Endovascular therapy versus medical management for ischemic stroke presenting beyond 24 hours: Systematic review and meta-analysis.

OBJECTIVE: The ideal management for ischemic stroke presenting in the very late time window, or beyond 24 hours from onset, is poorly understood. It is unknown if endovascular therapy (EVT) or best medical management (MM) is associated with superior clinical outcomes. METHODS: A systematic literature and comparative meta-analysis was completed to evaluate the safety and efficacy of EVT vs. MM for stroke presenting beyond 24 hours. Outcome measures included: 90 day functional independence (mRS 0-2), 90 day mortality, and symptomatic intracranial hemorrhage (sICH) occurrence. A random effects model was used for quantitative synthesis. RESULTS: From the five included studies, a total of 704 patients were included with 461 treated with EVT and 243 treated with MM alone. The proportion of patients achieving functional independence was significantly higher in patients treated with EVT (34.6 %) compared to MM alone (15.9 %) (OR: 4.24; CI: 2.61-6.88, P < 0.00001; I2 =0 %). While sICH occurred more in EVT patients (6.8 %) compared to MM (2.8 %), this was not significant (OR: 1.96; CI: 0.61-6.27, P=0.26; I2 = 67 %). Lastly, 90 day morality occurred significantly less in the EVT group (24.5 %) compared to patients treated with MM (33.1 %), and with significantly lower odds (OR: 0.51; CI: 0.35-0.73, P=0.0003; I2=0 %). CONCLUSIONS: In certain patients presenting beyond 24 hours with ischemic stroke, EVT is associated with a significantly higher odds of achieving functional independence and lower odds of mortality compared with MM. While these results do not function as proof, they do encourage further research into extending the window beyond 24 hours for EVT. Randomized clinical trials are warranted to validate these findings.

Total brain volume is associated with severity of transverse sinus stenosis in idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension (IIH) is a complex neurological condition characterized by symptoms of increased intracranial pressure of unclear etiology. While transverse sinus stenosis (TSS) is often present in patients with IIH, how and why it occurs remains unclear. METHODS: IIH patients and a set of age-matched normal controls were identified from our single-center tertiary care institution from 2016 to 2024. Brain MRIs before treatment were computationally segmented and parcellated using FreeSurfer software. Extent of TSS on MR venograms was graded using the Farb scoring system. Relationship between normalized brain volume, normalized brain-to-CSF volume, and TSS was investigated. Multiple linear regression was conducted to investigate the association between continuous variables, accounting for the covariates body mass index, sex, and age. RESULTS: In total, 84 IIH patients (mean age, 29.8 years; 87% female) and 15 normal controls (mean age, 28.1 years) were included. Overall, increasing/worsening TSS was found to be significantly associated with normalized total brain volume (p=0.018, R=0.179) and brain-to-CSF ratio volume (p=0.026, R=0.184). Additionally, there was a significant difference between controls and IIH patients with mild and severe stenosis regarding normalized total brain volume (ANCOVA, p=0.023) and brain-to-CSF ratio volume (ANCOVA, p=0.034). Likewise, IIH patients with severe TSS had a significantly higher brain-to-CSF volume compared with controls (p=0.038) and compared with IIH patients with mild TSS (p=0.038). CONCLUSIONS: These findings suggest that total brain volume is associated with extent of TSS, which may reflect extramural venous compression due to enlarged brain and/or venous hypertension with associated cerebral congestion/swelling.

Association of Extent of Transverse Sinus Stenosis With Cerebral Glymphatic Clearance in Patients With Idiopathic Intracranial Hypertension.

