Echocardiographic index E/e' in association with cerebral white matter hyperintensity progression.

Cerebral white-matter hyperintensities (WMHs) on MRI is associated with reduced compliance of the cerebral arterioles. We hypothesized that an echocardiography index for left ventricular (LV) diastolic function, E/e', might reflect the cerebral arteriolar compliance and evaluated the association between E/e' and long-term progression rate of the cerebral WMH volume. This retrospective study included individuals who were ≥ 50 years of age, with a preserved LV ejection fraction (≥ 50%) and neurological function status (modified Rankin scale score ≤1), and underwent initial and follow-up MRI evaluations within intervals of 34-45 months. Baseline clinical, laboratory, and echocardiography markers such as ejection fraction, LV mass index, and E/e' were obtained. WMH volume progression rate between the baseline and follow-up MRIs was designated as the outcome factor. 392 individuals (57.1% men; mean age: 66.7±8.4 years) were followed-up for 38.2±3.4 months. The mean WMH volume progression rate was 1.35±2.65 mL/year. The log-transformed value of WMH volume progression rate was linearly associated with the log-transformed E/e' (B coefficient = 0.365; 95% confidence interval [CI] 0.180-0.551; P = 0.001), along with the log-transformed values of baseline WMH volume (B = 0.142; 95% CI 0.106-0.179; P<0.001) and glomerular filtration rate (B = -0.182; 95% CI -0.321-0.044; P = 0.010). Additionally, a subgroup with an E/e' ≥15 exhibited a significantly higher WMH progression rate compared to the subgroups with lower E/e' values (P<0.001), especially in the lower quartiles (quartiles 1 and 2) of the baseline WMH volume. We concluded that echocardiographic marker E/e' is associated with the long-term progression rate of cerebral WMHs in population with preserved LV systolic function.

Periodicity of cerebral flow velocity during sleep and its association with white-matter hyperintensity volume.

Impaired sleep-related activation of the cerebral waste-clearance system might be related with the brain aging process. We hypothesized that cerebral blood-flow pattern changes during sleep might reflect the activation of the cerebral waste-clearance system and investigated its association with the cerebral white-matter hyperintensity (WMH) volume. Fifty healthy volunteers were prospectively recruited. In addition to the baseline transcranial Doppler parameters, the mean flow velocity (MFV) of the middle cerebral artery was monitored during waking and short-term non-REM sleep. Spectral density analysis was performed to analyze the periodic MFV variation patterns. For the aged subgroup (>50 years, n = 25), the WMH volumes in the total, subcortical, and periventricular regions were measured. The MFV periodic pattern during sleep was substantially augmented over that in the waking status. Spectral density analysis of MFV showed a noticeable peak in the very-low-frequency (VLF) band during sleep status (sleep/waking ratio 2.87 ± 2.71, P < 0.001). In linear regression analysis in the aged subgroup, the sleep/waking ratio of the VLF peak was inversely associated with total (P = 0.013) and subcortical (P = 0.020) WMH volumes. Sleep-related amplification of the cerebral flow-velocity periodicity might reflect the activation of cerebral waste clearance system during sleep, and be related to the pathogenesis of cerebral WMH.

Impact of stroke mechanism in acute basilar occlusion with reperfusion therapy.

