Moyamoya angiopathy - Is there a Western phenotype?

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.

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.

Memory, Executive, and Intellectual Functions in Adults with Moyamoya Disease

OBJECTIVE

Cognitive function can decline in adults with moyamoya disease (MMD). Memory, which is an essential but complex and multifaceted function, underpins executive and intellectual functions. However, the relationship between memory and executive or intellectual functions in adults with MMD has not been well studied. The relationship between memory and cerebral blood flow has also not been elucidated. This study investigated correlations between memory, executive function, and intellectual function, and associations between cerebral blood flow and memory in adults with MMD.

METHODS

Memory, executive function, and intellectual function were assessed using the Wechsler Memory Scale-Revised (WMS-R), Frontal Assessment Battery (FAB), and Wechsler Adult Intelligence Scale (WAIS) third or fourth edition, respectively, in 31 adults with MMD. Cerebral blood flow was measured with iodine 123I-iodoamphetamine single-photon emission computed tomography.

RESULTS

WMS-R scores correlated significantly with total FAB and WAIS scores before and after revascularization. Cerebral blood flow in the left posterior cerebral artery territory correlated positively with WMS-R and WAIS scores pre- and postoperatively. Postoperative cerebrovascular reserves of the right cerebellum, pons, and vermis were positively associated with visual memory, and postoperative cerebrovascular reserve of the pons was also associated with general memory.

CONCLUSIONS

Memory function correlates with executive and intellectual functions in adults with MMD. The FAB, which requires about 10 min to administer, might be useful to screen for memory dysfunction. Memory might be vulnerable to hypoperfusion in the posterior cerebral artery territory among adults with MMD. Postoperative cerebrovascular reserve might help predict memory dysfunction in adults with MMD.

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.

Whole-exome sequencing in moyamoya patients of Northern-European origin identifies gene variants involved in Nitric Oxide metabolism: A pilot study

Introduction

Moyamoya disease (MMD) is a chronic cerebrovascular steno-occlusive disease of largely unknown etiology. Variants in the RNF213 gene are strongly associated with MMD in East-Asia. In MMD patients of Northern-European origin, no predominant susceptibility variants have been identified so far.

Research question

Are there specific candidate genes associated with MMD of Northern-European origin, including the known RNF213 gene? Can we establish a hypothesis for MMD phenotype and associated genetic variants identified for further research?

Material and methods

Adult patients of Northern-European origin, treated surgically for MMD at Oslo University Hospital between October 2018 to January 2019 were asked to participate. WES was performed, with subsequent bioinformatic analysis and variant filtering. The selected candidate genes were either previously reported in MMD or known to be involved in angiogenesis. The variant filtering was based on variant type, location, population frequency, and predicted impact on protein function.

Results

Analysis of WES data revealed nine variants of interest in eight genes. Five of those encode proteins involved in nitric oxide (NO) metabolism: NOS3, NR4A3, ITGAV, GRB7 and AGXT2. In the AGXT2 gene, a de novo variant was detected, not previously described in MMD. None harboured the p.R4810K missense variant in the RNF213 gene known to be associated with MMD in East-Asian patients.

Discussion and conclusion

Our findings suggest a role for NO regulation pathways in Northern-European MMD and introduce AGXT2 as a new susceptibility gene. This pilot study warrants replication in larger patient cohorts and further functional investigations.

Validation of the Berlin Grading System for moyamoya angiopathy with the use of [15O]H2O PET

