Lipidomics, Acute Ischemic Stroke, Symptoms, and Outcomes: Observational Study Protocol.

BACKGROUND: Acute ischemic stroke is one of the leading causes of death and disability globally. Recent advances in omics methodology enable lipidomic profiling, which may provide knowledge of the underlying pathology of acute ischemic stroke and its associated outcomes. OBJECTIVE: This study aims to examine the longer-term relationships between symptoms and outcomes following acute ischemic stroke and the underlying lipidomic signatures over 6 months during recovery between acute ischemic stroke patients who received reperfusion therapies and those who did not. METHODS: This prospective cohort study will enroll 104 participants post-acute ischemic stroke in two groups based on their receipt of reperfusion therapy (Group 1) or not (Group 2; n = 52/group). Peripheral plasma samples will be collected from both groups for lipidomic analysis over 6 months. Arterial blood samples will be collected during the procedure for those receiving reperfusion. Self-reported symptoms and outcome data will be collected from both groups. DISCUSSION: We will compare and examine the associations among plasma lipidomic biomarkers and symptoms and cognitive, functional, and health-related quality of life outcomes over 6 months between acute ischemic stroke patients who did and did not receive reperfusion intervention.

Temporal sylvian fissure arachnoid cyst in children: treatment outcome following microsurgical cyst fenestration with special emphasis on cyst reduction and subdural collection.

OBJECTIVES: Controversy remains regarding surgical managements of sylvian fissure arachnoid cyst (SFAC). This review presents our experience in the microsurgical fenestration of pediatric patients with SFAC to define surgical indication, and risks and benefits with special emphasis on postoperative subdural fluid collection (SDFC) and cyst size reduction. METHODS: Thirty-four children with SFAC who underwent microsurgical cyst fenestration at a single institution over a 10-year period were retrospectively reviewed for their clinical presentation, neuroimaging findings, and postsurgical course. The SFACs were classified by a novel grading system based on the degree of arachnoid cyst extension from the sylvian fissure to the insular cistern shown on MR images: grade 0 - little or no prominence of sylvian fissure, grade I - SFAC confined to the sylvian fissure, grade II - SFAC partially extending to the insular cistern, grade III - SFAC extending to the entire insular cistern. RESULTS: There were 26 males and 8 females. SFAC was present in the left side in 24. Twelve patients presented with cyst rupturing to the subdural space. Cyst grading did not show significant difference compared with rupture status (p > 0.9). All patients underwent microsurgical cyst fenestration. Postoperative SDFC is common but often resolved overtime in two-thirds of the cases with the mean average of 6 months. However, 3 patients had symptomatic postoperative SDFC and needed reoperation shortly after the first operation. Microsurgical cyst fenestrations for SFAC effectively resolved the presenting symptoms and often showed restorations of intracranial structures on follow-up imaging. Cyst resolution or reduction greater than 75% was noted in 61.8% of the patients postoperatively which was noted in a half of the SFAC of children even with age of 11 years or older. During the follow-up, no cyst recurrence or SDFC was noted. Patients with greater surgical reduction of cyst size tended to occur in younger children, and those with lower MR grade. CONCLUSION: Our results showed a high reduction rate of SFAC and brain re-expansion after microsurgical fenestration together with symptomatic improvements regardless the patient's age. Considering the developing CNS during childhood, reductions of a large space-occupying lesion followed by restorations of the structural integrity of the developing brain are very desirable. However, a multi-center cooperative prospective longitudinal study on long-term comparative data of those treated and untreated of neuro-psychological outcome and cyst rupture incidence is needed.

Sex Differences in Cerebral Aneurysms and Subarachnoid Hemorrhage.

Sex differences in cerebral aneurysm occurrence and characteristics have been well described. Although sex differences in outcomes following ischemic stroke have been identified, the effect of sex on outcomes following hemorrhagic stroke, and in particular, aneurysm treatment has been less studied. We describe the current state of knowledge regarding the impact of sex on treatment and outcomes of cerebral aneurysms. Although prior studies suggest that aneurysm prevalence and progression may be related to sex, we did not find clear evidence that outcomes following subarachnoid hemorrhage vary based on sex. Last, we identify areas for future research that could enhance understanding of the role sex plays in this context.