Objective: We aimed to evaluate the impact of underlying mechanism of basilar artery (BA) occlusion on the outcomes after endovascular therapy (EVT) for reperfusion and the outcome factors associated with each mechanism, and to identify radiologic parameters enabling to distinguish the underlying mechanism. Methods: From a registry database, 194 consecutive patients with acute BA occlusion who underwent EVT were analyzed. Stroke mechanism, classified into in situ atherosclerotic thrombosis (ISAT) and embolism, clot sign location profiles in pre-angiography magnetic resonance image (MRI), parameters of angiography and EVT, and reperfusion were assessed. Poor outcome was defined as a modified Rankin-Scale score at 90 days of 3-6. Results: The mean age was 68.8±11.8 years (range 21-92 years) and seventy-eight (40.2%) were female patients. 102 (52.6%) patients were classified into an embolism mechanism and 92 (47.4%) into an ISAT mechanism. Overall, ISAT mechanism compared with embolism was significantly associated with poor outcomes (P = 0.002), along with the NIHSS scores, reperfusion status, and collateral status. In the embolism group, reperfusion (P = 0.001), NIHSS scores (P < 0.001), and onset-to-treatment time (P = 0.030) were significant outcome factors. However, in the ISAT group, baseline collateral status (P = 0.001) and NIHSS scores (P < 0.001) were significant outcome factors. A clot sign at the distal BA segment on pre-angiography MRI was strongly associated with embolism mechanism (P < 0.001). Interpretation: Stroke mechanism has a major influence on outcomes, and outcome predictors differ according to the underlying mechanism in acute BA occlusion with EVT. Clot sign profile on pre-angiography MRI might be useful to determine the underlying mechanism.

Association of Bone Mineral Density With the Risk of Intracranial Aneurysm.

Importance: Disruption of extracellular matrix integrity is critically involved in both intracranial aneurysm and bone fragility. Furthermore, both intracranial aneurysm and osteoporosis have a female predominance, and sex hormones are considered to affect this discrepancy. Objective: To evaluate the association between bone mineral density and intracranial aneurysm. Design, Setting, and Participants: A cross-sectional study conducted with 14 328 patients who underwent brain magnetic resonance angiography and bone mineral densitometry as a part of a health examination at a specialized center for comprehensive health examination in Seoul, the largest metropolitan area in the Republic of Korea, between December 2004 and November 2015. After excluding patients with insufficient clinical information (n = 1102) and with ambiguous intracranial arterial lesion (n = 441), 12 785 were included in the analysis. Exposures: Bone mineral density was measured at the lumbar vertebrae (L1 to L4), femur neck, and total hip using dual-energy x-ray absorptiometry. Main Outcomes and Measures: Multiple logistic regression or linear regression was used to examine the association between tertiles of bone mineral density and the presence, size, and multiplicity of intracranial aneurysms. In secondary analyses, we analyzed postmenopausal women and men 50 years and older (n = 8722) because they are particularly at risk of decreased bone mineral density. Results: Among 12 785 patients in the study (7242 women [56.6%]; mean [SD] age, 54.8 [10.1] years) intracranial aneurysms were found in 472 patients (3.7%). Lower bone mineral density was associated with an increased risk of harboring intracranial aneurysm. In multivariable logistic regression analyses, odds ratios for the highest compared with the lowest bone mineral density tertile were 1.30 (95% CI, 1.03-1.64) in the lumbar spine, 1.30 (95% CI, 1.03-1.64) in the femoral neck, and 1.27 (95% CI, 1.01-1.60) in the total hip after adjusting for age, sex, and vascular risk factors. In a linear regression model adjusted for age, sex, and vascular risk factors, the lowest tertile of bone mineral density in the lumbar spine was associated with an increased log-transformed size of aneurysm (ß, 0.196; SE, 0.047). In secondary analyses, these associations were more definite and a low T score (<-1 SD) was additionally associated with multiple aneurysms (OR, 1.84; 95% CI, 1.05-3.30) after adjusting for age, sex, and vascular risk factors. Conclusions and Relevance: Bone mineral density may be associated with the presence, size, and multiplicity of intracranial aneurysm. The study findings provide evidence for shared pathophysiology between intracranial aneurysm and bone fragility.

Association of Cardiac Hemodynamic Factors With Severity of White Matter Hyperintensities in Chronic Valvular Heart Disease.

