European Stroke Organisation (ESO) Guidelines on Moyamoya angiopathy: Endorsed by Vascular European Reference Network (VASCERN)

Moyamoya Across the Lifespan: Current Neurologic Care and Future Directions

Moyamoya arteriopathy is an important cause of stroke across the lifespan, with high rates of incident and recurrent stroke in affected individuals. Although it affects adults and children globally, moyamoya is more prevalent in East Asian countries, particularly Japan and Korea. The R4810K variant of the RNF213 gene, most common in Asian populations, is associated with severe, early onset, multisystem vasculopathy. Neuroimaging is critical for moyamoya diagnosis and treatment planning, with conventional imaging, catheter angiography, perfusion imaging, and cerebrovascular reactivity assessment all having a place within moyamoya care. Medical management of moyamoya entails reducing the competing risks of ischemic and hemorrhagic stroke as well as managing coexisting conditions, such as headache, epilepsy, and neuropsychological sequelae. Antiplatelet therapy is commonly prescribed to prevent thromboembolic stroke, although data supporting this practice are limited and practice patterns vary globally. Promoting cerebral oxygen and nutrient delivery with sufficient fluid intake, maintaining adequate blood pressure, and avoiding anemia and hypoglycemia aid in stroke prevention in moyamoya. Definitive treatment of moyamoya is predicated on surgical revascularization, which aims to augment perfusion to at-risk brain tissue and decrease the risk of hemorrhage from fragile moyamoya collaterals. Although surgery is highly effective in appropriately selected patients, perioperative ischemic events occur following 4%-18% of cases. Perioperative medical management aims to mitigate this risk by optimizing brain oxygen delivery through adequate cerebral perfusion and blood oxygenation, pain/nausea control, minimizing metabolic demand, and preventing thrombosis. Long-term neuroimaging surveillance, evaluation of the neuropsychological effect of moyamoya, and screening for and management of headache and epilepsy resulting from moyamoya are important aspects of the chronic care of all patients with moyamoya. In this review, we summarize key aspects of neurologic evaluation and management for moyamoya across the lifespan, highlight key differences between adult and pediatric moyamoya, and discuss ongoing research efforts that aim to improve care of children and adults with moyamoya.

The Role of TCD in Assessing Postoperative Collateral Development and Long-Term Clinical Outcome in Moyamoya Disease

AIMS

To explore the role of transcranial Doppler (TCD) parameters after encephaloduroarteriosynangiosis (EDAS) to identify collateral development in moyamoya disease (MMD) and assess the relationship between these collateral formations and long-term postoperative cerebrovascular events.

METHODS

A retrospective analysis of 91 MMD patients who underwent EDAS. Patients were categorized into rich or poor collateral groups based on postoperative angiography. TCD was used to monitor changes in hemodynamic parameters pre-and post-surgery. The association between clinical outcome, TCD parameters, and the degree of collateral development was investigated.

OUTCOMES

Ninety-one patients were assessed, with 45 (49.0%) exhibiting rich collaterals and 46 (51.0%) showing poor collaterals. Over 2 years, the rich collateral group experienced significantly fewer cerebrovascular events than the poor collateral group (p = 0.041). Postoperative evaluations demonstrated significant improvements in hemodynamic parameters within the rich collateral group, including increases in peak-systolic velocity (PSV), end-diastolic velocity (EDV), and mean velocity (MV), alongside decreases in resistance index (RI) and pulsatility index (PI) (p < 0.05). An EDV cutoff of > 16.62 cm/s in the superficial temporal artery (STA) effectively identified collateral development, yielding an area under the curve (AUC) of 0.907. Additionally, multivariate analysis revealed a strong association between preoperative MV of the STA and collateral formation.

CONCLUSION

TCD sonography is a non-invasive modality essential for assessing cerebral hemodynamics after revascularization in MMD. Collateral development shown on angiography corresponds to hemodynamic changes reflected in TCD. The postoperative EDV of the STA was a vital indicator of effective collaterals. Patients with well-developed collaterals were at a lower risk of long-term cerebrovascular events post-surgery.

Medical Management of Adult Moyamoya Disease: A Review and Relevant Cases With Ischemic Events

Moyamoya disease (MMD) is a rare and progressive cerebrovascular disorder characterized by stenosis or occlusion of the internal carotid arteries resulting in the development of fragile collateral vessels at the base of the brain. Surgical revascularization is the primary treatment option for preventing ischemic and hemorrhagic events; however, the role of medical management has become increasingly recognized, particularly in cases involving asymptomatic patients or those at a high risk for surgical complications. In this review, we aimed to investigate the current guidelines and evidence supporting various medical management strategies for MMD, including the importance of controlling risk factors and judicious use of antithrombotic therapy. Given the considerable variability in patient presentation, such as age of onset, symptomatology, and comorbid conditions, it is crucial to adopt tailored therapeutic approaches that address each patient's unique characteristics. The existing literature on medical management is limited. However, individualized strategies may effectively mitigate the risk of ischemic events and improve the overall patient outcomes. Further research is essential to develop comprehensive and standardized treatment protocols for medical management of adult patients with MMD. In addition, ongoing trials and efforts to develop disease-modifying agents are discussed.

