Posterior Cerebral Artery Involvement Research Articles

The Association of Heterozygous p.R4810K of RNF213 and Long-Term Unfavorable Outcomes after Encephaloduroarteriosynangiosis in Chinese Pediatric Patients with Moyamoya Disease

Background. Previous studies have established that heterozygous mutation for the p.R4810K variant can influence the severity of the clinical phenotype in patients with moyamoya disease (MMD) at disease onset. However, the relationship between the p.R4810K variant and the clinical phenotype of long-term unfavorable outcomes in Chinese pediatric patients remains unclear. Objectives. The primary aim of this study was to examine the association of heterozygous p.R4810K of RNF213 and long-term unfavorable outcomes after encephaloduroarteriosynangiosis (EDAS) in Chinese pediatric patients with MMD. Method. In this retrospective cohort study, we included 259 pediatric patients with MMD who possessed the known p.R4810K genotype. These individuals underwent EDAS along with genotyping analysis for p.R4810K via a TaqMan probe and the QuantStudio 6 Flex Real-Time PCR System. Subsequently, we evaluated their long-term outcomes. The variables we assessed were age at diagnosis, gender, p.R4810K genotypes, initial modified Rankin scale (mRS), clinical manifestations (such as hemorrhage and ischemia), posterior cerebral artery (PCA) involvement combined with angiographic stage, and their history of risk factors like hyperlipidemia and hyperhomocysteinemia. Furthermore, we scrutinized long-term unfavorable outcomes using both univariate analyses and multivariate logistic regression to identify independent predictive factors. Results. This study enrolled 259 Chinese pediatric patients with MMD, which included both newly and previously diagnosed cases, who underwent EDAS. The cohort comprised 130 male participants (50.19%) and 129 female participants (49.81%), with a median onset age of 8 years (median, IQR: 6-12 years). Among these patients, homozygous mutations were exceptionally rare, identified in only 4 individuals (1.54%), while the prevalence of heterozygous mutations was relatively higher, observed in 85 children (32.82%). The multivariate logistic regression showed that several factors were significantly associated with long-term unfavorable outcomes: older age at diagnosis (OR, 0.82 [95% CI, 0.7-0.96], P=0.014), onset with hematoma (OR, 12.76 [95% CI, 1.52-106.89], P=0.019), initial mRS (OR, 24.53 [95% CI, 6.51-92.41], P<0.001), perioperative infarction (OR, 22.16 [95% CI, 1.45-337.96], P=0.026), and infarction during follow-up (OR, 14.5 [95% CI, 2.04-103.12], P=0.008). Furthermore, the cumulative incidence of initial infarction suggested that pediatric patients with homozygous or heterozygous mutations typically present at a younger age and exhibit a higher incidence of initial infarction compared to those carrying wild-type genotypes. Conclusions. The study suggests that the p.R4810K variant is associated with the onset age of MMD in Chinese pediatric patients, potentially impacting long-term outcomes. Surprisingly low recurrent stroke rates were observed across all genotypes, including homozygous individuals for the pathogenic variant, indicating that nongenetic factors may also play a role in the course and outcomes of MMD in this population.

The Potential Role of Preoperative Posterior Cerebral Artery Involvement in Predicting Postoperative Transient Neurological Deficits and Ischemic Stroke After Indirect Revascularization in Patients With Moyamoya Disease

ObjectiveTransient neurological deficits (TNDs) are known to develop after direct bypass for moyamoya disease (MMD) and may be risk factors for subsequent stroke. However, the factors involved in the development of TNDs and stroke after indirect revascularization alone, including their association with subsequent stroke, remain unclear. The purpose of this study was to investigate this issue. MethodsThe subjects of the study were 30 patients with MMD who underwent a total of 40 indirect revascularization procedures at our institution. Clinical and radiological data were collected retrospectively. To examine factors associated with the development of postoperative TND/stroke/asymptomatic disease, the clinical characteristics of each group were statistically compared. ResultsThe mean age at surgery was 7 years (range 1-63). TNDs developed after surgery in 9 out of 40 patients (22.5%). Stroke in the acute postoperative period occurred in 3 patients (7.5%), all of whom experienced cerebral infarctions. Demographic data and preoperative clinical information were not different between the groups. However, posterior cerebral artery (PCA) involvement on preoperative imaging was significantly associated with the development of TNDs and stroke (p=0.006). Furthermore, postoperative stroke was associated with unfavorable outcomes (p=0.025). ConclusionsPCA involvement is significantly associated with the occurrence of TNDs. In contrast, TNDs after indirect revascularization have little relationship with the subsequent development of stroke. TNDs usually resolve without new strokes, and a better understanding of this particular pathology could help establish an optimal treatment regimen.