Importance: The cerebral white matter hyperintensity (WMH) is frequently noted in patients with chronic heart disease. Long-term alteration of cardiac hemodynamics might have an influence on the mechanism of cerebral WMH. Objective: To investigate the association between chronically altered cardiac hemodynamics and severity of cerebral WMH in patients with chronic valvular heart disease. Design, Setting, and Participants: This cross-sectional analysis identified 303 consecutive patients at a tertiary referral center between 2008 and 2016 who were 50 years or older, and diagnosed with severe chronic valvular heart disease and underwent cardiac catherization, echocardiography, and received brain magnetic resonance imaging. Among these patients, 71 with other demonstrated cardiac disease, central nervous system disease, and/or without sufficient catheterization data were excluded, and the remaining 232 patients were included in further analyses. Exposures: The site and mechanism of valve diseases, as well as clinical and medication profiles, were reviewed. Cardiac catheterization parameters such as right atrial (RA) mean pressure, right ventricular pressure, and aortic mean pressure were obtained. Comprehensive echocardiographic hemodynamic markers such as left ventricular (LV) ejection fraction, LV mass index, LV end diastolic volume, cardiac index, and E/e' ratio were also obtained. Main Outcomes and Measures: White matter hyperintensity volume was quantitatively evaluated using volumetric analysis. Results: This study included 232 patients (103 men [44.4%] and 129 women [55.6%]; mean [SD] (range) age, 65.6 [8.8] (51-88) years) in the final analysis. The mean (SD) WMH volume was 5.93 (7.14) mL (median [interquartile range], 4.33 [1.33-8.62] mL), and mean (SD) RA pressure was 10.0 (4.7) mm Hg. From the catheterization data, 147 patients (63.4%) were classified as having a disease involving the mitral valve; 93 (40.1%), aortic valve; 37 (15.9%), tricuspid valve; and 4 (1.7%), pulmonary valve. In multivariate linear regression analysis, adjusting the type and mechanism of valve disease and clinical, echocardiographic, and/or other catheterization parameters, WMH volume was linearly associated with mean RA pressure (B coefficient, 0.702; 95% CI, 0.373-1.031; P = .001), along with age (B coefficient, 0.145; 95% CI, 0.029-0.261; P = .01) and mean aortic pressure (B coefficient, 0.112; 95% CI, 0.034-0.190; P = .005). Conclusions and Relevance: Mean RA pressure was independently associated with the WMH volume in chronic valvular heart disease. Chronically altered RA hemodynamics might have a distinct influence on the pathomechanism underlying the development of WMH.

Cystatin C, a potential marker for cerebral microvascular compliance, is associated with white-matter hyperintensities progression.

Cerebral white matter hyperintensities (WMHs) are central MRI markers of the brain aging process, but the mechanisms for its progression remain unclear. In this study, we aimed to determine whether the baseline serum cystatin C level represented one mechanism underlying WMH progression, and whether it was associated with the long-term progression of cerebral WMH volume in MRI. 166 consecutive individuals who were ≥50 years of age and who underwent initial/follow-up MRI evaluations within an interval of 34-45 months were included. Serum cystatin C level, glomerular-filtration rate (GFR), and other laboratory parameters were measured at their initial evaluation and at the end of follow-up. Cerebrovascular risk factors, medications, and blood-pressure parameters were also reviewed. WMH progression rate was measured by subtracting WMH volume at baseline from that at the follow-up using volumetric analysis, divided by the MRI intervals. At baseline, WMH volume was 9.61±13.17 mL, mean GFR was 77.3±22.8 mL/min, and mean cystatin C level was 0.92±0.52 mg/L. After 37.9±3.4 months, the change in WMH volume was 3.64±6.85 mL, the progression rate of WMH volume was 1.18±2.28 mL/year, the mean ΔGFR was 2.4±7.9 mL/min, and the mean Δcystatin C was 0.03±0.34 mg/L. The progression rate of WMH volume was linearly associated with cystatin C level (B coefficient = 0.856; 95% confidence interval [CI] 0.174-1.538; P = 0.014), along with the baseline WMH volume (B = 0.039; 95% CI 0.019-0.059; P<0.001), after adjusting for the conventional vascular risk factors, laboratory parameters, medication profiles, and GFR. Especially, patients with a baseline level of cystatin C ≥1.00 mg/L exhibited a much higher progression rate of WMH as compared with those with a baseline level of cystatin C <1.00 mg/L (1.60±1.91 mL/year vs. 0.82±1.63 mL/year, P = 0.010). We concluded that serum cystatin C level is independently associated with the long-term progression rate of the cerebral WMH volume. Therefore, serum cystatin C level might predict the progression of cerebral WMH.