Role of scalp arteries in revascularization after side to side anastomosis in moyamoya disease patients

In our recent study, we introduced a novel side-to-side (S-S) bypass technique for adult moyamoya disease (MMD) patients. We aimed to validate the potential of this technique in enhancing postoperative revascularization. Patients undergoing S-S or end-to-side (E-S) bypass were enrolled, clinical data and angiography parameters were collected and compared. We included 44 E-S and 40 S-S MMD patients. There were no significant differences in basic characteristics and postoperative Matsushima grades between the two groups. However, in the S-S group, fewer patients had Matsushima grade D (0%) compared to the E-S group (11.4%, P = 0.028). The S-S group showed a greater occipital artery (OA) participation in revascularization (87.5% vs. 56.8%, P = 0.002) and higher postoperative caliber change ratio (CCR) of the superficial temporal artery (STA)-frontal branch (1.26 ± 0.43 vs. 1.04 ± 0.53, P = 0.038) compared to the E-S group. This difference was more pronounced in the subgroup with poor revascularization outcomes: in the S-S group, the CCR of the STA-frontal branch and the degree of participation in revascularization were 1.163 ± 0.168 and 58.8%, respectively, while in the E-S group, they were only 0.798 ± 0.494 and 6.7%. The S-S group also had a higher OA CCR (1.133 ± 0.257) and participation (82.4%) compared to the E-S group (0.941 ± 0.216 and 37.5%, respectively). In conclusion, the S-S bypass technique effectively utilizes scalp arteries, particularly the STA-frontal branch and OA, for direct revascularization via the preserved distal STA in adult MMD patients. Scalp arteries can serve as a supplementary source of donor arteries, especially beneficial for patients with suboptimal revascularization outcomes.

Coincidence of Concentric Vessel-Wall Contrast Enhancement in Moyamoya Disease and Acute Postoperative Ischemic Stroke During Revascularization Procedures

BACKGROUND

Concentric vessel-wall contrast enhancement (VW-CE) of the terminal carotid artery and its proximal branches may be linked to ischemic strokes, disease activity and progression in Moyamoya disease (MMD). The objective of this retrospective cohort study is to analyze the association between VW-CE and perioperative acute ischemic stroke (PAIS) occurring within 24 h after revascularization.

METHODS

All previously untreated MMD patients who required revascularization and who had undergone preoperative MRI with VW-CE-sequences were included. PAIS was detected by CT and/or diffusion-weighted MRI sequences within 24 h postoperatively.

RESULTS

Of the 110 patients included (female-to-male ratio: 2.7:1, median age: 45.1 (16.6-69.2); n = 247 revascularizations), a priori VW-CE was present in 67.3% (mean time from MRI to first surgery: 86 days ± 82 days). PAIS occurred in five patients undergoing primary revascularization (PAIS rate per revascularization: 2.1%), all of whom had a preoperative pathological VW-CE in the vascular segment corresponding to the stroke area. Two (40%) incidents of PAIS occurred in revascularized territory, while three (60%) occurred in non-revascularized vascular territory. In each case, the supplying artery exhibited VW-CE, indicating disease activity. No additional PAIS occurred during subsequent revascularizations in cases of multistage procedures (n = 38), such as ACA or PCA revascularization as a second step.

CONCLUSIONS

Preoperative VW-CE in one or more vascular segments may be a marker for postoperative stroke in the respective vascular territory at the time of revascularization. VW-CE imaging should be routinely performed when planning revascularization in MMD. If VW-CE is found, strict perioperative monitoring of these high-risk patients should be performed to achieve the best results possible.

Hemorrhagic Moyamoya Angiopathy in European Patients

BACKGROUND

Moyamoya angiopathy (MMA) is an important cause of juvenile stroke but an overall rare disease among European populations compared with East Asian cohorts. Consecutively, hemorrhagic MMA is described well in East Asian cohorts, but knowledge in non-Asian patients is limited. Literature suggests that disease presentation may vary between those cohorts, also including hemorrhage frequencies. Hence, this article aims to analyze hemorrhagic MMA in European patients.

METHODS

We screened for patients of European origin with MMA from a single-center consecutive database of a German hospital specialized on MMA. Those who had a record of intracranial hemorrhage were analyzed individually regarding the type of hemorrhage and use of antiplatelet therapy before and after bleeding onset. To identify associated factors of intracranial hemorrhage, an age- and sex-matched control group was identified from the pool of patients without a history of hemorrhage. Both groups had a comparable follow-up time and were compared in terms of disease presentation, therapeutic interventions, and imaging characteristics, using both univariate tests and multivariate logistic regression analysis.

RESULTS

From a pool of 332 patients with MMA we identified 288 of European ancestry. From those, 36 had a record of intracranial hemorrhage (12.5%). Thirty-three patients presenting with 37 events were included for further analysis and case-control-comparison. Most events were intracerebral hemorrhage (n=20; 54%) and subarachnoid hemorrhage (n=11; 30%). 78% developed hemorrhage although no antiplatelet therapy was in use (n=29). Seven patients developed intracranial hemorrhage ipsilateral to prior bypass surgery (21%), while 29 of the control patients had a bypass surgery (88%; P=0.0001). There was no significant difference in terms of unilateral or bilateral disease type, history of hypertension, as well as imaging characteristics (high Suzuki stage and the presence of collateral pathways in conventional angiography, as well as ischemic defects and the presence of microbleeds on cerebral magnetic resonance imaging; P>0.05 in multivariate analysis, respectively).

CONCLUSIONS

Bypass surgery was negatively associated with the development of intracranial hemorrhage in MMA in European patients. There was no difference in terms of a history of hypertension between groups, indicating that blood pressure is not the major contributor for rupture of fragile collateral vessels. The investigated imaging characteristics were not associated to hemorrhage onset and, therefore, are not suitable as a tool of screening for patients at risk.