The Berlin Grading System assesses clinical severity of moyamoya angiopathy (MMA) by combining MRI, DSA, and cerebrovascular reserve capacity (CVRC). Our aim was to validate this grading system using [15O]H2O PET for CVRC. We retrospectively identified bilateral MMA patients who underwent [15O]H2O PET examination and were treated surgically at our department. Each hemisphere was classified using the Suzuki and Berlin Grading System. Preoperative symptoms and perioperative ischemias were collected, and a logistic regression analysis was performed. A total of 100 hemispheres in 50 MMA patients (36 women, 14 men) were included. Using the Berlin Grading System, 2 (2.8%) of 71 symptomatic hemispheres were categorized as grade I, 14 (19.7%) as grade II, and 55 (77.5%) as grade III. The 29 asymptomatic hemispheres were characterized as grade I in 7 (24.1%) hemispheres, grade II in 12 (41.4%), and grade III in 10 (34.5%) hemispheres. Berlin grades were independent factors for identifying hemispheres as symptomatic and higher grades correlated with increasing proportion of symptomatic hemispheres (p < 0.01). The Suzuki grading did not correlate with preoperative symptoms (p = 0.26). Perioperative ischemic complications occurred in 8 of 88 operated hemispheres. Overall, complications did not occur in any of the grade I hemispheres, but in 9.1% (n = 2 of 22) and 9.8% (n = 6 of 61) of grade II and III hemispheres, respectively. In this study, we validated the Berlin Grading System with the use of [15O]H2O PET for CVRC as it could stratify preoperative symptomatology. Furthermore, we highlighted its relevance for predicting perioperative ischemic complications.

Clinical Outcome, Cognition, and Cerebrovascular Reactivity after Surgical Treatment for Moyamoya Vasculopathy: A Dutch Prospective, Single-Center Cohort Study

Background: It remains unclear whether revascularization of moyamoya vasculopathy (MMV) has a positive effect on cognitive function. In this prospective, single-center study, we investigated the effect of revascularization on cognitive function in patients with MMV. We report clinical and radiological outcome parameters and the associations between clinical determinants and change in neurocognitive functioning. Methods: We consecutively included all MMV patients at a Dutch tertiary referral hospital who underwent pre- and postoperative standardized neuropsychological evaluation, [15O]H2O-PET (including cerebrovascular reactivity (CVR)), MRI, cerebral angiography, and completed standardized questionnaires on clinical outcome and quality of life (QOL). To explore the association between patient characteristics, imaging findings, and change in the z-scores of the cognitive domains, we used multivariable linear- and Bayesian regression analysis. Results: We included 40 patients of whom 35 (27 females, 21 children) were treated surgically. One patient died after surgery, and two withdrew from the study. TIA- and headache frequency and modified Rankin scale (mRS) improved (resp. p = 0.001, 0.019, 0.039). Eleven patients (seven children) developed a new infarct during follow-up (31%), five of which were symptomatic. CVR-scores improved significantly (p < 0.0005). The language domain improved (p = 0.029); other domains remained stable. In adults, there was an improvement in QOL. We could not find an association between change in imaging and cognitive scores. Conclusion: In this cohort of Western MMV patients, TIA frequency, headache, CVR, and mRS improved significantly after revascularization. The language domain significantly improved, while others remained stable. We could not find an association between changes in CVR and cognitive scores.

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.

Microembolic signals and antiplatelet therapy in Moyamoya angiopathy

BACKGROUND

Embolism as a cause of stroke is widely neglected in Moyamoya angiopathy (MMA), and recommendations for use of antiplatelet therapy (APT) vary. We examined the presence of microembolic signals (MES) during transcranial Doppler (TCD) monitoring and assessed the effects of APT on the occurrence of MES in MMA.

PATIENTS AND METHODS

We retrospectively analysed patients with MMA treated at our centre between 2011 and 2021. TCD was performed at first presentation and at most visits, while number of visits varied between individual patients. TCD was performed for 30 min bilaterally. Patient demographics, vascular risk factors, and antiplatelet treatment were collected from each clinic visit and ischemic and haemorrhagic episodes were captured as recorded during follow-up visits.

RESULTS

209 patients were included in the analysis (mean age 38.7 ± 15.3, 28% male). 21 patients with 27 MES-positive TCD examinations were identified (10%). Patient characteristics were similar in MES-positive and MES-negative groups. However, recent ischemic events were detected at a significantly higher rate in MES-positive patients (42.9% vs 4.8%, p < 0.001). After MES detection, change of antiplatelet drug regime was performed, leading to loss of MES in all cases. Dual APT was preferably used in the MES-positive group (p < 0.001) but no significant difference of haemorrhage during follow-up-visits was observed. Reduction of APT before bypass-surgery triggered MES in four patients.

CONCLUSION

APT is required in patients with MMA. MES monitoring may help to identify risk patients in need of intensified APT.