BACKGROUND AND OBJECTIVES: Idiopathic intracranial hypertension (IIH) is a neurologic disorder characterized by symptoms of elevated intracranial pressure in the absence of a clear cause. There is a developing theory that IIH may, in part, be related to abnormal cerebral glymphatic clearance. In addition, transverse sinus stenosis (TSS) is a common finding in IIH of unclear pathophysiologic significance. Similarly, whether or not TSS is associated with glymphatic outflow in IIH is unknown. The aim of this investigation was to explore the possible association between glymphatic outflow and extent of TSS in patients with IIH. METHODS: The study cohort consisted of patients with IIH and healthy controls who were retrospectively identified from our tertiary care institution located in upstate New York from 2016 to 2023. Patients with IIH were included if they had brain MRIs completed with sufficient sequences for analysis. Brain MRIs were computationally analyzed using diffusion tensor imaging analysis along the perivascular space technique to quantify the glymphatic function in patients with IIH. Glymphatic clearance, the primary outcome, was then correlated with the degree of TSS on MR venography using 2 different scoring systems, the 'Farb score' and 'Carvalho score.' RESULTS: Overall, 81 patients with IIH (70 [86%] female, mean age 29.8 years [SD: 8.2 years], mean BMI 41 [SD: 8.4]) and 10 normal controls were identified with sufficient imaging. Based on the Carvalho TSS score, IIH patients without TSS had significantly lower glymphatic clearance than healthy controls (mean ALPS index: 1.196 [SD: 0.05] vs 1.238 [SD: 0.04], respectively; p = 0.018). Furthermore, IIH patients with TSS had significantly lower glymphatic outflow than healthy controls (1.129 [SD: 0.07] vs 1.238 [SD: 0.04], respectively; p < 0.0001) and IIH patients without TSS (1.129 [SD: 0.07] vs 1.196 [SD: 0.05], respectively; p < 0.0001). In addition, there was a significant association between increasing extent of TSS and declining glymphatic clearance (p < 0.0001, R = 0.62). Finally, IIH patients with severe TSS had significantly lower glymphatic flow than IIH patients with mild stenosis (1.121 [SD: 0.07] vs 1.178 [SD: 0.05], respectively; p < 0.0001). These findings were similarly recapitulated using the Farb TSS scoring system. DISCUSSION: These preliminary findings suggest that the extent of TSS is associated with the degree of glymphatic clearance in IIH, providing novel insights into IIH pathophysiology. Further research is required to clarify the possible causal relationship between TSS and impaired glymphatic clearance in IIH.

Improved Cerebral Glymphatic Flow after Transvenous Embolization of CSF-Venous Fistula.

Spontaneous intracranial hypotension is characterized by symptoms of low intracranial CSF volume due to various mechanisms of CSF leakage. One such mechanism is a CSF-venous fistula, treatable with transvenous embolization resulting in substantial radiographic and clinical improvement. However, the exact mechanisms underlying these improvements, including the potential involvement of the glymphatic system, remain unclear. To noninvasively assess glymphatic clearance in spontaneous intracranial hypotension, we used an advanced MR imaging technique called the DTI along the perivascular spaces in 3 patients with CSF-venous fistula before and after embolization. All 3 patients with spontaneous intracranial hypotension initially had low glymphatic flow, which improved postembolization. Two patients with symptomatic improvement exhibited a more substantial increase in glymphatic flow compared with a patient with minimal improvement. These findings suggest a possible link between cerebral glymphatics in spontaneous intracranial hypotension pathophysiology and symptomatic improvement, warranting larger studies to explore the role of the glymphatic system in spontaneous intracranial hypotension.

"Empty Cyst Sign" Appearance of CSF-Venous Fistula on Digital Spinal Myelography.

Cerebrospinal fluid venous fistulas (CSF-VFs) are an uncommon, yet increasingly recognized, cause of spontaneous intracranial hypotension.1-5 The workup involves magnetic resonance imaging (MRI) of the brain with and without contrast and MRI of the neuroaxis without contrast before dynamic myelography, either computed tomography or digital subtraction.6 The present case of an older woman with symptomatic intracranial hypotension is notable for the specific appearance of CSF-VFs on digital spinal myelography (Video 1). Among her numerous perineural cysts, it was the "disappearing" or "empty" cyst from which the fistula originated. The diagnosis was made using a second lateral fluoroscopy view, not typically used in digital spinal myelography, which demonstrated emptying of contrast from the T6 perineural cyst into the segmental vein at this level, or the "empty cyst sign." The patient then underwent transvenous onyx embolization with resolution of her orthostatic headaches and improvement of contrast-enhanced MRI of the brain with the Bern score decreasing from 7 to 0 at 3 months of follow-up.7 Because transvenous embolization of CSF-VFs is a relatively new procedure, the long-term outcomes of the procedure are not yet known.

