Internal Carotid Research Articles

Preclinical Experimental Study on New Cervical Implant Design to Improve Peri-Implant Tissue Healing

Objectives: In this preclinical study, we used an experimental rabbit model to investigate the effects of a new implant design that involves specific changes to the cervical portion, using a conventional implant design in the control group. Materials and Methods: We used 10 rabbits and 40 dental implants with two different macrogeometries. Two groups were formed (n = 20 per group): the Collo group, wherein implants with the new cervical design were used, which present a concavity (reduction in diameter) in the first 3.5 mm, the portion without surface treatment; the Control group, wherein conical implants with the conventional design were used, with surface treatment throughout the body. All implants were 4 mm in diameter and 10 mm in length. The initial implant stability quotient (ISQ) was measured immediately after the implant insertion (T1) and sample removal (T2 and T3). The animals (n = five animals/time) were euthanized at 3 weeks (T1) and 4 weeks (T2). Histological sections were prepared and the bone–implant contact (BIC%) and tissue area fraction occupancy (TAFO%) percentages were analyzed in the predetermined cervical area; namely, the first 4 mm from the implant platform. Results: The ISQ values showed no statistical differences at T1 and T2 (p = 0.9458 and p = 0.1103, respectively) between the groups. However, at T3, higher values were found for the Collo group (p = 0.0475) than those found for the Control group. The Collo samples presented higher BIC% values than those of the Control group, with statistical differences of p = 0.0009 at 3 weeks and p = 0.0007 at 4 weeks. There were statistical differences in the TAFO% (new bone, medullary spaces, and the collagen matrix) between the groups at each evaluation time (p < 0.001). Conclusions: Considering the limitations of the present preclinical study, the results demonstrate that the new implant design (the Collo group) had higher implant stability (ISQ) values in the samples after 4 weeks of implantation. Furthermore, the histomorphometric BIC% and TAFO% analyses showed that the Collo group had higher values at both measurement times than the Control group did. These findings indicate that changes made to the cervical design of the Collo group implants may benefit the maintenance of peri-implant tissue health.

High wall shear stress is related to complicated AHA lesion type VI plaques in mild to moderate internal carotid artery stenosis - a 3D cardiovascular MRI study.

Complicated American Heart Association (AHA) lesion type VI plaques (cCAPs), characterized by the presence of intraplaque hemorrhage, surface defect or thrombus, are strongly associated with ischemic stroke and stroke recurrence. Hemodynamics seem to play a relevant role for their development. Thus, we investigated the association of 4D flow-MRI derived local wall shear stress (WSS) and oscillatory shear stress (OSI) with the presence of cCAPs in patients with mild to moderate internal carotid artery (ICA) stenosis. From a prospective and consecutive cross-sectional study with 121 patients with high cardiovascular risk, 39 patients (49 carotid arteries) demonstrated a 10-50% ICA-stenosis and were included in this analysis. Plaque composition was determined according to the modified AHA classification of lesions by high-resolution multi-contrast 3T-MRI. We determined WSS (minimum, mean and maximum) and OSI in vivo by 4D flow-MRI at different locations within the stenosis (upstream, stenosis center and downstream). We studied the association of each hemodynamic parameter with the presence cCAPs by logistic regression analysis adjusted for age, sex and plaque thickness. 11 (22.4%) of the 49 ICA-stenosis in our cohort showed cCAP. WSS and OSI at the beginning of the stenosis did not differ between complicated and stable plaques. By contrast, WSS was significantly higher in the stenosis center and poststenotic region in cCAPs. OSI was significantly higher in the stenosis center of stable plaques. Logistic regression analysis revealed a significant association for WSSmean (OR per SD increase 1.97, 95%-CI 1.14-3.39, p=0.015) and for WSSmax (OR per SD increase 1.84; 95%-CI 1.10-3.08; p=0.020), but not for WSSmin and OSI with the presence of cCAPs. Higher wall shear stress in ICA stenosis was significantly associated with the presence of cCAPs underlining the potential role of hemodynamics in their development. cCAP, complicated carotid artery plaque; WSS, wall shear stress; OSI, oscillatory shear index.

Prolonged intracranial catheter dwell time exacerbates penumbral stress and worsens stroke thrombectomy outcomes

BackgroundThe duration of mechanical thrombectomy (MT) is a negative predictor of outcomes in acute ischemic stroke (AIS), yet the precise mechanisms are unclear. We investigated whether the placement of large-bore...