The Impact of Revascularization Surgery on Headaches in Association with Cerebrovascular Reactivity in Patients with Moyamoya Angiopathy

BACKGROUND/OBJECTIVES

Headaches in Moyamoya angiopathy are common but poorly understood. We aimed to investigate if headaches in Moyamoya angiopathy improve after revascularization surgery and whether this is associated with improvement in cerebrovascular reactivity on MRI (CVR-MRI).

METHODS

We included consecutive adult patients with Moyamoya angiopathy who had chart data on headaches, CVR-MRI, and underwent extracranial-intracranial bypass surgery between January 2010 and September 2022 at a tertiary neurovascular referral center. Clinical and CVR-MR imaging data of all patients were collected through systematic chart review, complemented by standard-of-care headache questionnaires from patients who were operated between 2018 and 2022. We evaluated headache features and explored the association between headaches and CVR before and after revascularization surgery.

RESULTS

Fifty-nine patients were included (mean age 47 ± 14 years, 43 females (73%)); among them, 41/59 (69%) reported headaches pre-surgery. Headache improved in 28/41 (68%) patients after revascularization surgery with a reduction in pain severity (median VAS-score from 5/10 to 2.5/10; p = 0.002), analgesic use (from 84% to 40%; p = 0.007), and sick leave (from 60% to 16%; p < 0.001). Improvement in headaches was associated with improvement in CVR (OR 5.3; 95% CI: 1.2-23.5) and sick leave reduction (OR 1.4; 95% CI: 1.6-121.4).

CONCLUSIONS

Headaches in Moyamoya angiopathy are common and disabling. They may improve in most patients after revascularization surgery and seem to be associated with improvement in CVR, supporting the hypothesis of a potential vascular origin of the headaches.

Comparison of American and European Guideline Recommendations for Diagnostic Workup and Secondary Prevention of Ischemic Stroke and Transient Ischemic Attack

Guidelines help to facilitate treatment decisions based on available evidence, and also to provide recommendations in areas of uncertainty. In this paper, we compare the recommendations for stroke workup and secondary prevention of ischemic stroke and transient ischemic attack of the American Heart Association (AHA)/American Stroke Association (ASA) with the European Stroke Organization (ESO) guidelines. The primary aim of this paper is to offer clinicians guidance by identifying areas where there is consensus and where consensus is lacking, in the absence or presence of high-level evidence. We compared AHA/ASA with the ESO guideline recommendations for 7 different topics related to diagnostic stroke workup and secondary prevention. We categorized the recommendations based on class and level of evidence to determine whether there were relevant differences in the ratings of evidence that the guidelines used for its recommendations. Finally, we summarized major topics of agreement and disagreement, while also prominent knowledge gaps were identified. In total, we found 63 ESO and 82 AHA/ASA recommendations, of which 38 were on the same subject. Most recommendations are largely similar, but not all are based on high-level evidence. For many recommendations, AHA/ASA and ESO assigned different levels of evidence. For the 10 recommendations with Level A evidence (high quality) in AHA/ASA, ESO only labeled 4 of these as high quality. There are many remaining issues with either no or insufficient evidence, and some topics that are not covered by both guidelines. Most ESO and AHA/ASA Guideline recommendations for stroke workup and secondary prevention were similar. However not all were based on high-level evidence and the appointed level of evidence often differed. Clinicians should not blindly follow all guideline recommendations; the accompanying level of evidence informs which recommendations are based on robust evidence. Topics with lower levels of evidence, or those with recommendations that disagree or are missing, may be an incentive for further clinical research.

Remote ischemic conditioning prevents ischemic cerebrovascular events in children with moyamoya disease: a randomized controlled trial

BACKGROUND

Moyamoya disease (MMD) is a significant cause of childhood stroke and transient ischemic attacks (TIAs). This study aimed to assess the safety and efficacy of remote ischemic conditioning (RIC) in children with MMD.

METHODS

In a single-center pilot study, 46 MMD patients aged 4 to 14 years, with no history of reconstructive surgery, were randomly assigned to receive either RIC or sham RIC treatment twice daily for a year. The primary outcome measured was the cumulative incidence of major adverse cerebrovascular events (MACEs). Secondary outcomes included ischemic stroke, recurrent TIA, hemorrhagic stroke, revascularization rates, and clinical improvement assessed using the patient global impression of change (PGIC) scale during follow-up. RIC-related adverse events were also recorded, and cerebral hemodynamics were evaluated using transcranial Doppler.

RESULTS

All 46 patients completed the final follow-up (23 each in the RIC and sham RIC groups). No severe adverse events associated with RIC were observed. Kaplan-Meier analysis indicated a significant reduction in MACEs frequency after RIC treatment [log-rank test (Mantel-Cox), P = 0.021]. At 3-year follow-up, two (4.35%) patients had an ischemic stroke, four (8.70%) experienced TIAs, and two (4.35%) underwent revascularization as the qualifying MACEs. The clinical improvement rate in the RIC group was higher than the sham RIC group on the PGIC scale (65.2% vs. 26.1%, P < 0.01). No statistical difference in cerebral hemodynamics post-treatment was observed.

CONCLUSIONS

RIC is a safe and effective adjunct therapy for asymptomatic children with MMD. This was largely due to the reduced incidence of ischemic cerebrovascular events.