Neurovascular Cell Sheet Transplantation in a Canine Model of Intracranial Hemorrhage.

Cell-based therapy for intracerebral hemorrhage (ICH) has a great therapeutic potential. However, methods to effectively induce direct regeneration of the damaged neural tissue after cell transplantation have not been established, which, if done, would improve the efficacy of cell-based therapy. In this study, we aimed to develop a cell sheet with neurovasculogenic potential and evaluate its usefulness in a canine ICH model. We designed a composite cell sheet made of neural progenitors derived from human olfactory neuroepithelium and vascular progenitors from human adipose tissue-derived stromal cells. We also generated a physiologic canine ICH model by manually injecting and then infusing autologous blood under arterial pressure. We transplanted the sheet cells (cell sheet group) or saline (control group) at the cortex over the hematoma at subacute stages (2 weeks from ICH induction). At 4 weeks from the cell transplantation, cell survival, migration, and differentiation were evaluated. Hemispheric atrophy and neurobehavioral recovery were also compared between the groups. As a result, the cell sheet was rich in extracellular matrices and expressed neurotrophic factors as well as the markers for neuronal development. After transplantation, the cells successfully survived for 4 weeks, and a large portion of those migrated to the perihematomal site and differentiated into neurons and pericytes (20% and 30% of migrated stem cells, respectively). Transplantation of cell sheets alleviated hemorrhage-related hemispheric atrophy (p = 0.042) and showed tendency for improving functional recovery (p = 0.062). Therefore, we concluded that the cell sheet transplantation technique might induce direct regeneration of neural tissue and might improve outcomes of intracerebral hemorrhage.

Progression of Cerebral White Matter Hyperintensities and the Associated Sonographic Index.

Purpose To evaluate the relationship between penetrating arterial pulsation and the progression of white matter hyperintensities (WMHs) by using the sonographic resistance index (RI) along the M1 segment of the middle cerebral artery (MCA). Materials and Methods The study design was approved by the institutional review board of Seoul National University Hospital. The study included 450 individuals who had undergone initial transcranial Doppler (TCD) sonography and magnetic resonance imaging, with follow-up imaging performed within 34-45 months, and who had no stenosis of 30% or more in the internal carotid artery or MCA or a history of stroke other than an old lacunar infarction. MRIR was defined as distal RI divided by proximal RI, where the distance between proximal MI and distal M1 was approximately 20 mm based on TCD evaluation. WMH progression was quantitatively evaluated by subtracting WMH volume at baseline from WMH volume at follow-up. Results At baseline, mean MRIR was 0.974 ± 0.045 (standard deviation), and mean WMH volume was 9.66 mL ± 14.54. After a mean of 38.3 months ± 3.4, the WMH volume change was 4.06 mL ± 7.35. WMH volume change was linearly associated with MRIR (r = 0.328, P < .001), along with the baseline WMH volume (r = 0.433, P < .001) and mean MCA pulsatility index (r = 0.275, P = .037). MRIR values greater than or equal to 1.000 were associated with a greater increase in WMH volume (P < .001). Conclusion MRIR might reflect the pulsation of penetrating arteries and is independently associated with WMH progression. © RSNA, 2017 Online supplemental material is available for this article.

Increased arterial pulsatility and progression of single subcortical infarction.