Development and validation of machine learning models to predict postoperative infarction in moyamoya disease.

Cerebral infarction is a common complication in patients undergoing revascularization surgery for moyamoya disease (MMD). Although previous statistical evaluations have identified several risk factors for postoperative brain ischemia, the ability to predict its occurrence based on these limited predictors remains inadequately explored. This study aimed to assess the feasibility of machine learning algorithms for predicting cerebral infarction after revascularization surgery in patients with MMD. This retrospective study was conducted across two centers and harnessed data from 512 patients with MMD who had undergone revascularization surgery. The patient cohort was partitioned into internal and external datasets. Using perioperative clinical data from the internal cohort, three distinct machine learning algorithms-namely the support vector machine, random forest, and light gradient-boosting machine models-were trained and cross-validated to predict the occurrence of postoperative cerebral infarction. Predictive performance validity was subsequently assessed using an external dataset. Shapley additive explanations (SHAP) analysis was conducted to augment the prediction model's transparency and to quantify the impact of each input variable on shaping both the aggregate and individual patient predictions. In the cohort of 512 patients, 33 (6.4%) experienced postrevascularization cerebral infarction. The cross-validation outcomes revealed that, among the three models, the support vector machine model achieved the largest area under the receiver operating characteristic curve (ROC-AUC) at mean ± SD 0.785 ± 0.052. Notably, during external validation, the light gradient-boosting machine model exhibited the highest accuracy at 0.903 and the largest ROC-AUC at 0.710. The top-performing prediction model utilized five input variables: postoperative serum gamma-glutamyl transpeptidase value, positive posterior cerebral artery (PCA) involvement on preoperative MRA, infarction as the rationale for surgery, presence of an infarction scar on preoperative MRI, and preoperative modified Rankin Scale score. Furthermore, the SHAP analysis identified presence of PCA involvement, infarction as the rationale for surgery, and presence of an infarction scar on preoperative MRI as positive influences on postoperative cerebral infarction. This study indicates the usefulness of employing machine learning techniques with routine perioperative data to predict the occurrence of cerebral infarction after revascularization procedures in patients with MMD.

Clinical characteristics, Risk factors, and outcomes of Posterior circulation stroke: A retrospective study between younger and older adults in Saudi Arabia

IntroductionPosterior circulation stroke (PCS) may be less prevalent than its anterior counterpart but contributes to substantial morbidity and mortality. The aim was to characterize PCS's demographics, clinical presentation, management, and outcomes between younger and older adults in Saudi Arabia. MethodsThis retrospective cohort study was conducted at two tertiary medical centers in Saudi Arabia between March 2016 and December 2020. All patients who presented with symptoms of posterior circulation stroke and had positive brain imaging were included. ResultsThe study involved 160 posterior circulation stroke patients, stratified into two age groups: 71 patients aged 18-59 years and 89 patients aged 60 years and above. The mean age of the entire cohort was 60.9 years, and 77 % were males. Hypertension was more prevalent in the older age group (88 % vs. 69 %, p=0.005), and smoking was significantly higher among younger patients (38 % vs. 15 %; p=0.0009). Only 22.4 % received thrombolysis and/or thrombectomy. Most strokes involved the posterior cerebral artery (45.6 %). Large artery atherosclerosis was the most common subtype. At discharge, younger patients had higher NIHSS compared to older patients. ConclusionOur investigation of 160 PCS patients in Saudi Arabia uncovers notable trends: a mere 22.4 % received thrombolysis and/or thrombectomy and a significant prevalence of posterior cerebral artery involvement due to large artery atherosclerosis. The study further reveals younger patients disproportionately had severe outcomes. Highlighting the need for improved stroke care and heightened awareness, this research contributes vital data to an underexplored domain, urging further study to optimize care and understand PCS dynamics in Saudi Arabia.