SURGICAL RESECTION OF A COMPLEX TUBERCULUM SELLAE MENINGIOMA ENCASING MAJOR ARTERIES

Introduction Though constituting only a minor proportion (1%) of sellar masses, suprasellar meningiomas pose a significant diagnostic challenge within the region of sellar and suprasellar tumors. Pituitary adenomas, at nearly 90% prevalence, dominate this anatomical region. Distinguishing these two entities is paramount, as both clinical presentation and, to some extent, biochemical profiles exhibit notable overlap. Accurate preoperative differentiation is critical due to the contrasting behaviors of these tumors. Meningiomas, with their robust vascularity supplied by dural and osseous arteries, present a heightened risk of intraoperative hemorrhage. Clinical Case A 53-year-old woman presented with a two-month history of worsening headaches and gradual vision loss. Neurological examination revealed only visual acuity decline. Her hormone profile showed elevated prolactin but lacked clinical features of prolactin excess, suggesting a possible prolactin-secreting pituitary macroadenoma. A contrast-enhanced MRI confirmed a significant sellar and suprasellar mass with homogeneous enhancement, extending to the right paramedian region and encasing the right internal carotid artery (ICA) at its critical segment involving the cavernous and supraclinoid portions. Furthermore, the right middle meningeal artery (M1) and anterior cerebral artery (A1) originated from this same location, highlighting the high surgical risk. Surgical resection was deemed necessary. The patient underwent a right pterional craniotomy, revealing a grayish, extradural soft mass lesion encasing the ICA bifurcation. Careful microsurgical dissection with basal devascularization was performed, followed by near-complete tumor removal using an ultrasonic aspirator to minimize damage to the encased arteries. Postoperative follow-up CT scan confirmed successful near-total tumor ablation. Conclusion This case underscores the critical role of meticulous preoperative diagnosis in managing complex sellar tumors. While pituitary adenomas dominate this region, suprasellar meningiomas, despite their rarity, demand a high index of suspicion. Overlapping clinical and biochemical presentations highlight the reliance on advanced imaging for accurate differentiation. The intricate vascularity of meningiomas, as exemplified by the encasement of critical arteries in this case, necessitates meticulous surgical technique with devascularization strategies. This successful near-complete tumor removal emphasizes the importance of such surgical expertise in navigating these diagnostically challenging sellar lesions.

INTRACRANIAL ANEURYSMS IN CHILDREN - A NEW PERSPECTIVE

Introduction Intracranial aneurysms in children are very rare pathologic entities. (1200 cases presented in literature from 1939-2011). Material and Methods The authors present 51 cases of children (aged: 0-16) operated between January 1999 and December 2023 - 24 years in three neurosurgical centers: “Bagdasar Arseni” Emergency University Hospital (Bucharest), Sanador Clinical Hospital (Bucharest) and Timis County Emergency Hospital (Timisoara). We collected data from many children’s intracranial aneurysms cases because “Bagdasar-Arseni” Emergency University Hospital has the most important pediatric neurosurgical unit in the country. Regarding our series, pediatric aneurysms represent 6.14% (51 cases) of all operated intracranial aneurysms (765 cases). The mean age of the patients was 14.3 years. There were 29 boys (58.7%) and 22 girls (41.2%). The clinical features are dominated by headache (48 cases - 95.7%), neck stiffness (45 cases - 91.4%), vomiting (44 cases - 89.3%), focal neurological deficit (24 cases - 44.6%), an altered level of consciousness (17 cases - 36.1%), seizures (24 cases - 44.6%, fever (20 cases - 34%). The majority of patients were Hunt & Hess Il at admittance (27 cases, 53%). All neuroimagistic investigations were done in the first 48 hours (CT, DSA, MRI). Locations: anterior communicating artery aneurysms (20 cases, 36.1%), followed by middle cerebral artery aneurysms (15 cases, 25.5%) and internal carotid artery bifurcation aneurysms (9 cases, 19.1%) and so on. Many aneurysms were large and giant (18 cases - 31.9%). Microsurgery approach was performed in 48 cases (99.7%) and 3 case (4.4%) were endovascular approached. This represents a new vision because the actual endovascular way is extremely efficient and performant in occluding pediatric intracranial aneurysms. The Glasgow Outcome Scale (GOS) at six months postop. showed GR in 40 cases (78.5%), MD in 9 cases (17.2%), SD in 1 patient (2.1%) and (preoperative) death in 1 patient (2.1%). Conclusions Intracranial aneurysms in children are a very rare pathologic entity. Early microsurgical or endovascular approach is mandatory and has excellent results (good recovery).

Endothelial progenitor cell-derived conditioned medium mitigates chronic cerebral ischemic injury through macrophage migration inhibitory factor-activated AKT pathway.