OBJECTIVE: We investigated the association of clinical, laboratory, sonographic and imaging parameters, in the progression of single subcortical infarctions. METHODS: Consecutive 169 patients with lacunar (n = 89) and striatocapsular infarctions (n = 80) in the middle cerebral artery (MCA) territory with nonstenotic MCAs were recruited and examined for stroke progression. The pulsatility index (PI) was measured by transcranial Doppler from ipsilateral M1. RESULTS: The striatocapsular infarction group exhibited more stroke progression. The patients with progressive lacunar infarctions had more diabetes, higher HbA1c levels, and higher initial National Institutes of Health Stroke Scale (NIHSS) scores, and the patients with progressive striatocapsular infarctions had more hypertension, higher cholesterol levels, and higher NIHSS scores. The MCA PI was higher in the lacunar infarction patients with progression (0.99 ± 0.19 vs. 0.90 ± 0.14, p = 0.048), while the striatocapsular infarction patients did not differ according to progression. From a multivariate analysis, higher MCA PI were independently associated with lacunar infarction progression (by 0.1 increase, OR 1.51; 95 % CI 1.06-2.15; p = 0.024). CONCLUSIONS: Higher pulsatility was associated with progression in lacunar infarction. PI measured by transcranial Doppler sonography might reflect downstream arterial resistance and vascular/paravascular perfusion status and be a possible indicator of stroke progression. KEY POINTS: • Higher pulsatility index was observed in progression group of lacunar infarction patients. • Higher pulsatility index seemed to be associated with progression in lacunar infarction patients. • Differences in the factors associated with stroke progression suggest different underlying pathophysiologies.

Inhibition of miR-203 Reduces Spontaneous Recurrent Seizures in Mice.

Inhibitory synaptic receptors are dysfunctional in epileptic brains, and agents that selectively target these receptors may be effective for the treatment of epilepsy. MicroRNAs interfere with the translation of target genes, including various synaptic proteins. Here, we show that miR-203 regulates glycine receptor-ß (Glrb) in epilepsy models. miR-203 is upregulated in the hippocampus of epileptic mice and human epileptic brains and is predicted to target inhibitory synaptic receptors, including Glrb. In vitro transfection, target gene luciferase assays, and analysis of human samples confirmed the direct inhibition of GLRB by miR-203, and AM203, an antagomir targeting miR-203, reversed the effect of miR-203. When intranasal AM203 was administered, AM203 reached the brain and restored hippocampal GLRB levels in epileptic mice. Finally, intranasal AM203 reduced the epileptic seizure frequency of mice. Overall, this study suggests that GLRB expression in the epileptic brain is controlled by miR-203, and intranasal delivery of AM203 showed therapeutic effects in chronic epilepsy mice.

Experimental Induction of Cerebral Aneurysms by Developmental Low Copper Diet.

Optimal models are needed to understand the pathophysiology of human cerebral aneurysms (CA). We investigated the development of experimental CA by decreasing the activity of lysyl oxidases by dietary copper deficiency from the time of gestation and then augmenting vascular stress by angiotensin II infusion in adulthood. Rats were fed copper-free, low-copper, or normal diets at different time periods from gestation to adulthood. The incidences of CAs were evaluated and autopsies performed to determine the coexistence of cardiovascular diseases. A copper-free diet from gestation was associated with high mortality rates (79.1%) resulting from rupture of ascending aorta aneurysms; a low-copper diet led to acceptable mortality rates (13.6%) and produced CAs and subarachnoid hemorrhage in 46.4% and 3.6% of animals, respectively. Higher proportions of CAs (up to 33.3%) in the rats primed for copper deficiency from gestation ruptured following angiotensin II infusion from adulthood. Gene expression array analyses of the CAs indicated that genes involving extracellular matrix and vascular remodeling were altered in this model. This model enables future research to understand the entire pathogenetic basis of CA development and rupture in association with systemic vasculopathies.

