–15 who presented to the emergency department (ED) of Antalya University Hospital in Turkey with blunt head trauma. Methods: We retrospectively reviewed the charts of patients with minor head trauma that received initial and repeat head CT results from July 1, 2013 to June 30, 2015. Clinical characteristics of patients were compared for two groups of patients: those with neurological deterioration, and those who had routine head CT not required by change in neurological status. Repeat head CT results were analyzed for radiological worsening and the necessity of a surgical or medical intervention such as craniotomy, ICP monitoring, VP shunt and mannitol or hypertonic saline administration. Results: Of 3578 patients with blunt head trauma, 656 (18.3%) patients had repeat head CT; 449 of these (68.4%) had a GCS score of 13–15. We analyzed 441 patients for CT and clinical changes. Eight patients were excluded because of poor image quality and/or penetrating injury. Neurological deterioration was the reason for repeat head CT in 73 (16.5%) patients Rates of medical (mannitol treatment) or surgical (craniotomy) intervention in this group were 26% (95% Confidence Interval [95% CI], 15.7–36.3%) in contrast to 0.8% (95% CI 0.1–1.7%) in the group of patients with routinely ordered head CT but without clinical deterioration. The following factors were statistically associated with need for intervention: use of anticoagulant or antithrombotic medication, fracture in middle meningeal artery territory, even a single point decrease in GCS score, increased headache, recurrent vomiting, neurological deficit, and finally, changes in repeat head CT. Conclusions: In patients with minor head injuries, those without neurological deterioration have a very low risk of need for medical or surgical intervention. Routinely ordering repeat head CT scans in this group may not be routinely indicated. [ABSTRACT FROM AUTHOR]

Background The middle meningeal artery (MMA) has been implicated in chronic headaches, but no studies have examined the relationship between MMA embolization and headaches. Methods Patients treated with MMA embolization for a chronic subdural hematoma (cSDH) between January 1, 2018, and December 31, 2020, were retrospectively assessed. Patients with a Glasgow Coma Scale (GCS) score of 15 at discharge received a follow-up telephone call to assess their history of chronic headache, defined as a headache ≥2 years before the cSDH and symptoms ≥2 days/month. A Headache Impact Test (HIT-6) was performed during the follow-up telephone call. The primary outcome was resolution or improvement of headaches after embolization. Results Of 76 patients undergoing MMA embolization for a cSDH during the study period, 56 (74%) had a discharge GCS score of 15. Of these 56 patients, 46 (82%) responded to a follow-up telephone call and were analyzed (mean [SD] age 68 [11] years; 36 [78%] men and 10 [22%] women). Nine (20%) reported chronic headaches before embolization. With a mean (SD) follow-up of 489 (173) days, eight of the nine patients reported improvement of chronic headaches, with seven having complete resolution. For these nine patients, the mean (SD) HIT-6 score was significantly higher before embolization than after embolization (64 [7.1] vs 40 [9.1], p<0.001). Conclusion In patients with chronic headaches who underwent MMA embolization for a cSDH, the majority reported improvement of headaches after the procedure. Future prospective studies are warranted to assess the usefulness of MMA embolization to treat chronic headaches. [ABSTRACT FROM AUTHOR]

