No abstract available.
Meningioma* ; Visual Fields*

BACKGROUND AND PURPOSE: Little is known about the relationships between provoking risk factors, prognosis, and optimal duration of anticoagulation in patients with cerebral venous thrombosis (CVT), especially in Asians. We aimed to investigate whether the prognosis and required duration of anticoagulation in CVT patients differ according to the provoking risk factors. METHODS: Prospectively recorded data from a tertiary medical center in South Korea were retrospectively reviewed. CVTs were categorized into three groups: unprovoked, those with possibly resolved provoking factors (PR), and those with persistent provoking factors (PP). The baseline characteristics, treatment, and prognosis of patients in these three groups were analyzed. RESULTS: From 2000 to 2015, 61 patients presented with CVT: 19 (31.1%) unprovoked, 11 (18.0%) with PR, and 31 (50.9%) with PP. The patients in our cohort had a slight female predominance and lower frequency of oral contraceptive use compared to Western cohorts. Median follow-up and duration of anticoagulation were 35 and 8 months, respectively. Despite the similarities in baseline characteristics, deaths (n=3; P=0.256) and recurrences (n=7; P=0.020) were observed only in the PP group. The median intervals to death and recurrence were 9 and 13 months, respectively. Death was associated with underlying disease activity, not with CVT progression. Recurrences in the PP group were associated with lack of anticoagulation (P=0.012). CONCLUSIONS: Although the prognosis of CVT is generally benign in Koreans, recurrence and death were observed in patients with persistent risk factors, suggesting their need for long-term treatment with anticoagulants.
Anticoagulants ; Asian Continental Ancestry Group ; Cohort Studies ; Female ; Follow-Up Studies ; Humans ; Korea ; Prognosis* ; Prospective Studies ; Recurrence ; Retrospective Studies ; Risk Factors* ; Venous Thrombosis*

BACKGROUND AND PURPOSE: The primary mechanism underlying paramedian pontine infarction (PPI) is atheroma obliterating the perforators. Here, we encountered a patient with PPI in the post-stenotic area of basilar artery (BA) without a plaque, shown by high-resolution magnetic resonance imaging (HR-MRI). We performed an experiment using a 3D-printed BA model and a particle image velocimetry (PIV) to explore the hemodynamic property of the post-stenotic area and the mechanism of PPI. METHODS: 3D-model of a BA stenosis was reconstructed with silicone compound using a 3D-printer based on the source image of HR-MRI. Working fluid seeded with fluorescence particles was used and the velocity of those particles was measured horizontally and vertically. Furthermore, microtubules were inserted into the posterior aspect of the model to measure the flow rates of perforators (pre-and post-stenotic areas). The flow rates were compared between the microtubules. RESULTS: A recirculating flow was observed from the post-stenotic area in both directions forming a spiral shape. The velocity of the flow in these regions of recirculation was about one-tenth that of the flow in other regions. The location of recirculating flow well corresponded with the area with low-signal intensity at the time-of-flight magnetic resonance angiography and the location of PPI. Finally, the flow rate through the microtubule inserted into the post-stenotic area was significantly decreased comparing to others (P<0.001). CONCLUSIONS: Perforator infarction may be caused by a hemodynamic mechanism altered by stenosis that induces a recirculation flow. 3D-printed modeling and PIV are helpful understanding the hemodynamics of intracranial stenosis.
Basilar Artery ; Constriction, Pathologic ; Fluorescence ; Hemodynamics* ; Humans ; Infarction* ; Magnetic Resonance Angiography ; Magnetic Resonance Imaging ; Microtubules ; Plaque, Atherosclerotic ; Rheology ; Silicon ; Silicones

BACKGROUND AND PURPOSE: The primary mechanism underlying paramedian pontine infarction (PPI) is atheroma obliterating the perforators. Here, we encountered a patient with PPI in the post-stenotic area of basilar artery (BA) without a plaque, shown by high-resolution magnetic resonance imaging (HR-MRI). We performed an experiment using a 3D-printed BA model and a particle image velocimetry (PIV) to explore the hemodynamic property of the post-stenotic area and the mechanism of PPI. METHODS: 3D-model of a BA stenosis was reconstructed with silicone compound using a 3D-printer based on the source image of HR-MRI. Working fluid seeded with fluorescence particles was used and the velocity of those particles was measured horizontally and vertically. Furthermore, microtubules were inserted into the posterior aspect of the model to measure the flow rates of perforators (pre-and post-stenotic areas). The flow rates were compared between the microtubules. RESULTS: A recirculating flow was observed from the post-stenotic area in both directions forming a spiral shape. The velocity of the flow in these regions of recirculation was about one-tenth that of the flow in other regions. The location of recirculating flow well corresponded with the area with low-signal intensity at the time-of-flight magnetic resonance angiography and the location of PPI. Finally, the flow rate through the microtubule inserted into the post-stenotic area was significantly decreased comparing to others (P<0.001). CONCLUSIONS: Perforator infarction may be caused by a hemodynamic mechanism altered by stenosis that induces a recirculation flow. 3D-printed modeling and PIV are helpful understanding the hemodynamics of intracranial stenosis.
Basilar Artery ; Constriction, Pathologic ; Fluorescence ; Hemodynamics* ; Humans ; Infarction* ; Magnetic Resonance Angiography ; Magnetic Resonance Imaging ; Microtubules ; Plaque, Atherosclerotic ; Rheology ; Silicon ; Silicones