Clinical Case of a 23-Year-Old Patient with Moyamoya Disease and Epilepsy in Bulgaria

Moyamoya disease is a cerebrovascular pathology characterized by progressive stenosis of the internal carotid arteries and their branches, leading to ischemic and/or hemorrhagic disorders of the cerebral circulation, primarily affecting children and young adults. We present a case of a 23-year-old woman with a history of recurrent cerebrovascular accidents since childhood. Despite experiencing focal motor seizures and transient ischemic attacks, her condition remained undiagnosed until 2006, when, at the age of 7, a digital subtraction angiography revealed characteristic bilateral internal carotid artery occlusions. Subsequent diagnostic challenges and treatments preceded a worsening of symptoms in adulthood, including generalized tonic-clonic seizures. Upon presentation to our clinic, the patient exhibited upper motor neuron syndrome and occipital lobe syndrome, consistent with the disease's pathophysiology, neuroimaging, and clinical manifestations. Imaging studies confirmed multiple ischemic lesions throughout the cerebral vasculature. Treatment adjustments were made due to the increased incidence of seizures, and the dose of her anti-seizure medication-divalproex sodium-was increased. This case underscores the diagnostic complexities and challenges in managing moyamoya disease, emphasizing the importance of early recognition and prompt intervention.

BOLD Cerebrovascular Reactivity and NOVA Quantitative MR Angiography in Adult Patients with Moyamoya Vasculopathy Undergoing Cerebral Bypass Surgery

Revascularization surgery for the symptomatic hemisphere with hemodynamic impairment is effective for Moyamoya vasculopathy patients. However, careful patient selection is crucial and ideally supported by advanced quantitative hemodynamic imaging. Recently, blood oxygenation level-dependent cerebrovascular reactivity (BOLD-CVR) and quantitative magnetic resonance angiography with non-invasive optimal vessel analysis (qMRA-NOVA) have gained prominence in assessing these patients. This study aims to present the results of BOLD-CVR and qMRA-NOVA imaging along with the changes in cerebral hemodynamics and flow status following flow augmentation with superficial temporal artery-middle cerebral artery (STA-MCA) bypass in our Moyamoya vasculopathy patient cohort. Symptomatic patients with Moyamoya vasculopathy treated at the Clinical Neuroscience Center of the University Hospital Zurich who underwent hemodynamic and flow imaging (BOLD-CVR and qMRA-NOVA) before and after bypass were included in the analysis. Reduced hemispheric volume flow rates, as well as impaired BOLD-CVR, were measured in all 12 patients with Moyamoya vasculopathy before STA-MCA bypass surgery. Following the surgical procedure, post-operative BOLD-CVR demonstrated a non-significant increase in BOLD-CVR values within the revascularized, symptomatic middle cerebral artery territory and cerebral hemisphere. The results of the statistical tests should be viewed as indicative due to the small sample size. Additionally, post-operative qMRA-NOVA revealed a significant improvement in the hemispheric volume flow rate of the affected hemisphere due to the additional bypass flow rate. Our findings affirm the presence of hemodynamic and flow impairments in the symptomatic hemisphere of the Moyamoya vasculopathy patients. Bypass surgery proves effective in improving both BOLD-CVR impairment and the hemispheric volume flow rate in our patient cohort.

MRI-Based Assessment of Risk for Stroke in Moyamoya Angiopathy (MARS-MMA): An MRI-Based Scoring System for the Severity of Moyamoya Angiopathy

Before revascularization, moyamoya patients require hemodynamic evaluation. In this study, we evaluated the scoring system Prior Infarcts, Reactivity and Angiography in Moyamoya Disease (PIRAMID). We also devised a new scoring system, MRI-Based Assessment of Risk for Stroke in Moyamoya Angiopathy (MARS-MMA), and compared the scoring systems with respect to the capability to predict impaired [15O]water PET cerebral perfusion reserve capacity (CPR). We evaluated 69 MRI, 69 DSA and 38 [15O]water PET data sets. The PIRAMID system was validated by ROC curve analysis with neurological symptomatology as a dependent variable. The components of the MARS-MMA system and their weightings were determined by binary logistic regression analysis. The comparison of PIRAMID and MARS-MMA was performed by ROC curve analysis. The PIRAMID score correlated well with the symptomatology (AUC = 0.784). The MARS-MMA system, including impaired breath-hold-fMRI, the presence of the Ivy sign and arterial wall contrast enhancement, correlated slightly better with CPR impairment than the PIRAMID system (AUC = 0.859 vs. 0.827, Akaike information criterion 140 vs. 146). For simplified clinical use, we determined three MARS-MMA grades without loss of diagnostic performance (AUC = 0.855). The entirely MRI-based MARS-MMA scoring system might be a promising tool to predict the risk of stroke.

Moyamoya syndrome in a patient with D-2-hydroxyglutaric aciduria type II: a rare association

PURPOSE

Several underlying conditions of moyamoya syndrome (MMS) are well established, but so far, D-2-hydroxyglutaric aciduria (D-2-HGA) has not been mentioned. We are the first to describe a case of a patient suffering from D-2-HGA developing MMS.

METHODS

The co-occurrence of D-2-HGA and MMS in a patient is reported. Furthermore, we describe the neurosurgical revascularization procedure performed and report on the follow-up.

RESULTS

A 7-year-old girl suffering from D-2-HGA developed two transient ischemic attacks (TIAs). Using MRI/MRA and invasive angiography MMS was diagnosed. We performed an encephalo-duro-arterio-myo-synangiosis (EDAMS) as an indirect revascularization procedure first on the right and 2 months later on the left hemisphere. We have followed her up until the age of 10. Since the second surgery, she has not suffered further TIAs and is in a better general medical condition.

CONCLUSION

Even though children with D-2-HGA often suffer epileptic attacks, every new (transient) neurological deficit should be followed up by an MRI/MRA so as not to oversee a possible underlying MMS. After diagnosis, EDAMS in combination with acetylsalicylic acid (ASA) is recommended to prevent further ischemic events.

