Advances and surgical considerations in the treatment of moyamoya disease

Cerebrovascular reactivity dispersion as a new biomarker of recent stroke symptomatology in moyamoya

Background

Moyamoya disease (MMD) is a non-atherosclerotic intracranial steno-occlusive condition placing patients at high risk for ischemic stroke. Direct and indirect surgical revascularization can improve blood flow in MMD; however, randomized trials demonstrating efficacy have not been performed and biomarkers of parenchymal hemodynamic impairment are needed to triage patients for interventions and evaluate post-surgical efficacy. We test the hypothesis that hypercapnia-induced maximum cerebrovascular reactivity (CVR MAX ) and the more novel indicator cerebrovascular reactivity (CVR) response time (CVR DELAY ), both assessed from time-regression analyses of non-invasive hypercapnic imaging, correlate with recent focal ischemic symptoms.

Methods

Hypercapnic reactivity medical resonance imaging (blood oxygenation level-dependent; echo time=35ms; spatial resolution=3.5×3.5×3.5mm) and catheter angiography assessments of cortical reserve capacity and vascular patency, respectively, in MMD participants (n=73) were performed in sequence. Time regression analyses were applied to quantify CVR MAX and CVR DELAY . Symptomatology information for each hemisphere (n=109) was categorized into symptomatic (ischemic symptoms within six months) or asymptomatic (no history of ischemic symptoms) and logistic regression analysis assessed the association of CVR metrics with ischemic symptoms after controlling for age and sex.

Results

Symptomatic hemispheres displayed lengthened CVR DELAY (p<0.001), which was more discriminatory between hemispheres than CVR MAX (p=0.037). CVR DELAY (p<0.001), but not CVR MAX (p=0.127), was found to be sensitively related to age in asymptomatic tissue (0.33-unit increase/year); age-dependent normative ranges are presented to enable quantitative assessment of patient-specific impairment. Furthermore, the area under the receiver operating characteristic curves shows that CVR DELAY predicts ischemic symptoms (p<0.001), whereas CVR MAX does not (p=0.056).

Conclusion

Findings support that CVR metrics are uniquely altered in hemispheres with recent ischemic symptoms, motivating the investigation of CVR as a surrogate of ischemic symptomatology and treatment efficacy.

Can combined high-resolution vessel wall imaging and multiple post-labeling delay 3D pseudo-continuous arterial spin labeling differentiate moyamoya disease from atherosclerotic moyamoya syndrome?

PURPOSE

To investigate whether moyamoya disease (MMD) and atherosclerotic moyamoya syndrome (AS-MMS) differ in vascular morphology and perfusion characteristics using T1w-CUBE imaging and multiple post-labeling delay 3D pseudo-continuous arterial spin labeling imaging (MP 3D-PcASL), and to explore the potential of the combined techniques for accurate diagnosis of both diseases.

METHOD

This prospective study enrolled 51 patients with moyamoya vasculopathy, including 26 with MMD and 25 with AS-MMS. All patients underwent digital subtraction angiography (DSA)/magnetic resonance angiography (MRA), T1w-CUBE imaging, and MP 3D-PCASL examinations. Morphological parameters, including the outer diameter, maximum wall thickness, luminal stenosis morphology, degree of wall enhancement, number of collateral vessels, and perfusion parameters, such as cerebral blood flow (CBF) and arterial transit time (ATT), were measured. After univariate analysis between the two groups, logistic regression models based on the derived parameters of T1w-CUBE imaging, MP 3D-PCASL, and combined imaging were implemented, and receiver operating characteristic (ROC) curves were generated to compare the discriminatory power of the different imaging methods for the diagnosis of MMD.

RESULTS

With T1w-CUBE imaging, MMD showed a smaller outer diameter (2.76 ± 0.39 vs. 3.07 ± 0.49 mm) and maximum wall thickness (1.27 ± 0.19 vs. 1.49 ± 0.24 mm) than AS-MMS (both P < 0.05). Using MP 3D-pcASL, the resultant CBF (36.64 ± 14.28 vs. 28.77 ± 8.63 mL/100 g/min) was higher in MMD relative to AS-MMS, while an opposite pattern was shown for ATT (1.61 ± 0.09 vs. 1.72 ± 0.13 s; both P < 0.05). Robust diagnostic efficacies for disease differentiation, confirmed by high areas under the ROC curve (AUCs) (>0.808), were separately shown with T1w-CUBE and MP 3D-pcASL derived parameters. However, the combined multivariate logistic regression model showed optimaldiagnostic efficacy(AUC: 0.938; P < 0.05).

CONCLUSIONS

Combined T1w-CUBE imaging and MP 3D-PCASL provides distinctive morphological and functional features to evaluate vessel walls and cerebral perfusion, and might help distinguish MMD from AS-MMS.

Role of human dural fibroblasts in the angiogenic responses of human endothelial cells: An in vitro dural model and the application of lab-on-a-chip for EDAS

Encephaloduroarteriosynangiosis (EDAS), an indirect anastomosis procedure, is widely accepted as a primary treatment for moyamoya disease (MMD) to improve collateral blood flow. During surgical intervention, dural fibroblasts (DuF) are thought to produce various proteins that create an angiogenic microenvironment. However, the biophysiological evidence supporting the angiogenic properties of this surgical technique has not been thoroughly elucidated. The purpose of these studies was to determine whether DuF releases pro-angiogenic factors and chemokines and promotes angiogenic properties in human endothelial cells (ECs) under IL-1β-mediated wound conditions, which are expected to occur during the process of neo-vascularization within the dura mater. Furthermore, a microfluidic chemotaxis platform was implemented to investigate the angiogenic activity of ECs in response to a reconstituted dura model. Transcriptome sequencing revealed that IL-1β stimulation on DuF induced a significant upregulation of various pro-angiogenic genes, including IL-6, IL-8, CCL-2, CCL-5, SMOC-1, and SCG-2 (p < 0.05). Moreover, compared to ECs cultured in naïve media or naïve DuF media, those exposed to IL-1β-DuF conditioned media expressed higher mRNA and protein levels of these pro-angiogenic factors (p < 0.001). ECs co-cultured with IL-1β-DuF also exhibited considerable migration on the microfluidic chemotaxis platform. Furthermore, the chemotactic effects on the ECs were reduced upon neutralization of IL-8 or inhibition of NF-κB signaling. Our findings demonstrate that IL-1β-DuFs release factors that activate and enhance the angiogenic properties of ECs. These results suggest a potential interaction between DuF and ECs following EDAS for MMD, and these components could be targeted for the development of therapeutic biomarkers.

Angioarchitectural Factors Associated with Postoperative Cerebral Infarction in Ischemic Moyamoya Disease

Objective: To investigate the angioarchitectural factors associated with postoperative cerebral infarction in ischemic moyamoya disease. Methods: Data on patients who underwent surgery for ischemic MMD from 1 October 2015 to 31 October 2020, at Peking University International Hospital were collected and retrospectively analyzed. General conditions such as patient sex, age, site of surgery, preoperative manifestations such as TIA attack and old cerebral infarction, and seven angioarchitectural factors of the MMD based on DSA were selected and measured. Statistical analysis was performed by the Pearson chi-square statistic, analysis of variance (ANOVA), and multifactor logistic regression analysis. Results: Age (OR, 0.969; 95%CI, 0.939–1.000; p = 0.049), A1stenosis (OR, 5.843; 95%CI, 1.730–19.732; p = 0.004), M1stenosis (OR, 6.206; 95%CI, 2.079–18.526; p = 0.001), PCA anomalies (OR, 4.367; 95%CI, 1.452–13.129; p = 0.049), Unstable compensation (OR, 5.335; 95%CI, 1.427–19.948; p = 0.013), TIA (OR, 4.264; 95%CI, 1.844–9.863; p = 0.001), Old cerebral infarction (OR, 2.972; 95%CI, 1.194–7.397; p = 0.019). The above seven factors can be used in the regression equation to predict the probability of postoperative cerebral infarction. The prediction accuracy is 90.2%. Conclusions: Age, TIA attack, old cerebral infarction, and five angioarchitectural factors of MMD are strongly associated with postoperative cerebral infarction. Seven factors, including age, TIA attack, old infarction, and four angioarchitectural factors, can be taken to quantify the probability of surgical cerebral infarction in MMD.