Background Chronic subdural hematoma (CSDH) is a common neurosurgical condition with high recurrence rates. Repeated microbleedings from fragile neo-vessels supplied by peripheral branches of the middle meningeal artery (MMA) are believed to be responsible for the growth and recurrence of CSDH. Thus, MMA embolization might be a promising method to prevent re-bleedings and recurrences. This study aims to assess the efficacy, complication rates, and mid-term outcome of MMA embolization with or without burr hole irrigation compared with burr hole irrigation alone. Methods Patients diagnosed with CSDH who underwent MMA embolization and/or surgical treatment were retrospectively recruited to this single-center study. The outcome variables were defined as treatment-related complications, clinical outcome at discharge, rate of revision surgery, and CT findings during the follow-up period. Results A total of 132 patients with CSDH were included in the study. The use of antiplatelet/ anticoagulant medication was significantly higher in the combined treatment and embolization group (p<0.001). A trend towards fewer revision surgeries was found in the group of patients who received MMA embolization combined with burr hole irrigation (p=0.083). Follow-up was available for 73 patients (55.3%) with a mean follow-up period of 3.4±2.2 months. Eight patients (15.1%) of the surgery group showed hematoma re-accumulation and needed surgical rescue, whereas only one patient (5.0%) of the combined treatment group needed revision surgery. In all patients treated with only MMA embolization, complete hematoma resolution was found. Conclusion MMA embolization is a safe and efficacious minimal invasive adjuvant and/or alternative procedure for the treatment of CSDH with a reduced recurrence rate. [ABSTRACT FROM AUTHOR]

The pharyngo-tympano-stapedial middle meningeal artery (PTS-MMA) variant has been described in one case report and never in the setting of arterial supply to a dural arteriovenous fistula, to our knowledge. We report the case of a middle-aged patient with severe, daily headache who presented to our institution for angiography and treatment. CT angiography and MRI demonstrated an enlarged left middle meningeal artery coursing to a large venous varix in the falcotentorial region. Dural arteriovenous fistula was confirmed by subsequent cerebral angiography. Endovascular treatment was performed but without complete obliteration of the fistula. Follow-up angiography demonstrated parasitized arterial supply from a right middle meningeal artery arising from the proximal cervical internal carotid artery coursing through the middle ear consistent with a PTS-MMA variant. The fistula was then treated surgically without recurrence at the 6-month follow-up. [ABSTRACT FROM AUTHOR]

Background The dural vasculature plays a key role in several important conditions, including dural fistulas and subdural collections. While in vivo investigations of intrinsic dural arterial angioarchitecture are rare, no angiographic studies of dural venous drainage exist to our knowledge. Objective To describe methods by which dural venous drainage might be visualized with current angiographic equipment and technique, and to correlate our results with existing ex vivo literature. Methods Digital subtraction angiography and 3D angiography (rotational and Dyna CT) of dural neurovasculature were acquired in the context of subdural hematoma embolization and normal dura. Protocols for visualization of dural venous drainage were established, and findings correlated with ex vivo studies. Results Meningeal arteries supply both the skull and dura. Normal dural enhancement is accentuated by the presence of hypervascular membranes. Intrinsic meningeal veins/sinuses parallel outer layer arteries with well- known tram- tracking appearance. Dura adjacent to main arterial trunks drains via skull base foramina into the pterygopalatine venous plexus, or via emissary veins into the temporalis venous plexus. Dura near the sinuses drains into venous pouches adjacent to the sinus, before emptying into the sinus proper--possibly the same pouches implicated in the angioarchitecture of dural fistulas. Finally, posterior temporoparietal convexity dura, situated in a watershed- like region between middle and posterior meningeal territories, frequently empties into diploic and emissary veins of the skull. Wide variation in balance is expected between these three routes. Drainage patterns appear to correlate with venous embryologic investigations of Padget and ex vivo studies in adults. Conclusions Continued attention to dural venous drainage may prove useful in the diagnosis and management of dural- based vascular diseases. [ABSTRACT FROM AUTHOR]

Patients with left ventricular assist devices (LVADs) provide a unique challenge with regard to the management of subdural hematomas (SDH), due to preexisting comorbidities and induced coagulopathy. We report on the case of a 63-year-old female with a preexisting LVAD who developed an acute on chronic SDH with 15 mm of midline shift. She was successfully treated with middle meningeal artery (MMA) embolization and placement of a bedside subdural evacuating port system without hematoma recurrence at 1-year follow-up. Both operative and nonoperative management of SDHs in patients with LVAD is associated with high risk of mortality and morbidity. Chronic SDHs in this patient population can be successfully managed with a minimally invasive approach that includes MMA embolization and bedside subdural drain placement. [ABSTRACT FROM AUTHOR]