Abstract WP226: Perioperative Stroke and Cardiac Anomalies Associated With Posterior Cerebral Artery Stenosis in Children With Moyamoya

Introduction: Moyamoya is a progressive steno-occlusive arteriopathy of the intracranial circulation affecting the anterior circulation and less often the posterior circulation. Risk factors and severity of disease progression in children with moyamoya and posterior cerebral artery (PCA) stenosis have not been well described in the literature. Previous research has shown an association between PCA stenosis and increased risk of post-operative stroke. We wanted to further explore this relationship in children with moyamoya and delineate the associated risk factors. Methods: Children with moyamoya who underwent surgical revascularization at our institution between December 2015 and December 2022 were reviewed for presence of PCA stenosis. Clinical and radiographic features were compared between children with moyamoya with and without PCA involvement. Categorical variables were compared using Fisher's exact test and continuous variables using Wilcoxon rank-sum. Associations between perioperative stroke and PCA stenosis were analyzes using a multivariate logistic regression. Results: In our cohort of 160 children with moyamoya, 45 (28%) had PCA stenosis; 26 of these 45 (57%) had PCA stenosis at time of diagnosis. Of the 19 children who did not have PCA stenosis at time of diagnosis but developed it during follow up, the median time to development of PCA stenosis was 1.0 years. Children with moyamoya and PCA stenosis had significant more cardiac anomalies than those without (p=0.02). Other associated disorders were found in 13 (28%) including trisomy 21 (6, 13%), cranial radiation (2,4%) and NF1 (3,7%). Interestingly, we found no significant difference in age, sex or prevalence of bilateral disease between the groups. Children with moyamoya and PCA stenosis had a 3.5 higher odds of having a stroke within 2 weeks of surgery (p=0.049). Conclusion: Children with moyamoya and PCA stenosis had a 3 fold higher odds of perioperative stroke compared to those without PCA stenosis. Genetic evaluations may be warranted given association of PCA stenosis and cardiac anomalies.

Synergistic Interaction of Thyroid Autoantibodies and Ring Finger Protein 213 Variant in Moyamoya Disease.

Recently, thyroid autoantibodies were found to be associated with moyamoya disease (MMD). The ring finger protein 213 (RNF213) p.R4810K variant represents the most important susceptibility genotype of this disease, but its relationship with thyroid autoantibodies remains to be elucidated. Thus, in this study, we aimed to evaluate the clinical relevance of thyroid autoantibodies in each RNF213 genotype in patients with MMD. Included in this study were patients with MMD without a thyroid disease history and in euthyroid status; they were then classified into the mutated or nonmutated based on the RNF213 p.R4810K genotype and positive or negative based on thyroid autoantibody (thyroperoxidase and thyroglobulin) levels. Clinical data of each group were thereafter evaluated. Among the 209 patients, the mutated RNF213 p.R4810K variant and positive thyroid autoantibodies were detected in 155 and 41 patients, respectively. Positive thyroid autoantibodies were found to be more common in the nonmutated patients than in the mutated patients (31.5% vs. 15.5%; P = 0.011). In the mutated patients, as compared to autoantibody-negative patients, autoantibody-positive patients were determined to be more likely to have advanced disease with posterior cerebral artery involvement (54.2% vs. 29.0%; P = 0.017), white matter infarction (58.3% vs. 37.6%; P = 0.046), and a higher modified Rankin Scale at last visit (16.7% vs. 3.1%; P = 0.021). These results suggest that thyroid autoantibodies can act as an immunity inducer in patients with MMD lacking the susceptibility gene RNF213 p.R4810K variant. Moreover, the simultaneous presence of thyroid autoantibodies and the variant seems to aggravate the disease, which indicates synergy between thyroid autoantibodies and the variant.

Neuregulin 1 as a potential biomarker for disease progression in moyamoya disease: A case-control study in Chinese population

ObjectiveMoyamoya disease (MMD) is a rare and progressive stenosis of cerebral arteries characterized by abnormally proliferative vasculopathy. Current studies have demonstrated that Neuregulin 1 (NRG1) plays a key role in angiogenesis-related disorders. Thus, the aim of our study is to investigate the serum NRG1 levels and their clinical correlations in MMD patients. MethodsIn this study, thirty adult patients with MMD and age-gender matched healthy controls were enrolled from our hospital between July 2020 and April 2022. Peripheral blood samples were collected at baseline, and clinical data were obtained from the electronic medical record system. Serum NRG1 concentrations were measured by enzyme-linked immunosorbent assay. Sanger sequencing was applied to detect the RNF213 p.R4810K mutation. ResultsThe serum NRG1 levels were significantly higher in MMD patients compared to controls (14.48 ± 10.81 vs.7.54 ± 6.35mmol/L, p < 0.001). No statistical difference in baseline clinical characteristics was found between both groups. Correlation analyses showed that NRG1 levels were positively associated with Suzuki staging (r = 0.4137, p = 0.023) while not related to other clinical features (reduced cerebral blood flow, posterior cerebral artery involvement, bilateral or unilateral steno-occlusive changes). Furthermore, subgroup analysis revealed that MMD patients with the RNF213 p.R4810K mutation presented with significantly higher NRG1 levels than those without the mutation (9.60 ± 0.929 vs. 25.89 ± 4.338 mmol/L, p = 0.001). ConclusionsOur study suggests that increased serum NRG1 levels may constitute a characteristic feature of MMD, indicating a potential positive correlation with disease progression and the presence of the RNF213 mutation. This positions NRG1 as a potentially crucial target for further studies aimed at comprehending the pathogenesis of MMD.