Aplastic or twiglike middle cerebral artery with contralateral middle cerebral artery stenosis showing transient ischemic attack: illustrative case

BACKGROUND

Aplastic or twiglike middle cerebral artery (Ap/T-MCA) is a rare anomaly characterized by a unilateral MCA occlusion with plexiform vessels that causes hemorrhagic and (less commonly) ischemic strokes. The reasons for this are rarely discussed, and thus optimal treatment for ischemic Ap/T-MCA remains controversial. Here, the authors report a case of Ap/T-MCA with transient ischemic attacks treated by bypass surgery and discuss the mechanism of ischemic development and treatment methods.

OBSERVATIONS

A 62-year-old hypertensive man with transient, recurrent left hemiparesis visited the authors’ hospital. Magnetic resonance angiography showed proximal occlusion of the right MCA and stenosis in the left MCA. Digital subtraction angiography revealed occlusion of the right MCA and abnormal vascular networks, leading to a diagnosis of Ap/T-MCA with contralateral MCA stenosis. Antiplatelet therapy with aspirin was insufficient, and a superficial temporal artery–MCA bypass was performed. There were no ischemic or hemorrhagic events postoperatively.

LESSONS

Atherosclerosis seems to have a significant impact on the development of ischemic stroke in patients with Ap/T-MCA, and the presence of coexisting atherosclerotic stenotic vascular lesions outside the Ap/T-MCA site is substantial in its development. Bypass surgery is a promising treatment option for ischemic Ap/T-MCA.

Minimally invasive cerebral revascularization in moyamoya disease in adult patients

BACKGROUND

Moyamoya disease (MMD) affects young patients, is generally progressive, and results in strokes or cerebral hemorrhages for which medical management is not effective.

OBJECTIVE

To determine the effectiveness of surgical management with minimally invasive cerebral revascularization in MMD.

MATERIAL AND METHODS

We conducted a retrospective cohort study of patients undergoing extracranial-intracranial microsurgical revascularization surgery with mini-craniotomy, analyzing the epidemiological, clinical, neuroimaging, postoperative evolution, and complications. We describe the technique in detail. Key outcomes included graft patency, complications, and recurrence of ischemic or hemorrhagic stroke.

RESULTS

From September 2017 to December 2020, 12 brain revascularization procedures for MMD were performed in eight patients (four bilateral), and all 12 grafts were classified as patent. The main complication was contralateral cerebral infarction identified by postoperative neuroimaging in a patient without clinical symptomatology. There was no case of scalp ischemia or necrosis when performing the minimally invasive approach with linear incision.

CONCLUSIONS

The results of this study suggest that the minimally invasive extracranial-intracranial cerebral revascularization procedure for MMD in adults is effective, with graft patency in all cases and minimal morbidity.

Effects of Aspirin Therapy on Bypass Efficacy and Survival of Patients Receiving Direct Cerebral Revascularization

Background: Both patency maintenance and neoangiogenesis contribute to cerebrovascular bypass efficacy. However, the combined impact of the aforementioned two indicators on postoperative revascularization following superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass has been less well elucidated. Meanwhile, there is a paucity of evidence with conflicting results about postoperative aspirin therapy.

Objective: The objective of the study was to investigate the correlation between aspirin use and STA-MCA bypass efficacy, including patency, postoperative neoangiogenesis, and follow-up outcomes.

Methods: A total of 181 MMD patients (201 procedures) undergoing STA-MCA bypass at our institution (2017–2019) were retrospectively reviewed. The bypass efficacy level and postoperative complications were compared between aspirin and non-aspirin groups.

Results: Among 95 PS-matched pairs, the aspirin group presented a significantly more favorable bypass efficacy than the non-aspirin group [odds ratio (OR) 2.23, 95% confidence interval (CI) 1.11–4.61; p = 0.026]. Multivariate logistic regression analysis confirmed the profound impact of aspirin as an independent predictor of bypass efficacy [adjusted OR 2.91, 95% CI 1.34–6.68; p = 0.009]. A remarkable negative correlation was found between bypass efficacy and the rate of ischemic complications (Phi = −0.521). Postoperative aspirin therapy was associated with a non-significant trend toward a lower incidence of ischemic events [OR 0.73, 95% CI 0.23–2.19; p = 0.580]. No significant difference in bleeding rates was observed between aspirin and control groups [OR 1.00, 95% CI 0.12–8.48; p = 1.000].

Conclusion: Among patients undergoing STA-MCA bypass procedures, bypass efficacy is a good predictor of follow-up outcomes. Postoperative aspirin therapy can improve patency, neoangiogenesis, and overall bypass efficacy, thereby protecting against postoperative ischemic complications.

Clinical Trial Registration:http://www.chictr.org.cn/, identifier CTR2100046178.

The microbiota-gut-brain axis participates in chronic cerebral hypoperfusion by disrupting the metabolism of short-chain fatty acids

BACKGROUND

Chronic cerebral hypoperfusion (CCH) underlies secondary brain injury following certain metabolic disorders and central nervous system (CNS) diseases. Dysregulation of the microbiota-gut-brain axis can exacerbate various CNS disorders through aberrantly expressed metabolites such as short-chain fatty acids (SCFAs). Yet, its relationship with CCH remains to be demonstrated. And if so, it is of interest to explore whether restoring gut microbiota to maintain SCFA metabolism could protect against CCH.

RESULTS

Rats subjected to bilateral common carotid artery occlusion (BCCAO) as a model of CCH exhibited cognitive impairment, depressive-like behaviors, decreased gut motility, and compromised gut barrier functions. The 16S ribosomal RNA gene sequencing revealed an abnormal gut microbiota profile and decreased relative abundance of some representative SCFA producers, with the decreased hippocampal SCFAs as the further evidence. Using fecal microbiota transplantation (FMT), rats recolonized with a balanced gut microbiome acquired a higher level of hippocampal SCFAs, as well as decreased neuroinflammation when exposed to lipopolysaccharide. Healthy FMT promoted gut motility and gut barrier functions, and improved cognitive decline and depressive-like behaviors by inhibiting hippocampal neuronal apoptosis in BCCAO rats. Long-term SCFA supplementation further confirmed its neuroprotective effect in terms of relieving inflammatory response and hippocampal neuronal apoptosis following BCCAO.

CONCLUSION

Our results demonstrate that modulating the gut microbiome via FMT can ameliorate BCCAO-induced gut dysbiosis, cognitive decline, and depressive-like behaviors, possibly by enhancing the relative abundance of SCFA-producing floras and subsequently increasing SCFA levels. Video abstract.