Chronic cerebral ischemia (CCI) is a significant health issue characterized by hypoperfusion due to damage or occlusion of the cerebral or carotid arteries. CCI may lead to progressive cognitive impairment that is considered as a prelude to neurodegenerative diseases, including dementia and Alzheimer's disease (AD). Endothelial progenitor cells (EPCs) have been implicated in vascular repair in ischemic cerebrovascular diseases, primarily by differentiating into endothelial cells (ECs) or through paracrine effects. However, the clinical transplantation of stem cell therapies remains limited. In this study, we investigated the effects of EPC-derived conditioned medium (EPC-CM) on the impaired vasculature and neurological function in a rodent model of CCI and the mechanism involved. EPC-CM was analyzed by cytokine array to identify key factors involved in angiogenesis and cellular senescence. The effects and mechanism of the candidate factors in the EPC-CM were validated in vitro using oxygen-glucose deprivation (OGD)-injured ECs and EPCs. The therapeutic effects of EPC-CM and the identified key factor were further examined in a rat model of CCI, which was induced by bilateral internal carotid artery ligation (BICAL). EPC-CM was administered via intracisternal injection one week post BICAL. The cerebral microvasculature and neurobehavior of the rats were examined three weeks after BICAL. Macrophage migration inhibitory factor (MIF) was identified as a key factor in the EPC-CM. Recombinant MIF protein promoted angiogenesis and prevented senescence in the injured EPCs and ECs. The effect was similar to that of the EPC-CM. These therapeutic effects were diminished when the EPC-CM was co-treated with MIF-specific antibody (Ab). Additionally, the vascular, motor, and cognitive improvements observed in the BICAL rats treated with EPC-CM were abolished by co-treated with MIF Ab. Furthermore, we found MIF promoted angiogenesis and anti-senescence via activating the AKT pathway. Inhibition of the AKT pathway diminished the protective effects of MIF in the in vitro study. We demonstrated that EPC-CM protected the brain from chronic ischemic injury and promoted functional recovery through MIF-mediated AKT pathway. These findings suggest EPC-CM holds potential as a novel cell-free therapeutic approach for treating CCI through the actions of MIF.

Cerebral Arterial Inflow and Venous Outflow Assessment Using 4D Flow MRI in Adult and Pediatric Patients

Background and Purpose: The cerebral circulation is highly regulated to maintain brain perfusion, keeping an equilibrium between the brain tissue, cerebrospinal fluid (CSF) and blood of the arterial and venous systems. Cerebral venous drainage abnormalities have been implicated in multiple cerebrovascular diseases. The purpose of this study is to evaluate the relationship between the arterial inflow (AI) and the cerebral venous outflow (CVO) and their correlation with the cardiac outflow in healthy adults and children to understand the role of the emissary veins in normal venous drainage. Materials and Methods: A total of 31 healthy volunteers (24 adults (39.5 ± 16.0) and seven children (3.4 ± 2.2)) underwent intracranial 4D flow with full circle of Willis coverage and 2D PC-MRI at the level of the transverse sinus for measurement of the AI and CVO, respectively. The AI was calculated as the sum of the flow values in the bilateral internal carotid and basilar arteries. The CVO was calculated as the sum of the flow values in the bilateral transverse sinuses. The cardiac outflow was measured via 2D PC-MRI with retrospective ECG gating with images acquired at the proximal ascending aorta (AAo) and descending (DAo) aorta. The ratios of the AI/AAo flow and CVO/AI were calculated to characterize the fraction of cerebral arterial inflow in relation to cardiac outflow and venous blood draining through the transverse sinuses, respectively. Results: The AI and CVO were significantly correlated (r = 0.81, p < 0.001). The CVO constituted approximately 60–70% of the AI. The CVO/AI ratio was significantly lower in children versus adults (p = 0.025). In adults, the negative correlation of the AI with age remained strong (r = −0.81, p < 0.001). However, the CVO was not significantly associated with age. Conclusion: The CVO/AI ratio suggests an important role of the emissary veins, accounting for approximately 30–40% of venous drainage. The lower CVO/AI ratio in children, although partially related to decreased AI with age, suggests a greater role of the emissary veins in childhood, which strongly decreases with age.

Case Report: Delayed Cerebral Ischemia with Infarction following an Undiagnosed Aneurysmal Rupture - The Diagnostic and Management Challenge

Delayed Cerebral Ischemia (DCI) typically occurs a few days after a patient suffers subarachnoid hemorrhage and can lead to a range of poor outcomes. It is primarily driven by vasospasm and its delayed and variable presentation complicates diagnosis and treatment. Here we report a case of DCI in a 31-yearold man who presented with acute onset aphasia, right-sided weakness, and difficulty swallowing. He had experienced a severe headache accompanied by nausea and vomiting 5 days prior, with an initial NIH stroke scale score of 10. Imaging revealed a left internal carotid artery aneurysm and a watershed infarct between the anterior cerebral artery and middle cerebral artery. The patient was treated with aneurysmal coiling, intraarterial verapamil, and oral nimodipine for suspected DCI secondary to subarachnoid hemorrhage. Close monitoring of the patient and treatment led to the resolution of neurological deficits over the subsequent days., with imaging confirming reperfusion. This case presents a unique challenge due to the delayed presentation and vague history. Diagnosis and treatment of DCI following aneurysmal rupture are complicated due to its delayed and variable onset. It is crucial to consider acute aneurysmal subarachnoid hemorrhage and DCI when evaluating patients who present with multiple stroke-like symptoms over several days as the management and prognosis differ from other cases of acute ischemic stroke.

