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 angiopathy is a rare cerebrovascular condition characterized by insufficient cerebral blood flow resulting from arterial vessel narrowing or occlusion, potentially leading to cerebral ischemia due to inadequate oxygen and nutrient supply to the brain tissue. The development of collateral vessels in stenotic regions, inherently fragile and prone to rupture, may further precipitate intracerebral hemorrhage. Alongside focal neurological symptoms, the common clinical presentations of Moyamoya angiopathy encompass headaches, dizziness, cognitive impairments, seizures, and involuntary movements. When associated with an underlying systemic illness, including Down Syndrome, cranial radiation, neurofibromatosis type 1, or meningitis, the condition is termed Moyamoya syndrome; whereas when idiopathic and a genetic mutation are identified, it is referred to as Moyamoya disease. In this report, we present a case of the rare Moyamoya syndrome, which was attributed to syphilis and HIV infection and was identified during an investigation into the etiology of ischemic stroke in a young patient.

OBJECTIVE: 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).
CONCLUSIONS: 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.

Moyamoya arteriopathy is a condition where chronic, progressive stenosis of large intracranial arteries, primarily of the anterior circulation, results in ischemia and the growth of small, abnormal collateral vessels. There is increasing evidence that infectious pathologies, such as COVID-19, may serve as a sort of trigger, or \"second hit,\" for the development of moyamoya arteriopathy. In this article, we present the case of a 13-year-old female with Down syndrome and unilateral moyamoya arteriopathy who developed contralateral internal carotid artery (ICA) dissection and thrombus in the setting of a positive COVID-19 test and subsequently developed rapidly progressive contralateral ICA and bilateral anterior cerebral artery (ACA) moyamoya-like stenosis. The rapidly progressive contralateral ICA and bilateral ACA moyamoya-like stenosis are likely multifactorial in nature. The contralateral ICA may have had a predisposition for injury and stenosis due to the preexisting moyamoya arteriopathy, making stenosis more likely after COVID-19-induced vascular inflammation and injury as well as after a possible thrombectomy-associated injury. Based on this presentation, patients with moyamoya arteriopathy may be at risk for rapid progression of their moyamoya pathology when exposed to catalysts, including infection, such as COVID-19, and vascular injury, such as thrombectomy-induced injury. In these circumstances, high suspicion and close monitoring are essential for addressing ischemia related to the stenosis before permanent injury.

Moyamoya angiopathy is a chronic progressive cerebrovascular disease characterized by stenosis and occlusion of the distal segments of the internal carotid arteries and/or proximal segments of the middle and anterior cerebral arteries, with a gradual compensatory restructuring of the cerebral circulation to the system of the external carotid arteries. Today, the main treatment method for Moyamoya angiopathy is surgical revascularization of the brain. A search and analysis of publications on the treatment of adult patients with Moyamoya angiopathy was carried out in the PubMed and Medscape databases over the past 10 years. We present a case of an adult female patient with a hemorrhagic form of Moyamoya angiopathy stage IV according to J. Suzuki, who underwent staged combined revascularization of both cerebral hemispheres. Surgical revascularization included the creation of a low-flow extra-intracranial shunt combined with a combination of indirect synangiosis. The combination of direct and indirect methods of surgical revascularization enables to achieve the development of an extensive network of collaterals and fully compensate for cerebral circulatory disorders both in the early and late postoperative periods, which is confirmed by instrumental diagnostic data. Combined revascularization is the most effective modern method of treating patients with Moyamoya angiopathy due to the complementary influence of direct and indirect components of revascularization.
Ангиопатия моямоя — хроническое прогрессирующее цереброваскулярное заболевание, характеризующееся стенозом и окклюзией дистальных сегментов внутренних сонных артерий и/или проксимальных сегментов средних и передних мозговых артерий, с постепенной компенсаторной перестройкой мозгового кровообращения на систему наружных сонных артерий. На сегодняшний день основным методом лечения ангиопатии моямоя признана хирургическая реваскуляризация головного мозга. Осуществлен поиск и анализ публикаций по лечению взрослых пациентов с ангиопатией моямоя в базах данных PubMed и Medscape за последние 10 лет. Представлено клиническое наблюдение: взрослая пациентка с геморрагической формой ангиопатии моямоя IV стадии по J. Suzuki, которой проведена этапная комбинированная реваскуляризация обоих полушарий мозга. Хирургическая реваскуляризация включала создание низкопоточного экстра-интракраниального шунта в сочетании с комбинацией непрямых синангиозов. Сочетание прямых и непрямых методов хирургической реваскуляризации позволяет добиться развития обширной сети коллатералей и полностью компенсировать нарушения мозгового кровообращения как в раннем, так и в отдаленном послеоперационных периодах, что подтверждается данными инструментальной диагностики. Комбинированная реваскуляризация является наиболее эффективным современным методом лечения пациентов с ангиопатией моямоя за счет взаимодополняющего влияния прямых и непрямых компонентов реваскуляризации.