Background Recently, middle meningeal artery (MMA) embolization has emerged as a potential alternative treatment option for chronic subdural hematomas (SDH). Imaging following MMA embolization often shows high density material in the subdural space, usually representing contrast leakage through the dura or, less commonly, hemorrhage. These cannot be reliably differentiated on conventional CT. Dual energy CT (DECT) provides the ability to differentiate materials that otherwise appear similar on conventional CT such as blood and iodine. Methods A retrospective review was conducted to evaluate patients who underwent MMA embolization for SDH between May 2019 and April 2020. Post- procedural head CT performed on an IQon Elite Spectral CT detector- based DECT scanner enabled two- material decomposition to separate iodine from blood. The dual energy reconstructions used included the virtual non- contrast and iodine no- water images. Results Four representative illustrative cases were selected to highlight the ability of DECT to characterize new hyperdensity on head CT following MMA embolization as blood, contrast or a combination. Conclusions DECT allows objective differentiation of contrast leakage from blood following MMA embolization. This technology can obviate the need for additional follow-up scanning and prolonged patient observation, which in turn can result in reduced costs and radiation exposure to patients. [ABSTRACT FROM AUTHOR]

Middle meningeal artery (MMA) embolization has been proposed as a minimally invasive treatment for chronic subdural hematoma (cSDH). The aim of this systematic review and meta- analysis is to compare outcomes after MMA embolization versus conventional management for cSDH. We performed a systematic review of PubMed, Embase, Oxford Journal, Cochrane, and Google Scholar databases from April 1987 to October 2020 in accordance with PRISMA guidelines. Studies reporting outcomes after MMA embolization for ≥3 patients with cSDH were included. A meta- analysis comparing MMA embolization with conventional management was performed. The analysis comprised 20 studies with 1416 patients, including 718 and 698 patients in the MMA embolization and conventional management cohorts, respectively. The pooled recurrence, surgical rescue, and in- hospital complication rates in the MMA embolization cohort were 4.8% (95% CI 3.2% to 6.5%), 4.4% (2.8% to 5.9%), and 1.7% (0.8% to 2.6%), respectively. The pooled recurrence, surgical rescue, and in- hospital complication rates in the conventional management cohort were 21.5% (0.6% to 42.4%), 16.4% (5.9% to 27.0%), and 4.9% (2.8% to 7.1%), respectively. Compared with conservative management, MMA embolization was associated with lower rates of cSDH recurrence (OR=0.15 (95% CI 0.03 to 0.75), p=0.02) and surgical rescue (OR=0.21 (0.07 to 0.58), p=0.003). In- hospital complication rates were comparable between the two cohorts (OR=0.78 (0.34 to 1.76), p=0.55). MMA embolization is a promising minimally invasive therapy that may reduce the need for surgical intervention in appropriately selected patients with cSDH. Additional prospective studies are warranted to determine the long- term durability of MMA embolization, refine eligibility criteria, and establish this endovascular approach as a viable definitive treatment for cSDH. [ABSTRACT FROM AUTHOR]

Migraine is a prevalent and debilitating neurologic disorder. Advancements in understanding the underlying pathophysiological mechanisms are spearheading the effort to introduce disease-specific treatment options. In recent years this effort has largely focused on alteration of endogenous neuropeptide signaling, namely the peptides calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP). Human studies into the pathophysiological underpinnings of CGRP and PACAP in migraine are manifold and here we review the works investigating these neuropeptides in patients suffering from migraine in order to elucidate the background for developing new treatment options for this vastly disabling disorder.