Acute Symptomatic Basilar Artery Stenosis: MR Imaging Predictors of Early Neurologic Deterioration and Long-term Outcomes.

Purpose To determine clinical, laboratory, and radiologic factors associated with early neurologic deterioration (END) and long-term outcomes in patients with medically treated symptomatic basilar artery stenosis (BAS). Materials and Methods The study design was approved by the institutional review board. From a database of all consecutive patients with cerebrovascular ischemia, the authors retrospectively included 292 patients with medically treated symptomatic BAS with at least 70% stenosis of the basilar artery. The authors evaluated various clinical factors, including National Institutes of Health Stroke Scale (NIHSS) score, C-reactive protein (CRP) level, fibrinogen level, and radiologic factors, including diffusion-weighted (DW) magnetic resonance (MR) imaging-based posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS), hyperintense basilar artery at fluid-attenuated inversion recovery (FLAIR) imaging (FLAIR-hyperintense vessel [FHV]), and clot signs. The outcomes were defined as the development of END and with the 90-day modified Rankin Scale score (favorable score: 0-2). The authors performed a χ(2) test, followed by logistic regression analysis, to identify independent outcome predictors. Results The development of END was highly correlated with unfavorable 90-day modified Rankin Scale score (P < .001). The significant predictors for END were CRP level of at least 1.5 mg/dL (P < .001), NIHSS score of at least 4 (P = .002), pc-ASPECTS of 6 or less (P < .001), and proximal FHV (P = .022). Proximal FHV (P = .010), pc-ASPECTS of 6 or less (P = .002), brainstem involvement (P = .036), and NIHSS score of at least 4 (P < .001) were associated with an unfavorable 90-day modified Rankin Scale score. Neither aggressive medical treatment nor delayed intervention was associated with a favorable 90-day modified Rankin Scale score. Conclusion In medically treated symptomatic BAS, MR imaging parameters such as proximal basilar FHV and DW imaging-based pc-ASPECTS have independent prognostic values for END development and long-term outcomes. (©) RSNA, 2016.

Intracranial plaque enhancement from high resolution vessel wall magnetic resonance imaging predicts stroke recurrence.

BACKGROUND: Intracranial atherosclerosis is associated with frequent stroke recurrence. High resolution vessel wall magnetic resonance imaging (HRMRI) can provide atheroma information related to its vulnerability. AIMS: We performed HRMRI in stroke patients with intracranial atherosclerosis to determine whether plaque characteristics from vessel wall imaging can predict future stroke recurrence. METHODS: Between July 2011 and June 2013, acute stroke patients with symptomatic intracranial atherosclerosis were prospectively enrolled and 3-tesla HRMRI was performed on the relevant artery. The plaque enhancement was visually determined from T1 post-gadolinium enhancement image. Stroke recurrence was monitored after index event and multivariate Cox proportional hazards model was constructed to identify factors related to future stroke recurrence. RESULTS: A total of 138 patients were included with a median follow-up of 18 months. There were 39 stroke recurrences. Plaque enhancement was detected in 108 patients (78.3%), and 37 of them experienced stroke recurrence. Among 30 stroke patients without plaque enhancement, two patients experienced stroke recurrence. Kaplan-Meier curves demonstrated a significant difference in event free survival between the patients with plaque enhancement and those patients without plaque enhancement (event rates at year 1: 30.3% vs. 6.8%, log-rank test, p = 0.004). Multivariate Cox-regression analysis showed that the plaque enhancement from HRMRI was independently associated with stroke recurrence (hazard ratio: 7.42, 95% confidence interval: 1.74-31.75, p = 0.007). CONCLUSION: Intracranial plaque enhancement from HRMRI is associated with stroke recurrence among the patients with symptomatic intracranial atherosclerosis.

Prognosis of spontaneous cervical artery dissection and transcranial Doppler findings associated with clinical outcomes.