Epidemiology of Moyamoya Angiopathy in Eastern India

Introduction

Moyamoya angiopathy (MMA) is a chronic, progressive intracranial vasculopathy with variation in prevalence and clinical manifestations across different populations. This study was aimed to estimate the frequency of MMA as an etiology of stroke and its epidemiological features in the largest cohort of MMA patients in India.

Method

A single-centered cross-sectional observational study over a period of 5 years (2016–2021) was undertaken among consecutive stroke and transient ischemic attack (TIA) patients to look for the presence of MMA angiographically. Each patient with angiographically proven MMA was further evaluated for demographic, clinical, and radiological characteristics.

Results

Among 10,250 consecutive stroke and TIA patients (ischemic = 78%, hemorrhagic = 22%), frequency of MMA was 1.56% (n = 160); 15.3% among children. Female preponderance (Male:Female = 1:1.4) was noted among 160 MMA patients, with bimodal age distribution, first peak at 3–8 years, and a shorter second peak at 41–47 years. Childhood-onset MMA was seen in 75 (46.9%) with commonest initial neurological symptom of fixed-motor-weakness (44.0%), followed by TIA (26.7%); while 85 (53.1%) had adult-onset MMA with fixed-motor-weakness (50.6%) followed by headache (24.7%) as the predominant initial neurological symptom; seizure significantly higher in children (p < 0.001) and headache in adults (p = 0.012). Transient and fixed neurological manifestations constituted 87.5 and 69.4% respectively, of symptoms throughout the disease course. Cerebral infarction (45.0%) and TIA (21.9%) were the commonest types of MMA. On brain imaging, infarction was noted in 80.6%, hemorrhage in 11.3%, significantly higher among adults (p < 0.001). Cortical infarct and Gyral pattern were commoner in children (p = 0.004), subcortical infarcts in adults (p = 0.018). Frequent Suzuki staging observed was stage 4 (31.3%), followed by stage 3 (30.0%). Involvement of posterior circulation was detected in 55.6%, brain atrophy at the time of diagnosis was seen in 65.0%.

Conclusion

MMA is an important etiological consideration in patients with stroke, especially in children. It can present with a myriad of transient neurological symptoms, frequently overlooked, leading to delayed diagnosis, and contributing to socio-economic burden. Indian MMA showed aberrations in its gender predisposition, age distribution, frequency of familial cases, disease manifestation, and type of stroke, in comparison to its Japanese and Caucasian counterparts pointing to the inter- and intra-continent differences of MMA phenotype. Future development of the Indian MMA national registry is of essence.

The Genetic Basis of Moyamoya Disease

Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive spontaneous bilateral occlusion of the intracranial internal cerebral arteries (ICA) and their major branches with compensatory capillary collaterals resembling a “puff of smoke” (Japanese: Moyamoya) on cerebral angiography. These pathological alterations of the vessels are called Moyamoya arteriopathy or vasculopathy and a further distinction is made between primary and secondary MMD. Clinical presentation depends on age and population, with hemorrhage and ischemic infarcts in particular leading to severe neurological dysfunction or even death. Although the diagnostic suspicion can be posed by MRA or CTA, cerebral angiography is mandatory for diagnostic confirmation. Since no therapy to limit the stenotic lesions or the development of a collateral network is available, the only treatment established so far is surgical revascularization. The pathophysiology still remains unknown. Due to the early age of onset, familial cases and the variable incidence rate between different ethnic groups, the focus was put on genetic aspects early on. Several genetic risk loci as well as individual risk genes have been reported; however, few of them could be replicated in independent series. Linkage studies revealed linkage to the 17q25 locus. Multiple studies on the association of SNPs and MMD have been conducted, mainly focussing on the endothelium, smooth muscle cells, cytokines and growth factors. A variant of the RNF213 gene was shown to be strongly associated with MMD with a founder effect in the East Asian population. Although it is unknown how mutations in the RNF213 gene, encoding for a ubiquitously expressed 591 kDa cytosolic protein, lead to clinical features of MMD, RNF213 has been confirmed as a susceptibility gene in several studies with a gene dosage-dependent clinical phenotype, allowing preventive screening and possibly the  development of new therapeutic approaches. This review focuses on the genetic basis of primary MMD only.