External carotid artery to internal carotid artery transposition to augment flow for a superficial temporal artery to middle cerebral artery bypass associated with severe external carotid artery stenosis.

BACKGROUND: Donor vessel quality can impact the outcome of extracranial-intracranial (EC-IC) bypass. External carotid artery (ECA) disease may produce embolism into the anastomosis and cerebral territory and possibly reduce flow in the superficial temporal artery (STA). Previously reported remedies to ECA stenosis include ECA endarterectomy, stenting, and angioplasty. Clinical presentation A middle-aged patient with chronic left MCA occlusion, progressive ischemic symptoms on maximal medical therapy, and imaging confirmation of compromised hemodynamic reserve was evaluated for EC-IC bypass. Angiography demonstrated severe ECA origin stenosis. An ECA-ICA transposition was performed, primarily to eliminate the risk of emboli and secondarily to possibly improve the STA flow. The patient sustained an excellent radiological and clinical outcome, and the STA donor cut-flow was increased modestly by 22% (45 to 55 mL/min). CONCLUSION: This case is the first report of an ECA to internal carotid artery transposition as an option in the management of ECA stenosis in preparation for an STA-MCA bypass for the purpose of flow augmentation.

Determining the role of adjuvant radiotherapy in the management of meningioma: a Surveillance, Epidemiology, and End Results analysis.

OBJECTIVEThe aim of this study was to illustrate the demographic characteristics of meningioma patients and observe the effect of adjuvant radiation therapy on survival by using the Surveillance, Epidemiology, and End Results (SEER) database. More specifically, the authors aimed to answer the question of whether adjuvant radiotherapy following resection of atypical meningioma confers a cause-specific survival benefit. Additionally, they attempted to add to previous characterizations of the epidemiology of primary meningiomas and assess the effectiveness of the standard of care for benign and anaplastic meningiomas. They also sought to characterize the efficacy of various treatment options in atypical and anaplastic meningiomas separately since nearly all other analyses have grouped these two together despite varying treatment regimens for these behavior categories.METHODSSEER data from 1973 to 2015 were queried using appropriate ICD-O-3 codes for benign, atypical, and anaplastic meningiomas. Patient demographics, tumor characteristics, and treatment choices were analyzed. The effects of treatment were examined using a multivariate Cox proportional hazards model and Kaplan-Meier survival analysis.RESULTSA total of 57,998 patients were included in the analysis of demographic, meningioma, and treatment characteristics. Among this population, cases of unspecified WHO tumor grade were excluded in the multivariate analysis, leaving a total of 12,931 patients to examine outcomes among treatment paradigms. In benign meningiomas, gross-total resection (HR 0.289, p = 0.013) imparted a significant cause-specific survival benefit over no treatment. In anaplastic meningioma cases, adjuvant radiotherapy imparted a significant survival benefit following both subtotal (HR 0.089, p = 0.018) and gross-total (HR 0.162, p = 0.002) resection as compared to gross-total resection alone. In atypical tumors, gross-total resection plus radiotherapy did not significantly change the hazard risk (HR 1.353, p = 0.628) compared to gross-total resection alone. Similarly, it was found that adjuvant radiation did not significantly benefit survival after a subtotal resection (HR 1.440, p = 0.644).CONCLUSIONSThe results of this study demonstrate that the role of adjuvant radiotherapy, especially after the resection of atypical meningioma, remains somewhat unclear. Thus, given these results, prospective randomized clinical studies are warranted to provide clear information on the effects of adjuvant radiation in meningioma treatment.

Intramedullary amputation neuroma: a case report and review of the literature.