Abstract 4118076: Right Innominate Artery Endovascular Intervention Via Single Radial Access and Use Of Embolic Protection

Introduction: The occurrence of innominate artery stenosis is less prevalent compared to subclavian artery disease. Small studies suggest up to 8% of individuals initially diagnosed with suspected subclavian steal syndrome may present with innominate artery lesions. Deployment of an embolic protection filter within the internal carotid artery during percutaneous intervention of the innominate artery presents a solution to mitigate embolism. Case: A 70-year-old female with a history of peripheral vascular disease presented with claudication in both arms, manifested as pain in both arms. Her left subclavian was stented months prior to presentation. An aortogram revealed severe stenosis of the innominate artery (Figure 1). Since multiple attempts to cross the lesion antegrade from the femoral access site were unsuccessful, we proceeded with the successful deployment of an embolic protection filter in the right internal carotid artery via our right radial artery access site (Figure 2). Using the right radial artery, we passed a long run-through guidewire into the distal abdominal aorta. Due to severe aortic tortuosity, we were unable to snare the wire from the aorta. Therefore, we upsized the radial sheath to 7 French over both wires (runthrough and bare). Using a support catheter, we exchanged the runthrough wire for a Glidewire Advantage. We advanced an 8 x 29mm balloon expandable stent to the area of innominate stenosis and deployed it (Figure 3). We postdilated the stent with a 14mm balloon. Angiography demonstrated adequate expansion. On follow up, the patient was without claudication and had triphasic flow in the innominate and left subclavian arteries. Discussion: Treating innominate artery stenosis via radial access employing a sole entry point for both embolic protection and treatment administration offers a substitute where additional access is infeasible. Modern embolic protection techniques are superior due to their flexibility and ease of use. In this case, placing the embolic protection device in the carotid artery was mandatory through the sole radial access to prevent trapping the filter behind the innominate artery stent. We were able to perform both the embolic device placement and the stenting with the same radial access. Conclusion: Endovascular intervention of innominate artery stenosis via radial access, utilizing a single radial access for both embolic protection and treatment delivery, presents an alternative when femoral access is not feasible.

Correlation between nova volume flow rate and TOF signal intensity ratio: value in unilateral internal carotid artery occlusion.

Non-invasive optimal vessel analysis quantitative magnetic resonance angiography (NOVA-QMRA) has emerged as a valuable tool to characterize cerebral hemodynamics in intracranial atherosclerotic disease (ICAD). Our aim was to explore the eventual correlation between volume flow rate (VFR) measured via NOVA-QMRA and signal intensity ratio (SIR) of time-of-flight (TOF) MRA in M1- and P2-segments bilaterally in patients with unilateral internal carotid artery (ICA) occlusion. Patients with acute, subacute or chronic unilaterall ICA occlusion receiving NOVA-QMRA between June 2019 and June 2021 were retrospectively included. In bilateral M1- and P2-segments VFR was assessed by means of NOVA-QMRA and a region of interest (ROI) was selected to measure TOF SIR. A correlation between TOF SIR and VFR was tested by means of Pearson correlation coefficient. Mean difference of TOF SIR and VFR between ipsilateral (to occluded ICA) and contralateral M1- and P2-segments was analyzed using a two-sided Welch's t test. Fifty-five patients with unilateral ICA occlusion were included (acute: 28; subacute: 8; chronic: 19). Both ipsilateral (r = 0.536, p < 0.001) and contralateral (r = 0.757, p < 0.001) TOF SIR correlated significantly with NOVA VFR. This observation proved especially true for patients with chronic ICA occlusion. Both VFR (165.18 vs 110.60, p < 0.001) and TOF SIR (4.96 vs 2.70, p < 0.001) were higher in contralateral than ipsilateral M1-segments; whereas, the contrary was observed for P2-segments (VFR 72.35 vs 102.12, p < 0.001, TOF SIR 2.87 vs 3.39, p = 0.016). The study results showed that TOF SIR significantly correlated with phase-contrast derived flow volume in patients with symptomatic ICA occlusion. This correlation remains the same regardless of the stage of the ischemic stroke (acute vs subacute vs chronic). Furthermore, significantly high VFR and TOF SIR in ipsilateral P2-segments may provide evidence of leptomeningeal collateralization in acute patients. Standardly performed TOF SIR Sequences might be of help for a qualitative evaluation of the flow in M1- and P2-segments in patients with unilateral ICA occlusions. NOVA QMRA allows precise quantitative measurements of the flow in cerebral vessels.