Stroke emboli from patients with atrial fibrillation enriched with neutrophil extracellular traps.

Background: Recent literature has demonstrated remarkable heterogeneity in the composition of acute ischemic stroke (AIS) emboli, which may impact susceptibility to therapy. Objectives: In this study, we explored differences in proteomic composition of retrieved embolic material from patients with stroke with and without atrial fibrillation (AF) (AF+ and AF-, respectively). Methods: The full proteome of retrieved thromboembolic material from 24 patients with AIS was obtained by mass spectrometry. Known marker proteins were assigned groups representing broad classes of embolus components: red blood cells, platelets, neutrophils, eosinophils, histones, complement, and other clotting-associated proteins (eg, fibrinogen). Relative protein abundances were compared between AF+ and AF- samples. Functional implications of differences were explored with gene set enrichment analysis and Gene Ontology enrichment analysis and visualization tool. Results: One hundred sixty-six proteins were differentially expressed between AF+ and AF- specimens. Eight out of the 15 neutrophil proteins (P < .05; fold change, >2) and 4 of the 14 histone proteins were significantly enriched in AF+ emboli (P < .05; fold change, >2). Gene set enrichment analysis revealed a significant representation of proteins from published neutrophil extracellular trap (NET) proteomic gene sets. The most significantly represented functional Gene Ontology pathways in patients with AF involved neutrophil activation and degranulation (P < 1 × 10-7). Conclusion: The present analysis suggests enrichment of NETs in emboli of patients with stroke and AF. NETs are a significant though understudied structural component of thrombi. This work suggests not only unique stroke biology in AF but also potential therapeutic targets for AIS in this population.

Histone content, and thus DNA content, is associated with differential in vitro lysis of acute ischemic stroke clots.

BACKGROUND: Fibrin, von Willebrand factor, and extracellular DNA from neutrophil extracellular traps all contribute to acute ischemic stroke thrombus integrity. OBJECTIVES: In this study, we explored how the proteomic composition of retrieved thromboemboli relates to susceptibility to lysis with distinct thrombolytics. METHODS: Twenty-six retrieved stroke thromboemboli were portioned into 4 segments, with each subjected to 1 hour of in vitro lysis at 37 °C in 1 of 4 solutions: tissue plasminogen activator (tPA), tPA + von Willebrand factor-cleaving ADAMTS-13, tPA + DNA-cleaving deoxyribonuclease (DNase) I, and all 3 enzymes. Lysis, characterized by the percent change in prelysis and postlysis weight, was compared across the solutions and related to the corresponding abundance of proteins identified on mass spectrometry for each of the thromboemboli used in lysis. RESULTS: Solutions containing DNase resulted in approximately 3-fold greater thrombolysis than that with the standard-of-care tPA solution (post hoc Tukey, P < .01 for all). DNA content was directly related to lysis in solutions containing DNase (Spearman's ρ > 0.39 and P < .05 for all significant histones) and inversely related to lysis in solutions without DNase (Spearman's ρ < -0.40 and P < .05 for all significant histones). Functional analysis suggests distinct pathways associated with susceptibility to thrombolysis with tPA (platelet-mediated) or DNase (innate immune system-mediated). CONCLUSION: This study demonstrates synergy of DNase and tPA in thrombolysis of stroke emboli and points to DNase as a potential adjunct to our currently limited selection of thrombolytics in treating acute ischemic stroke.