Whole Exome Sequencing in a Series of Patients with a Clinical Diagnosis of Tuberous Sclerosis Not Confirmed by Targeted TSC1/TSC2 Sequencing

BACKGROUND

Approximately fifteen percent of patients with tuberous sclerosis complex (TSC) phenotype do not have any genetic disease-causing mutations which could be responsible for the development of TSC. The lack of a proper diagnosis significantly affects the quality of life for these patients and their families.

METHODS

The aim of our study was to use Whole Exome Sequencing (WES) in order to identify the genes responsible for the phenotype of nine patients with clinical signs of TSC, but without confirmed tuberous sclerosis complex 1/ tuberous sclerosis complex 2 (TSC1/TSC2) mutations using routine molecular genetic diagnostic tools.

RESULTS

We found previously overlooked heterozygous nonsense mutations in TSC1, and a heterozygous intronic variant in TSC2. In one patient, two heterozygous missense variants were found in polycystic kidney and hepatic disease 1 (PKHD1), confirming polycystic kidney disease type 4. A heterozygous missense mutation in solute carrier family 12 member 5 (SLC12A5) was found in one patient, which is linked to cause susceptibility to idiopathic generalized epilepsy type 14. Heterozygous nonsense variant ring finger protein 213 (RNF213) was identified in one patient, which is associated with susceptibility to Moyamoya disease type 2. In the remaining three patients WES could not reveal any variants clinically relevant to the described phenotypes.

CONCLUSION

Patients without appropriate diagnosis due to the lack of sensitivity of the currently used routine diagnostic methods can significantly profit from the wider application of next generation sequencing technologies in order to identify genes and variants responsible for their symptoms.

The angiographic presentation of European Moyamoya angiopathy

Background and purpose

Little is known about the angiographic presentation of Moyamoya angiopathy (MMA) in non-Asian patients.

Methods

Conventional cerebral angiograms from 155 Caucasian patients diagnosed as MMA were analyzed with respect to extracranial champagne bottle neck sign, Suzuki stages, collateral status, as well as presence of aneurysms and posterior cerebral artery stenosis.

Results

In 84 of 155 angiograms, the extracranial carotid artery was visualized, in 65 of them (77.4%), a champagne bottle neck sign was noted. Of the 278 analyzable hemispheres, 13.7%,11.2%, 37.8%, 27.3%, 8.6%, and 1.4% were classified as Suzuki stage I, stage II, stage III, stage IV, stage V, and stage VI, respectively. Among 280 hemispheres, in 53 hemispheres (18.9%) isolated basal collaterals (pathway I) and in 104 hemispheres (37.1%) choroidal and pericallosal collaterals (including basal collaterals, pathway II) were found. In 74 hemispheres (26.4%) ethmoidal collaterals (pathways III), and in 17 hemispheres (6.1%) vault collaterals were visualized. Patients with higher Suzuki stages IV–VI (p = 0.008) and ethmoidal collaterals (p < 0.001) suffered more often from cerebral hemorrhage. Transient ischemic attacks occurred more frequently in patients with Suzuki stage I to III (p < 0.001). In 10 of 155 patients (6.5%), the angiogram revealed a cerebral aneurysm. In 13 patients (8.4%), a stenotic P1 segment of the posterior cerebral artery was found.

Conclusions

This is so far the largest observational study about angiography in Caucasian European MMA patients. A comparison with Asian data indicates similarity of disease in Caucasian and Asian patients.

Patients with Moyamoya Vasculopathy Evaluated at a Single-Center in The Netherlands; Clinical Presentation and Outcome