BACKGROUND AND IMPORTANCE: Amputation neuromas consist of non-neoplastic collections of myelinated axons and Schwann cells and typically arise in injured peripheral nerves. Rarely, however, neuromas occur within the spinal cord. Intramedullary amputation neuromas have been described both with and without a history of trauma within the peripheral nervous system. We report a rare case of an isolated intramedullary spinal cord amputation neuroma. CLINICAL PRESENTATION: This 43-year-old man presented with progressive and severe gait deterioration for ~ 7 years. Neurological exam revealed multiple positive findings consistent with cervical myelopathy, including positive Babinski and Hoffman signs, sustained clonus with patellar and Achilles reflexes, bilateral lower extremity weakness with increased muscular tone and spasticity, and inability to tandem walk. Magnetic resonance imaging demonstrated a 0.6-cm, homogeneously enhancing, intramedullary tumor with surrounding signal change at the C6 level. The lesion was excised and histologic examination revealed microscopic features compatible with an amputation neuroma. CONCLUSION: Intramedullary amputation neuromas are rare and associated with either trauma or other CNS lesions. Our case represents an amputation neuroma in an unusual location in a patient without subjective preceding history of trauma or presence of a second lesion.
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WITHDRAWN: A narrative review of techniques for surgical revascularization of the extracranial vertebral artery in vertebrobasilar insufficiency.

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Neurochirurgie, volume 70. https://doi.org/10.1016/j.neuchi.2023.101516. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal.

Glue embolization of ruptured pseudoaneurysm secondary to reversible cerebral vasoconstriction syndrome: An illustrative case.

BACKGROUND: Reversible cerebral vasoconstriction syndrome (RCVS) is an increasingly recognized condition characterized by thunderclap headache with or without other neurological deficits and diffuse vasoconstriction of cerebral arteries. Altered cerebrovascular tone may produce hemorrhage or stroke. METHODS: A retrospective review of patients with RCVS at our institution (2000-2023) yielded one case of pseudoaneurysm secondary to RCVS. RESULTS: Diagnostic cerebral angiogram demonstrated diffuse multifocal segmental narrowing consistent with RCVS and a left M4 pseudoaneurysm in proximity to the cortical hemorrhage. The pseudoaneurysm was treated with branch vessel sacrifice using nBCA glue in a 1 : 3 ratio with ethiodized oil. After securing the source of hemorrhage, the patient received an intra-arterial infusion of Verapamil. CONCLUSION: This unique presentation of pseudoaneurysm secondary to RCVS in this patient highlights the impact of hemodynamic alteration as a possible source of bleeding and demonstrates a potential management strategy. Endovascular management with nBCA glue embolization successfully treated this lesion.

Assessing the efficacy of VerifyNow platelet-function testing in predicting postoperative thromboembolic complications of neuroendovascular surgery: A systematic review and meta-analysis (part 1).

BACKGROUND: Despite the heavily debated use of routine platelet-function testing, the VerifyNow Platelet Reactivity Unit (PRU) assay has been increasingly adopted as standard of care for assessing risk of postoperative thromboembolic complications of neuroendovascular surgery. OBJECTIVE: We conducted a systematic review and meta-analysis to examine the relationship between platelet response and risk of ischemic events from neuroendovascular surgery, assess the efficacy of point-of-care platelet-function testing in predicting thromboembolic outcomes, and assess whether a clinically useful threshold for platelet response can be defined in order to standardize guidelines. METHODS: PubMed, Embase, and Scopus were searched. Following deduplication, articles were first screened for relevance by title and abstract, followed by full text. RESULTS: Of 735 resultant articles, 22 studies consisting of 3266 patients undergoing neuroendovascular intervention were included. Diagnoses included both intracranial and extracranial pathologies, of which 45.8% were treated with flow diversion, 16.4% with stent-assisted coil embolization, 15.8% with intracranial stenting, 12.0% with simple coil embolization, 3.4% with balloon-assisted coil embolization, 3.6% with extracranial stenting, and 3.0% with an alternate method. 54.5% (12/22) of studies determined platelet hyporesponse to be an independent predictor of postoperative thromboembolic complications, with 27.3% (6/22) of studies reporting a similar, but non-statistically significant trend. 18.2% (4/22) of studies found no relationship between platelet response and postoperative thromboembolic complications. The estimated clinical threshold for PRU to prevent thromboembolic complications varied greatly across studies (Range: > 144-295 PRU). Meta-analysis found platelet hyporesponse to have a 2.23-fold increased risk of thromboembolic complications compared to normoresponders (RR = 2.23, P = 0.03). CONCLUSION: While PRU demonstrates a significant predictive value for postoperative thromboembolic complications of neuroendovascular surgery, the target therapeutic threshold for minimizing ischemic events remains unclear. Further studies, such as large multicenter cohorts of the existing data, are needed to standardize guidelines.