Vaso-Occlusive Pain Management in a Patient With Sickle Cell Disease Associated With Moyamoya Syndrome

Moyamoya syndrome in a sickle cell disease patient may be a difficult task to manage in the setting of a vaso-occlusive pain crisis. Maintaining stable blood pressure is necessary to prevent stroke as both hypertension and hypotension can be detrimental to the patient, leading to hemorrhagic and ischemic stroke, respectively. Opioid management for pain control in such patients must be taken into consideration. Because every patient is unique, opioid regimens should be optimized to relieve patients’ specific pain while also practicing non-maleficence in preventing hypotension and strokes.

Western Moyamoya Phenotype: A Scoping Review

Moyamoya, a rare angiographic finding, is characterized by chronic and progressive stenosis at the terminal end of the internal carotid artery, followed by collateralization of the cerebral vasculature at the base of the skull. Coined by Suzuki and Takaku in 1969, the term "moyamoya" means a "puff of smoke" in Japanese, a reference to the angiographic appearance of moyamoya collateralization. Moyamoya is most commonly found in East Asian countries, where much governmental and civilian effort has been expended to characterize this unique disease process. However, despite its rarity, the occurrence of moyamoya in Western countries is associated with significant divergence regarding incidence, gender, sex, age at diagnosis, clinical presentation, and outcomes. Here, we attempted to review the Western literature on moyamoya presentation using the PubMed database to characterize the Western phenotype of moyamoya. We were guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR). We reviewed papers generated from a search with keywords "moyamoya case report," those reported from a Western institution, and those reported on a relevant association. Our scoping review demonstrated various clinical associations with moyamoya. Moreover, we summarized the demographic profile and clinical symptomatology, as well as reported disease associations to better elucidate the Western phenotype of moyamoya.

A Prospective, Longitudinal Magnetic Resonance Imaging Evaluation of Cerebrovascular Reactivity and Infarct Development in Patients With Intracranial Stenosis

BACKGROUND

Patients with symptomatic atherosclerotic and non-atherosclerotic (i.e., moyamoya) intracranial steno-occlusive disease experience high 2-year infarct rates.

PURPOSE

To investigate whether cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) measures may provide biomarkers of 1-to-2-year infarct risk.

STUDY TYPE

Prospective, longitudinal study.

SUBJECTS

Adult participants (age = 18-85 years) with symptomatic intracranial atherosclerotic disease (N = 26) or non-atherosclerotic (i.e., moyamoya; N = 43) and stenosis ≥50% of a major intracranial artery were initially scanned within 45 days of stroke. Follow-up imaging (target  = 1.5 years) was acquired for new infarct assessment.

FIELD STRENGTH/SEQUENCE

3.0 Tesla with normocapnic arterial spin labeling (ASL) and blood oxygenation level-dependent (BOLD) imaging acquired during an interleaved hypercapnic (3 minutes) and normocapnic (3 minutes) respiratory stimulus.

ASSESSMENT

CBF, maximum CVR, and time-to-maximum CVR (i.e., CVR_DELAY ) were calculated. Laterality indices (difference between infarcted and contralesional hemispheres divided by sum of absolute values) of metrics at enrollment were contrasted between participants with vs. without new infarcts on follow-up.

STATISTICAL TESTS

Laterality indices were compared using non-parametric Wilcoxon tests (significance: two-sided P < 0.05) and effect sizes as Cohen's d. Continuous variables are presented as mean ± SD.

RESULTS

New infarcts were observed on follow-up in 15.0% of participants. The laterality index of the CVR_DELAY was elevated (P = 0.01) in participants with atherosclerosis with new infarcts (index = 0.13) compared to participants without new infarcts (index = 0.05).

DATA CONCLUSION

Elevated CVR_DELAY may indicate brain parenchyma at increased risk for new infarcts in patients with symptomatic intracranial atherosclerotic disease treated with standard-of-care medical management.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 3.

RNF213 gene silencing upregulates transforming growth factor β1 expression in bone marrow-derived mesenchymal stem cells and is involved in the onset of Moyamoya disease

Moyamoya disease (MMD) is a chronic and progressive cerebrovascular occlusion disease, the precise etiology of which is poorly understood. Ring finger protein 213 (RNF213) has been previously identified as a susceptibility gene that serves an important role in angiogenesis, where it has been shown to be closely associated with the onset of MMD. Patients with MMD exhibit increased expression levels of various pro-inflammatory molecules and angiogenic factors. Under certain conditions, bone marrow mesenchymal stem cells (BMSCs) have the ability to differentiate to form neuron-like and microglia-like cells. In the present study, a total of 40 MMD patients and 40 healthy individuals were enrolled. ELISA assays revealed that the expression of serum vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGF-β1) were higher than that in healthy controls. Furthermore, rat BMSCs (rBMSCs) were isolated and cultured using the whole bone marrow adherence method, which were then phenotyped using flow cytometry. Osteogenic and adipogenic differentiation were determined by using Alizarin red and oil red O staining, respectively. RNF213 was knocked-down using a lentivirus-mediated short hairpin RNA system in passage three rBMSCs, and successful transfection of the RNF213 was confirmed by RT-qPCR and fluorescence imaging. The expression levels of VEGF and TGF-β1 in these rBMSCs were measured on days 7 and 14, respectively. The results demonstrated that RNF213 knockdown upregulated TGF-β1 at both protein and mRNA levels, but did not exert any effect on VEGF gene expression. In conclusion, these findings suggested that that RNF213 knockdown may contribute to aberrant TGF-β1 expression via a pathway that remains to be unidentified, indicating that quantitative changes in RNF213 gene expression may serve an important role in the pathogenesis of MMD.

Current trends in pediatric moyamoya: a survey of international practitioners

OBJECTIVE

Moyamoya angiopathy (MM) is a chronic, progressive steno-occlusive arteriopathy of the distal internal carotid artery and its proximal branches. MM is recognized as a shared end-pathway common to a broad range of inciting pathologies, suggesting that tailored management is important. Pediatric MM differs from MM in adults. Currently, there are many uncertainties and controversies regarding the diagnosis and management of children with MM. Hence, we conducted an international survey to identify the contemporary management trends followed worldwide.

METHODS

A survey relating to lifestyle modifications, medical management, diagnosis, surgical management, and follow-up for pediatric MM was circulated across web-based platforms, through various international pediatric neurological and neurosurgical societies. Data collected included geographic region of practice, experience, responses to questions, and comments.

RESULTS

One hundred twenty-seven responses were evaluated (104 neurosurgeons and 23 neurologists, from 32 countries, across 6 continents). We found wide variations in the recommendations for management and lifestyle modification, with significant differences between regions of practice. Eighty percent recommend restrictions on physical activity, particularly for symptomatic and non-operated patients. Eighty-four percent prescribe aspirin. Sixty-five percent perform indirect revascularization. Seventy-eight percent recommend performing a staged surgery for bilateral MM. Only 26% perform acetazolamide challenge SPECT to evaluate brain perfusion. Only 15% of responders were from highly experienced centers.

CONCLUSION

This survey reflects the contemporary trends in management of pediatric MM, while highlighting the heterogeneity in the management approach of these patients. There is a need for multicenter, international studies to evaluate the safety, efficacy, and long-term outcome of various aspects of treatment of these patients.

Direct vs Indirect Revascularization in a North American Cohort of Moyamoya Disease

BACKGROUND

In adults with ischemic moyamoya disease (MMD), the efficacy of direct vs indirect revascularization procedures remains a matter of debate.

OBJECTIVE

To investigate the outcomes of ischemic MMD in a North American cohort treated by direct and indirect revascularizations.