Abstract 4122092: Carotid plaque progression predicts persistent endothelial dysfunction in an infarct-related coronary artery in STEMI survivors

Background and Aim: Persistent coronary endothelial vasomotor dysfunction predicts future coronary events; however, performing multiple invasive endothelial function tests is difficult in actual clinical practice. This study examined whether carotid plaque changes can predict persistent coronary endothelial dysfunction using serial assessments of the coronary vasomotor response to acetylcholine (ACh) in the infarct-related artery (IRA) among patients with ST-elevation acute myocardial infarction (STEMI). Methods: This study included 169 consecutive patients with a first acute STEMI due to the left anterior descending coronary artery (LAD) occlusion who underwent successful reperfusion therapy with percutaneous coronary intervention. The vasomotor response to ACh in the LAD was measured within two weeks of acute myocardial infarction (AMI) (first test) and repeated at six months (second test) after AMI under optimal anti-atherosclerotic therapy. Ultrasonography of the bilateral common carotid artery (CCA) and internal carotid artery (ICA) was performed during the acute phase, and the thickest intima media thickness (IMT) of either artery was measured as the maximum IMT. After six months, the IMT at the site of maximal IMT was measured to determine whether there was an increase or decrease in IMT. Results: Finally, 87 STEMI patients analyzed in this study. At 6 months, 25 patients (28.7%) showed carotid plaque progression. In a multivariable adjusted analysis, carotid plaque progression was identified as an independent predictor of persistent coronary endothelial dysfunction, both in terms of coronary diameter response [OR 3.22, 95% confidence interval1.13 - 9.15, P = 0.03] and coronary flow response [OR 2.65, 95% confidence interval 1.01 - 7.00, P = 0.04]. Conclusions: Carotid plaque progression could independently predict persistent endothelial vasomotor dysfunction in the IRA of STEMI survivors.

Co-administration of dexmedetomidine with total intravenous anaesthesia in carotid endarterectomy reduces requirements for propofol and improves haemodynamic stability: A single-centre, prospective, randomised controlled trial.

Total intravenous anaesthesia guided by electroencephalography and neurophysiological monitoring may be used for carotid endarterectomy. Reduction of brain metabolic demand during cross-clamping of the internal carotid artery with propofol titrated to burst suppression requires effect-site concentrations that may delay emergence and interfere with intraoperative neurophysiological monitoring. To test the hypothesis that dexmedetomidine decreases the effect-site concentration of propofol required for burst-suppression in patients undergoing carotid endarterectomy. Randomised controlled trial. Patients undergoing carotid endarterectomy. University Hospital of Berne, Switzerland, from October 2018 to September 2024. Patients were randomised into a control (n = 23) and a dexmedetomidine groups (n = 22). Total intravenous anaesthesia was administered to both groups. Patients in the dexmedetomidine group received an intravenous bolus of dexmedetomidine (0.4 μg kg-1 over 10 min) before induction, followed by a continuous intravenous infusion (0.4 μg kg-1 h-1). The effect-site concentrations of propofol were titrated against frontal electroencephalography parameters. Burst suppression was induced with propofol during cross-clamping of the internal carotid artery. The primary outcome was the effect-site concentration of propofol required for burst-suppression. The secondary outcomes were the requirement for vasoactive substances, neurophysiological monitoring parameters, and postoperative delirium. The effect-site concentration of propofol required for burst suppression was 4.0 μg ml-1 [3.50 to 4.90] (median [interquartile range]) in the dexmedetomidine group compared with 6.0 μg ml-1 [5.5 to 7.3] in the control group (P < 0.001). Less norepinephrine was required in the dexmedetomidine group (total 454 μg [246 to 818] compared with 1000 μg [444 to 1326] (P = 0.015) in the control group). Dexmedetomidine did not affect intraoperative neurophysiological monitoring. Co-administration of dexmedetomidine to total intravenous anaesthesia for carotid endarterectomy decreased the effect-site concentrations of propofol required for burst suppression by 33%. The propofol-sparing effect and peripheral alpha-agonism of dexmedetomidine may explain the reduced requirement for vasopressors. Clinicaltrials.gov identifier: NCT04662177.

Management of internal carotid artery pathology with a covered stent: illustrative cases.

Endovascular treatment of internal carotid artery (ICA) pathology includes reconstructive or deconstructive options. One reconstructive option is covered stent placement, although this is limited by a lack of devices designed specifically for neurointervention. The PK Papyrus is a balloon-mounted covered coronary stent that has a lower profile and is more flexible than other stent grafts, which makes it more suitable for treating ICA lesions. The PK Papyrus was used to treat patients with iatrogenic cavernous ICA injury and symptomatic cervical ICA pseudoaneurysms. In both cases, the stent could be easily delivered without the use of an intermediate catheter or stiff microwire. Stent deployment resulted in immediate angiographic resolution of the pathology, and there were no peri- or postoperative complications. The PK Papyrus covered coronary stent is a good option for treating cervical and cavernous carotid pathology. Its single-layer design makes it more flexible and deliverable than other stent grafts, but additional case series are needed. https://thejns.org/doi/10.3171/CASE24517.

Complement Molecule C3a Exacerbates Early Brain Injury After Subarachnoid Hemorrhage by Inducing Neuroinflammation Through the C3aR-ERK-P2X7-NLRP3 Inflammasome Signaling Axis.