Assessing the efficacy of VerifyNow platelet-function testing in predicting postoperative hemorrhagic complications of neuroendovascular surgery: A systematic review and meta-analysis (part 2).

BACKGROUND: Dual antiplatelet therapy is used to reduce the risk of thromboembolic complications in neuroendovascular surgery. However, the predictive utility of preoperative platelet-sensitivity testing for decreasing bleed risk in patients undergoing endovascular neurointervention remains unclear. OBJECTIVE: We conducted a systematic review and meta-analysis to illustrate the association between platelet response and risk of hemorrhagic complications from neuroendovascular surgery, examine the efficacy of the VerifyNow platelet reactivity unit (PRU) assay in predicting hemorrhagic outcomes, and assess whether a clinically useful threshold for platelet response can be defined to standardize guidelines. METHODS: PubMed, Embase, and Scopus were searched. Articles were screened for relevance by title and abstract, followed by full text. RESULTS: Of 735 resultant articles, 17 studies of 2084 patients undergoing neuroendovascular intervention were included. Diagnoses included both intracranial and extracranial pathologies, of which 37.8% were treated with flow diversion, 22.4% with stent-assisted coil embolization, 14.3% with intracranial stenting, 12.8% with simple coil embolization, 5.8% with balloon-assisted coil embolization, 2.0% with extracranial stenting, and 4.8% with an alternate method. Precisely, 52.9% (9 out of 17) of studies determined platelet hyperresponse to be an independent predictor of postoperative hemorrhagic complications, with 11.8% (2 out of 17) of studies reporting a similar but non-statistically significant trend. 35.3% (6 out of 17) of studies found no relationship between platelet response and postoperative hemorrhagic complications. The estimated clinical threshold for PRU to prevent hemorrhagic complications varied considerably across studies (range: <46-118 PRU). Meta-analysis found platelet hyperresponse to have more than a 3-fold increased risk of hemorrhagic complications compared to normoresponders (relative risk = 3.2, p = 0.001). CONCLUSION: Although this meta-analysis shows the predictive utility of the P2Y12 assay for postoperative hemorrhagic complications in neuroendovascular surgery, the optimal therapeutic threshold for minimizing bleeding risk is still uncertain. To better understand the utility of the P2Y12 assay in the perioperative period, further prospective research is needed.

5-year stroke rates in nonvalvular atrial fibrillation after watchman compared to direct oral anticoagulants.

BACKGROUND: The WATCHMAN device (Boston Scientific; Marlborough, MA, USA) is noninferior to warfarin in preventing ischemic strokes while reducing bleeding risks associated with long term anticoagulation in nonvalvular atrial fibrillation (AFib). The device's performance compared to direct oral anticoagulants (DOAC) is less well known. OBJECTIVE: To compare 5-year major bleeding and ischemic stroke rates in patients with nonvalvular AFib who received a WATCHMAN device or DOAC therapy after a major bleeding event. METHODS: This retrospective, multicenter, 1:1 matched cohort study was derived from the PearlDiver Mariner database from 2010 to 2020. Patients with nonvalvular AFib on oral anticoagulation who had a major bleeding event were identified. Those who received either WATCHMAN or DOAC after resolution of the bleeding event were selected. The two groups were exactly matched 1:1 based on various comorbidities. Rates of ischemic stroke, transient ischemic attack (TIA), major bleeding, and hemorrhagic stroke were compared over 5 years. RESULTS: Each cohort consisted of 2248 patients after 1:1 matching. The mean CHADS2-VASC score was 4.81 ±â€¯1.25. At 5 years, the WATCHMAN cohort had significantly lower rates of major bleeding events [OR 0.24 (0.21, 0.27)], TIAs [OR 0.75 (0.58, 0.95)], and ischemic strokes [OR 0.72 (0.61, 0.86)]. There was no significant difference in hemorrhagic strokes [OR 1.14 (0.83, 1.58)]. CONCLUSION: Even in a high-risk population, the WATCHMAN is comparable to DOAC therapy in the primary prevention of hemorrhagic strokes and may provide benefit in the rates of bleeding events, TIAs, and ischemic strokes.