Information on presentation and outcome of moyamoya vasculopathy (MMV) in European countries is limited. We investigated patient characteristics, treatment and outcome of patients with MMV. We retrieved patient characteristics and treatment information and determined functional outcome (modified Rankin Score (mRS); type of school/work) by structured telephone interviews. We performed uni- and multivariable logistic regression analysis to determine predictors of poor outcome. We included 64 patients with bilateral MMV. In children (31 patients), median age was 5 years (interquartile range (IQR) 2-11) and in adults (33 patients), it was 33 years (IQR 28-41). Predominant mode of presentation was ischemia (children 84%; adults 88%). Modified Rankin Scale (mRS) at presentation was ≤2 in 74%. Revascularization was performed in 42 patients (23 children). Median follow-up time was 46 months (IQR 26-90). During this period, 16 patients had recurrent stroke(s) and four patients died. In 73% of the patients (83% surgical group; 55% medically treated group), mRS was ≤2; 46% were able to return to regular school or work, of whom only 41% were on the same level. Univariable analysis revealed that surgical treatment was associated with lower odds of poor outcome ((mRS ≥ 3), OR 0.24; p = 0.017). This association was no longer statistically significant (OR 3.47; p = 0.067) in the multivariable model, including age and diagnosis (moyamoya disease or moyamoya syndrome). In this cohort of patients with MMV who presented in a single European center, a large proportion had good functional outcome. Nevertheless, less than half were able to attend regular school or were able to work at their previous level, indicating a large impact of the disease on their life.

Moyamoya disease and moyamoya syndrome in Ireland: patient demographics, mode of presentation and outcomes of EC-IC bypass surgery

BACKGROUND

There are no previously published reports regarding the epidemiology and characteristics of moyamoya disease or syndrome in Ireland.

AIMS

To examine patient demographics, mode of presentation and the outcomes of extracranial-intracranial bypass surgery in the treatment of moyamoya disease and syndrome in Ireland.

METHODS

All patients with moyamoya disease and syndrome referred to the National Neurosurgical Centre during January 2012-January 2019 were identified through a prospective database. Demographics, clinical presentation, radiological findings, surgical procedures, postoperative complications and any strokes during follow-up were recorded.

RESULTS

Twenty-one patients were identified. Sixteen underwent surgery. Median age at diagnosis was 19 years. Fifteen were female. Mode of presentation was ischaemic stroke in nine, haemodynamic TIAs in eight, haemorrhage in three and incidental in one. Sixteen patients had Moyamoya disease, whereas five patients had moyamoya syndrome. Surgery was performed on 19 hemispheres in 16 patients. The surgical procedures consisted of ten direct (STA-MCA) bypasses, five indirect bypasses and four multiple burr holes. Postoperative complications included ischaemic stroke in one patient and subdural haematoma in one patient. The median follow-up period in the surgical group was 52 months; there was one new stroke during this period. Two patients required further revascularisation following recurrent TIAs. One patient died during follow-up secondary to tumour progression associated with neurofibromatosis type 1.

CONCLUSIONS

Moyamoya is rare but occurs in Caucasians in Ireland. It most commonly presents with ischaemic symptoms. Surgical intervention in the form of direct and indirect bypass is an effective treatment in the majority of cases.

The disease presentation of Moyamoya angiopathy in Eastern India

INTRODUCTION

Clinical spectrum of Moyamoya angiopathy (MMA) differs across populations with different ethnicity. This study, the largest one done among Indian population was undertaken to assess clinico-radiological profile of MMA patients in eastern India.

METHODS

A single centre cross-sectional study was undertaken among 76 MMA cases. Each patient was evaluated for epidemiological, clinical and radiological characteristics. SPSS 25 was used for statistical analysis. P < 0.05 was taken as statistically significant.

RESULTS

36 (47.4%) were children without gender preponderance. There were female predominance among adults (male:female = 1:2.33). Mean age at onset of first neurological symptoms for children was 4.2 ± 2.0years, followed by 34.9 ± 58.2months of latency with final diagnosis at the mean age of 7.4 ± 3.5years. For adults, mean age of onset of first neurological symptoms was 31.5 ± 12.3years, followed by 14.7 ± 41.7months time gap and diagnosed at the mean age of 33.5 ± 12.5years. There was a statistically significant difference between child and adult regarding the diagnostic latency (p = 0.035). Fixed motor weakness (FMW) was the predominant symptom across the whole disease course. Among children predominant first neurological symptom was fixed motor weakness (FMW) (52.8%), followed by seizures (22.2%). FMW was predominant (55%) first neurological complaint, followed by headache (22.5%) among adults. Seizure was more prevalent among children both as first (p = 0.002) and presenting symptom at the time of diagnosis (p = 0.048). Over the course of the disease seizure was more common among children (p = 0.001), while headache was more common among adults (p = 0.017). Recurrence of symptoms was more common among children (p = 0.059). Infarcts were more common among children (91.7%) than adults (72.5%), while hemorrhage was seen only among adults (25%) (p = 0.004). Isolated cerebral cortex was involved more commonly among children (59.4%) than adults (36.1%), while isolated subcortical involvement was seen only among adults (19.4%) (p = 0.016). Majority of the MMA cases were of Suzuki stage 4 (39.5%) and 5 (27.6%). Brain atrophy was associated with diagnostic latency (p = 0.009).