Introduction The middle meningeal artery (MMA) is an important artery in neurosurgery. As the largest branch of the maxillary artery, it provides nutrition to the meninges and to the frontal and parietal regions. Diseases, including dural arteriovenous fistula (DAVF), pseudoaneurysm, true aneurysm, traumatic arteriovenous fistula (TAVF), Moya-Moya disease (MMD), recurrent chronic subdural hematoma (CSDH), migraine, and meningioma, may be related to the MMA. The aim of the present study is to describe the anatomy of the MMA and to correlate it with brain diseases. Methods A literature review was performed using the PubMed, Scielo, Scientific Direct, Ebsco, LILACS, TripDataBase and Cochrane databases, with the following descriptors: neurosurgery, neuroanatomy, meninges and blood supply. Discussion The MMA is embedded in a cranial groove, and traumatic or iatrogenic factors can result in MMA-associated pseudoaneurysms or arteriovenous fistulas (AVFs). In hemodynamic stress, true aneurysms can develop. Arteriovenous fistulas, pseudoaneurysms, and true aneurysms can be effectively treated by endovascular or surgical removal. In MMD, the MMA plays a role in the development and in the improvement of collateral circulation. Finally, in cases of CSDH, when standard surgery and drainage fail, MMA embolization can constitute a great alternative. Conclusion The MMA is a relevant structure for the understanding of neurosurgical diseases. In conclusion, every neurosurgeon must know the anatomy of the MMA sufficiently to correlate it with the diagnosed pathology, thus obtaining treatment effectiveness and preventing brain lesion.

Epidural hematoma (EDH) can result in a catastrophic outcome of traumatic brain injury. Current management guidelines do not consider the source of hemorrhage in decision making. The purpose of this study was to examine the relationship between EDH location and the source of hemorrhage. We report retrospectively reviewed, prospectively obtained surgical data of patients with acute traumatic cranial EDH treated between 2007 and 2018. Computed tomography (CT) scans were used to categorize EDH location as lateral or medial. The source of hemorrhage was identified intraoperatively by a single surgeon. Overall, of 92 evacuated EDHs (in 87 patients), 71 (77.2%) were in the lateral location. Arterial bleeding was the cause of EDH in 63.4% of the lateral EDHs and 9.2% of the medial EDHs (P < 0.0001). In the cases where surgery was done primarily to treat EDH, 65.3% had an arterial bleed source (P < 0.0001). In those treated for primary reasons other than EDH evacuation, 75% had a venous bleed source (P = 0.002). The location of EDH correlates with the source of hemorrhage. The decision to operate on EDH may be influenced by this factor. [ABSTRACT FROM AUTHOR]

Background Recently, middle meningeal artery (MMA) embolization has emerged as a potentially safe and effective method of treating chronic subdural hematoma (cSDH). Objective To report a single-center experience with MMA embolization and examines the type of embolic material used, the extent of penetration, and the number of MMA branches embolized. Methods A retrospective analysis of all patients with MMA embolization from 2018 through 2019 was performed. A failed outcome was defined as either surgical rescue and/or greater than 10 mm of hematoma residual or reaccumulation following embolization. Results Of 35 patients, surgery had failed for 9 (26%) and initial conservative treatment had failed for 6 (17%). Of 41 MMA embolizations, including those in six patients with bilateral cSDH who underwent bilateral MMA embolization, 29 (72%) were performed using ethylene vinyl alcohol copolymer (Onyx), 7 (17%) using particles, and 5 (12%) using n-butyl cyanoacrylate. Both the anterior and posterior MMA divisions were embolized in 29 cases (71%); distal penetration of these branches was achieved in 25 embolizations (61%). Twenty-six (63%) cSDHs completely resolved. Complete resolution was seen in 22 of 29 hematomas (76%) in which both anterior and posterior MMA branches were occluded versus 4 of 12 (33%) following single-branch embolization (p=0.014). Embolization of one cSDH (2%) failed. Conclusion MMA embolization of cSDHs appears to be both safe and efficacious. Furthermore, embolization of both the anterior and posterior MMA branches may be associated with increased odds of complete resolution. [ABSTRACT FROM AUTHOR]