An important aspect of the pathophysiology of early brain damage (EBI) after subarachnoid hemorrhage (SAH) is inflammasome-mediated neuroinflammation. It has been demonstrated that C3aR activation exacerbates neuronal damage in a number of neurological disorders. This study aims to explore the role of C3a in activating the NLRP3 inflammasome and exacerbating neuroinflammation after SAH. Preprocessing of RNA-seq transcriptome datasets using bioinformatics analysis, and screening of differentially expressed genes between SAH patients and healthy individuals from the GEO database. Internal carotid artery puncture was performed to establish SAH models in rats and mice. SAH grading, neurological scoring, brain water content, behavioral analysis, and assessments using ELISA, Western blot, immunofluorescence, and immunohistochemistry were conducted. An in vitro model of SAH was induced in BV-2 cells treated with heme (200μM). The mechanism of C3a in post-SAH neuroinflammation was studied by interfering with and inhibiting C3aR. Results showed that the expression of C3aR was upregulated in the GEO dataset (serum of SAH patients) and identified as a key differential gene in SAH. Further, elevated levels of C3a were found in the cerebrospinal fluid of clinically collected SAH patients. In the cerebral cortex and/or serum of SAH rats, expression of C3a, IL-1β, IL-6, TNF-α, CD11b, and Ki67 were significantly increased, while IL-10 was significantly decreased. Correlation analysis revealed that C3a showed negative correlation with IL-10 and positive correlation with IL-1β, IL-6, TNF-α, CD11b, and Ki67. After stimulation with heme, protein levels of C3a increased in BV-2 cells. Interfering with C3aR significantly reduced LDH release, IL-1β secretion, Caspase1 activation, levels of NLRP3 expression and ASC oligomerization, and ATP release after heme stimulation in BV-2. Subsequently, the addition of inhibitors of ERK1/2 phosphorylation demonstrated that C3a promotes ATP efflux by activating ERK1/2 phosphorylation, thereby activating P2X7. Further addition of JNJ-55308942 (a P2X7R antagonist) revealed that C3a activated the NLRP3 inflammasome via P2X7. Finally, administering SB290157 (a C3aR inhibitor) in vivo effectively alleviated brain edema, reduced mortality, improved Garcia score, ameliorated motor dysfunction, and suppressed inflammation and NLRP3 inflammasome activation in mice after SAH. Overall, C3a exacerbates EBI-associated NLRP3 inflammasome and neuroinflammation via the C3aR-ERK-P2X7 pathway after SAH. Inhibiting C3aR may serve as a one possible treatment approach to alleviate SAH after EBI.

RADT-41. RADIOSURGERY FOR GLOMUS TUMORS: IMPACT OF MRI-PET FUSION ON TREATMENT PLANNING AND OUTCOMES

Abstract Paragangliomas present a challenge for stereotactic radiosurgery (SRS) treatment planning, particularly regarding the delineation of tumor boundaries. We propose that integrating 68Ga-DOTATATE PET scans alongside MRI in SRS planning will facilitate superior target identification and tumor coverage compared to reliance on MRI alone. A retrospective analysis of 9 patients diagnosed with paraganglioma who underwent MRI and 68Ga-DOTATATE PET imaging over a 20-month period was conducted. Images were imported into GammaPlan treatment planning software, partitioned into separate sessions: one with MRI and another with MRI-PET fusion. A single evaluator contoured paragangliomas as gross tumor volume (GTV) initially using MRI alone and subsequently with PET/MRI fusion. The pre- and post-PET fusion GTV volumes were compared. The standard deviation of the percentage increases in volume was calculated to assess variability across the sample. Of included 9 patients, 7 were females and median age was 58.3 years. Four patients had prior surgery. Seven patients were treated with Gamma Knife, while 2 with LINAC. Two patients were treated with single fraction SRS while 7 with hypofractionated SRS. Across all treated patients (n=9), GTV volumes significantly increased with PET fusion, with an average volume increase of 26.02% (n=8). One patient reported dryness of throat after SRS. Significant PET avidity over structures like temporal bone, internal jugular vein, petrous internal carotid artery and sigmoid sinus-IJV junction were included in PET/MRI fusion GTVs, which were missed on isolated MRI contours. At median 6-month follow up, all patients had a stable radiological response. Integration of 68Ga-DOTATATE PET scans with MRI enhances the visualization of paragangliomas in patients undergoing SRS. Further extensive studies are warranted to validate this observation and to better understand the variability in treatment response observed across the patient population. Our practice has initiated routine utilization of DOTATATE-PET imaging in paraganglioma patients undergoing SRS planning.

Neuroprotective Effects of Rapid Local Ischemic Postconditioning in Successful Endovascular Thrombectomy Patients.

