Silent Cerebral Infarction In Patients Research Articles

Quantitative susceptibility mapping (QSM) and R2* of silent cerebral infarcts in sickle cell anemia.

Silent cerebral infarction (SCI) is the most commonly reported radiological abnormality in patients with sickle cell anemia (SCA) and is associated with future clinical stroke risk. To date, there have been few histological and quantitative MRI studies of SCI and multiple radiological definitions exist. As a result, the tissue characteristics and composition of SCI remain elusive. The objective of this work was therefore to investigate the composition of segmented SCI lesions using quantitative MRI for R and quantitative magnetic susceptibility mapping (QSM). 211 SCI lesions were segmented from 32 participants with SCA and 6 controls. SCI were segmented according to two definitions (FLAIR+/-T1w-based threshold) using a semi-automated pipeline. Magnetic susceptibility (χ) and R maps were calculated from a multi-echo gradient echo sequence and mean SCI values were compared to an equivalent region of interest in normal appearing white matter (NAWM). SCI χ and R were investigated as a function of SCI definition, patient demographics, anatomical location, and cognition. Compared to NAWM, SCI were significantly less diamagnetic (χ = -0.0067 ppm vs. -0.0153 ppm, p < 0.001) and had significantly lower R (16.7 s-1 vs. 19.2 s-1, p < 0.001). SCI definition had a significant effect on the mean SCI χ and R , with lesions becoming significantly less diamagnetic and having significantly lower R after the application of a more stringent T1w-based threshold. SCI-NAWM R decrease was significantly greater in patients with SCA compared with controls (-2.84 s-1 vs. -0.64 s-1, p < 0.0001). No significant association was observed between mean SCI-NAWM χ or R2* differences and subject age, lesion anatomical location, or cognition. The increased χ and decreased R in SCI relative to NAWM observed in both patients and controls is indicative of lower myelin or increased water content within the segmented lesions. The significant SCI-NAWM R differences observed between SCI in patients with SCA and controls suggests there may be differences in tissue composition relative to NAWM in SCI in the two populations. Quantitative MRI techniques such as QSM and R mapping can be used to enhance our understanding of the pathophysiology and composition of SCI in patients with SCA as well as controls.

Abnormal blood pressure circadian rhythms are relevant to cerebral infarction and Leukoaraiosis in hypertensive patients

BackgroundTo investigate the relationships between blood pressure (BP) circadian rhythms and acute cerebral infarction (ACI), silent cerebral infarction (SCI) and the severity of leukoaraiosis in hypertensive patients.MethodsA retrospective case-control study was performed among hypertensive patients with 24-h ambulatory blood pressure monitoring (ABPM) and cranial magnetic resonance imaging (MRI).ResultsA total of 1267 patients were enrolled. Lower nocturnal blood pressure (BP) decreases were observed in ACI patients than in controls (3.3% vs 8.2%, P<0.001). Reverse-dipper pattern (RD) and non-dipper pattern (ND) were found to be independent risk factors for ACI. In ACI patients, both RD and ND BP circadian rhythms were revealed to be independent risk factors for moderate-severe leukoaraiosis. In addition, in SCI patients, RD (OR = 1.7, 95% CI, 0.9–3.0; P = 0.047) or extreme-dipper pattern (ED) (OR = 2.9, 95% CI, 1.2–7.0; P = 0.015) were found to be independent risk factors for moderate-severe leukoaraiosis. Moreover, the greater the severity of leukoaraiosis was, the higher the ratio of abnormal BP circadian rhythms.ConclusionRD and ND BP circadian rhythms might not only be relevant to the onset of ACI but also correlate with the severity of leukoaraiosis. Thus, when modulating BP with antihypertensive drugs, the BP circadian rhythms, and not merely the BP level, should warrant more attention.

Relationship between silent cerebral infarcts and quality of anticoagulation in patients with prosthetic mitral valves.