Evaluation of the contribution of individual arteries to the cerebral blood supply in patients with Moyamoya angiopathy: comparison of vessel-encoded arterial spin labeling and digital subtraction angiography

PURPOSE

Vessel-encoded arterial spin labeling (VE-ASL) is able to provide noninvasive information about the contribution of individual arteries to the cerebral perfusion. The aim of this study was to compare VE-ASL to the diagnostic standard digital subtraction angiography (DSA) with respect to its ability to visualize vascular territories.

METHODS

In total, 20 VE-ASL and DSA data sets of 17 patients with Moyamoya angiopathy with and without revascularization surgery were retrospectively analyzed. Two neuroradiologists independently assessed the agreement between VE-ASL and DSA using a 4-point Likert scale (no- very high agreement). Additionally, grading of the vascular supply of subterritories (A1-A2, M1-M6) on the VE-ASL images and angiograms was performed. The intermodal agreement was calculated for all subterritories in total and for the subdivision into without and after revascularization (direct or indirect bypass).

RESULTS

There was a very high agreement between the VE-ASL and the DSA data sets (median = 1, modus = 1) with a substantial inter-rater agreement (kw = 0.762 (95% CI 0.561-0.963)). The inter-modality agreement between VE-ASL and DSA in vascular subterritories was almost perfect for all subterritories (k = 0.899 (0.865-0.945)), in the subgroup of direct revascularized subterritories (k = 0.827 (0.738-0.915)), in the subgroup of indirect revascularized subterritories (k = 0.843 (0.683-1.003)), and in the subgroup of never revascularized subterritories (k = 0.958 (0.899-1.017)).

CONCLUSION

Vessel-encoded ASL seems to be a promising non-invasive method to depict the contributions of individual arteries to the cerebral perfusion before and after revascularization surgery.

Neurovascular Issues in Antiphospholipid Syndrome: Arterial Vasculopathy from Small to Large Vessels in a Neuroradiological Perspective

Antiphospholipid syndrome (APS) is an autoimmune prothrombotic condition characterized by venous thromboembolism, arterial thrombosis, and pregnancy morbidity. Among neurological manifestations, arterial thrombosis is only one of the possible associated clinical and neuroradiological features. The aim of this review is to address from a neurovascular point of view the multifaceted range of the arterial side of APS. A modern neurovascular approach was proposed, dividing the CNS involvement on the basis of the size of affected arteries, from large to small arteries, and corresponding clinical and neuroradiological issues. Both large-vessel and small-vessel involvement in APS were detailed, highlighting the limitations of the available literature in the attempt to derive some pathomechanisms. APS is a complex disease, and its neurological involvement appears multifaceted and not yet fully characterized, within and outside the diagnostic criteria. The involvement of intracranial large and small vessels appears poorly characterized, and the overlapping with the previously proposed inflammatory manifestations is consistent.

3D exoscopic versus microscopic superficial temporal artery to middle cerebral artery bypass surgery for moyamoya disease - a comparative series

PURPOSE

Superficial temporal artery to middle cerebral artery (STA-MCA) direct bypass surgery is the most common surgical procedure to treat moyamoya disease (MMD). Here, we aim to compare the performance of the 3D exoscope in bypass surgery with the gold standard operative microscope.

METHODS

All direct STA-MCA bypass procedures performed at a single university hospital for MMD between 2015 and 2023 were considered for inclusion. Data were retrospectively collected from patient files and surgical video material. From 2020 onwards, bypass procedures were exclusively performed using a digital three-dimensional exoscope as visualization device. Results were compared with a microsurgical bypass control group (2015-2019). The primary endpoint was defined as total duration of surgery, duration of completing the vascular anastomosis (ischemia time), bypass patency, number of stiches to perform the anastomosis, added stiches after leakage testing of the anastomosis and the Glasgow outcome scale (GOS) at last follow-up as secondary outcome parameter.

RESULTS

A total of 16 consecutive moyamoya patients underwent 21 STA-MCA bypass procedures. Thereof, six patients were operated using a microscope and ten patients using an exoscope (ORBEYE® n = 1; AEOS® n = 9). Total duration of surgery was comparable between devices (microscope: 313 min. ± 116 vs. exoscope: 279 min. ± 42; p = 0.647). Ischemia time also proved similar between groups (microscope: 43 min. ± 19 vs. exoscope: 41 min. ± 7; p = 0.701). No differences were noted in bypass patency rates. The number of stiches per anastomosis was similar between visualization devices (microscope: 17 ± 4 vs. exoscope: 17 ± 2; p = 0.887). In contrast, more additional stiches were needed in microscopic anastomoses after leakage testing the bypass (p = 0.035).

CONCLUSION

Taking into account the small sample size, end-to-side bypass surgery for moyamoya disease using a foot switch-operated 3D exoscope was not associated with more complications and led to comparable clinical and radiological results as microscopic bypass surgery.

Angiopoietin-2 associates with poor prognosis in Moyamoya angiopathy

OBJECTIVE

Moyamoya angiopathy (MA) is a rare cerebrovascular disorder characterized by recurrent ischemic/hemorrhagic strokes due to progressive occlusion of the intracranial carotid arteries. The lack of reliable disease severity biomarkers led us to investigate molecular features of a Caucasian cohort of MA patients.