We aim to assess the efficacy of rapid local ischemic postconditioning (RL-IPostC) following successful reperfusion in patients with acute ischemic stroke with anterior circulation large vessel occlusion who underwent endovascular thrombectomy. We conducted an ambidirectional cohort study with 78 prospectively enrolled patients with RL-IPostC and endovascular thrombectomy and 129 retrospectively enrolled patients with endovascular thrombectomy. The RL-IPostC procedure involved 5 cycles of 15-s balloon inflation and deflation in the ipsilateral internal carotid artery. The primary outcome was functional independence, defined as a modified Rankin Scale score of 0 to 2. Secondary outcomes included excellent outcomes (modified Rankin Scale score, 0-1) and early therapeutic response. Imaging outcomes involved infarct volume changes and cerebral edema measurements. Outcomes were compared with postpropensity score matching (1:1) and assessed using univariable and multivariable regression models. In the matched cohort of 136 patients (mean age, 71±14 years; 70 men [51%]), RL-IPostC was associated with a higher rate of functional independence (adjusted odds ratio, 2.47 [95% CI, 1.10-5.68]; P=0.030). The RL-IPostC group exhibited significantly reduced infarct volumes at 24 hours (difference, -12.2 [95% CI, -23.9 to -0.53]; P=0.041) and less infarct growth (difference, -12.2 [95% CI, -23.9 to -0.45]; P=0.042). Furthermore, RL-IPostC correlated with lower increases in net water uptake (difference, -0.04 [95% CI, -0.07 to -0.01]; P=0.018), lower decrease cerebrospinal fluid volume (difference, -7.75 [95% CI, -11.7 to -3.84]; P<0.001), and reduced midline shift at 24 hours (difference, -1.39 [95% CI, -2.48 to -0.30]; P=0.013). RL-IPostC tends to promote functional independence and reduces infarct growth and cerebral edema in patients with acute ischemic stroke post-reperfusion.

Quantitative Evaluation of Enamel Thickness in Maxillary Central Incisors in Different Age Groups Utilizing Cone Beam Computed Tomography a Retrospective Analysis

Background/Objectives: The presence of enamel on the tooth surface is crucial for the long-term success of minimally invasive adhesive restorations such as dental veneers. Our study aims to evaluate the enamel thickness in the incisal, middle, and cervical portions of the labial surface of the upper central incisors using cone beam computed tomography (CBCT). This imaging method provides detailed and accurate three-dimensional images with a low radiation dose, allowing an accurate assessment of enamel thickness. The analysis aims to identify variations in enamel thickness depending on the age and different levels of the labial tooth surface. Methods: 800 CBCT scans performed for diagnostic or therapeutic purposes on patients aged 18–60 years were analyzed. The data were gathered from the imaging archives of private practitioners from Targu Mures and the “George Emil Palade” University of Medicine, Pharmacy, Science, and Technology of Targu Mures. Enamel thickness measurements were conducted using the OnDemand3D Communicator CBCT evaluation program, with subsequent statistical analysis performed using GraphPad Instat Prism software. Results: Results showed significant variation in enamel thickness between the incisal, middle, and cervical segments of the labial surface of the upper central incisors. A decrease in enamel thickness with age has been observed. In patients aged 18–40, mean values of enamel thickness 1 mm and 3 mm above the cementoenamel junction (CEJ) were 0.48 ± 0.092, respectively, 0.819 ± 0.158. In patients over 40, the mean values were 0.454 ± 0.116 and 0.751 ± 0.067 at 1 mm, respectively, 3 mm above the CEJ. Statistically significant differences were found between the two age groups at 1 mm and 3 mm above the CEJ, with p &lt; 0.0001 and p = 0.0214. Conclusions: A statistically significant decrease can be observed in enamel thickness in almost the entire labial surface of the upper central incisors with aging. The varied thickness of the enamel at different tooth levels requires individualized planning for each patient to maximize the long-term aesthetic and functional results.

Clinical efficacy of DSA-based features in predicting outcomes of acupuncture intervention on upper limb dysfunction following ischemic stroke

Background and objectivesThis study aimed to employ machine learning techniques to predict the clinical efficacy of acupuncture as an intervention for patients with upper limb motor dysfunction following ischemic stroke, as well as to assess its potential utility in clinical practice.MethodsMedical records and digital subtraction angiography (DSA) imaging data were collected from 735 ischemic stroke patients with upper limb motor dysfunction who were treated with standardized acupuncture at two hospitals. Following the initial screening, 314 patient datasets that met the inclusion criteria were selected. We applied three deep-learning algorithms (YOLOX, FasterRCNN, and TOOD) to develop the object detection model. Object detection results pertaining to the cerebral vessels were integrated into a clinical efficacy prediction model (random forest). This model aimed to classify patient responses to acupuncture treatment. Finally, the accuracies and discriminative capabilities of the prediction models were assessed.ResultsThe object detection model achieved an optimal recognition rate, The mean average precisions of YOLOX, TOOD, and FasterRCNN were 0.61, 0.7, and 0.68, respectively. The prediction accuracy of the clinical efficacy model reached 93.6%, with all three-treatment response classification area under the curves (AUCs) exceeding 0.95. Feature extraction using the prediction model highlighted the significant influence of various cerebral vascular stenosis sites within the internal carotid artery (ICA) on prediction outcomes. Specifically, the initial and C1 segments of the ICA had the highest predictive weights among all stenosis sites. Additionally, stenosis of the middle cerebral, anterior cerebral, and posterior cerebral arteries exerted a notable influence on the predictions. In contrast, the stenosis sites within the vertebral artery exhibited minimal impact on the model's predictive abilities.ConclusionsResults underscore the substantial predictive influence of each cerebral vascular stenosis site within the ICA, with the initial and C1 segments being pivotal predictors.