Diffusion-Weighted Imaging Reveals Impaired Glymphatic Clearance in Idiopathic Intracranial Hypertension.

BACKGROUND AND PURPOSE: The pathophysiology underlying idiopathic intracranial hypertension (IIH) remains incompletely understood. While one theory postulates impaired cerebral glymphatic clearance in IIH, there is a paucity of methods to quantify glymphatic activity in human brains. The purpose of this study was to use advanced diffusion-weighed imaging to evaluate the glymphatic clearance of IIH patients and how it may relate to clinical severity. MATERIALS AND METHODS: DWI was used to separately evaluate the diffusivity along the cerebral perivascular spaces and lateral association and projection fibers, with the degree of diffusivity used as a surrogate for glymphatic function (diffusion tensor image analysis along the perivascular space. Patients with IIH were compared with normal controls. Glymphatic clearance was correlated with several clinical metrics, including lumbar puncture opening pressure and Frisen papilledema grade (low grade: 0-2; high grade: 3-5). RESULTS: In total, 99 patients with IIH were identified and compared with 6 healthy controls. Overall, patients with IIH had significantly lower glymphatic clearance based on DWI-derived diffusivity compared with controls (P = .005). Additionally, in patients with IIH, there was a significant association between declining glymphatic clearance and increasing Frisen papilledema grade (P = .046) but no correlation between opening pressure and glymphatic clearance (P = .27). Furthermore, healthy controls had significantly higher glymphatic clearance compared with patients with IIH and low-grade papilledema (P = .015) and high-grade papilledema (P = .002). Lastly, patients with IIH and high-grade papilledema had lower glymphatic clearance compared with patients with IIH and low-grade papilledema (P = .005). CONCLUSIONS: Patients with IIH possess impaired glymphatic clearance, which is directly related to the extent of clinical severity. The DWI-derived parameters can be used for clinical diagnosis or to assess response to treatment.

Safety and efficacy comparison of embolic agents for middle meningeal artery embolization for chronic subdural hematoma.

OBJECTIVE: To perform a systematic review and meta-analysis evaluating the efficacy of middle meningeal artery embolization in terms of both clinical and radiographic outcomes, when performed with different embolic agents. METHODS: A systematic literature review and meta-analysis was performed to evaluate the impact of embolic agents on outcomes for middle meningeal artery (MMA) embolization. The use of polyvinyl alcohol (PVA) with or without (±) coils, N-butyl cyanoacrylate (n-BCA) ± coils, and Onyx alone were separately evaluated. Primary outcome measures were recurrence, the need for surgical rescue and in-hospital periprocedural complications. RESULTS: Thirty-one studies were identified with a total of 1,134 patients, with 786 receiving PVA, 167 receiving n-BCA, and 181 patients receiving Onyx. There was no difference in the recurrence rate (5.5% for PVA, 4.5% for n-BCA, and 6.5% for Onyx, with P=0.71) or need for surgical rescue (5.0% for PVA, 4.0% for n-BCA, and 6.9% for Onyx, with P=0.89) based on the embolic agent. Procedural complications also did not differ between embolic agents (1.8% for PVA, 3.6% for n-BCA, and 1.6% for Onyx, with P=0.48). CONCLUSIONS: Rates of recurrence, need for surgical rescue, and periprocedural complication following MMA embolization are not impacted by the type of embolic agent utilized. Ongoing clinical trials may be used to further investigate these findings.

Symptomatic carotid artery intraluminal thrombus: risk of medical management failure and distal embolization.