Analysis of cerebral venous sinus stenosis by flat panel angiographic CT (FP-CT) to guide treatment for idiopathic intracranial hypertension.

INTRODUCTION: Cerebral venous sinus stenting (CVSS) is an effective treatment for idiopathic intracranial hypertension (IIH) secondary to dural venous sinus stenosis. Traditional selection of patients for CVSS has been made by microcatheter manometry, but pressure measurements are often equivocal. Here we present the results of a series of cases in which venous flat-panel CT (FP-CT) was used as an adjunct to microcatheter manometry to improve decision making and precise stent placement during CVSS. METHODS: Ten consecutive patients with IIH underwent angiography with microcatheter manometry and venous FP-CT, with CVSS if indicated by the results. Cross-sectional measurements of the narrowed sinus were obtained on FP-CT before and after stenting. After the procedure, clinical outcomes were tracked. Follow-up with quantitative MRA with sinus flow measurements was also performed, when available. RESULTS: There was an exponential correlation between measured pressure gradient and degree of stenosis calculated using venous FP-CT. All patients with both a high degree of stenosis measured by FP-CT and a high pressure gradient across the stenosis showed a clinical benefit from stenting. CONCLUSIONS: True measurement of the cross-sectional area of the dural sinus, made by venous phase FP-CT, has a high degree of correlation with elevated venous pressure gradient across the point of stenosis. Even in a limited series of cases, we found an exponential decrease in flow with increasing severity of stenosis. Furthermore, patients with both an elevated venous pressure gradient and critical stenosis of the sinus on FP-CT showed symptomatic improvement after stenting.

Does disease etiology matter in long-term patency in extracranial-intracranial bypass?

OBJECTIVE: Extracranial-intracranial (EC-IC) bypass has been well described in chronic vaso-occlusive cerebrovascular diseases, including both moyamoya disease (MMD) and atherosclerotic disease (AD). This study aimed to compare factors associated with bypass occlusion between these two diseases. METHODS: An institutional database of 357 patients with intracranial bypass procedures performed between August 2001 and May 2022 was retrospectively reviewed. Patients with MMD and AD were selected for study. Baseline characteristics, surgical technique, and flow-related measurements were compared in relation to the outcome of bypass occlusion. RESULTS: A total of 232 patients met inclusion criteria (AD, n = 108; MMD, n = 124). The average age and sex differed significantly between groups (AD 57.2 years, 56.5% male; MMD 36.6 years, 31.5% male; p < 0.001). The modified Rankin Scale scores at surgery and at follow-up were higher in the AD group (p = 0.004 and p < 0.001, respectively), showing a slightly worse baseline functional status, and higher rates of stroke were observed in the AD group by last follow-up (p = 0.005). Patients with AD also were more likely to require an interpositional graft (p < 0.001). At last follow-up, rates of occlusion did not differ between AD and MMD groups (25.2% vs 25.4%, respectively). Of occluded bypasses, the AD group had more occlusions within 1 week compared to MMD (51.9% vs 35.5%, p = 0.176), although the difference was not significant. In patients with more than 1 year of follow-up and in those with more than 2 years of follow-up, MMD tended to have higher rates of occlusion (31.2% vs 26.1% [p = 0.558], and 26.4% vs 20.7% [p = 0.564]). Flow measurements did not differ between AD and MMD groups, but in subgroup analyses of patients with AD and those with MMD, both bypass flow and cut flow index predicted occlusion in both groups. CONCLUSIONS: Despite different disease etiologies treated with bypass, rates of occlusion at last follow-up did not vary between groups, although short-term follow-up would suggest earlier bypass failure in AD, and extended follow-up trended toward higher occlusion rates in MMD. Additionally, patients with AD were more likely to have further occurrences of stroke by last follow-up. Importantly, the bypass flow and cut flow index at the time of surgery predicted occlusion in both AD and MMD.