Background Middle meningeal artery (MMA) embolization results in fewer treatment failures than surgical evacuation for chronic subdural hematomas (cSDHs). We compared the total 1-year hospital cost for MMA embolization versus surgical evacuation for patients with cSDH. Methods Data for patients who presented with cSDHs from January 1, 2018, through May 31, 2020, were retrospectively reviewed. Patients were grouped by initial treatment (surgery vs MMA embolization), and total hospital cost was obtained. A propensity-adjusted analysis was performed. The primary outcome was difference in mean hospital cost between treatments. Results Of 170 patients, 48 (28%) underwent embolization and 122 (72%) underwent surgery. cSDHs were larger in the surgical (20.5 (6.7) mm) than in the embolization group (16.9 (4.6) mm; P<0.001); and index hospital length of stay was longer in the surgical group (9.8 (7.0) days) than in the embolization group (5.7 (2.4) days; P<0.001). More patients required additional hematoma treatment in the surgical cohort (16%) than in the embolization cohort (4%; P=0.03), and more required readmission in the surgical cohort (28%) than in the embolization cohort (13%; P=0.04). After propensity adjustment, MMA embolization was associated with a lower total hospital cost compared to surgery (mean difference -$32 776; 95% CI -$52 766 to -$12 787; P<0.001). A propensity-adjusted linear regression analysis found that unexpected additional treatment was the only significant contributor to total hospital cost (mean difference $96 357; 95% CI $73 886 to $118 827; P<0.001). Conclusions MMA embolization is associated with decreased total hospital cost compared with surgery for cSDHs. This lower cost is directly related to the decreased need for additional treatment interventions. [ABSTRACT FROM AUTHOR]

Transorbital puncture to embolize cavernous sinus (CS) dural arteriovenous fistulas (DAVF) is a useful strategy when conventional transvenous routes are inaccessible. We report a case of bilateral CS DAVF associated with bilateral middle meningeal artery (MMA) origin of ophthalmic arteries (OA) who had recently undergone transvenous coil embolization. She presented with persistent symptoms of conjunctival congestion and proptosis in the left eye. Angiogram revealed residual left CS DAVF with dilated SOV. Inferior petrosal sinus or facial vein access was not possible. Transorbital access of the SOV was planned. Cone-beam CT (CBCT) angiography was used to delineate the relationship between the variant OA and SOV and also to plan a safe trajectory. Using fluoroscopy guidance, the SOV was punctured and embolization was done using Onyx-18. CBCT is a valuable tool in planning and executing transorbital treatment of CS DAVF, especially in the setting of variant OA. [ABSTRACT FROM AUTHOR]

Background: Existent animal models of migraine are not without drawbacks and limitations. The aim of our study was to evaluate imaging photoplethysmography (PPG) as a method of assessing intracranial blood flow in rats and its changes in response to electrical stimulation of dural trigeminal afferents. Methods: Experiments were carried out with 32 anesthetized adult male Wistar rats. Trigeminovascular system (TVS) was activated by means of electrical stimulation of dural afferents through a closed cranial window (CCW). Parameters of meningeal blood flow were monitored using a PPG imaging system under green illumination with synchronous recording of an electrocardiogram (ECG) and systemic arterial blood pressure (ABP). Two indicators related to blood-flow parameters were assessed: intrinsic optical signals (OIS) and the amplitude of pulsatile component (APC) of the PPG waveform. Moreover, we carried out pharmacological validation of these indicators by determining their sensitivity to anti-migraine drugs: valproic acid and sumatriptan. For statistical analysis the non-parametric tests with post-hoc Bonferroni correction was used. Results: Significant increase of both APC and OIS was observed due to CCW electrical stimulation. Compared to saline (n = 11), intravenous administration of both the sumatriptan (n = 11) and valproate (n = 10) by using a cumulative infusion regimen (three steps performed 30 min apart) lead to significant inhibitory effect on the APC response to the stimulation. In contrast, intravenous infusion of any substance or saline did not affect the OIS response to the stimulation. It was found that infusion of either sumatriptan or valproate did not affect the response of ABP or heart rate to the stimulation. Conclusions: Imaging PPG can be used in an animal migraine model as a method for contactless assessment of intracranial blood flow. We have identified two new markers of TVS activation, one of which (APC) was pharmacologically confirmed to be associated with migraine. Monitoring of changes in APC caused by CCW electrical stimulation (controlling efficiency of stimulation by OIS) can be considered as a new way to assess the peripheral mechanism of action of anti-migraine interventions. [ABSTRACT FROM AUTHOR]