The purpose of this study was to investigate the use of decision tree for the classification of antimicrobial peptides. The classification was based on the activities of known antimicrobial peptides against common microbes including Escherichia coli and Staphylococcus aureus. A feature selection was employed to select an effective subset of features from available attribute sets.Sequential applications of decision tree with 17 nodes with 9 leaves and 13 nodes with 7 leaves provided the classification rates of 76.74% and 74.66% against E. coli and S. aureus, respectively. Angle subtended by positively charged face and the positive charge commonly gave higher accuracies in both E. coli and S. aureus datasets. In this study, we describe a successful application of decision tree that provides the understanding of the effects of physicochemical characteristics of peptides on bacterial membrane.
Classification* ; Dataset ; Decision Trees* ; Escherichia coli ; Membranes ; Peptides ; Staphylococcus aureus

BACKGROUND: C677T single nucleotide polymorphism (SNP) of Methylentetrahydrofolate reductase (MTHFR) has been known to be associated with plasma homocysteine (Hcy) levels, which is an independent risk factor for stroke. However, recent large clinical trials did not show any benefits of Hcy lowering therapy with vitamins on the prevention of stroke. We hypothesized that the Hcy lowering effect by vitamins would be different according to the MTHFR C677T SNP types (CC, CT or TT), which may influence the benefits of vitamins by Hcy lowering on stroke prevention. METHODS: The authors retrospectively studied acute stroke patients with information of the genotype of MTHFR and serial levels of Hcy during a recent 4 year period (July 2002 - Dec 2005). Vitamins (folic acid 1 mg, and/or cobalamin 750 microgram and pyridoxine 75 mg) were prescribed to the patients whose basal plasma Hcy levels were above 12 umol/L. RESULTS: Among 172 patients, 68 patients took vitamins. The mean basal Hcy level was significantly higher in the TT type than the others, and was decreased by vitamin therapy. Distribution of homocysteine grading (normal, intermediate or high) in follow up was not significantly different according to these SNP types. CONCLUSIONS: The Hcy lowering effect by vitamins was not different by MTHFR genetic polymorphism. Considering the higher prevalence of certain gene types in stroke and our study results, genetic factors such as MTHFR polymorphism may play an important role on the development of stroke rather than the plasma Hcy levels.
Follow-Up Studies ; Genotype ; Homocysteine* ; Humans ; Oxidoreductases ; Plasma* ; Polymorphism, Genetic ; Polymorphism, Single Nucleotide* ; Prevalence ; Pyridoxine ; Retrospective Studies ; Risk Factors ; Stroke* ; Vitamin B 12 ; Vitamins*

BACKGROUND AND PURPOSE: The absence of acute ischemic lesions in diffusion-weighted imaging (DWI) in transient ischemic attack (TIA) patients makes it difficult to diagnose the true vascular etiologies. Among patients with DWI-negative TIA, we investigated whether the presence of a perfusion-weighted imaging (PWI) abnormality implied a true vascular event by identifying new acute ischemic lesions in follow-up magnetic resonance imaging (MRI) in areas corresponding to the initial PWI abnormality. METHODS: The included patients underwent DWI and PWI within 72 hours of TIA and also follow-up DWI at 3 days after the initial MRI. These patients had visited the emergency room between July 2009 and May 2015. Patients who demonstrated initial DWI lesions were excluded. The initial PWI abnormalities in the corresponding vascular territory were visually classified into three patterns: no abnormality, focal abnormality, and territorial abnormality. RESULTS: No DWI lesions were evident in initial MRI in 345 of the 443 TIA patients. Follow-up DWI was applied to 87 of these 345 DWI-negative TIA patients. Initial PWI abnormalities were significantly associated with follow-up DWI abnormalities: 8 of 43 patients with no PWI abnormalities (18.6%) had new ischemic lesions, whereas 13 of 16 patients with focal perfusion abnormalities (81.2%) had new ischemic lesions in the areas of initial PWI abnormalities [odds ratio (OR)=15.1, 95% confidence interval (CI)=3.6–62.9], and 14 of 28 patients with territorial perfusion abnormalities (50%) had new lesions (OR=3.7, 95% CI=1.2–11.5). CONCLUSIONS: PWI is useful in defining whether or not the transient neurological symptoms in DWI-negative TIA are true vascular events, and will help to improve the understanding of the pathomechanism of TIA.
Emergency Service, Hospital ; Follow-Up Studies ; Humans ; Ischemic Attack, Transient* ; Magnetic Resonance Imaging ; Perfusion

We report herein a case of subclavian steal syndrome due to occlusive disease in multiple branches of the aortic arch, which was successfully treated by axilloaxillary bypass and subclavian stent insertion. The hemodynamic changes were evaluated using duplex sonography and transcranial Doppler before and after each procedure. The waveform and parameters of blood flow revealed an objective improvement in cerebral perfusion. These findings correlated well with clinical outcome. Neurosonologic evaluation can provide objective evidence for improved hemodynamic status after treatment.
Aorta, Thoracic ; Hemodynamics ; Perfusion ; Stents ; Subclavian Steal Syndrome