BACKGROUND: Carotid artery intraluminal thrombus (ILT), or free-floating thrombus, is an uncommon cerebrovascular entity with considerable equipoise regarding its clinical management. Likewise, in patients treated with medical management (MM), distal embolization and/or intracranial hemorrhage (ICH) may still occur. METHODS: All patients with symptomatic ILT from 2016 to 2023 were identified from our tertiary care institution. Patients with MM failure (recurrent cerebral ischemia and/or symptomatic ICH) were compared with patients with MM non-failure. Differences in ILT volume and length were calculated. Receiver operator characteristic (ROC) curve analysis was used to identify the cut-off volume and length for risk of MM failure. RESULTS: In total, 45 patients with ILT were identified with 41 treated with frontline MM. Of these 41 patients treated with MM, seven (17%) had MM failure with six (14.6%) having new embolic stroke and one (2.3%) with symptomatic ICH. Patients with MM failure had a significantly higher mean thrombus volume than MM non-failure patients (257 mm3 vs 59.6 mm3, P=0.0006). Likewise, patients with MM failure had significantly longer thrombus on average (21 mm vs 6.6 mm, P=0.0009). ROC curve analysis showed that an ILT volume of 90 mm3 resulted in a sensitivity of 71.4% and specificity of 85.3% for MM failure (AUC 0.775; CI 0.55 to 1.0, P=0.023). CONCLUSIONS: Carotid ILTs that fail MM are significantly larger and longer. These findings suggest that a thrombus volume of 90 mm3 may serve as a guide for intervention with good sensitivity and specificity for risk of MM failure.

Ischemic Stroke Thrombus Perviousness Is Associated with Distinguishable Proteomic Features and Susceptibility to ADAMTS13-Augmented Thrombolysis.

BACKGROUND AND PURPOSE: Perviousness is the differential attenuation on CT of an intracranial arterial occlusive thrombus before and after IV contrast administration. While perviousness/permeability has been shown to be related to various clinical outcomes and reflects histopathologic composition, it remains unclear whether perviousness is also associated with differences in proteomic composition. MATERIALS AND METHODS: Retrieved clots from 59 patients were evaluated with quantitative mass spectrometry. Proteomic differences between high-perviousness (≥11 HU) and low-perviousness (<11 HU) clots were investigated. Perviousness as a continuous variable was also correlated with protein abundance. Last, an ex vivo lysis assay was performed to investigate the differential susceptibility to tPA, deoxyribonuclease, and ADAMTS13 thrombolysis as a function of perviousness. RESULTS: In total, 2790 distinct proteins were identified. Thrombus perviousness was associated with distinct proteomic features, including depletion of the macrophage marker CD14 (P = .039, z = 1.176) and hemoglobin subunit ζ (P = .046, z = 1.68) in pervious clots. Additionally, proteins involved in platelet cytoskeleton remodeling (tropomyosin α-3-chain) and granule secretion/aggregation (synaptotagmin-like protein 4/FC region receptor II-a) were associated with increasing perviousness (P < .006), among numerous other proteins. Monocyte/macrophage-associated proteins (apoptosis-associated specklike protein containing a CARD/SAMHD1) were also depleted in pervious emboli (P < .002). Ex vivo lysis indicated that pervious clots were more susceptible to ADAMTS13-augmented tPA thrombolysis compared with impervious clots (P < .05), though without differences in deoxyribonuclease digestion. CONCLUSIONS: Thrombus perviousness is associated with complex proteomic features, including differential abundance of platelet-related proteins in highly permeable clots with monocyte/macrophage depletion. This association may help to explain why highly pervious thrombi were also found more susceptible to ADAMTS13-augmented thrombolysis.

Efficacy of transvenous embolization of CSF-venous fistula in spontaneous intracranial hypotension: Case-series.

BACKGROUND: Spontaneous intracranial hypotension is a debilitating neurological condition which can be caused by a cerebrospinal fluid-venous fistula. Transvenous embolization is a promising technique to provide minimally invasive yet durable treatment. METHODS: A retrospective single-center case series was performed on all patients who underwent transvenous embolization of a cerebrospinal fluid (CSF)-venous fistula. Clinical and radiographic parameters, including Bern score, were reported preoperatively and at 3-month follow-up. RESULTS: Six patients underwent embolization of a CSF-venous fistula. All fistulae were located in the thoracic spine and technical success was achieved in all cases. Three patients had symptom resolution, two had significant improvement, and one had stable symptoms on follow-up. The mean Bern score was 6.83 (SD = 1.47) preoperatively and 1.83 (SD = 1.64) postoperatively with a mean improvement in Bern score of 5.0 (SD = 1.9, p = 0.0013). CONCLUSIONS: CSF-venous fistulas are an increasingly recognized clinical entity which may be treated with transvenous embolization. This case series serves to further validate this technique and suggests it can be performed with similar outcomes in lower volume centers.