Background: Traumatic pseudoaneurysm of the middle meningeal artery (TPMMA) is uncommon. Intraparenchymal hemorrhage (IPH) caused by rupture of a TPMMA is extremely rare. Such ruptures are associated with high mortality, so an early diagnosis of this risky condition is recommended. We report a case of TPMMA giving rise to an acute IPH. Case description: A 60-year-old man suffered an IPH after a head injury. Computed tomography revealed a large hematoma in the right temporal lobe, small epidural hemorrhage in the right temporal area, and a small cerebral contusion in right frontal lobe. External carotid angiogram also demonstrated a suspicious TPMMA in right side, which was treated successfully by surgery. We observed rapid epidural bleeding from the base of the temporal bone during bone removal and a 2 cm linear dural tear beneath a temporal skull fracture. And we identified that the TPMMA was connected to the IPH via the dural tear. These findings indicate one mechanism for an acute IPH development caused by a TPMMA. Conclusion: Acute IPH caused by rupture of a TPMMA is rare. A rupture of TPMMA contacted with dural tear could cause IPH via this dural defect. Clinicians should suspect this clinical manifestation, which can be an emergency.

The middle meningeal artery is a proposed surrogate marker for activation of trigeminal nociceptors during migraine. Previous studies focused on the extracranial part of the artery; hence, vasoreactivity in the intradural arteries during migraine is unknown. Thirty-four patients with migraine without aura were given sildenafil on one day and calcitonin gene-related peptide on another in double-blind crossover fashion. Patients were scanned with 3.0 T MR angiography before drug administration and again 6 hours later during induced attacks of migraine. We measured circumference of the intradural segment of the middle meningeal artery before and during induced migraine attacks. The middle cerebral and superficial temporal arteries were also examined. Fourteen patients had attacks during the second scan after both study drugs and 11 had a migraine after either one or the other, resulting in a total of 39 attacks included in the final analysis. Mean circumference of the intradural middle meningeal artery at baseline was 3.18 mm with an increase of 0.11 mm during attacks (P = 0.005), corresponding to a relative dilation of 3.6% [95% CI: 1.4%-5.7%]. Middle cerebral artery dilated by 9.4% [95% CI: 7.1%-11.7%] and superficial temporal artery by 2.3% [95% CI: 0.2%-4.4%]. Our study shows that the intradural middle meningeal artery and the middle cerebral artery are dilated during migraine induced by calcitonin gene-related peptide as well as sildenafil. We propose that intradural vasculature is affected by migraine-driven activation of trigeminal afferents during migraine attacks. [ABSTRACT FROM AUTHOR]