METHODS

We retrospectively reviewed medical records of adult patients with MMD with ischemic presentation from 1984 to 2018 at the Brigham and Women's Hospital and Massachusetts General Hospital who underwent either direct or indirect bypasses. Early postoperative events and outcome at more than 6 mo postoperatively were evaluated using multivariable logistic regression analyses. Multivariable Cox proportional hazards regression analyses were used to evaluate delayed ischemic and hemorrhagic events. Analyses were performed per hemisphere.

RESULTS

A total of 95 patients with MMD and 127 hemispheres were included in this study. A total of 3.5% and 8.6% of patients had early surgical complications in the direct and indirect bypass cohorts, respectively (P = .24). Hemispheres with direct bypasses had fewer long-term ischemic and hemorrhagic events at latest follow-up (adjusted hazard ratio [HR] 0.19, 95% confidence interval [CI] 0.058-0.63, P = .007; median follow-up 4.5 [interquartile range, IQR 1-8] yr). There was no difference between the direct and indirect bypass groups when the endpoint was limited to infarction and hemorrhage only (P = .12). There was no difference in outcome (modified Rankin Scale [mRS] ≥ 3) between the 2 cohorts (P = .92).

CONCLUSION

There was no difference in early postoperative events, long-term infarction or hemorrhage, or clinical outcome between direct and indirect revascularization. However, there was a significant decrease in all ischemic and hemorrhagic events combined in direct revascularizations compared to indirect revascularizations.

Current Surgical Options for Moyamoya Disease

Moyamoya disease (MMD) is a cerebrovascular disease of unknown etiology characterized by stenotic and occlusive arterial changes of the anterior circulation, with subsequent proliferative development of arterial collateralization. In spite of there being limited understanding of the clear etiology of MMD, surgical revascularization for MMD is considered the standard treatment to prevent further stroke. While the use of surgical revascularization to prevent future hemorrhagic stroke in MMD is still controversial, it is considered effective in the case of ischemic stroke. This article presents a review of the current surgical management of MMD based on an analysis of the most recent data from peer-reviewed articles and opinion based on personal experience with surgical revascularization in the treatment of MMD.

Acute Ischemic Stroke in Sickle Cell Disease Challenges for Thrombolysis

Sickle cell disease (SCD) is a hemoglobinopathy disorder that was recognized in 1949. Stroke is one of the most devastating complications of this disorder. The risk of stroke in SCD patients varies with the genotype; the highest rate has been reported with hemoglobin S. Tissue type plasminogen activator (t PA) is class I recommended therapy for acute ischemic stroke (AIS) since 1996. Although it is unclear if SCD patients were included in the t PA trail, SCD has never been identified as contraindication. The debate of offering t PA for adult SCD patient presenting with AIS continued for at least 2 decades. It is not up and until 2 years ago when the American Heart Association and American stroke association (AHA/ASA) announced that intravenous (IV) t PA can be offered to adult SCD patients presenting with AIS. Here, we report a case where successful IV thrombolytic therapy was offered to an adult SCD patient presenting with AIS with excellent outcome.

Clinical Course of Unilateral Moyamoya Disease

BACKGROUND

The natural history of unilateral moyamoya disease (MMD) progressing to bilateral MMD remains an enigma in modern vascular neurosurgery. Few, small series with limited follow-up have reported relatively high rates of contralateral stenosis progression.

OBJECTIVE

To review our large series of unilateral MMD patients and evaluate radiographic and surgical progression rates, and identify any factors associated with progression.

METHODS

We included all unilateral MMD cases treated from 1991 to 2017 in an observational study. We examined time to contralateral radiographic progression and contralateral progression requiring surgery. Using Cox regression analysis, we evaluated factors potentially associated with contralateral progression.

RESULTS

There were 217 patients treated for unilateral MMD. About 71% were female, and the average age at first surgery was 33.8 yr. Average follow-up was 5.8 yr (range 1-22 yr). A total of 18 patients (8.3%) developed contralateral progression. And 8 of these (3.7%) developed progression requiring bypass surgery. Baseline stenosis and hyperlipidemia (HLD) were significantly associated with radiographic progression (hazard ratio [HR] = 9.7, P = .006; HR = 4.0, P = .024). Baseline stenosis was associated with surgical progression (HR = 44.2, P = .002). Results were similar when controlling for possible confounders using multivariate regression.

CONCLUSION

Previous series showed relatively high rates of progression in unilateral MMD (15%-30%), but these studies were small and long-term follow-up was rarely available. Our large series indicates that the rate of progression is lower than previously reported but still warrants yearly noninvasive screening. These data may provide indirect support for statin therapy in MMD.

Endothelial Progenitor Cells Induce Angiogenesis: a Potential Mechanism Underlying Neovascularization in Encephaloduroarteriosynangiosis

Encephaloduroarteriosynangiosis (EDAS) is one of the most commonly used indirect vascular reconstruction methods. EDAS aids in the formation of collateral vessels from the extracranial to the intracranial circulation in patients with moyamoya disease (MMD). However, the underlying mechanism of collateral vessel formation is not well understood. Endothelial progenitor cells (EPCs) differentiate to form the vascular endothelial cells and play a very important role in angiogenesis. We designed this prospective clinical trial to investigate the presence of EPCs in patients with MMD and to explore the neovascularization mechanism mediated by the EPCs in EDAS. The patients who were diagnosed with MMD were recruited between February 5, 2017, and January 7, 2018. The blood samples were obtained from an antecubital vein and were analyzed using flow cytometry. EPCs were defined as CD34^brCD133⁺CD45^dimKDR⁺. All the patients enrolled in the study underwent EDAS. Cerebral arteriography was performed 6 months post-EDAS to assess the efficacy of synangiosis. The correlation between EPC count and good collateral circulation was evaluated. Among the 116 patients with MMD enrolled in this study, 73 were women and 43 were men. The average age of the patients was 33.8 ± 15.2 years. The EPC count of the patients with MMD was 0.071% ± 0.050% (expressed as percentage of the peripheral blood mononuclear cells). The EPC count in the good postoperative collateral circulation group was significantly higher (0.085% ± 0.054%) than that in the poor collateral circulation group (0.048% ± 0.034%) (P = 0.000). The age, modified Suzuki-Mugikura grade, and EPC count were significantly correlated with the good collateral circulation post-EDAS in the multivariate analysis (P = 0.018, P = 0.007, and P = 0.003, respectively). The formation of collateral vessels by EDAS is primarily driven by angiogenesis. The EPC count may be the most critical factor for collateral circulation. The therapeutic effect of EDAS is more likely to benefit younger or severe ischemic patients with MMD.

Pregnancy after direct cerebral bypass for moyamoya disease

OBJECTIVE

Moyamoya disease (MMD) disproportionately affects young to middle-aged women. The main treatment for this challenging disease is cerebral bypass surgery. Vascular neurosurgeons often need to counsel women regarding pregnancy following bypass for MMD, but there is a paucity of data. The authors set out to examine neurological and obstetric outcomes in an extensive cohort of MMD patients who had pregnancies following cerebral revascularization at the Stanford Medical Center.

METHODS

The authors identified all patients at their institution who underwent cerebral bypass for MMD from 1990 through 2018 and who later became pregnant. Some of these patients also had pregnancies prior to undergoing bypass surgery, and the authors examined these pregnancies as well. They performed a chart review and brief telephone survey to identify obstetric complications, transient ischemic attacks (TIAs), and strokes. Neurological and obstetric outcomes were compared to published rates. They also compared pre- and post-bypass pregnancy complication rates using logistic regression techniques.