METHODS

The participants consisted of 30 MA patients and 40 controls. We measured cerebrospinal fluid (CSF) levels of angiogenic/inflammatory factors (ELISA). We then applied quantitative real-time PCR on cerebral artery specimens for expression analyses of angiogenic factors. By an immunoassay based on microfluidic technology, we examined the potential correlations between plasma protein expression and MA clinical progression. A RNA interference approach toward Ring Finger Protein 213 (RNF213) and a tube formation assay were applied in cellular model.

RESULTS

We detected a statistically significant (p < 0.000001) up-regulation of Angiopoietin-2 (Ang-2) in CSF and stenotic middle cerebral arteries (RQ >2) of MA patients compared to controls. A high Ang-2 plasma concentration (p = 0.018) was associated with unfavorable outcome in a subset of MA patients. ROC curve analyses indicated Ang-2 as diagnostic CSF biomarker (>3741 pg/mL) and prognostic plasma biomarker (>1162 pg/mL), to distinguish stable-from-progressive MA. Consistently, MA cellular model showed a significant up-regulation (RQ >2) of Ang-2 in RNF213 silenced condition.

INTERPRETATION

Our results pointed out Ang-2 as a reliable biomarker mirroring arterial steno-occlusion and vascular instability of MA in CSF and blood, providing a candidate factor for patient stratification. This pilot study may pave the way to the validation of a biomarker to identify progressive MA patients deserving a specific treatment path.

Moyamoya disease in Southeast Asians: genetic and autopsy data, new cases, systematic review, and meta-analysis of all patients from the literature

BACKGROUND

Moyamoya disease (MMD) is a rare disorder causing ischemic and hemorrhagic juvenile stroke. It is associated with the founder susceptibility variant p.R4810K in the RNF213 gene in East Asia. Our aim was to enhance understanding of MMD in so far poorly characterized Southeast Asians and exploring differences with Caucasian Europeans.

METHODS

By retrospective analysis of medical records and systematic database search on PubMed for all published cases, we identified Southeast Asian patients with MMD. We extracted and pooled proportions using fixed-effects models. Our own cohort was tested for the East Asian RNF213 founder variant p.R4810K. One of our Southeast Asian patients underwent post-mortem histopathological examination.

RESULTS

The study cohort comprised 32 Southeast Asians. Mean age at onset in the entire cohort was 32.5 ± 20.3 years (n = 24), 43.4 ± 8.7 years in patients admitted to our center (n = 11), and 23.4 ± 22.4 years in patients from the international literature (n = 13). Female-to-male ratio was 1.6:1. MMD predominantly affected bilateral anterior intracranial vessels. Cerebral ischemia outnumbered transient ischemic attacks (TIAs) and intracranial hemorrhage. TIAs, arterial hypertension and obesity were significantly less frequent in Southeast Asian patients compared to Caucasian Europeans. p.R4810K was absent in all examined Southeast Asians despite of typical histopathological signs of MMD in one autopsy case.

CONCLUSION

Clinical and histopathological manifestations of MMD in Southeast Asians are similar to those in Caucasian Europeans. The genotype of MMD in Southeast Asians differs from that of most East Asian patients.

Vascular risk profile and changes of arterial hypertension after surgical revascularization in adult Moyamoya patients

Moyamoya disease (MMD) is a rare stenoocclusive cerebral vasculopathy often treated by neurosurgical revascularization using extracranial-intracranial bypasses to prevent ischemic or hemorrhagic events. Little is known about the vascular risk profile of adult MMD patients compared to the general population. We therefore analyzed 133 adult MMD patients and compared them with data from more than 22,000 patients from the German Health Update database. Patients with MMD showed an age- and sex-adjusted increased prevalence of arterial hypertension, especially in women between 30 and 44 years and in patients of both sexes between 45 and 64 years. Diabetes mellitus was diagnosed significantly more frequently in MMD patients with increasing age, whereas the vascular risk profile in terms of obesity, nicotine and alcohol consumption was similar to that of the general population. Antihypertensive medication was changed one year after surgical revascularization in 67.5% of patients with a tendency towards dose reduction in 43.2% of all patients. After revascularization, physicians need to be aware of a high likelihood of changes in arterial hypertension and should adjust all other modifiable systemic vascular risk factors to achieve the best treatment possible.

Virtual hospital and artificial intelligence: a first step towards the application of an innovative health system for the care of rare cerebrovascular diseases

The development of virtual care options, including virtual hospital platforms, is rapidly changing the healthcare, mostly in the pandemic period, due to difficulties in in-person consultations. For this purpose, in 2020, a neurological Virtual Hospital (NOVHO) pilot study has been implemented, in order to experiment a multidisciplinary second opinion evaluation system for neurological diseases. Cerebrovascular diseases represent a preponderant part of neurological disorders. However, more than 30% of strokes remain of undetermined source, and rare CVD (rCVD) are often misdiagnosed. The lack of data on phenotype and clinical course of rCVD patients makes the diagnosis and the development of therapies challenging. Since the diagnosis and care of rCVDs require adequate expertise and instrumental tools, their management is mostly allocated to a few experienced hospitals, making difficult equity in access to care. Therefore, strategies for virtual consultations are increasingly applied with some advantage for patient management also in peripheral areas. Moreover, health data are becoming increasingly complex and require new technologies to be managed. The use of Artificial Intelligence is beginning to be applied to the healthcare system and together with the Internet of Things will enable the creation of virtual models with predictive abilities, bringing healthcare one step closer to personalized medicine. Herein, we will report on the preliminary results of the NOVHO project and present the methodology of a new project aimed at developing an innovative multidisciplinary and multicentre virtual care model, specific for rCVD (NOVHO-rCVD), which combines the virtual hospital approach and the deep-learning machine system.