Although patients with prosthetic heart valves have an increased risk of clinically overt cerebrovascular events, evidence for the risk of silent cerebral infarction (SCI) is scarce. Serum neuron-specific enolase (NSE) is suggested to be a valid biomarker that allows for the quantification of the degree of neuronal injury. We aimed to assess whether NSE is elevated as a marker of recent SCI in patients with a prosthetic mitral valve. We measured the NSE levels in 103 patients with a prosthetic mitral valve (PMV), admitted to our outpatient clinics for routine evaluation. International normalized ratio (INR) and time in target therapeutic range (TTR) were noted as anticoagulation quality measures. Most of the patients were females (58%), and a mean age was 65 years. NSE values of >12 ng/mL, suggesting a recent SCI, was detected in 25 patients (24%). NSE was negatively correlated with admission INR (r=-0.307, p=0.002). Multivariate analyses demonstrated subtherapeutic INR (INR <2.5) and suboptimal TTR as independent predictors of SCI [odds ratio (OR) 5.420; 95% confidence interval (CI) 1.589 to 18.483; p=0.007, and OR 4.149; 95% CI 1.019 to 16.949; p=0.047, respectively]. Being a current smoker (OR 10.798; 95% CI 2.520 to 46.272; p=0.001), large left atrium (OR 6.763; 95% CI 2.253 to 20.302; p=0.001), and not using aspirin (OR 10.526; 95% CI 1.298 to 83.333; p=0.027) were other independent predictors. Our data suggest that silent brain infarcts are very prevalent among patients with a PMV, as one fourth of them had the event during their routine outpatient visit. Poor quality of anticoagulation partly explains the increased prevalence.

Risk factors and localization of silent cerebral infarction in patients with atrial fibrillation

It is important to identify the risk factors and localization of silent cerebral infarction (SCI), especially in younger patients with atrial fibrillation (AF). The purpose of this study was to examine the characteristics and risk factors for SCI in AF patients, with particular attention to localization of SCI. The study enrolled 286 consecutive neurologically asymptomatic patients who underwent AF ablation from January 2014 to July 2017 (age 61.7 ± 10.2 [SD] years; 208 male and 78 female). All patients underwent magnetic resonance imaging (MRI) before ablation. SCIs were classified independently by 2 radiologists as follows: cardiogenic SCI in 19 (10.6%), lacunar SCI in 13 (8.9%), undetermined causes in 6 (1.6%), and no SCI in 248 (controls, 78.7%). Importantly, no patients with CHA2DS2-VASc score 0 had SCI on MRI. In univariable analysis, significant risk factors for lacunar SCI included age (P = .007), hypertension (P = .037), congestive heart failure (P = .040), left atrial (LA) diameter (P=.013), and cardio-ankle vascular index (P = .004). In multivariable analysis, significant risk factors for cardiogenic SCI were AF duration (odds ratio [OR] 1.01; 95% confidence interval [CI] 1.00-1.02; P = .038), ankle-brachial pressure index (OR 0.002; 95% CI 0-0.68; P = .030), and LA abnormality (OR 8.99; 95% CI 2.78-31.00; P <.001), defined by the presence of spontaneous echo contrast and/or decreased LA appendage emptying velocity. The study results indicate that among AF patients, SCIs localized in the cerebral cortex and cerebellum are frequently noted, for which cardiogenic mechanisms may be mainly involved; CHA2DS2-VASc score could be useful for screening SCI; and LA abnormality is the specific marker for cardiogenic SCI, providing useful information for risk stratification of SCI.

New Silent Cerebral Infarction in Patients with Acute Non-Cerebral Amyloid Angiopathy Intracerebral Hemorrhage as a Predictor of Recurrent Cerebrovascular Events.

BackgroundThe aim of this study was to investigate the incidence and related risk factors of new silent cerebral infarction in patients with acute non-cerebral amyloid angiopathy (non-CAA) intracerebral hemorrhage (ICH) and to explore clinical cerebrovascular event recurrence within 1 year.Material/MethodsThis prospective study observed 152 patients with non-CAA ICH diagnosed by computed tomography within 3 days after onset. All patients underwent magnetic resonance imaging on day 14 to identify silent cerebral infarction, and their subsequent clinical cerebrovascular events were followed up regularly within 1 year.ResultsOf the 152 patients, 46 (30.26%) had silent cerebral infarctions. Multiple logistic regression analysis revealed that the white blood cell (WBC) count, cerebral microbleeds (CMBs), and leukoaraiosis were silent cerebral infarction risk factors. At 1-year follow-up, 34 (22.37%) had clinical cerebrovascular events, with 8 (23.53%) having vascular-related deaths. Multiple logistic regression analysis showed that silent cerebral infarction was the only independent predictor of future clinical cerebrovascular events.ConclusionsSilent cerebral infarction is common during acute non-CAA ICH and is independently related to WBC counts, CMBs, and leukoaraiosis. The risk of clinical cerebrovascular events in non-CAA ICH patients with silent cerebral infarction increases in the following year; thus, silent cerebral infarction may be a useful predictor of recurrent cerebrovascular events.