RESULTS

There were 71 pregnancies among 56 women whose mean age was 30.5 years. Among 59 post-bypass pregnancies, there were 5 (8%) perinatal TIAs. There were no MRI-confirmed strokes or strokes with residual deficits. Among 12 pre-bypass pregnancies, there were 3 (25%) TIAs and 2 (17%) MRI-confirmed strokes. There were no hemorrhagic complications in either group. In the generalized estimating equations analysis, performing cerebral revascularization prior to pregnancy versus after pregnancy was associated with lower odds of perinatal stroke or TIA (OR 0.15, p = 0.0061). Nine pregnancies (13%) were complicated by preeclampsia, and there was one (1%) instance of eclampsia. The overall rate of cesarean delivery was 39%. There were 2 miscarriages, both occurring in the first trimester. There were no maternal deaths.

CONCLUSIONS

The authors present neurological and obstetric outcomes data in a large cohort of MMD patients. These data indicate that post-bypass pregnancy is accompanied by low complication rates. There were no ischemic or hemorrhagic strokes among post-bypass pregnant MMD patients. The rate of obstetric complications was low overall. The authors recommend close collaboration between the vascular neurosurgeon and the obstetrician regarding medical management, including blood pressure goals and continuation of low-dose aspirin.

Moyamoya disease versus moyamoya syndrome: comparison of presentation and outcome in 338 hemispheres

OBJECTIVE

Phenotypic differences between moyamoya disease (MMD) and moyamoya syndrome (MMS) remain unclear. The purpose of this study was to evaluate whether such differences exist when presentation, procedure-related, and outcome variables are compared quantitatively.

METHODS

The study cohort included 185 patients with moyamoya presenting to the Johns Hopkins Medical Institutions between 1994 and 2015. Baseline demographic, angiographic, and clinical characteristics were compared between patients with MMS and MMD, in addition to procedure-related complications and length of stay (LOS) after surgery. Stroke-free survival was compared between both disease variants after diagnosis. Kaplan-Meier analysis and Cox proportional hazards regression were used to compare stroke-free survival between surgically treated and conservatively managed hemispheres in both types of disease, while evaluating interaction between disease variant and management.

RESULTS

The cohort consisted of 137 patients with MMD (74%) with a bimodal age distribution and 48 patients with MMS (26%) who were mostly under 18 years of age (75%). Underlying diseases included sickle cell disease (48%), trisomy 21 (12%), neurofibromatosis (23%), and other disorders (17%). Patients with MMS were younger (p < 0.001) and less likely to be female (p = 0.034). Otherwise, baseline characteristics were statistically comparable. The rate of surgical complications was 33% in patients with MMD and 16% in patients with MMS (p = 0.097). Both groups of patients had a similar LOS after surgery (p = 0.823). Survival analysis (n = 330 hemispheres) showed similar stroke-free survival after diagnosis (p = 0.856) and lower stroke hazard in surgically managed patients in both MMD (hazard ratio [HR] 0.29, p = 0.028) and MMS (HR 0.62, p = 0.586). The disease variant (MMD vs MMS) did not affect the relationship between management approach (surgery vs conservative) and stroke hazard (p = 0.787).

CONCLUSIONS

MMD and MMS have largely comparable clinical and angiographic phenotypes with analogously favorable responses to surgical revascularization.

Phase-Contrast Magnetic Resonance Imaging Analysis of Cerebral Hyperperfusion Syndrome After Surgery in Adult Patients with Moyamoya Disease

OBJECTIVE

To investigate potential risk factors for cerebral hyperperfusion syndrome (CHS) after surgery in patients with moyamoya disease (MMD) using phase-contrast magnetic resonance imaging (MRI).

METHODS

The study included 84 adult patients (89 brain hemispheres) with MMD who underwent surgery. Preoperative phase-contrast MRI scans were performed for all patients. Peak velocity, average velocity, average flow, forward volume, and region of interest area of the bilateral internal and external carotid arteries, superficial temporal artery, and vertebral artery were calculated and analyzed. Patients were divided into CHS and non-CHS groups. Patients' age, sex, clinical symptoms, Suzuki stage, and MRI flow examination results were compared between the 2 groups.

RESULTS

Nineteen of 84 patients (89 hemispheres) with MMD were in the CHS group. Patients with ischemic onset symptoms were more likely to develop CHS after surgery (P < 0.05). There were no significant differences in age, sex, and Suzuki stage between the 2 groups. For surgery ipsilateral vessels, peak velocity, average flow and forward volume of superficial temporal artery and average flow of external carotid artery and region of interest area of internal carotid artery in the CHS group were significantly lower compared with the non-CHS group (P < 0.05). For surgery contralateral vessels, forward volume of superficial temporal artery and external carotid artery in the CHS group was significantly lower compared with the non-CHS group (P < 0.05).

CONCLUSIONS

Patients with MMD and ischemic onset symptoms are more likely to develop CHS after surgery. Preoperative phase-contrast MRI analysis may be helpful to predict CHS in patients with MMD after surgery.

A Comprehensive Meta-Analysis for Bypass Surgery in Adult Moyamoya

OBJECTIVE

To evaluate the outcomes of bypass surgery for adult moyamoya and compare different surgical modalities by performing a comprehensive meta-analysis of relevant studies.

METHODS

A systematic literature search was performed and articles regarding different treatments for adult patients with moyamoya were included. Odds ratios (ORs) were calculated to evaluate stroke recurrence, mortality, perioperative complications, and angiographic revascularization among different surgical methods and conservative treatment (CT).

RESULTS

A total of 17 studies with 2224 adult patients with moyamoya were included in the meta-analysis. Compared with CT, surgical revascularization significantly decreased the future stroke events in the total population ([OR] 0.404; 95% confidence interval [CI] 0.279-0.585; P < 0.001) and in the hemorrhagic-onset patients as well (OR 0.259; 95% CI 0.138-0.486; P < 0.001). However, for those patients with moyamoya and ischemia, there was no significant difference for future stroke events between the bypass and CT groups (OR 0.470; 95% CI 0.140-1.579; P = 0.222). Bypass also showed no mortality reduction compared with CT (OR 0.372; 95% CI 0.120-1.154; P = 0.087). For different surgical techniques, no differences for future stroke events, mortality, and perioperative complications were found between direct bypass and indirect bypass, whereas the degree of angiographic revascularization was better in the direct bypass group than in the indirect group (OR 4.720; 95% CI 1.222-18.230; P = 0.024).

CONCLUSIONS

The bypass treatment was superior to conservative treatment in preventing recurrent stroke in adult patients with moyamoya, especially in those with a hemorrhagic onset. Direct bypass is associated with better revascularization results compared with indirect bypass.

Pedicled temporoparietal fascial flap for combined revascularization in adult moyamoya disease

Moyamoya disease (MMD) is a progressive, idiopathic cerebrovascular occlusive disease. Various revascularization techniques including direct, indirect, and combined microvascular bypasses have been described. This article presents a modified revascularization technique for MMD utilizing a pedicled temporoparietal fascial flap (TPFF) for combined revascularization. This technique combines a large area of coverage for indirect revascularization with the benefits of a direct bypass. The pedicled TPFF also benefits from intact venous drainage to minimize the risk of flap swelling that could result in complications from mass effect.

Combined (direct and indirect) revascularization in adult patients with moyamoya disease

The study objective is to analyze the results of combined (direct and indirect) brain revascularization in adult patients with moyamoya disease. 