Are hemodynamics responsible for inflammatory changes in venous vessel walls? A quantitative study of wall-enhancing intracranial arteriovenous malformation draining veins.

OBJECTIVE: Signal enhancement of vascular walls on vessel wall MRI might be a biomarker for inflammation. It has been theorized that contrast enhancement on vessel wall imaging (VWI) in draining veins of intracranial arteriovenous malformations (AVMs) may be associated with disease progression and development of venous stenosis. The aim of this study was to investigate the relationship between vessel wall enhancement and hemodynamic stressors along AVM draining veins. METHODS: Eight AVM patients with 15 draining veins visualized on VWI were included. Based on MR venography data, patient-specific 3D surface models of the venous anatomy distal to the nidus were segmented. The enhanced vascular wall regions were manually extracted and mapped onto the venous surface models after registration of image data. Using image-based blood flow simulations applying patient-specific boundary conditions based on phase-contrast quantitative MR angiography, hemodynamics were investigated in the enhanced vasculature. For the shear-related parameters, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (RRT) were calculated. Velocity, oscillatory velocity index (OVI), and vorticity were extracted for the intraluminal flow-related hemodynamics. RESULTS: Visual observations demonstrated overlap of enhancement with local lower shear stresses resulting from decreased velocities. Thus, higher RRT values were measured in the enhanced areas. Furthermore, nonenhancing draining veins showed on average slightly higher flow velocities and TAWSS. Significant decreases of 55% (p = 0.03) for TAWSS and of 24% (p = 0.03) for vorticity were identified in enhanced areas compared with near distal and proximal domains. Velocity magnitude in the enhanced region showed a nonsignificant decrease of 14% (p = 0.06). Furthermore, increases were present in the OSI (32%, p = 0.3), RRT (25%, p = 0.15), and OVI (26%, p = 0.3) in enhanced vessel sections, although the differences were not significant. CONCLUSIONS: This novel multimodal investigation of hemodynamics in AVM draining veins allows for precise prediction of occurring shear- and flow-related phenomena in enhanced vessel walls. These findings may suggest low shear to be a local predisposing factor for venous stenosis in AVMs.

Refinement of nBCA embolization technique in treatment of metastatic spinal tumors: Case series and technical report.

BACKGROUND AND OBJECTIVES: Preoperative embolization of metastatic spinal tumors (MSTs) has proven advantageous in limiting intraoperative blood loss (IBL) during resection. N-butyl cyanoacrylate (nBCA) is a liquid embolic agent known for its rapid hemostatic effects. However, nBCA is associated with a higher risk of distal nontarget embolization. This study highlights the refinement of the embolization technique and assesses its efficacy in performing an initial distal segmental artery plug with concentrated nBCA followed by proximal diluted nBCA for MSTs. METHODS: A retrospective review of patients with MST (2018-2023) was performed. Patients who underwent preoperative nBCA endovascular embolization prior to tumor resection and spinal instrumentation were included. Baseline standard spinal angiography was performed. RESULTS: Sixteen patients (13 men, 3 women; 56.0 ± 12.4 years) met inclusion criteria. And 43.75% (7 of 16) had thoracic levels, 37.5% (6 of 16) lumbar, and 18.75% (3 of 16) sacral. The most common primary tumor was renal cell carcinoma (43.75%, 7 of 16). A total of 43 pedicles were embolized (median 3), resulting in complete/near complete obliteration of the tumor blush. Most pedicles (83.7%, 36 of 43) received a single dilute concentration of nBCA; however, 16.3% (7 of 43) received two separate concentrations of nBCA, a denser concentration distally into the segmental artery and a diluted concentration proximally into the tumor bed. Mean IBL was 1150 ± 1201 mL in 3 distal plug patients distal plug patients versus 1625 ± 681 mL in 12 other patients. There were no complications related to embolization. CONCLUSION: Performing a distal, concentrated nBCA plug during preoperative nBCA embolization of MSTs may increase tumor penetration and reduce IBL.