Long-term stroke risk in Moyamoya disease

BACKGROUND

Moyamoya disease (MMD) is considered a progressive disease with an ongoing risk of recurrent stroke. However, there is a lack of long-term observational data to quantify the extent of the stroke risk.

METHODS

This study aimed to provide insight into the long-term stroke risk in MMD and explore possible risk factors for stroke. Records from all patients diagnosed with MMD in 13 clinical departments from 6 different Danish hospitals between 1994 and 2017 were retrospectively reviewed until 2021.

RESULTS

The cohort comprised 50 patients (33 females and 17 males). Patients were followed up for a median of 9.4 years, with more than 10 years of follow-up for 24 patients. Ten patients had 11 new stroke events-6 ischemic strokes and 5 brain hemorrhages. Events occurred at a median of 7 years and up to 25 years after diagnosis. The overall Kaplan-Meier 5-year stroke risk was 10%. Patients with bypass performed had significantly fewer events than conservatively treated patients (HR 0.25, 95% confidence interval (CI) 0.07-0.91, p < 0.05). All but one event occurred in females, a difference that reached statistical significance.

CONCLUSIONS

The study provides data on the extent of the risk of recurrent stroke in MMD. Bypass surgery patients had fewer stroke events than those treated conservatively. There was a trend toward a higher stroke risk in females.

DATA ACCESS STATEMENT

The data supporting this study's findings are available from the corresponding author upon reasonable request.

Health-Related Quality of Life and Neuropsychological Outcome After EC-IC Bypass Revascularization in Adult Patients With Moyamoya Disease

BACKGROUND AND OBJECTIVES

Patients with Moyamoya disease (MMD) have an above-average incidence of neuropsychological impairment and psychiatric comorbidities such as depression. Prevalence and correlation with preoperative imaging findings were identified in previous studies, and a reduced health-related quality of life (HRQOL) has been shown. This study investigates changes in neuropsychological performance and HRQOL after revascularization.

METHODS

Thirty-two adult patients with MMD (23 female, 9 male; mean age 39.1 year ±14.7) with revascularization were included in this retrospective cohort study, and their results of structured neuropsychological testing were analyzed preoperatively and 1 year postoperatively. Sensorimotor deficits assessed with the National Institutes of Health Stroke Scale were considered to be possible confounders.

RESULTS

Patients with preoperatively poor test results showed improvement in various items such as psychological well-being (95% CI [0.55-2.25], P = .002), vitality (95% CI [0.23-1.68], P = .007), general health perception (95% CI [0.09-1.44], P = .014), psychoticism (95% CI [-12.24 to -4.85], P < .001), and psychomotor processing speed (95% CI [0.10-1.14], P = .010), whereas the intensity of depression fell by a mean of 6.9 points (95% CI [-10.14 to -3.61], P < .001). For patients without preoperative neuropsychological or HRQOL deterioration, preservation of these functions without relevant worsening after revascularization was observed. Significant improvement in vitality, psychological well-being, psychoticism, psychomotor processing speed, and depression were also seen in patients with unchanged National Institutes of Health Stroke Scale.

CONCLUSION

Chronic steno-occlusive cerebral hypoperfusion in patients with MMD not only may lead to neurological deficits but is also associated with neuropsychological impairment, reduced HRQOL, and increased depression. The results of this study show that patients with preoperative neuropsychological deterioration might benefit from revascularization surgery, whereas patients without preoperative impairment continue to remain stable postoperatively. Neuropsychological assessment should be routinely evaluated and considered a relevant variable when determining treatment for patients with MMD.

[Moyamoya in Aragon: epidemiology and self-perception of quality of life]

INTRODUCTION

Moyamoya angiopathy is a vasculopathy caused by stenosis/occlusion of one or both intracranial internal carotid arteries. Although more common in Eastern countries, its prevalence is increasing in the West. An angioresonance or angiography is essential for its diagnosis. There are two options for treatment: conservative (medical) treatment or surgical bypass techniques.

PATIENTS AND METHODS

Nineteen patients were selected using International Classification of Diseases codes, and their demographic characteristics and health outcomes were studied. They were administered a scale for the screening of anxious-depressive syndrome (the Hospital Anxiety and Depression Scale - HADS) and another scale for self-perceived quality of life (SF-36). After applying the inclusion/exclusion criteria, eight of these patients were studied.

RESULTS

Nineteen patients were studied (52.63% male, 57.89% European) and the Aragonese prevalence was estimated at 1.37/100,000 inhabitants. The most frequent clinical presentation was ischaemic stroke (73.68%). The HADS detected two positive cases of anxiety and one case of depression. According to the SF-36, the worst self-rated aspects were vitality (median: 35/100) and general health (median: 42.5/100), while the best rated was physical function (mean: 93.57/100).

CONCLUSIONS

This is the Spanish series with the highest prevalence and the only one that addresses self-perceived health and screening of the anxious-depressive syndrome. Further research is needed to address this entity and determine its true prevalence in the West.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Moyamoya Disease: Clinical and Radiological Characteristics in Adult Greek Patients

BACKGROUND AND PURPOSE

The aim of our study is to present, for the first time, the clinical, radiological, and neurocognitive characteristics of Greek adult patients with Moyamoya disease (MMD).

METHODS

We analyzed prospectively collected data of 12 patients referred to our department from 2004 to 2019. All patients underwent a thorough diagnostic work up, including extensive clinical, neuroradiological, and neurocognitive assessment.

