Determinants of Basal Collaterals in Moyamoya Disease: Clinical and Genetic Factors.

BACKGROUND/AIMS: To enable the diagnosis of moyamoya disease (MMD), detection of distal internal carotid artery stenosis and hazy network of basal collaterals (BCs) are required. This study aimed at evaluating the factors that could determine the degree of BCs in patients with angiographically confirmed MMD. METHODS: We analyzed 146 consecutive patients with MMD (age 26.2 ± 19.6, range 1-75). The degree of BCs (%) was measured based on conventional angiography. Factors associated with the degree of BCs, including clinico-radiological and genetic factors (p.Arg4810Lys variant), were analyzed. RESULTS: The degree of BCs varied among MMD patients and significantly decreased with an increase in the age of diagnosis of MMD (coefficient -1.55; p < 0.001). Although the degree of BC development depends on the MMD stage (Suzuki stage), it is less prominent in adult-onset (>18 years) MMD compared to childhood MMD. The presence of p.Arg4810Lys variant, types of MMD (bilateral vs. unilateral) and stroke (ischemic, hemorrhagic, or asymptomatic), shrinkage (outer diameter) of intracranial vessels, external carotid collateral status, and cortical neovascularization were not associated with the degree of BCs. CONCLUSION: Although prominent BCs are required for diagnosis of MMD, BCs are decreased with aging, suggesting that angiogenic capacity is altered in adult onset MMD compared to childhood MMD.

How Cerebral Vessel Tortuosity Affects Development and Recurrence of Aneurysm: Outer Curvature versus Bifurcation Type.

BACKGROUND AND PURPOSE: Previous studies have assessed the relationship between cerebral vessel tortuosity and intracranial aneurysm (IA) based on two-dimensional brain image analysis. We evaluated the relationship between cerebral vessel tortuosity and IA according to the hemodynamic location using three-dimensional (3D) analysis and studied the effect of tortuosity on the recurrence of treated IA. METHODS: We collected clinical and imaging data from patients with IA and disease-free controls. IAs were categorized into outer curvature and bifurcation types. Computerized analysis of the images provided information on the length of the arterial segment and tortuosity of the cerebral arteries in 3D space. RESULTS: Data from 95 patients with IA and 95 controls were analyzed. Regarding parent vessel tortuosity index (TI; P<0.01), average TI (P<0.01), basilar artery (BA; P=0.02), left posterior cerebral artery (P=0.03), both vertebral arteries (VAs; P<0.01), and right internal carotid artery (P<0.01), there was a significant difference only in the outer curvature type compared with the control group. The outer curvature type was analyzed, and the occurrence of an IA was associated with increased TI of the parent vessel, average, BA, right middle cerebral artery, and both VAs in the logistic regression analysis. However, in all aneurysm cases, recanalization of the treated aneurysm was inversely associated with increased TI of the parent vessels. CONCLUSIONS: TIs of intracranial arteries are associated with the occurrence of IA, especially in the outer curvature type. IAs with a high TI in the parent vessel showed good outcomes with endovascular treatment.

Intraventricular meningiomas: radiological findings and clinical features in 12 patients.

PURPOSE: To characterize the computed tomography (CT) and magnetic resonance (MR) imaging findings and clinical features of intraventricular (IV) meningiomas. MATERIALS AND METHODS: CT (n=8) and MR (n=12) images and medical records of 12 patients (five men and seven women; mean age, 36 years; range, 14-68 years) with pathologically proven IV meningiomas were retrospectively reviewed. Particular attention was put on the size and shape of the mass; internal architecture such as necrosis or calcification within the tumor; peritumoral edema; associated hydrocephalus and clinical features such as symptoms, treatment, and prognosis. RESULTS: There were five of benign, three of atypical, and four of malignant subtype. All lesions were located in the lateral ventricle ranging in maximum diameters from 4.0 to 7.3 cm (mean, 5.4 cm). All tumors had lobulated shape. Five (71%, 5/7) of the atypical and malignant IV meningiomas, but just two (40%, 2/5) benign IV meningiomas, had irregular lobulation. The tumors were isointense (n=7) or hypointense (n=5) to gray matter on T1-weighted images, whereas isointense (n=9) or hyperintense (n=3) on T2-weighted images. On gadolinium-enhanced T1-weighted images, homogeneous enhancement was seen in five lesions, and heterogeneous enhancement was seen in seven lesions, Most patients (n=10) had associated localized hydrocephalus due to ventricular entrapment. Intratumoral necrosis was seen in two cases (17%, 2/12), all of these were malignant subtype. In two cases of atypical and malignant subtypes, recurrences were found during the follow-up period after surgical resection. CONCLUSION: More than half (n=7, 58%) of the IV meningiomas were of atypical (n=3) or malignant (n=4) subtype. IV meningiomas tend to have a lobulated shape, especially irregular lobulation, and intratumoral necrosis was frequently seen in the atypical or malignant subtypes.