The correlation of cerebral arteriovenous malformation flow measured by quantitative MR angiography on MR-detected arteriovenous malformation microhemorrhage.

OBJECTIVE: The objective of this study was to assess the relationship of arteriovenous malformation (AVM) blood flow measured by quantitative MR angiography (QMRA) in nonruptured AVMs with MR-detected microhemorrhage. METHODS: All patients with unruptured AVMs who received baseline QMRA and gradient echo or susceptibility-weighted MRI were retrospectively reviewed (2004-2022). Imaging data, clinical history, and AVM angioarchitectural and flow features were collected and assessed. AVM flow was calculated from the difference of flow within primary arterial feeders from their contralateral counterparts. A review of the MR images determined the presence of microhemorrhages. Analysis of descriptive statistics, chi-square test, and binomial logistic regression were performed. RESULTS: Of 634 patients with cerebral AVMs at a single center, 89 patients met the inclusion criteria (54 with microhemorrhage and 35 without microhemorrhage). The calculated AVM flow was significantly higher in the group with a microhemorrhage (447.9 ± 193.1 ml/min vs 287.6 ± 235.7 ml/min, p = 0.009). In addition, the presence of venous anomaly, arterial ectasia, and diffuse nidus was significantly associated with microhemorrhage (p = 0.017, p = 0.041, and p = 0.041, respectively). Binary logistic regression found that higher flow predicted the presence of microhemorrhage (OR 1.002, 95% CI 1.000-1.004; p = 0.031). The highest AVM flow quartile significantly predicted the presence of venous anomaly (OR 3.840, 95% CI 1.037-14.213; p = 0.044), diffuse nidus (OR 6.800, 95% CI 1.766-25.181; p = 0.005), and arterial ectasia (OR 13.846, 95% CI 1.905-122.584; p = 0.018). CONCLUSIONS: This study represents the first to examine the association between flow measurements on QMRA with microhemorrhage in unruptured AVMs. Higher AVM flow, venous anomaly, arterial ectasia, and diffuse AVM nidus were related to a higher likelihood of AVM microhemorrhage. Higher AVM flow was present in AVMs with venous anomalies, a diffuse nidus, and arterial ectasia, indicating a possible interaction between these angioarchitectural findings, AVM flow, and microhemorrhage. These findings suggest a relationship between higher AVM flow and the risk of microhemorrhage.

Part 1: Pushing the boundaries of neurointerventional surgery: A historical review of the work of Dr Gerard Debrun.

French-American neurointerventionalist and pioneer, Dr Gerard Debrun, laid the groundwork for treatments which have become irreplaceable in neurointerventional surgery today. This article aims to outline the career of Dr Debrun while highlighting his accomplishments and contributions to the field of neurointerventional surgery. We selected relevant articles from PubMed authored or co-authored by Dr Debrun between 1941 and 2023. All included articles discuss the accomplishments and contributions of Dr Debrun. Dr Debrun began his career in France by investigating neurointerventional techniques, most notably the intravascular Detachable Balloon Catheter (DBC). His work was recognized by renowned neurosurgeon Dr Charles Drake, who recruited him to London, Ontario. Dr Debrun created the foundation for homemade manufacturing of DBCs, building on one of the largest series for use of DBCs in cerebrovascular disease. Dr Debrun spent time as faculty at Massachusetts General Hospital (MGH) and Johns Hopkins Hospital, before arriving at the University of Illinois Chicago (UIC) where he remained until his retirement. Dr Debrun's subsequent contributions included the calibrated-leak balloon catheter, pioneering of glue embolization, setting the foundation for preoperative AVM embolizations, and as an early adopter of the Guglielmi detachable coil (GDC), including mastering the balloon remodeling technique for wide neck aneurysms. Dr Debrun established the first integrated neurointerventional surgery program at UIC, establishing a well sought-after fellowship program. Dr Debrun lectured extensively and was a prolific writer on neurointerventional surgery throughout this career. His contributions established the foundation for several techniques which have since become standard practice in present-day neurointerventional surgery.