RESULTS

Our study population consisted of 7 females and the median age at the time of the diagnosis was 43.5 years. No patient had a positive family history of the disease and roughly 50% were hypertensives. Ten patients presented with transient or permanent cerebrovascular ischemia and two patients suffered from hemorrhagic complications. The median NIHSS was 7.5 (0-23) and clinical status remained stable during follow-up with conservative treatment in most of the patients. The majority (83.3%) had bilateral disease confirmed by DSA. All lesions exclusively affected the anterior circulation, with 50% of patients presenting with stenoocclusive changes. No aneurysm or AVM were revealed. The most common neurocognitive deficits were in the executive and language domains.

CONCLUSIONS

Our MMD patients had a later onset of the disease and an absence of familial occurrence. The most common manifestation was ischemia, transient or permanent, and all lesions affected the anterior circulation, whereas no vascular malformations (AVM, aneurysms) were demonstrated in brain imaging. These findings in Greek patients imply a probable different, Mediterranean phenotype.

Progression of initially unilateral Moyamoya angiopathy in Caucasian Europeans

BACKGROUND

Moyamoya angiopathy (MMA) is a rare cause of stroke in Caucasians, but it is much more frequent in East Asia. Since 2021, diagnostic criteria not only comprise bilateral, but also unilateral MMA. Hitherto, progression of unilateral MMA has predominantly been described in East Asians. Our study aimed to analyze the occurrence and characteristics of progression of initially unilateral MMA in Caucasian Europeans.

METHODS

By retrospective analysis of medical records of 200 European Caucasians with MMA, admitted to our German center between 2010 and 2022, cases of unilateral MMA and its progression, i.e. progressive ipsi- or novel contralateral arterial stenosis, during follow-up were identified. Kruskal Wallis Test and Fisher's Exact Test were used to identify statistically significant differences between progressive and stable patients concerning demographic, clinical, laboratory, and radiographic features.

RESULTS

Our cohort comprised 63 patients with initially unilateral MMA. Fourteen (22.2%) had an ipsi- (n = 3, 21.4%) or contralateral (n = 11, 78.6%) progression. Mean age of patients with progressive MMA at symptom onset was 32 ± 14.1 years. The ratio of women to men in this subgroup was 2.5:1. Mean follow-up period was 5.4 ± 3.7 years, mean age at progression was 39.9 ± 12.7 years. Mean time interval between penultimate follow-up and progression was 4.8 ± 4.5 years. Patients with progression showed affection of the posterior cerebral artery (p = 0.009) and suffered from vertigo (p = 0.009) significantly more often.

CONCLUSION

Unilateral MMA progresses in a substantial proportion in European Caucasians. Long-term follow-up is required due to potential late progression with consecutive symptoms and the need for bypass surgery.

Proteome Profiling of the Dura Mater in Patients with Moyamoya Angiopathy

Moyamoya angiopathy (MMA) is an uncommon cerebrovascular disease characterized by a progressive steno-occlusive lesion of the internal carotid artery and the compensatory development of an unstable network of collateral vessels. These vascular hallmarks are responsible for recurrent ischemic/hemorrhagic strokes. Surgical treatment represents the preferred procedure for MMA patients, and indirect revascularization may induce a spontaneous angiogenesis between the brain surface and dura mater (DM), whose function remains rather unknown. A better understanding of MMA pathogenesis is expected from the molecular characterization of DM. We performed a comprehensive, label-free, quantitative mass spectrometry-based proteomic characterization of DM. The 30 most abundant identified proteins were located in the extracellular region or exosomes and were involved in extracellular matrix organization. Gene ontology analysis revealed that most proteins were involved in binding functions and hydrolase activity. Among the 30 most abundant proteins, Filamin A is particularly relevant because considering its well-known biochemical functions and molecular features, it could be a possible second hit gene with a potential role in MMA pathogenesis. The current explorative study could pave the way for further analyses aimed at better understanding such uncommon and disabling intracranial vasculopathy.

Antiplatelet therapy may improve the prognosis of patients with moyamoya disease: a 12-year retrospective study

OBJECTIVES

The clinical value of antiplatelet therapy (APT) for moyamoya disease (MMD) remains controversial. Our study attempts to clarify the value of APT in this disease.

METHODS

We collected basic information, treatment strategies, and prognostic information on patients with MMD from 2010 to 2022 at our center. The data were divided into two groups, depending on whether APT was used or not, and compared by Pearson Chi-Square, Fisher's exact test, or Wilcoxon rank-sum test. We used propensity scores or inverse probability of treatment weighting to balance the covariates. Following this, we performed a meta-analysis of APT use in MMD.

RESULTS

177 patients were enrolled, with a median follow-up of 41.1 months. APT did not affect the prognosis of patients with perioperative MMD, ischemic MMD, or asymptomatic MMD (P > 0.05), without increasing cerebral hemorrhagic risk. In contrast, APT was found to reduce mortality among patients with hemorrhagic MMD (P = 0.019), without affecting functional status, increasing stroke risk, or causing intracerebral hemorrhage (P > 0.05). But the small group cannot show the effect of APT. Our meta-analysis included nine articles involving 28,925 patients with MMD. It showed that APT could reduce stroke risk (odds ratio, OR = 0.57, 95% CI 0.49 to 0.65) and the Modified Rankin Scale (mRS) (weighted mean difference, WMD = - 0.07, 95% CI 0.14-0.00) during follow-up. The cohort study has limited weight (1.97% and 19.29%) in the meta-analysis.

CONCLUSION

Although the limited number of included documents, APT could be beneficial to the prognosis of MMD.