CONCLUSION

Indian Moyamoya presents similar to disease presentation in Caucasian and Japanese patients. It is a frequently overlooked cause of stroke in young, often with various non-motor presentations, failure to recognize which leads to delay in diagnosis. Radiological burden disproportionate to number of acute vascular events, with subtle neurological manifestations like headache or seizure, often with cognitive decline, should raise suspicion of MMA.

Moyamoya vasculopathy in a young Caucasian woman with significant methamphetamine use

Background

Moyamoya is a rare cerebrovascular disorder seen predominantly in Asian populations. Methamphetamine use is a recognised cause of stroke in young people, but its pathophysiology is not fully understood. The incidence of moyamoya vasculopathy in methamphetamine-associated stroke is unknown due to a lack of sufficient data. We present a rare case of moyamoya syndrome in a young Caucasian woman with methamphetamine-associated stroke.

Case

A 31-year-old Caucasian woman presented with progressive right arm weakness, speech disturbance and seizures on a background of escalating methamphetamine use in the 9 months prior to admission. She did not have a personal or family history of stroke. MRI revealed both embolic and watershed infarcts in bilateral frontal regions and CT angiography showed development of new lenticulostriate collateral vessels. Digital subtraction angiography confirmed steno-occlusive disease of the bilateral anterior circulations and a ‘puff of smoke’ appearance.

Conclusion

In young patients who present with stroke with unclear aetiology, it is important to obtain a thorough substance use history. Moyamoya vasculopathy should be considered when evaluating the pathophysiology of stroke in young people.

Internal carotid artery origin of the anterior cerebral artery: A rare anatomic intracranial arterial variation in a child with morning glory disc anomaly and moyamoya vascular pattern; case report and review of literature

Morning glory disc anomaly (MGDA) characterizes a congenital dysgenetic disorder of the optic disc, coexisting with arterial intracranial abnormalities, including Moyamoya vascular disease, a significantly rare disease in the European populations. We report a 2.5-year-old female child from Greece previously diagnosed with MGDA, who presented with right-hand paresis, accompanied by focal epileptic spasms, followed by an episode of brief absence seizure, as well as some arm clonic spasms. Magnetic resonance angiography scan revealed the presence of an anomalous origin of the anterior cerebral artery (ACA) from the internal carotid artery (ICA) along with vascular abnormalities, compatible with Moyamoya pattern. To the very best of our knowledge, this is the first reported case of anomalous origin of ACA from the supraclinoid ICA accompanied by severe occlusive intracranial disease (moyamoya-like pattern) in a patient with known MGDA, highlighting the embryonic character of the vascular manifestations in MGDA. It also verifies the association of Moyamoya pattern with MGDA, thus linking vascular dysgenesis as a possible cause of MGDA.

Moyamoya Disease May Mimic Multiple Sclerosis?

Introduction

A wide range of medical conditions may mimic multiple sclerosis. Among them, cerebrovascular diseases, including moyamoya disease, need to be excluded since they share common clinical features and radiographic findings with multiple sclerosis.

Case Report

A 44-year-old woman experienced transient numbness of her right sided face and arm and was referred to our unit due to small brain lesions in magnetic resonance imaging, with a possible diagnosis of multiple sclerosis. Neurological examination was unremarkable except for plantar reflexes and jerky deep tendon reflexes. Brain magnetic resonance angiography revealed findings typically seen in moyamoya disease, confirmed with digital subtraction angiography. Antiplatelet therapy started, but few days later, she developed suddenly global aphasia and right hemiparesis (National Institutes of Health Stroke Scale/NIHSS 6). Brain magnetic resonance imaging revealed acute infarct in the distribution of the left middle cerebral artery. At her discharge, she was significantly improved (NIHSS 3).