Part 2: The development and advancement of the detachable balloon catheter; a historical and technical review.

The detachable balloon catheter (DBC) was a revolutionary technique for the treatment of cerebrovascular pathologies. It was used to treat carotid cavernous fistulas (CCFs), vertebro-jugular fistulas, arteriovenous malformations (AVMs), and aneurysms. The DBC became the foundation for neurointerventional techniques, leading to the development of coil embolization and bioactives. Our team selected relevant articles from PubMed published between 1974 and 2023. Articles were excluded if they did not discuss the use or development of the detachable balloon catheter or subsequent technologies. The DBC was used to occlude vessels, either temporarily or permanently. Dr Gerard Debrun implemented findings from Dr Fedor Serbinenko's research to develop an intravascular detachable balloon technique. He developed many variations using type I and type II balloon catheters that differed in size, length, and material, allowing for the personalization of treatment based on the lesion. This revolutionary thinking showed that every pathology has a different shape and anatomy that require a unique approach. The DBC would offer the first alternative to the conventional practice of carotid occlusion in CCF treatment at the time. The DBC would later be used in aneurysm occlusion and the embolization of AVMs, with additional benefit in traumatic vascular sacrifice. Although the DBC has largely been replaced, it is still useful in a small subset of patients, and has financial incentive as it is more affordable than coils. This technique was a monumental stride in the history of neurointervention and helped propel the specialty to the current era of patient-specific interventions.

Hemorrhagic versus non-hemorrhagic presentation of presumed reversible cerebral vasoconstriction syndrome (RCVS): Presentations and outcomes.

INTRODUCTION: Reversible cerebral vasoconstriction syndrome (RCVS) can present with hemorrhage, ischemia, or both. We aim to compare the differences in presentation and outcomes between patients with RCVS. METHODS: The hemorrhagic presentation group had 58 patients, and the non-hemorrhagic presentations had 30 patients. Subgroup analysis compared patients with evidence of one or more types of hemorrhage (n = 53), no evidence of hemorrhage or infarction (n = 23), evidence of infarction only (n = 7), and combination of hemorrhage and infarction (n = 5). Clinical and radiographic data were analyzed. RESULTS: Migraine (p = 0.030) and intracranial tumors (p = 0.004) were more frequent in non-hemorrhagic presentation. Seizures on admission (p = 0.047) and higher than average C-reactive protein (CRP) (p = 0.037) were seen at a higher rate in patients with hemorrhagic presentation. RCVS2 scores were not unexpectedly higher in patients with hemorrhage than non-hemorrhagic presentations (p = 0.010). Outcomes between the hemorrhagic and non-hemorrhagic groups were comparable. Subgroup analysis found a higher subset of patients with opiate use (p = 0.046) in the hemorrhage-only group. Patients with hemorrhage presented with a thunderclap headache (p < 0.001) more often when compared to the other three groups. RCVS2 score was not unexpectedly higher in the hemorrhage-only group compared with the other groups (p = 0.004). CONCLUSION: A history of migraines was associated with ischemia, while intracranial tumor was significantly associated with evidence of either an infarct, or no changes on imaging. Exposure to opiates, and seizures or thunderclap headache on presentation were associated with hemorrhage. If our data are reproducible, the RCVS2 score may benefit from inclusion of other, small hemorrhages as criterion for diagnosis for RCVS.