Background Middle meningeal artery (MMA) embolization is an emerging therapy for the resolution of subacute or chronic subdural hematoma (CSDH). CSDH patients are often elderly and have several comorbidities. We evaluated our experience with transradial access (TRA) for MMA embolization using predominantly Onyx under conscious sedation. Methods Data for consecutive patients who underwent transradial MMA embolization for CSDH during a 2-year period (2018-2019) were analyzed from a singlecenter, prospectively-maintained database. Patient demographics, comorbidities, ambulatory times, subdural hematoma resorption status, and guide catheter type were recorded. Conversion to femoral access and complication rates were also recorded. Univariate and multivariate analyses were performed. results Forty-six patients (mean age, 71.7±14.4 years) were included in this study. Mean CSDH size was 14±5.5 mm. Most (91.3%) Tra embolizations were performed with 6-French 0.071-inch Benchmark guide catheters (Penumbra). MMA embolization was successful in 44 patients (95.7%) (including two cases of Tra conversion). Twenty-one (48%) patients had a severe Charlson Comorbidity index (>5). symptomatic improvement was noted in 39 of 44 patients (88.6%). Mean length of stay was 4±3 days. Patients were ambulated immediately postprocedure. at mean follow-up (8±4 weeks), 86.4% of patients had complete or partial CSDH resolution. Persistent use of antiplatelet agents after the procedure was associated with failed or minimal CSDH resorption (5 of 6, 83.3% vs 9 of 38 23.7% with complete or near-complete resolution; P=0.009). Conclusion Transradial Onyx MMa embolization under conscious sedation is safe and effective for CSDH treatment. Tra may be especially useful in elderly patients with numerous comorbidities. [ABSTRACT FROM AUTHOR]

background embolization of the middle meningeal artery (MMA) has emerged as a potential treatment of chronic subdural hematomas (CSDHS). Objective To evaluate the impact on recurrence rate of postsurgical embolization of CSDH in patients with a higher than average risk of recurrence. Methods a monocentric retrospective study was performed on retrospectively collected data. From March 2018 to December 2019, embolization of the MMA was proposed as an adjunct postoperative treatment after burr-hole surgery in patients operated for a recurrent CSDH or a CSDH with an independent recurrence risk factor, including antiplatelet therapy, full anticoagulation therapy, coagulation disorder, hepatopathy, or chronic alcoholism. Patients who had undergone postoperative embolization were compared with a historic group of patients operated between March 2016 and March 2018, selected based on the same inclusion criteria. Results During the study period, 89 patients (with 74 unilateral and 15 bilateral CSDHS) were included and underwent an embolization procedure, leading to 91 out of a total of 104 MMA being embolized (88%). These were compared with 174 patients (138 unilateral and 36 bilateral CSDH) in the historic control group. One major procedure-related adverse event was registered. Four of the 89 patients (4%) required surgery for a CSDH recurrence in the embolization group, significantly less than the 24 of 174 patients (14%) in the control group (Or=0.28, 95% ci 0.07 to 0.86, p=0.02). Conclusions Postsurgical embolization of the MMA may reduce the recurrence rate of CSDHS with a risk factor of recurrence. [ABSTRACT FROM AUTHOR]

Traumatic arteriovenous fistulas (AVFs) involving the external carotid artery are exceedingly rare in young adults. Since an AVF is the most common life-threatening cause for pulsatile tinnitus (PT), meticulous evaluation and treatment of patients with PT is crucial. Here, we present two traumatic AVF cases treated with coil embolization leading to no residual fistulous connections followed by an immediate and complete resolution of PT. A 20-year-old man developed left ear tinnitus three months after a traumatic brain injury involving the right temporal bone fracture. Cerebral angiography demonstrated an enlarged left middle meningeal artery (MMA) and a fistular point at the posterior branch of the MMA draining to the middle meningeal vein (MMV) and the left pterygoid plexus, suggesting an AVF. Another 18-year-old girl developed left tinnitus, left exophthalmos, and conjunctival injection 6 months after a traffic accident involving no demonstrable abnormal findings in the radiologic exam. Magnetic resonance angiography demonstrated a markedly dilated left MMA draining to the MMV, left cavernous sinus, and left superior ophthalmic vein. In both cases, coil embolization was performed with total obliteration of the fistular point. [ABSTRACT FROM AUTHOR]