もやもや病

BACKGROUND: Although the hemodynamic mechanism of ischemic symptoms is widely accepted in moyamoya disease (MMD), acute thrombotic occlusion at a preexisting stenotic site may cause unexpected ischemic stroke. This phenomenon has rarely been addressed, particularly in relation to vessel wall MRI findings. OBSERVATIONS: Among 247 patients with MMD, 3 adults (1.2%, age range 33-59 years) exhibited radiological findings compatible with acute in situ thrombotic occlusion, defined as imaging-documented acute occlusion at a preexisting stenotic site and/or spontaneous recanalization on serial imaging. All 3 patients developed sudden-onset ischemic stroke despite relatively early angiographic stages and without preceding transient ischemic attacks. Two patients showed infarct patterns atypical for purely hemodynamic stroke, with basal ganglia involvement. Vessel wall MRI revealed marked contrast enhancement of the arterial wall at the site corresponding to the acute occlusion in all 3 patients. Neurological deficits remained after stroke in 2 patients, whereas the patient who had been receiving antiplatelet therapy had no residual deficits. LESSONS: These cases highlight presumed acute in situ thrombotic occlusion as a possible mechanism of ischemic stroke in adult MMD and suggest a potential role for vessel wall MRI in risk stratification and management. https://thejns.org/doi/10.3171/CASE26208.

OBJECTIVE: The aim of this study was to identify preoperative clinical, angiographic, and quantitative perfusion predictors of postoperative neovascularization (PNV) after indirect bypass (IB) in adult moyamoya disease (MMD). METHODS: The authors retrospectively reviewed 128 hemispheres in 106 adults with MMD who underwent IB at a single institution between January 2018 and December 2024. Preoperative time-to-maximum (Tmax) volumes were obtained from CT perfusion analysis using thresholds of > 4 seconds and > 6 seconds. PNV was evaluated 6 months after surgery using the Matsushima grading system. Multivariable logistic regression analyses were performed to identify independent predictors of favorable PNV in two models, defined as Matsushima grade (MG) A and as MG A or B, respectively. Receiver operating characteristic curve analysis was used to determine optimal cutoff values. RESULTS: At 6 months postoperatively, 38.3% of hemispheres achieved MG A PNV, and 67.2% achieved MG A or B PNV. For MG A PNV, younger age (OR 0.95, 95% CI 0.91-0.99; p = 0.009) and larger preoperative volume of Tmax > 6 seconds (OR 1.022, 95% CI 1.01-1.03; p < 0.001) were significant predictors, with an optimal cutoff value of 33.5 mL for Tmax > 6 seconds (area under the curve [AUC] 0.805, sensitivity 76%, specificity 75%). For MG A or B PNV, transient ischemic attack at presentation (OR 2.90, 95% CI 1.12-7.97; p = 0.033) and larger preoperative volume of Tmax > 4 seconds (OR 1.019, 95% CI 1.01-1.03; p < 0.001) were identified as significant predictors, with an optimal cutoff value of 111.5 mL for Tmax > 4 seconds (AUC 0.817, sensitivity 70%, specificity 93%). CONCLUSIONS: In adult MMD, greater preoperative ischemic burden measured by volumes of tissue with Tmax delays > 4 seconds or > 6 seconds predicted favorable PNV after IB. Younger age and transient ischemic attack at presentation were also associated with better PNV. This study highlights the role of perfusion parameters, together with clinical factors, in surgical decision-making and individualized treatment planning.

Moyamoya disease (MMD) is a rare cerebrovascular disease characterised by gradual progressive stenosis and occlusion of the terminal internal carotid arteries, anterior cerebral arteries and proximal middle cerebral arteries bilaterally. This pathology leads to the formation of a compensatory and fragile collateral vascular network at the brain's base. With disease progression, MMD may result in ischaemic or haemorrhagic stroke. However, the lack of reliable and effective methods to assess disease progression leaves many patients at high risk of stroke without timely clinical intervention. Therefore, determining the disease course and assessing stroke risk are critical. Cerebrovascular reserve (CVR) reflects the ability of brain tissue to increase blood flow under stress. CVR evaluation assists clinicians in understanding MMD severity, guiding therapeutic decisions and determining prognosis. This narrative review analyses recent literature, highlights the advantages and disadvantages of various CVR assessment techniques, and discusses the interplay between CVR and MMD. In addition, it examines the role of CVR in evaluating disease progression and associated treatments.

A 17-year-old female patient with hemoglobin SS sickle cell disease, Moyamoya disease, a history of stroke, and pulmonary embolism was incidentally found to have a large pedunculated right atrial mass on cardiac magnetic resonance imaging. The differential diagnosis included thrombus, tumor, and vegetation. She underwent cardiac catheterization for therapeutic removal and pathologic confirmation of the diagnosis. This case highlights the diagnostic challenges of right atrial masses and the importance of integrating clinical context with multimodality imaging.