Materials and methods. From February 2015 to August 2016, 12 operations were performed on 12 hemispheres in 7 patients (2 men, 5 women) with moyamoya disease. Six patients had bilateral disease, 1 – unilateral. The age of patients ranged from 25 to 60 year old, the average – 41 year old. Multislice computed tomography (MSCT) perfusion imaging of the brain with a stress test was made in every patient, MSCT angiography of the extraand intracranial arteries was perfomed. Stages of the disease were determined according to the Suzuki–Takaku classification: stage III was revealed in 5 patients, stage IV – in 2. To evaluate the clinical course of the disease the Matsushima classification was used: type VI – in 2 cases, type III – in 2, type IV – in 1, type V – in 1. In 1 case, the pathological vascular network of 1 hemisphere was detected by accident. Extracranial-intracranial (EC–IC) bypass and encephaloduromyosynangiosis (EDMS) was used in 3 cases; a double-barreled EC–IC bypass and EDMS – in 3; a double-barreled EC–IC bypass and encephaloduroperiosteomyosynangiosis – in 1; EC–IC bypass and encephaloduroarteriomyosynangiosis (EDAMS) – in 3. In 1 case was perfomed EC–IC bypass and encephaloduroperiosteosynangiosis. Only indirect revascularization was performed in 1 case – EDAMS. We assessed the neurological status in the follow-up period (5–11 months); MSCT angiography and MSCT perfusion imaging of the brain were performed. 

Results. All patients in follow-up period demonstrated the increase of cerebrovascular reserve according to MSCT perfusion imaging of the brain with stress tests. Stroke, epilepsy, surgical complications were not detected in the postoperative period. In 1 case, the left-hand monoparesis regressed.

Conclusion. The combined (direct and indirect) revascularization may be effective in adult patients with moyamoya disease. To obtain more objective conclusions it is necessary to analyze the long-term results of interventions.

Treatment course and outcomes after revascularization surgery for moyamoya disease in adults

BACKGROUND

International trials suggest benefit of revascularization surgery (RS) for moyamoya disease (MMD). However, nationally representative US data on demographics and outcomes after RS in MMD are lacking.

AIMS

To estimate causes and rates of readmission after RS for MMD.

METHODS

In the Nationwide Readmissions Database, index admissions for ECICB for MMD and readmissions for ischemic stroke (IS), subarachnoid hemorrhage (SAH), and intracerebral hemorrhage (ICH) were identified using validated International Classification of Diseases, Ninth Revision, Clinical Modification codes. We summarized demographics and comorbidities, and calculated 30-, 60-, and 90-day readmission rates per 100,000 index admissions.

RESULTS

Among 201 index admissions for RS for MMD, mean age (SD) was 41.7 (12.6) years; 75% were female; 24% had diabetes; 53% had hypertension; 40% had hypercholesterolemia; 3% had ICH; 16% had IS; and 1% had SAH. RS was performed at large hospitals in 83%, urban hospitals in 85%, and teaching hospitals in 97%. 80% were discharged home. 34% had a readmission during follow-up. Leading reasons for readmission up to 90 days included MMD (62%), postoperative infection (10%), sickle cell crisis (4%), ischemic stroke (4%), epilepsy (2%), subdural hemorrhage (2%) and headache (2%). Readmission rates (per 100,000 index admissions) were 559 at 30 days, 1829 at 60 days, and 2027 at 90 days for IS. There were no readmissions for SAH or ICH.

CONCLUSIONS

This analysis of nationally representative US data suggests that although readmission after RS for MMD is not uncommon, cerebral hemorrhagic events during the 90-day postoperative period are rare.

Hemodynamic mechanisms underlying elevated oxygen extraction fraction (OEF) in moyamoya and sickle cell anemia patients

Moyamoya is a bilateral, complex cerebrovascular condition characterized by progressive non-atherosclerotic intracranial stenosis and collateral vessel formation. Moyamoya treatment focuses on restoring cerebral blood flow (CBF) through surgical revascularization, however stratifying patients for revascularization requires abilities to quantify how well parenchyma is compensating for arterial steno-occlusion. Globally elevated oxygen extraction fraction (OEF) secondary to CBF reduction may serve as a biomarker for tissue health in moyamoya patients, as suggested in patients with sickle cell anemia (SCA) and reduced oxygen carrying capacity. Here, OEF was measured (TRUST-MRI) to test the hypothesis that OEF is globally elevated in patients with moyamoya (n = 18) and SCA (n = 18) relative to age-matched controls (n = 43). Mechanisms underlying the hypothesized OEF increases were evaluated by performing sequential CBF-weighted, cerebrovascular reactivity (CVR)-weighted, and structural MRI. Patients were stratified by treatment and non-parametric tests applied to compare study variables (significance: two-sided P < 0.05). OEF was significantly elevated in moyamoya participants (interquartile range = 0.38-0.45) compared to controls (interquartile range = 0.29-0.38), similar to participants with SCA (interquartile range = 0.37-0.45). CBF was inversely correlated with OEF in moyamoya participants. Elevated OEF was only weakly related to reductions in CVR, consistent with basal CBF level, rather than vascular reserve capacity, being most closely associated with OEF.

Moyamoya disease in a Moroccan baby: a case report

Background

A stroke in a baby is uncommon, recent studies suggested that their incidence is rising. Moyamoya disease is one of the leading causes of stroke in babies. This condition is mostly described in Japan. In Morocco, moyamoya disease has rarely been reported and a few cases were published. We report a rare Moroccan case of a 23-month-old baby boy who presented with left-sided hemiparesis and was diagnosed as having moyamoya disease.

Case presentation

A 23-month-old full-term Moroccan baby boy born to a non-consanguineous couple was referred to our hospital with the complaint of sudden onset left-sided hemiparesis. On neurological examination, there were no signs of meningeal irritation, his gait was hemiplegic, tone was decreased over left side, power was 2/5 over left upper and lower limb, and deep tendon reflexes were exaggerated. Preliminary neuroimaging suggested an arterial ischemic process. Clinical and laboratory evaluation excluded hematologic, metabolic, and vasculitic causes. Cerebral angiography confirmed the diagnosis of moyamoya disease. Our patient was treated with acetylsalicylic acid 5 mg/kg per day and referred to follow-up with pediatric neurosurgeon. Cerebral revascularization surgery using encephaloduroarteriosynangiosis was performed. At 8-month follow-up, his hemiparesis had improved and no further ischemic events had occurred.

Conclusion

This case highlights the importance of considering moyamoya disease to be one of the classic etiologies of acute ischemic strokes in children from North Africa. It also emphasizes the rare presentation among the African population and the use of neurovascular imaging techniques to facilitate diagnosis of moyamoya disease.

[Revascularization experience and results in ischaemic cerebrovascular disease: Moyamoya disease and carotid occlusion]

INTRODUCTION

Cerebral revascularization techniques are an indispensable tool in the current armamentarium of vascular neurosurgeons. We present revascularization surgery experience and results in both moyamoya disease and occlusive cerebral ischaemia.

PATIENTS AND METHODS

Patients with ischaemic occlusive disease and moyamoya disease who underwent microsurgical revascularization between October 2014 and September 2017 were analysed.

RESULTS

In the study period, 23 patients with occlusive ischaemic disease underwent microsurgical revascularization. Three patients presented with serious postoperative complications (2 intraparenchymal haemorrhages in the immediate postoperative period and one thrombosis of the femoral artery). All patients, except one, achieved normalization of the cerebral hemodynamic reserve (CHR) in the SPECT study. Twenty patients had a good neurological result, with no ischaemic recurrence of the revascularized territory. Among patients with moyamoya, 20 had moyamoya disease and 5 had moyamoya syndrome with unilateral involvement. Five patients were treated at paediatric age. Haemorrhagic onset occurred in 2 patients. The CHR study showed hemodynamic compromise in all patients. Cerebral SPECT at one year showed resolution of the hemodynamic failure in all patients. There have been 4 postoperative complications (acute subdural hematoma, two subdural collections and one dehiscence of the surgical wound). No patient presented with neurological worsening at 6 and 12months of follow-up.