Coexistence of anterior choroidal artery and posterior cerebral artery retia mirabilia presenting with subarachnoid hemorrhage: illustrative case.

A rete mirabile is a rare vascular anomaly, with posterior cerebral artery (PCA) involvement being especially rare. Its pathogenesis has been speculated as a remnant of "distal annexation" between the primitive anterior choroidal artery (AchA) and the PCA at this site, but the exact mechanisms remain unclear. A 29-year-old man presented with subarachnoid hemorrhage. Arteriovenous malformation in the medial temporal lobe was initially suspected, but an arteriovenous shunt was not detected. First, conservative treatment was administered; however, rebleeding occurred 1 month later. Carotid angiography revealed a network-like cluster of blood vessels at the choroidal point of the AchA, suggesting a rete mirabile; these vessel clusters led to the persistent temporo-occipital branch of the AchA. Furthermore, an aneurysm was detected at the junction between the rete mirabile and the persistent temporo-occipital branch of the AchA. Additionally, vertebral angiography demonstrated a rete mirabile at the P2 segment. These findings suggested the coexistence of AchA and PCA retia mirabilia. Consequently, the aneurysm was clipped using a subtemporal approach to prevent re-rupture, and the postoperative course was uneventful. This first report of coexisting AchA and PCA retia mirabilia supports the remnant of distal annexation between the primitive AchA and the PCA as the reason for rete formation at this site.

Posterior cerebral artery involvement in unilateral moyamoya disease is exclusively ipsilateral and influenced by RNF213 mutation gene dose: The SUPRA Japan study: PCA involvement in unilateral moyamoya

ObjectivesThe characteristics and clinical implications of posterior cerebral artery (PCA) involvement in unilateral moyamoya disease (U-MMD), such as laterality, frequency of the RNF213 p.R4810K mutation, and clinical outcomes, have not been well studied. Population and methodsWe analyzed a cohort of 93 patients with U-MMD who participated in the SUPRA Japan study. Clinical characteristics and radiological examinations were collected from medical records. The presence of the p.R4810K mutation was determined using a TaqMan assay. The clinical outcome was assessed using the modified Rankin Scale (mRS). Univariate and multivariate logistic regression analyses were performed to assess the associations. ResultsAmong the patients with U-MMD, PCA involvement was observed in 60.0 % (3/5) of patients with homozygous mutation, 11.3 % (7/62) of those with heterozygous mutation, and 3.8 % (1/26) of those with wild type, showing a significant linear trend (p < 0.001 for trend). PCA involvement was observed exclusively on the same side as the affected anterior circulation. Dyslipidemia and cerebral infarction at initial onset were independently associated with mRS ≥1. Hypertension was associated with mRS ≥1 and it was also linked to infarction at initial onset, suggesting a potential confounding effect. Although PCA involvement showed a trend for higher mRS, it was not statistically significant. ConclusionsOur findings indicate a gene dose effect of the p.R4810K mutation on PCA involvement, with the homozygous state showing the most significant effect. Both genetic and modifiable factors such as dyslipidemia may influence the progression of U-MMD.

A long-term study of posterior circulation changes after revascularization in patients with moyamoya disease.