Middle meningeal artery pseudoaneurysm and pterygoid plexus fistula following percutaneous radiofrequency rhizotomy: illustrative case.

BACKGROUND: Percutaneous treatment for trigeminal neuralgia is a safe and effective therapeutic methodology and can be accomplished in the form of balloon compression, glycerol rhizotomy, and radiofrequency thermocoagulation. These procedures are generally well tolerated and demonstrate minimal associated morbidity. Moreover, vascular complications of these procedures are exceedingly rare. OBSERVATIONS: We present the case of a 64-year-old female with prior microvascular decompression and balloon rhizotomy who presented after symptom recurrence and underwent a second balloon rhizotomy at our institution. Soon thereafter, she presented with pulsatile tinnitus and a right preauricular bruit on physical examination. Subsequent imaging revealed a middle meningeal artery (MMA) to pterygoid plexus fistula and an MMA pseudoaneurysm. Coil and Onxy embolization were used to manage the pseudoaneurysm and fistula. LESSONS: This case illustrates the potential for MMA pseudoaneurysm formation as a complication of percutaneous trigeminal balloon rhizotomy, which has not been seen in the literature. Concurrent MMA-pterygoid plexus fistula is also a rarity demonstrated in this case.

Prevalence of SLEC-negative spontaneous intracranial hypotension in patients with spinal nerve root sleeve diverticula on MRI.

PURPOSE: While there is thought to be an association between spinal nerve root diverticula (NRD) and spontaneous intracranial hypotension (SIH) without a spinal longitudinal epidural collection (SLEC), it remains unclear what the overall prevalence of SLEC-negative SIH is in patients with NRD on MRI. METHODS: Spine MRI imaging reports from our single institution were electronically screened for instances of NRD over a 9-year period (2016-2023). From these cases, patients with brain MRIs consistent with SIH were also identified. Subsequently, the overall proportion of SLEC-negative SIH was determined as a function of total cases with NRD based on spinal level. RESULTS: In total, 83,843 patients with spinal MRIs were screened which identified 4174 (4.97%) with NRD. From these, there were 1203 cervical, 622 thoracic, and 2979 lumbosacral spine MRIs. In total, 16 patients (0.38%; Standard Error [SE]: 0.48%-0.28%) had a brain MRI compatible with SLEC-negative SIH and met ICHD-3 criteria. Patients with cervical NRD had SIH in 2 cases (0.16%; SE: 0.27%-0.05%). SLEC-negative SIH was present in 11 patients with lumbosacral NRD (0.34%; SE: 0.44%-0.24%). In patients with diverticula in the thoracic spine, 14 (2.3%; SE: 2.8%-1.8%) had SLEC-negative SIH. SLEC-negative SIH was significantly more prevalent in patients with thoracic diverticula compared to those with cervical (p<.0001) or lumbosacral NRD (p<.0001). CONCLUSION: In patients with spinal NRD, concurrent SLEC-negative SIH is present in approximately 0.38% of patients, suggesting that in the vast majority of cases, they are an incidental finding. However, SIH is present in approximately 2.3% of patients with thoracic NRD and may be more specific for leak localization.

Direct percutaneous puncture versus transarterial embolization for head and neck paragangliomas: A systematic review and meta-analysis.