Conclusion

Diagnosis of multiple sclerosis is often challenging. In particular, in young patients with transient neurological symptoms and atypical white matter lesions in magnetic resonance imaging, cerebrovascular disorders such as moyamoya disease should be considered in the differential diagnosis. Detailed clinical and neuroimaging evaluation are mandatory for the correct diagnosis.

Incidence of Moyamoya Disease in Denmark: A Population-Based Register Study

In this first population-based study of moyamoya disease (MMD) in Europe, the authors identified 56 patients with MMD in Denmark during the period 1994-2015 using nationwide registers. The overall incidence was 0.047 per 100,000 person-years, which is about one-tenth that reported in Japan. Otherwise the epidemiological features were comparable: there was a bimodal age distribution with peaks in the age groups 0-9 years and 30-39 years, with twice as many females as males.

Moyamoya angiopathy: long-term follow-up study in a Finnish population

BACKGROUND AND PURPOSE

Moyamoya angiopathy (MMA) is a chronic cerebrovascular disorder predominantly starting in childhood or early adulthood and thus affects the whole lifetime. Little is known on MMAs long-term outcomes in European patients. We report long-term follow-up data on Finnish MMA patients.

METHODS

We included patients from our Helsinki University Hospital MMA database and arranged long-term follow-up visits for all the patients. This follow-up included a review of the medical records accumulated in due time, detailed neurological and neuropsychological evaluation, and outcome measures modified Rankin Scale (mRS) and Barthel Index (BI).

RESULTS

There were 61 MMA patients with a mean follow-up period of 9.5 years (SD 6.7 years; range 1.3-35.4 years; 581 patient-years). Only two patients had died and two-thirds (n = 40, 65.6%) had no new events during the follow-up period. Eight patients (13.1%) had an ischemic and five patients (8.2%) a hemorrhagic stroke during the follow-up. There were no differences between operated (n = 26) and conservatively (n = 35) treated groups regarding recurrent events or the outcome measured with mRS or BI. Finnish MMA patients reported significantly poorer physical and psychological health aspects of QOL when compared to the general Finnish population. Symptoms of low mood were found in 27 (56%) patients.

CONCLUSIONS

Finnish MMA patients have a benign and stable course with a ~3.5 % annual stroke risk. We found no differences in the clinical outcomes between the operated and conservative groups, however, the psychosocial well-being requires more attention in MMA patients.

Moyamoya vasculopathy shows a genetic mutational gradient decreasing from East to West

BACKGROUND

Moyamoya disease (MMD) is a chronic, occlusive cerebrovascular disease characterized by bilateral steno-occlusive changes at the terminal portion of the internal carotid arteries and an abnormal vascular network at the base of the brain determining stroke in children. Patients with a similar vasculopathy and associated conditions are affected by the moyamoya syndrome (MMS). Most of the studies focused on MMD were carried out on East-Asian population. Ring Finger 213 (RNF213) has been identified as the strongest susceptibility gene for MMD in East-Asian people. Overall, 74.5% of the East-Asian patients carry the founder variant p.Arg4810Lys of RNF213 never reported in Caucasians. A different genetic landscape among the diverse ethnic populations seems to exist.

METHODS

We sequenced the coding sequence region of RNF213, TGFB1 and PDGFRB in 21 ethnically homogeneous Italian children with moyamoya; comprehensive sequencing data are available from parents of eight of them. The analyses were carried out by NGS on Thermo-fisher PGM platform. We also performed a comprehensive review of the literature about the variations of these three genes in Caucasian patients.

RESULTS

Several new variants of RNF213 gene were detected, in particular, two new pathogenic mutations on RNF213 (p.Trp4677Leu and p.Cys4017Ser) were identified in one MMS case and in one MMD case, respectively. Moreover, in a MMS case a new probably causing disease mutation p.Pro1063Thr of PDGFRB was detected.

CONCLUSIONS

The genetic susceptibility of Asian moyamoya vasculopathy seems to differ from the Caucasian disease. No additional differences seem to exist between MMD and MMS.