This study aimed to explore the long-term course of posterior circulation changes and predictors in patients with moyamoya disease (MMD). The authors retrospectively enrolled patients who were diagnosed with MMD and underwent encephaloduroarteriosynangiosis (EDAS) surgery at the authors' department from December 2002 to September 2011. A comparative study between short-term (6-12 months) and long-term (≥ 9 years) follow-up angiography was conducted. The progression of lesions was defined from lower to higher stages of the posterior cerebral artery (PCA). Eighty-eight patients who received indirect EDAS were enrolled in the study. The mean age at first surgery was 28.1 ± 15.0 years. Among these 88 patients with MMD, 39 (44.3%) exhibited transient ischemic attack and 27 (30.7%) exhibited infarction, comprising 5 with occipital lobe infarction, 14 (15.9%) with hemorrhagic symptoms, and 8 (9.1%) with atypical symptoms as the initial symptoms. Heterozygous mutations occurred significantly more frequently in the cases that presented with PCA involvement. During follow-up, stage progression of PCA was observed in 21 patients (28 hemispheres). At short-term follow-up, 21/176 (11.9%) hemispheres had progression of steno-occlusive lesions in the PCA. At long-term follow-up, 7 (4.0%) hemispheres had progression of steno-occlusive lesions in the PCA. At short-term follow-up, the progression of steno-occlusive lesions in the PCA was associated with progression of the internal carotid artery. Stage progression of PCA occurred significantly more frequently in the cases with PCA involvement on preoperative angiography. Nine strokes (10.2%) occurred in 88 patients during long-term follow-up. Four patients (4.5%) presented with ischemic stroke, including 2 with occipital lobe infarctions. Progression of PCA stenosis is common in patients with MMD, even if the PCA is normal initially. Mutations of RNF213 p.R4810K may predict PCA involvement or progression. Follow-up of the PCA in MMD patients should be conducted, and timely surgical revascularization is needed.

Ischemic patterns and their angiographic risk factors in adult patients with moyamoya disease.

The present study aims to determine whether angiographic differences increase the risk of ischemic pattern among adult patients with moyamoya disease (MMD). From January 2020 to December 2021, we retrospectively enrolled 123 ischemic or asymptomatic adult patients diagnosed as MMD. Angiographic changes including Suzuki stage, moyamoya vessels, anterior choroidal artery (AChoA) dilatation, lenticulostriate artery (LSA) dilatation, posterior communicating artery (PcomA) dilatation, and posterior cerebral artery (PCA) involvement were evaluated for all patients. Among the 123 participants, 35 ischemic patients and 88 asymptomatic patients were analyzed. There was no significant difference of Suzuki stage, AChoA dilatation, LSA dilatation, and PcomA dilatation between ischemic group and asymptomatic group. The grading of moyamoya vessels differed significantly but was not a factor associated with ischemic pattern after adjusting multiple related confounders. However, the frequency of PCA steno-occlusive changes in ischemic patients was statistically higher than that in asymptomatic patients (54.3% vs 34.1%, p = 0.039). Furthermore, PCA involvement was a risk factor associated with ischemic form and remained statistically significant after the multivariate adjustment (p = 0.033, 95% CI 1.092-8.310). PCA involvement is closely related to the presentation of ischemic stroke but other angiographic features had no association with ischemic pattern in adult MMD.

Bypass Surgery for Adult-Onset Hemorrhagic Moyamoya Disease: Analysis Classified by Site of Initial Bleeding

Prevention of rebleeding events is crucial for patients with hemorrhagic moyamoya disease (MMD), as these increase the risk of mortality. Bypass surgery is effective in preventing subsequent hemorrhage, particularly in patients with posterior hemorrhage, but its efficacy in those with anterior hemorrhage remains unclear. We analyzed the effects of surgical intervention, stroke risk factors, and radiological features on rebleeding events. Patients with hemorrhagic-onset MMD who were followed at our institution between 2000 and 2022 were included (41 adult patients, 45 hemispheres). Baseline characteristics and radiological features (anterior or posterior hemorrhagic site, Suzuki grade, posterior cerebral artery involvement, and periventricular anastomosis) were thoroughly reviewed. Of the 45 hemispheres, hemorrhage developed in 9 (20%) hemispheres, with a median duration until rebleeding of 38 (range: 1-44) months. Rebleeding rates were significantly lower in the surgical group than in the nonsurgical group (odds ratio: 0.09; 95% confidence interval [CI]: 0.01-0.79; P= 0.011), and Kaplan-Meier analysis revealed a significantly longer interval between bleeding events in the surgical group (1.3%/y vs. 5.3%/y; P= 0.002), especially in the anterior hemorrhage group (1.3%/y vs. 5.1%/y; P= 0.019). The hazard ratio of surgical intervention for rebleeding with initial anterior hemorrhage was 0.11 (95% CI: 0.01-0.98; P= 0.048). In the nonsurgical group, the presence of hypertension shortened the time to subsequent hemorrhage (P= 0.004). Surgical intervention may decrease the risk of rebleeding in hemorrhagic onset MMD patients, even in those presenting with anterior hemorrhage. Hypertension was a significant risk factor for rebleeding in nonsurgical patients.