Regional cerebral perfusion and sympathetic activation during exercise in hypoxia and hypercapnia: preliminary insight into'Cushing's mechanism'.

We examined the interactive influence of hypoxia and exercise, and hypercapnia and exercise,on regional cerebral perfusion and sympathetic activation. Twenty healthy young adults (seven women) completed study trials including (1) rest in normoxia ( : ∼96%, : ∼36mmHg), normocapnic hypoxia ( : ∼84%, : ∼36mmHg), and normoxic hypercapnia ( : ∼98%, : ∼46mmHg) and (2) unilateral rhythmic handgrip exercise (45% of maximal voluntary contraction at 1Hz for 3min) under the same gas conditions. Based on the exercising arm, blood flow in the contralateral internal carotid (ICABF) and ipsilateral vertebral (VABF) arteries, anterior and posterior cerebral O2 delivery ( ), and muscle sympathetic nerve activity (MSNA) were measured in each trial. During exercise in hypoxia, ICABF, VABF, anterior and posterior were significantly lower, whereas total MSNA was significantly greater, than the sum of the responses evoked by either hypoxia or exercise alone. During exercise in hypercapnia, ICABF and anterior were significantly greater, whereas MSNA was lower, than the sum of the responses evoked by either hypercapnia or exercise alone. The VABF and posterior responses to hypercapnic exercise were not different from the summated responses. These findings suggest that the brain is hypoperfused and sympathetic outflow potentiated during hypoxic exercise, and that the brain is hyperperfused and sympathetic discharge constrained during hypercapnic exercise. The contrasting consequences for cerebral perfusion and sympathetic activation indicate a potential involvement of Cushing's mechanism in the autonomic control during exercise in healthy humans. KEY POINTS: Brain O2-demand and -supply are mismatched, and muscle sympathetic nerve activity (MSNA) is enhanced in humans exercising at high altitude; the link between the two phenomena remains elusive. We evaluated the isolated and interactive effects of exercise, hypoxia, and hypercapnia on blood flow in the internal carotid (ICABF) and vertebral (VABF) arteries, and MSNA. The interaction of hypoxia and exercise was hypo-additive for ICABF and VABF and anterior and posterior cerebral O2 delivery ( ), but hyper-additive for MSNA. The interaction of hypercapnia and exercise was hyper-additive for ICABF and anterior , additive for VABF and posterior , and hypo-additive for MSNA. These observations indicate that a suboptimal brain perfusion during hypoxic exercise coincides with a potentiated sympathetic outflow, while a (supra-)optimal brain perfusion during hypercapnic exercise coincides with a suppressed sympathetic outflow. Our findings suggest that Cushing's mechanism may play a role in the autonomic control in exercising humans.

Temporal Bone Gunshot Wounds: A Multi-institutional Retrospective Study.

To investigate management practices and outcomes in a retrospective cohort of patients who have sustained temporal bone gunshot wounds (TBGSW). Retrospective chart review. Five participating hospitals. Twenty-two patients met inclusion criteria: experienced a TBGSW, survived ≥30 days following the injury, and were evaluated and managed by a neurotologist between 2019 and 2023. No specific interventions were performed for the purposes of this study. Characteristics, evaluation, management, and outcomes of TBGSW survivors. Patients were found to have a mean age of 33 ± 18 years and were predominantly male (18/22, 81.8%). Majority of patients (17/22, 77.3%) had mastoid injury. Most patients (14/22, 63.6%) had some evidence for vascular injury, most frequently the internal carotid artery (9/22, 40.9%). Almost three-quarters (17/22, 77.3%) of patients had clinical exam findings of facial nerve injury, which was the most common indication for surgery. Otologic surgery was performed in 72.7% (16/22), with delayed adverse events most commonly including cholesteatoma and external auditory canal stenosis. Though evidence for hearing impairment was clinically present in at least 15 of 22 patients (68.2%), hearing rehabilitation was pursued in only two patients. With increasing numbers of TBGSW survivors, there is a growing need for practicing neurotologists to be familiar with the wide spectrum of injury patterns and possible complications to inform clinical management in these patients. Early neurotologic assessment and follow-up beyond the acute period is crucial to minimize morbidity in this high-risk cohort.