OBJECTIVES: We categorised spontaneous cervical artery dissection (sCAD) by radiological features and investigated factors associated with favourable outcomes. METHODS: We retrospectively analysed 128 patients with sCAD with a median follow-up duration of 25 months. Twenty-nine constituted the aneurysm group, 52 the stenotic group, and 47 the occlusive group. Various relevant factors, including National Institute of Health Stroke Scale (NIHSS) scores, type of antithrombotic therapy, stroke progression in the first week, and transcranial Doppler (TCD) flow-waveforms (in the occlusive subgroup) were analysed. Favourable outcomes were defined as a 1-year modified Rankin-Scale score of 0-1. Favourable anatomical outcomes were defined as a reversal of dissection-associated stenosis during follow-up. RESULTS: The aneurysm and stenotic groups showed favourable outcomes, while the occlusive group outcomes were less favourable. In the stenotic group, anticoagulation, an NIHSS score ≥4, and stroke progression were inversely associated with favourable long-term outcomes. Remarkably, in the occlusive group, flow abnormality more severe than minimal flow was associated with stroke progression, unfavourable long-term outcome, and arterial irreversibility. CONCLUSIONS: The outcome of sCAD depends on its radiological subtype. In the occlusive subtype, which is associated with the worst outcome, TCD flow analysis may predict acute stroke progression and long-term outcome. KEY POINTS: • Outcomes in cervical artery dissection may be determined by radiological subtypes. • The aneurysm and stenotic groups had favourable outcomes. • The occlusive group had less favourable functional outcomes. • Flow-waveform analysis by TCD could predict functional and anatomical outcomes.

Sonographic findings associated with stenosis progression and vascular complications in moyamoya disease.

OBJECT The progression of arterial stenosis in patients with moyamoya disease (MMD) has variable courses and an unclear mechanism. The authors hypothesized that elevated wall shear stress (WSS) at the terminal internal carotid artery (ICA) and proximal middle cerebral artery (MCA) may facilitate MMD progression. They indirectly evaluated the relative magnitude of WSS (WSS value [WSSV]) with MR angiography (MRA) and transcranial Doppler to determine its predictive value for stenosis progression (SP) and the development of vascular complications. METHODS Thirty-one medically treated patients (58 hemispheres and 95 nonoccluded vessels) were analyzed with serial MRA (median follow-up 23 months). The parameters studied were SP, SP rates (SPRs) for individual ICAs/MCAs, and their mean values from the ipsilateral hemispheres as mean SP (MSP) and MSP rates (MSPRs). Significant progression was defined as decrements of ≥ 20% for SP and MSP and ≥ 10%/year for SPR and MSPR. The development of vascular complications in relevant hemispheres was also recorded. The WSSV (dyne/cm(2)) was defined as the shear rate multiplied by blood viscosity. RESULTS After adjusting the initial stenosis degree and MRA stage of MMD, an SP of ≥ 20% and an SPR of ≥ 10%/year were associated with the highest-quartile WSSVs for all individual vessels and for MCAs and ICAs separately. For each hemisphere, an MSP of ≥ 20% and an MSPR of ≥ 10%/year were associated with the highest-quartile mean WSSVs. Furthermore, significant SP was highly correlated with vascular complications, and the highest-quartile mean WSSV was independently associated with vascular complications in relevant hemispheres. CONCLUSIONS An elevated WSSV is an independent predictor for SP and vascular complications in nonoccluded MMD.

Central nervous system complications after liver transplantation.