Association between DIAPH1 variant and posterior circulation involvement with Moyamoya disease

Moyamoya disease (MMD) is a chronic and progressive cerebrovascular stenosis or occlusive disease that occurs near Willis blood vessels. The aim of this study was to investigate the mutation of DIAPH1 in Asian population, and to compare the angiographic features of MMD patients with and without the mutation of the DIAPH1 gene. Blood samples of 50 patients with MMD were collected, and DIAPH1 gene mutation was detected. The angiographic involvement of the posterior cerebral artery was compared between the mutant group and the non-mutant group. The independent risk factors of posterior cerebral artery involvement were determined by multivariate logistic regression analysis. DIAPH1 gene mutation was detected in 9 (18%) of 50 patients, including 7 synonymous mutations and 2 missense mutations. However, the incidence of posterior cerebral artery involvement in mutation positive group was very higher than that in mutation negative group (77.8% versus 12%; p = 0.001). There is an association between DIAPH1 mutation and PCA involvement (odds ratio 29.483, 95% confidence interval 3.920–221.736; p = 0.001). DIAPH1 gene mutation is not a major genetic risk gene for Asian patients with moyamoya disease but may play an important role in the involvement of posterior cerebral artery.

Meta-analysis of the association between RNF213 polymorphisms and clinical features of moyamoya disease in Asian population

BackgroundWe performed this study to explore the relationship between ring finger protein 213 (RNF213) gene polymorphisms and clinical features in moyamoya disease (MMD). MethodsElectronic databases (PubMed, Google Scholar, Embase, Scopus, Cochrane Library) were conducted from inception to May 15th, 2022. Odds ratios (ORs) with 95 % confidence intervals (CIs) were generated as effect size for binary variants. Subgroup analyses were performed by the RNF213 polymorphisms. Sensitivity was used to examine the robustness of associations. ResultsA total of 16 articles and 3061 MMD patients were included and the association of five RNF213 polymorphisms on 9 clinical features of MMD were identified. Patients under 18 years of age at onset, familial MMD, cerebral ischemic stroke and posterior cerebral artery involvement (PCi) were significantly more common in mutant type compared with wild type of RNF213. Compared with each wild type, subgroup analysis showed that rs11273543 and rs9916351 remarkably increased risk of MMD on early onset, but rs371441113 evidently delayed the onset of MMD. Rs112735431 in mutant type was significantly higher than wild type in patients with PCi. Subgroup analysis in mutant type showed that rs112735431 conspicuously decreased intracerebral/ intraventricular hemorrhage (ICH/IVH) risk and yet rs148731719 obviously increased the risk in ICH/IVH. ConclusionMore attention should be paid to patients on whom the ischemic MMD occurs younger than 18 years old. RNF213 polymorphism screening and cerebrovascular imaging examination should be performed to evaluate intracranial vascular involvement, to achieve early detection and early treatment and avoid more serious cerebrovascular events.

Posterior Reversible Encephalopathy Syndrome (PRES), Hypoxic Injury and Stroke: A Sequelae of Bath Salt Inhalation? (P2-5.012)

<h3>Objective:</h3> To describe a case of bath salt inhalation causing PRES, hypoxic injury, and acute stroke. <h3>Background:</h3> Bath salts contain 3,4-methylenedioxypyrovalerone, a substance similar to cocaine and amphetamines, and can lead to vasospasm by inhibiting dopamine and norepinephrine reuptake. PRES and stroke can be caused by hypertension, but its coexistence in a patient with bath salt inhalation has been not described. <h3>Design/Methods:</h3> This is a case report of a 48-year-old female patient with a history of heroin abuse was found unresponsive. On arrival, was noted to have a systolic blood pressure over 200s and was seizing. On exam, she had expressive and receptive aphasia. Initial labs including a urine toxicology screen were unremarkable. CTA was concerning for vasospasm vs vasculitis. MRI Brain revealed multiple infarcts in bilateral hemisphere with extensive involvement of left posterior cerebral artery and T2 hyperintensities in the bilateral cerebellum and pons. Moreover, T2 FLAIR hyperintensities were noted in bilateral frontal and parietal white matter indicative of PRES. There was also injury to bilateral thalami and watershed vascular distributions suggestive of hypoxic insult. Extensive workup including TEE and LP failed to show an embolic source or vasculitis. <h3>Results:</h3> On further history, mother reported that patient routinely inhales bath salts. PRES findings were improved on repeat MRI 5 days later, but ischemia persisted. Her BP was hard to manage as stroke requires permissive hypertension and PRES requires BP control. She remained aphasic. <h3>Conclusions:</h3> Bath salt inhalation is shown to be associated with ischemic colitis and myocardial infarction, but no instances of stroke or PRES have been reported. The pathophysiological mechanisms between PRES and stroke differ, but may be secondary to vasospasm in the setting of bath salt inhalation. <b>Disclosure:</b> Dr. Mufti has nothing to disclose. Dr. Shi has nothing to disclose. Dr. Mufti has nothing to disclose. Dr. Hasan has nothing to disclose.