INTRODUCTION: Embolization of head and neck paragangliomas (HNPs) is a well-established treatment strategy and adjunctive therapy. However, the optimal mode of intervention, whether by direct percutaneous puncture (DP) or via transarterial embolization (TAE), remains unclear. METHODS: The aim of this study was to complete a systematic literature review and meta-analysis to compare the safety and efficacy of DP versus TAE for HNP embolization. The Cochrane Library and MEDLINE databases were used to identify studies describing the clinical outcomes of either DP or TAE for HNP embolization. Outcome measures included: complete angiographic devascularization, major complications, and minor complications. Pooled rates were calculated for each variable which were then compared with meta-regression using a random effects model. RESULTS: Thirty-one retrospective studies met inclusion criteria, detailing 394 patients with 411 HNPs. Overall, DP was associated with a higher rate of complete devascularization (91.5%, 95% confidence interval [CI]: 85.6% to 97.4%; I2 = 0%) when compared to TAE technique (40.1%, CI: 27.2% to 58.9%; I2 = 93%). However, there was no difference regarding major complication rates between DP (6%, CI:1.3% to 10.8%; I2 = 0%) and TAE for HNP embolization (3.3%, CI: 1.4% to 5.3%; I2 = 0%) (p = 0.370), nor in minor complications between the techniques (p = 0.211). Subgroup analysis of TAE embolic agents revealed that particle embolics were associated with a significantly lower rate of major complications (2.5%; 0.4% to 4.6%; I2 = 0%) when compared to liquid embolics (10.6%, CI:4% to 17.3%; I2 = 48%; p = 0.022). CONCLUSIONS: A DP approach for HNP embolization results in a higher rate of complete devascularization and with a similar complication profile when compared to TAE. These findings also suggest that particle embolics are associated with fewer major complications compared to liquid embolics when TAE is utilized.

A pictorial review of imaging findings associated with upper cervical trauma.

The diagnosis of cervical spine injury in the emergency department remains a critical skill of emergency room physicians as well as radiologists. Such diagnoses are often associated with high morbidity and mortality unless readily identified and treated appropriately. Both computed tomography (CT) and magnetic resonance imaging (MRI) often are crucial in the workup of spinal injury and play a key role in arriving at a diagnosis. Unfortunately, missed cervical spine injuries are not necessarily uncommon and often precede detrimental neurologic sequalae. With the increase in whole-body imaging ordered from the emergency department, it is critical for radiologists to be acutely aware of key imaging features associated with upper cervical trauma, possible mimics, and radiographic clues suggesting potential high-risk patient populations. This pictorial review will cover key imaging features from several different imaging modalities associated with upper cervical spine trauma, explore patient epidemiology, mechanism, and presentation, as well as identify confounding radiographic signs to aid in confident and accurate diagnoses.

CT hyperdense cerebral artery sign reflects distinct proteomic composition in acute ischemic stroke thrombus.

BACKGROUND: Hyperdense cerebral artery sign (HCAS) is an imaging biomarker in acute ischemic stroke (AIS) that has been shown to be associated with various clinical outcomes and stroke etiology. While prior studies have correlated HCAS with histopathological composition of cerebral thrombus, it is unknown whether and to what extent HCAS is also associated with distinct clot protein composition. METHODS: Thromboembolic material from 24 patients with AIS were retrieved via mechanical thrombectomy and evaluated with mass spectrometry in order to characterize their proteomic composition. Presence (+) or absence (-) of HCAS on preintervention non-contrast head CT was then determined and correlated with thrombus protein signature with abundance of individual proteins calculated as a function HCAS status. RESULTS: 24 clots with 1797 distinct proteins in total were identified. 14 patients were HCAS(+) and 10 were HCAS(-). HCAS(+) were most significantly differentially abundant in actin cytoskeletal protein (P=0.002, Z=2.82), bleomycin hydrolase (P=0.007, Z=2.44), arachidonate 12-lipoxygenase (P=0.004, Z=2.60), and lysophospholipase D (P=0.007, Z=2.44), among other proteins; HCAS(-) clots were differentially enriched in soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (P=0.0009, Z=3.11), tyrosine-protein kinase Fyn (P=0.002, Z=2.84), and several complement proteins (P<0.05, Z>1.71 for all), among numerous other proteins. Additionally, HCAS(-) thrombi were enriched in biological processes involved with plasma lipoprotein and protein-lipid remodeling/assembling, and lipoprotein metabolic processes (P<0.001), as well as cellular components including mitochondria (P<0.001). CONCLUSIONS: HCAS is reflective of distinct proteomic composition in AIS thrombus. These findings suggest that imaging can be used to identify mechanisms of clot formation or maintenance at the protein level, and might inform future research on thrombus biology and imaging characterization.