UNASSIGNED: In Moyamoya angiopathy (MMA), mechanisms underlying cognitive impairment remain debated. We aimed to assess the association of cognitive impairment with the degree and the topography of cerebral hypoperfusion in MMA.
UNASSIGNED: A retrospective analysis of neuropsychological and perfusion MRI data from adults with MMA was performed. Ischemic and haemorrhagic lesion masks were created to account for cerebral lesions in the analysis of cerebral perfusion. Whole brain volume of hypoperfused parenchyma was outlined on perfusion maps using different Tmax thresholds from 4 to 12 s. Regional analysis produced mean Tmax values at different regions of interest. Analyses compared perfusion ratios in patients with and without cognitive impairment, with multivariable logistic regression analysis to identify predictive factors.
UNASSIGNED: Cognitive impairment was found in 20/48 (41.7%) patients. Attention/processing speed and memory were equally impaired (24%) followed by executive domain (23%). After adjustment, especially for lesion volume, hypoperfused parenchyma volume outlined by Tmax > 4 s or Tmax > 5 s thresholds was an independent factor of cognitive impairment (OR for Tmax > 4 s = 1.06 [CI 95% 1.008-1.123]) as well as attention/processing speed (OR for Tmax > 4 s = 1.07 [CI 95% 1.003-1.133]) and executive domains (OR for Tmax > 5 s = 1.08 [CI 95% 1.004-1.158]). Regarding cognitive functions, patients with processing speed and flexibility impairment had higher frontal Tmax compared to other ROIs and to patients with normal test scores.
UNASSIGNED: Cerebral hypoperfusion emerged as an independent factor of cognitive impairment in MMA particularly in attention/processing speed and executive domains, with a strong contribution of frontal areas.
UNASSIGNED: Considering this association, revascularization surgery could improve cognitive impairment.

OBJECTIVE: 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)).
CONCLUSIONS: 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.

This study is aimed at analyzing clinical outcome, absence of stroke recurrence, revascularization, and complications and long-term follow-up in the surgical treatment of moyamoya angiopathy (MMA) using the multiple burr holes (MBH) technique with dura opening and arachnoid preservation as a single procedure. To the best of our knowledge, this is the first to describe an MBH technique with arachnoid preservation.
We retrospectively reviewed all patients operated from June 2001 to March 2021, for a symptomatic and progressive MMA operated with opening of the dura but arachnoid preservation. Clinical examinations were obtained in all patients, and radiological monitoring was performed by cerebral 3D-magnetic resonance angiography (MRA) with perfusion or single-photon emission computed tomography (SPECT) with acetazolamide.
In total, 21 consecutive patients (6 children and 15 adults) were included with a mean age of 7.4 years in the pediatric group and 36.9 years in the adult group. Initial presentation was permanent ischemic stroke in 15 cases, transient ischemic attack (TIA) in 5 cases, and cerebral hemorrhage in one case. The MBH with dura opening and arachnoid preservation was performed bilaterally in 9 cases (43%) and unilaterally in 12 cases (57%). One patient died due to intraoperative bilateral ischemic stroke. Of the 20 other patients, 30% demonstrated clinical stability and 70% showed partial or complete recovery. Although one patient experienced a perioperative stroke, we did not observe any pseudomeningocele or postoperative ischemic stroke (IS) recurrence in all surviving cases during the average follow-up period of 55.5 months (range: 1-195). These outcomes emphasize the importance of preoperative monitoring to ensure the effectiveness and safety of the intervention. Postoperative angiography studies showed revascularization in 96.3% of treated hemispheres (100% in the adult group vs 80% in the pediatric group).
Our results on this small cohort suggest that the MBH technique with opening of the dura and arachnoids preservation can prevent recurrent strokes and reduce the risk of pseudomeningocele.

Moyamoya disease (MMD) is a rare idiopathic progressive vaso-occlusive disease characterized by irreversible vascular occlusion and collateral development of distal internal carotid arteries. Initially perceived as an exclusive entity to the East Asian population, the disease is now being reported globally, affecting individuals of diverse ethnicities. We present a case of a 55-year-old African American male patient with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) and a prior history of cryptococcal meningitis presenting to the emergency department with recurrent episodic headaches, which was refractory to routine medical therapy. Neuroimaging with computed tomography angiogram of the head and neck and magnetic resonance imaging of the brain led to the subsequent diagnosis of moyamoya syndrome (MMS). To our knowledge, MMS is uncommon in adult HIV/AIDS patients. It is crucial that clinicians are aware of the disease progression. For effective recognition and prevention of the condition, it is of utmost importance that clinicians possess a comprehensive understanding of the disease and its clinical manifestations.

BACKGROUND: Cerebral vasculopathies frequently lead to severe medical conditions such as stroke or intracranial hemorrhage and have a broad range of possible etiologies that require different therapeutic regimens. However, vasculopathies sometimes present with characteristic angiographic findings, that - if recognized - can guide a more specific diagnostic work-up. Certain ACTA2 variants are associated with a distinctive cerebrovascular phenotype characterized by an anomalously straight course of intracranial arteries, dilatation of proximal ICA and stenosis of distal ICA, in the absence of a compensatory basal collateral network found in Moyamoya disease. Until recently, this ACTA2 cerebral arteriopathy has been reported only in ACTA2 variants impairing Arg179.
METHODS: We report a familial case of a missense ACTA2 variant p.Arg198Cys with angiographic features of an ACTA2 cerebral arteriopathy. We analyzed the neuroimaging features of all four variant carrying family members and discussed the cerebrovascular abnormalities we found on the background of the current literature on ACTA2 arteriopathies.
RESULTS: Neuroimaging of the variant carriers revealed angiographic abnormalities characteristic for ACTA2 cerebral arteriopathy such as stenoses of the terminal internal carotid artery, occlusion of the proximal middle cerebral artery and an anomalously straight course of the intracranial arteries. In our index patient catheter angiography showed a Moyamoya-like basal collateral network alongside with the above-mentioned features of an ACTA2 cerebral arteriopathy. The detected missense ACTA2 variant p.Arg198Cys was not known to be associated a cerebral arteriopathy, so far. One of the patients later died from aortic dissection - a common vascular complication of ACTA2 variants.
CONCLUSIONS: The familial case expands the phenotype of the detected ACTA2 variant p.Arg198Cys and hereby broadens the range of ACTA2 variants associated with a cerebral arteriopathy. Further, it emphasizes the importance of an interdisciplinary approach of vasculopathies.