Risk factors and a novel cerebral infarction extent scoring system for postoperative cerebral ischemia in patients with ischemic Moyamoya disease

Postoperative cerebral ischemic complication is the most common complication of revascularization surgery for patients with moyamoya disease (MMD). This retrospective study was conducted on 63 patients with ischemic MMD. Postoperative ischemia occurred in 15 of the 70 revascularization operations performed for patients after surgical revascularization, translating to an incidence of 21.4%. Univariate analysis revealed that onset infarction (p = 0.015), posterior cerebral artery involvement (p = 0.039), strict perioperative management (p = 0.001), interval time between transient ischemic attack (TIA) or infarction presentation and operation (p = 0.002) and preoperatively cerebral infarction extent score (CIES) (p = 0.002) were significantly associated with postoperative cerebral ischemia. Multivariate analysis revealed that strict perioperative management (OR = 0.163; p = 0.047), and preoperatively CIES (OR = 1.505; p = 0.006) were independently associated with postoperative cerebral ischemia-related complications. After comprehensive improvement of perioperative management protocol, the incidence of symptomatic infarction declined to 7.4% (4 out of 54). Analysis of the area under the receiver operating characteristic curve (AUROC) indicated CIES was a predictor for both postoperative ischemia and high follow-up modified Rankin Scale scores. In summary, strict perioperative management and CIES were identified as independent risk factors for postoperative ischemic complications in ischemic MMD, demonstrating that comprehensive and individualized perioperative management improve postoperative outcomes in patients with MMD. Furthermore, application of CIES to evaluate pre-existing cerebral infarction can improve the management of patients.

The genetic landscape and clinical implication of pediatric Moyamoya angiopathy in an international cohort

Pediatric Moyamoya Angiopathy (MMA) is a progressive intracranial occlusive arteriopathy that represents a leading cause of transient ischemic attacks and strokes in childhood. Despite this, up to now no large, exclusively pediatric MMA cohort has been subjected to systematic genetic investigation. In this study, we performed molecular karyotyping, exome sequencing and automated structural assessment of missense variants on a series of 88 pediatric MMA patients and correlated genetic, angiographic and clinical (stroke burden) findings. The two largest subgroups in our cohort consisted of RNF213 and neurofibromatosis type 1 (NF1) patients. While deleterious RNF213 variants were associated with a severe MMA clinical course with early symptom onset, frequent posterior cerebral artery involvement and higher stroke rates in multiple territories, NF1 patients had a similar infarct burden compared to non-NF1 individuals and were often diagnosed incidentally during routine MRIs. Additionally, we found that MMA-associated RNF213 variants have lower predicted functional impact compared to those associated with aortic disease. We also raise the question of MMA as a feature of recurrent as well as rare chromosomal imbalances and further support the possible association of MMA with STAT3 deficiency. In conclusion, we provide a comprehensive characterization at the genetic and clinical level of a large exclusively pediatric MMA population. Due to the clinical differences found across genetic subgroups, we propose genetic testing for risk stratification as part of the routine assessment of pediatric MMA patients.

Post-stroke Chorea in the Neurology Department of Ignace Deen Hospital of Conakry, Guinea.

Chorea is an uncommon complication of stroke. The pathophysiology, the exact location of the lesions, and the evolution of this type of chorea are still poorly understood. The objective was to describe the epidemiological, clinical, and imaging profile of post-stroke chorea in a tropical environment in the context of a stroke epidemic. We conducted a five-year retrospective observational study from 2015 to 2020 on stroke patients who presented with chorea in our department. Epidemiological, clinical, and imaging data were registered. Fourteen patients presented with chorea after their stroke, a frequency of 0.6%. The average age was 57.1 years with a male predominance. Hypertension was the cardiovascular risk factor in half of the patients; three patients (21.4) were diabetic. Chorea was the initial manifestation of the stroke in eight patients (57.1%). Thirteen patients (92.9%) had an ischaemic strokeand one had a cerebral haemorrhage. The middle cerebral artery (MCA) was involved in nine patients (64.3%), the anterior cerebral artery (ACA) in three patients (21.4%), and two patients (14.3%) had posterior cerebral artery (PCA) involvement. The lesions were cortical in five patients (35.7%), five other patients (35.7%) had a deep location, and four patients (28.6%) had both deep and cortical locations of their lesions. The structures affected were the lentiform nucleus (50%), the insula (35.7%), the caudate nucleus (14.3%), and the thalamus (14.3%). Post-stroke chorea is poorly studied in the tropics. In the presence of any acute abnormal movement associated with cardiovascular risk factors, post-stroke chorea should be considered. Recovery is rapid when treated early.