CONCLUSIONS

Cerebral revascularization through end-to-side anastomosis between the superficial temporal artery and a cortical branch of the middle cerebral artery is an indisputable technique in the treatment of moyamoya disease and possibly in a subgroup of patients with symptomatic occlusive ischaemic cerebrovascular disease.

Clinical and angiographic outcomes after combined direct and indirect bypass in adult patients with moyamoya disease: A retrospective study of 76 procedures

The present retrospective study was performed to evaluate the clinical outcome, as well as post-operative collateral formation and revascularization patterns in combined bypass. Surgical revascularization has been the mainstay of treatment for moyamoya patients. A total of 76 hemispheres from 64 moyamoya patients undergoing combined superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and encephalo-duro-myo-synangiosis (EDMS) were retrospectively reviewed. Computed tomography perfusion and DSA were routinely performed. Modified Rankin scale (mRS) scoring and Kaplan-Meier analysis were performed, and post-operative collateral grading on digital subtraction angiography (DSA), reconstruction patterns and vessel diameter were measured to evaluate the revascularization area and vascular compensatory effect. During the follow-up period, the chief complaint was partially alleviated in 57/64 patients (89.1%). In all patients, mRS was significantly decreased after the operation. Good revascularization was established in most patients at 6 months after the surgery: 92.1% of sides were scored as 2 and 77.6% were scored as 3 by post-operative collateral grading on DSA. Dominant collateral revascularization originating from EDMS was more frequent than that from STA-MCA anastomosis (31 vs. 19 hemispheres) at 6-month follow-up. Morphologically, the calibers of the STA main trunk (2.60±0.65 mm) increased profoundly at the first 10 post-operative days (3.32±1.05 mm) and shrank back to pre-operative status at 6 months (2.20±1.01 mm) and 12 months (2.36±0.73 mm) according to DSA examination. Middle meningeal artery (MMA) and deep temporal artery (DTA) demonstrated continuous augmentation during the follow-up time (from 1.30±0.46 to 1.87±0.69 mm for MMA and 1.11±0.25 to 2.11±1.16 mm for DTA). These results strongly suggested that combined STA-MCA bypass and EDMS provided efficient revascularization and reduced acute cerebral events. The direct STA-MCA bypass provided early augmentation of cerebral perfusion, whereas the indirect EDMS provided a more durable long-term revascularization, indicating a complementary association between the two revascularization methods.

Treatment of Progressive Herpes Zoster-Induced Vasculopathy with Surgical Revascularization: Effects on Cerebral Hemodynamics

BACKGROUND

Herpes zoster ophthalmicus (HZO) is caused by reactivation of the herpes simplex virus in the trigeminal nerve. HZO-initiated cerebral vasculopathy is well characterized; however, there are no documented cases that report the efficacy of surgical revascularization for improving cerebral hemodynamics following progressive HZO-induced vasculopathy. We present a case in which quantitative anatomic and hemodynamic imaging were performed longitudinally before and after surgical revascularization in a patient with HZO and vasculopathic changes.

CASE DESCRIPTION

A 57-year-old female with history of right-sided HZO presented with left-sided hemiparesis and dysarthria and multiple acute infarcts. Angiography performed serially over a 2-month duration revealed progressive middle cerebral artery stenosis, development of new moyamoya-like lenticulostriate collaterals, and evidence of fibromuscular dysplasia in cervical portions of the internal carotid artery. Hemodynamic imaging revealed right hemisphere decreased blood flow and cerebrovascular reserve capacity. In addition to medical therapy, right-sided surgical revascularization was performed with the intent to reestablish blood flow. Follow-up imaging 13 months post revascularization demonstrated improved blood flow and vascular reserve capacity in the operative hemisphere, which paralleled symptom resolution.

CONCLUSIONS

HZO can lead to progressive, symptomatic intracranial stenoses. This report suggests that surgical revascularization techniques can improve cerebral hemodynamics and symptomatology in patients with aggressive disease when medical management is unsuccessful; similar procedures could be considered in managing HZO patients with advanced or progressive vasculopathy.

Effects of different surgical modalities on the clinical outcome of patients with moyamoya disease: a prospective cohort study

OBJECTIVE Bypass surgery is the most common treatment for moyamoya disease (MMD), but there is controversy over which surgical modality is best. The objective of this study was to evaluate the clinical outcome of patients with MMD after undergoing different surgical modalities. METHODS A series of 696 consecutive MMD patients treated between June 2009 and May 2015 were screened in this prospective cohort study. Patients who did not undergo revascularization surgeries and those who underwent different surgical modalities in bilateral hemispheres were excluded. Finally, 529 patients who were observed for at least 12 months were included: 438 patients underwent unilateral surgery, and 91 patients underwent bilateral surgery. Of these, 241 patients underwent direct bypass (DB); 81, a combined bypass (CB); and 207, an indirect bypass (IB). Three clinical outcomes were evaluated and compared between surgical groups: recurrent stroke events, modified Rankin Scale (mRS) scores, and change in the main symptoms. RESULTS The mean follow-up period was 40 months. During the follow-up period, recurrent stroke was observed in 43 patients, including 15 patients with hemorrhage, 26 patients with ischemia (transient ischemic attack in 19 patients and infarction in 7 patients), and 2 patients with both hemorrhage and cerebral infarction. Kaplan-Meier analysis showed that patients who underwent a CB or DB had a longer ischemia-free time than those who underwent IB (p = 0.013); however, there was no significant difference in the hemorrhage-free time between the different surgical modalities (p = 0.534). A good neurological status (mRS score ≤ 2) was achieved in 495 patients (93.6%) and was significantly achieved by more children (98.2%) than adults (92.3%; p = 0.022). Surgical modalities were not significantly associated with outcome neurological status (p = 0.860). Moreover, improvement in symptoms was observed in 449 patients (84.9%) and was also significantly more common in children (93.0%) than in adults (82.7%; p = 0.006). No significant difference was observed between the different surgical modalities (p = 0.548). CONCLUSIONS CB and DB are more effective at preventing recurrent ischemic strokes than IB. However, there is no evidence that these 3 surgical modalities demonstrate significant differences in preventing recurrent hemorrhage.

Long-Term Outcome After Conservative Treatment and Direct Bypass Surgery of Moyamoya Disease at Late Suzuki Stage

OBJECTIVE

To investigate the long-term outcomes after conservative and direct surgical treatment for patients with moyamoya disease (MMD) at late Suzuki stage.

METHODS

We retrospectively reviewed 82 patients (164 hemispheres) with MMD at late Suzuki stage at Beijing Tiantan Hospital. Clinical features, radiologic findings, and outcomes were analyzed.

RESULTS

The mean age at diagnosis was 36.4 ± 11.7 years. The distribution of the initial Suzuki stage of MMD was as follows: stage 4, n = 113; stage 5, n = 45; stage 6, n = 6, posterior cerebral artery involvement was observed in 41 hemispheres (25.0%). The incidence of postoperative stroke (<48 hours) was 6.7%. During the average follow-up of 55.1 ± 16.2 months, including postoperative and follow-up strokes, 7 of 75 conservatively treated hemispheres (9.3%) and 9 of 89 surgically treated patients (10.1%) experienced a stroke event; there was no statistical significance in the Kaplan-Meier curve of stroke incidence between the surgical group and conservative group (log-rank test, P = 0.848). However, the rate of perfusion improvement in direct bypass surgically treated patients was higher than in those conservatively treated patients 3 months after discharge (P < 0.05).