We investigated the diversity of central nervous system complications after liver transplantation in terms of clinical manifestations and temporal course. Liver transplantation is a lifesaving option for end stage liver disease patients but post-transplantation neurologic complications can hamper recovery. Between 1 January 2001 and 31 December 2010, patients who had undergone liver transplantation at a single tertiary university hospital were included. We reviewed their medical records and brain imaging data and classified central nervous system complications into four categories including vascular, metabolic, infectious and neoplastic. The onset of central nervous system complications was grouped into five post-transplantation intervals including acute (within 1 month), early subacute (1-3 months), late subacute (3-12 months), chronic (1-3 years), and long-term (after 3 years). During follow-up, 65 of 791 patients (8.2%) experienced central nervous system complications, with 30 occurring within 1 month after transplantation. Vascular etiology was the most common (27 patients; 41.5%), followed by metabolic (23; 35.4%), infectious (nine patients; 13.8%), and neoplastic (six patients). Metabolic encephalopathy with altered consciousness was the most common etiology during the acute period, followed by vascular disorders. An initial focal neurologic deficit was detected in vascular and neoplastic complications, whereas metabolic and infectious etiologies presented with non-focal symptoms. Our study shows that the etiology of central nervous system complications after liver transplantation changes over time, and initial symptoms can help to predict etiology.

Site-Specific Relationship Between Intracranial Aneurysm and Aortic Aneurysm.

BACKGROUND AND PURPOSE: The high prevalence of intracranial aneurysms (IAs) in patients with a bicuspid aortic valve or coarctation of the aorta suggests a link between IA and aortic pathology. However, studies reporting this link do not sufficiently address the heterogeneity of IAs arising from different anatomic locations. This study aimed to explore whether a location-specific relationship exists between the 2 kinds of aneurysms. METHODS: Retrospective institutional analysis of patients aged ≥18 years with both IA and an aortic aneurysm (AA) was performed from 2005 to 2014. IAs were categorized based on their locations: internal carotid artery, other anterior circulation, and posterior arteries. AAs were classified as ascending, descending, infrarenal, or multiple. We analyzed the clinical characteristics and the distribution of IA in each AA group. RESULTS: Of 2375 patients, 660 with available intracranial angiography were screened for IA. We identified 71 patients with 97 IAs. The frequency of both anterior circulation-IAs and internal carotid artery-IAs differed significantly among the AA groups (P=0.001 and P=0.01, respectively). Anterior circulation-IAs were most frequently observed in ascending AA group and least frequently in infrarenal AA group. In contrast, internal carotid artery-IAs were found mostly in infrarenal AA group, least in ascending AA group. Proportions of patients having anterior circulation-IA and internal carotid artery-IA were also highest in ascending AA group and infrarenal AA group, respectively. The number of posterior arteries-IAs was too small to characterize. CONCLUSIONS: The differing distribution patterns of IA among AA groups suggest a site-specific sharing of pathomechanism between the 2 types of aneurysms.

Atherosclerosis-Related Circulating MicroRNAs as a Predictor of Stroke Recurrence.

MicroRNAs (miRNAs) are short sequenced non-coding RNAs that posttranscriptionally regulate gene expression. We investigated circulating miRNA expression levels in acute stroke patients and its relationship with future vascular event. We included acute ischemic stroke patients who admitted to a university hospital between May 1, 2011, and July 31, 2012, and the patients with vascular risk factors but not incident stroke as controls. We collected 5 ml of venous blood, and circulating miRNA levels were evaluated by quantitative real-time polymerase chain reaction. Five miRNAs (miR-17, miR-21, miR-106a, miR-126, and miR-200b), which had been reported to be related to atherosclerosis, were measured. The levels of miRNAs were compared with the presence of acute stroke, vascular risk factors, stroke subtypes, and stroke recurrence after index stroke. A total of 120 patients were included in the study, with 83 acute stroke patients. The levels of miR-17 were significantly increased in acute stroke patients, and the levels of miR-126 had positive correlation with cerebral atherosclerosis (r = 0.254, p = 0.021). Among the 83 stroke patients, eight experienced stroke recurrence during follow-up and higher level of miR-17 was associated with shorter event-free survival (p = 0.047). This study shows that the miR-17 level was elevated in acute ischemic stroke and associated with future stroke recurrence.