Monitoring Posterior Cerebral Perfusion Changes With Dynamic Susceptibility Contrast-Enhanced Perfusion MRI After Anterior Revascularization Surgery in Pediatric Moyamoya Disease.

To determine whether dynamic susceptibility contrast-enhanced (DSC) perfusion magnetic resonance imaging (MRI) can be used to evaluate posterior cerebral circulation in pediatric patients with moyamoya disease (MMD) who underwent anterior revascularization. This study retrospectively included 73 patients with MMD who underwent DSC perfusion MRI (age, 12.2 ± 6.1 years) between January 2016 and December 2020, owing to recent-onset clinical symptoms during the follow-up period after completion of anterior revascularization. DSC perfusion images were analyzed using a dedicated software package (NordicICE; Nordic NeuroLab) for the middle cerebral artery (MCA), posterior cerebral artery (PCA), and posterior border zone between the two regions (PCA-MCA). Patients were divided into two groups; the PCA stenosis group included 30 patients with newly confirmed PCA involvement, while the no PCA stenosis group included 43 patients without PCA involvement. The relationship between DSC perfusion parameters and PCA stenosis, as well as the performance of the parameters in discriminating between groups, were analyzed. In the PCA stenosis group, the mean follow-up duration was 5.3 years after anterior revascularization, and visual disturbances were a common symptom. Normalized cerebral blood volume was increased, and both the normalized time-to-peak (nTTP) and mean transit time values were significantly delayed in the PCA stenosis group compared with those in the no PCA stenosis group in the PCA and PCA-MCA border zones. TTPPCA (odds ratio [OR] = 6.745; 95% confidence interval [CI] = 2.665-17.074; P < 0.001) and CBVPCA-MCA (OR = 1.567; 95% CI = 1.021-2.406; P = 0.040) were independently associated with PCA stenosis. TTPPCA showed the highest receiver operating characteristic curve area in discriminating for PCA stenosis (0.895; 95% CI = 0.803-0.986). nTTP can be used to effectively diagnose PCA stenosis. Therefore, DSC perfusion MRI may be a valuable tool for monitoring PCA stenosis in patients with MMD.

Preoperative Brain Functional Connectivity Improve Predictive Accuracy of Outcomes After Revascularization in Moyamoya Disease.

In patients with moyamoya disease (MMD), focal impairments in cerebral hemodynamics are often inconsistent with patients' clinical prognoses. Evaluation of entire brain functional networks may enable predicting MMD outcomes after revascularization. To investigate whether preoperative brain functional connectivity could predict outcomes after revascularization in MMD. We included 34 patients with MMD who underwent preoperative MRI scanning and combined revascularization surgery. We used region of interest analyses to explore the differences in functional connectivity for 90 paired brain regions between patients who had favorable outcomes 1 year after surgery (no recurrent stroke, with improved preoperative symptoms, or modified Rankin Scale [mRS]) and those who had unimproved outcomes (recurrent stroke, persistent symptoms, or declined mRS). Variables, including age, body mass index, mRS at admission, Suzuki stage, posterior cerebral artery involvement, and functional connectivity with significant differences between the groups, were included in the discriminant function analysis to predict patient outcomes. Functional connectivity between posterior cingulate cortex and paracentral lobule within the right hemisphere, and interhemispheric connection between superior parietal gyrus and middle frontal gyrus, precuneus and middle cingulate cortex, cuneus and precuneus, differed significantly between the groups (P < .001, false discovery rate corrected) and had the greatest discriminant function in the prediction model. Although clinical characteristics of patients with MMD showed great accuracy in predicting outcomes (64.7%), adding information on functional connections improved accuracy to 91.2%. Preoperative functional connectivity derived from rs-fMRI may be an early hallmark for predicting patients' prognosis after revascularization surgery for MMD.