CONCLUSIONS

Although direct bypass surgery was shown to effectively improve the cerebral perfusion in patients with MMD at late Suzuki stage, compared with conservative treatment, it did not reduce the risk of recurrent stroke. Further study is needed to determine whether direct bypass surgery is effective in patients with MMD at late Suzuki stage.

More Precise Imaging Analysis and Diagnosis of Moyamoya Disease and Moyamoya Syndrome Using High-Resolution Magnetic Resonance Imaging

BACKGROUND

The diagnosis of moyamoya disease (MMD) is often uncertain. Moyamoya syndrome (MMS) is often misdiagnosed as MMD. High-resolution magnetic resonance imaging (HR-MRI) enables vessel wall assessment to obtain more precise diagnoses. The aim of this study was to determine the true etiologies of arterial steno-occlusion in patients with an angiographic diagnosis of MMD or MMS using HR-MRI.

METHODS

HR-MRI was performed in 21 adult patients with angiographically proven MMD or MMS. A definite diagnosis was based on the HR-MRI findings. The diagnoses made via the 2 different imaging technologies were compared, and significant findings were analyzed.

RESULTS

A total of 21 patients were enrolled, including 7 patients with angiographically proven MMD and 14 patients with angiographically proven MMS. Among the 7 patients with MMD, HR-MRI confirmed the diagnosis of MMD in 6; the remaining patient was considered to have atherosclerosis in the bilateral distal internal carotid arteries (ICAs) and the left middle cerebral artery. Among the 14 patients with MMS, HR-MRI confirmed MMD in 6 patients (including 2 patients with unilateral MMD), atherosclerosis in 5 patients (including 3 patients with bilateral atherosclerosis and 2 with unilateral atherosclerosis), arterial dissection of the left ICA in 1 patient, and MMD in the left cerebral hemisphere with atherosclerosis in the right hemisphere in 2 patients.

CONCLUSIONS

Differentiating MMD from MMS is difficult in certain situations, and HR-MRI may help provide a more in-depth understanding of MMD and MMS, thereby achieving a more reliable diagnosis.

One sided bypass for bilateral Moyamoya disease, a case report and review of the literatures

•

Moyamoya disease (MMD) is a rare condition which can present both in children and adults.

•

Diagnosis is usually established after imagine.

•

Treatment is aiming at stroke prevention by improving blood flow.

•

When surgical intervention is considered, unilateral revascularisation might be sufficient even for patients with bilateral lesion.

Background

Moyamoya disease (MMD) is a rare condition, where the most appropriate treatment for it is yet to be determined. Surgery remains an important method of choice although it is considered a form of palliative care. The outcome following surgery is very difficult to judge, and there is no standardised measurement to assess it. It is therefore important to know which approach for such patient is adequate.

Clinical presentation

A 21-year-old male patient presented with signs and symptoms of intracranial haemorrhage. Upon investigation, a diagnosis of bilateral MMD was made, and one sided direct bypass surgery was subsequently performed. At 3-year follow-up, there is no evidence of recurrent cerebral vascular event.

Conclusion

This case provided further evidence that direct bypass surgery is beneficial for patient in terms of blood flow improvement and symptom relieve. Although there is no consensus on whether bilateral surgical intervention is mandatory for patient with bilateral MMD, unilateral bypass might be sufficient enough. Further study is required to evaluate the best approach for such group of patient.

The Efficacy of Surgical Treatment for the Secondary Prevention of Stroke in Symptomatic Moyamoya Disease: A Meta-Analysis

The treatment of moyamoya disease (MMD) is controversial and often depends on the doctor's experience. In addition, the choice of surgical procedure to treat MMD can differ in many ways. In this study, we performed a meta-analysis to determine whether surgical treatment of MMD is superior to conservative treatment and to provide evidence for the selection of an appropriate surgical treatment.The human case-control studies regarding the association of MMD treatment were systematically identified through online databases (PubMed, Web of Science, Elsevier Science Direct, and Springer Link). Inclusion and exclusion criteria were defined for the eligible studies. The fixed-effects model was performed when homogeneity was indicated. Alternatively, the random-effects model was utilized.This meta-analysis included 16 studies. Surgical treatment significantly reduced the risk of stroke (odds ratio (OR) of 0.17, 95% confidence interval (CI), 0.12-0.26, P < 0.01). A subgroup analysis showed that surgical treatment was more beneficial to hemorrhagic MMD (OR of 0.23, 95% CI, 0.15-0.38, P < 0.01), but there was no significant difference between surgical treatment and conservative treatment on ischemic MMD treatment (OR of 0.45, 95% CI, 0.15-1.29, P = 0.14). Further analysis indicated that compared to direct bypass surgery, indirect bypass surgery had a lower efficacy on secondary stroke risk reduction (OR of 1.79, 95% CI, 1.14-2.82, P = 0.01), while no significant difference was detected for perioperative complications.Surgery is an effective treatment for symptomatic MMD patients, and direct bypass surgery may bring more benefits for these patients.

[Secondary prevention of ischemic non cardioembolic stroke]

Stroke patients are at high risk for recurrence or new occurrence of other cardiovascular events or cardiovascular mortality. It is estimated that a high percentage of non-cardioembolic ischemic stroke can be prevented by a suitable modification of lifestyle (diet and exercise), reducing blood pressure (BP) with antihypertensive medication, platelet aggregation inhibitors, statins and high intake reducing consumption of. Unfortunately the degree of control of the different risk factors in secondary prevention of stroke is low. The clinical practice guidelines show clear recommendations with corresponding levels of evidence, but only if implemented in a general way they will get a better primary and secondary stroke prevention.

Rapid resolution of brain ischemic hypoxia after cerebral revascularization in moyamoya disease

BACKGROUND

In moyamoya disease (MMD), cerebral revascularization is recommended in patients with recurrent or progressive ischemic events and associated reduced cerebral perfusion reserve. Low-flow bypass with or without indirect revascularization is generally the standard surgical treatment. Intraoperative monitoring of cerebral partial pressure of oxygen (PtiO2) with polarographic Clark-type probes in cerebral artery bypass surgery for MMD-induced chronic cerebral ischemia has not yet been described.

OBJECTIVE

To describe basal brain tissue oxygenation in MMD patients before revascularization as well as the immediate changes produced by the surgical procedure using intraoperative PtiO2 monitoring.

METHODS

Between October 2011 and January 2013, all patients with a diagnosis of MMD were intraoperatively monitored. Cerebral oxygenation status was analyzed based on the Ptio2/PaO2 ratio. Reference thresholds of PtiO2/PaO2 had been previously defined as below 0.1 for the lower reference threshold (hypoxia) and above 0.35 for the upper reference threshold (hyperoxia).

RESULTS

Before STA-MCA bypass, all patients presented a situation of severe tissue hypoxia confirmed by a PtiO2/PaO2 ratio <0.1. After bypass, all patients showed a rapid and sustained increase in PtiO2, which reached normal values (PtiO2/PaO2 ratio between 0.1 and 0.35). One patient showed an initial PtiO2 improvement followed by a decrease due to bypass occlusion. After repeat anastomosis, the patient's PtiO2 increased again and stabilized.

CONCLUSION

Direct anastomosis quickly improves cerebral oxygenation, immediately reducing the risk of ischemic stroke in both pediatric and adult patients. Intraoperative PtiO2 monitoring is a very reliable tool to verify the effectiveness of this revascularization procedure.