Preoperative Embolization of Meningiomas Facilitates Reduced Surgical Complications and Improved Clinical Outcomes : A Meta-analysis of Matched Cohort Studies.

PURPOSE: The utility of preoperative embolization (PE) of intracranial meningiomas is unclear and controversial. The aim of this study was to investigate the effect of PE on meningioma surgical resection by completing a meta-analysis of matched cohort studies. METHODS: A systematic review and meta-analysis of matched cohort studies was completed to evaluate the effect of PE on meningioma resection and outcomes. Outcome measures included: intraoperative blood loss, major surgical complications, total surgical complications including minor ones, total major complications including major surgical and embolization complications, total overall complications, and postoperative functional independence defined as modified Rankin Score (mRS) of 0-2. Pooled odds ratios (OR) were determined via a fixed effects model. RESULTS: A total of 6 matched cohort studies were identified with 219 embolized and 215 non-embolized meningiomas. There was no significant difference in intraoperative blood loss between the two groups (P = 0.87); however, the embolization group had a significantly lower odds ratio of major surgically related complications (OR: 0.37, 95% confidence interval, CI: 0.21-0.67, P = 0.0009, I2 = 0%), but no difference in minor surgical complications (P = 0.86). While there was a significantly lower odds ratio of total overall surgical and PE-related complications in PE cases (OR: 0.64, CI: 0.41-1.0, P = 0.05, I2 = 66%), there was no difference in total combined major complications between the groups (OR: 0.57, CI: 0.27-1.18, P = 0.13, I2 = 33%). Lastly, PE was associated with a higher odds ratio of functional independence on postoperative follow-up (OR: 2.3, CI: 1.06-5.02, P = 0.04, I2 = 0%). CONCLUSION: For certain meningiomas, PE facilitates lower overall complications, lower major surgical complications, and improved functional independence. Further research is required to identify the particular subset of meningiomas that benefit from PE.

Mechanical Thrombectomy for Ischemic Stroke Secondary to Large Vessel Occlusions in Patients on Extracorporeal Membrane Oxygenation.

INTRODUCTION: The use of short-term mechanical circulatory support (MCS) devices and procedures for function- and life-sustaining therapy is becoming a routine practice at many centers. Concomitant with the increasing use of MCS is the increasing recognition of acute brain injuries, including acute ischemic stroke, which may be caused by a myriad of MCS-driven factors. The aim of this case series was to document our experience with mechanical thrombectomy (MT) for ischemic stroke in extracorporeal membrane oxygenation (ECMO) patients. METHODS: We retrospectively reviewed a prospectively maintained database of patients undergoing endovascular thrombectomy for large vessel occlusion at our institution. We identified patients that were on ECMO and underwent thrombectomy. Baseline demographics and procedural and functional outcomes were collected. RESULTS: Three patients on ECMO were identified to have a large vessel occlusion and underwent thrombectomy. Two patients had an internal carotid artery terminus occlusion and one had a basilar artery occlusion. An mTICI 3 recanalization was achieved in all patients without postoperative hemorrhagic complications. Two patients achieved a 3-month mRS of 1, while one had mRS 4. CONCLUSION: Ischemic stroke can be associated with significant morbidity in MCS patients. We demonstrate that MT can be safely performed in this patient population with good outcomes.