Relationships between blood pressure variability and silent cerebral infarction in patients with primary hypertension

AimsThis study aimed to investigate the relationship between blood pressure variability and the incidence of silent cerebral infarction (SCI) in patients with primary hypertension. MethodsThe 346 hospitalized patients with primary hypertension were divided into primary hypertension group (160 cases) and primary hypertension combined with SCI group (186 cases). The 24-h ambulatory blood pressure was measured. Clinical data were collected. Univariate and multivariate logistic regression analysis was performed. ResultsThere were significant differences between patients with primary hypertension combined with SCI and patients with primary hypertension only in age, stroke history, diabetes history, smoking, alcohol consumption, FBG, Hcy, and Lp-PLA2. The 24-h ambulatory blood pressure monitoring results suggested that dSBP, dSSD, 24hSBP, nSSD, dDBP, dDSD, nDSD, 24hDSD, ddnSBP, and ddnDBP in patients with hypertension and SCI were higher than those in patients with primary hypertension only. Non-dipper blood pressure was more common. Multivariate logistic regression analysis showed dSSD (OR: 1.374, 95%CI [1.173–1.609]), 24 h DSD (OR: 1.194, 95%CI [1.017,1.402]), dSBP (OR: 1.062, 95%CI [1.022, 1.103]), age (OR: 1.042, 95%CI [1.005, 1.080]), smoking (OR: 2.610, 95%CI [1.495, 4.556]), fasting plasma glucose (OR: 1.183, 95%CI [1.040, 1.345]), and Lp-PLA2 (OR: 1.004, 95%CI [1.003, 1.006]) were positively correlated with SCI in hypertension patients. ConclusionsBlood pressure variability (dSSD and24hDSD) is independently associated with SCI in patients with primary hypertension. In addition, traditional risk factors, blood pressure level (dSBP), age, smoking, fasting plasma glucose, and Lp-PLA2 were also independently associated with SCI in patients with primary hypertension.

Acute and subacute silent cerebral infarction in patients before elective coronary intervention

Acute and subacute silent cerebral infarction in patients before elective coronary intervention

Silent Cerebral Infarction in East Asian vs. Non-Asian Atrial Fibrillation Patients - Meta-Analysis.

Atrial fibrillation (AF) is the most common arrhythmia in the ageing population in East Asia. Silent cerebral infarction (SCI) is defined as cerebral infarction in the absence of corresponding clinical symptoms, and is a highly prevalent and morbid condition in AF. SCI is increasingly being recognized as a risk factor for future stroke, which can lead to cognitive decline or dementia. The latter is an increasingly common health problem in East Asia.Methods and Results:We conducted a meta-analysis to compare the association of AF and SCI between East Asian and non-Asian patients. AF was associated with SCI in patients with no symptomatic stroke history (relative risk [RR], 2.24; 95% CI: 1.26-3.99, I2=83%; P=0.006) although the prevalence varied widely between studies (P for heterogeneity<0.001). In non-Asian patients, the prevalence of SCI in AF is higher than that in controls (RR, 1.85; 95% CI: 1.65-2.08, I2=17%; P<0.001). There was no significant racial difference between Asian and non-Asian studies (P=0.53). In East Asia, AF was significantly associated with SCI and no racial difference was seen between East Asian and non-Asian patients. The present findings offer clinicians new insights into the association between AF and SCI.

Silent Cerebral Infarctions with Reduced, Mid-Range and Preserved Ejection Fraction in Patients with Heart Failure.

Heart failure predisposes to an increased risk of silent cerebral infarction, and data related to left ventricular ejection fraction are still limited. Our objective was to describe the clinical and echocardiographic characteristics and factors associated with silent cerebral infarction in patients with heart failure, according to the left ventricular ejection fraction groups. A prospective cohort was performed at a referral hospital in Cardiology between December 2015 and July 2017. The left ventricular ejection fraction groups were: reduced (≤ 40%), mid-range (41-49%) and preserved (≥ 50%). All patients underwent cranial tomography, transthoracic and transesophageal echocardiography. Seventy-five patients were studied. Silent cerebral infarction was observed in 14.7% of the study population (45.5% lacunar and 54.5% territorial) and was more frequent in patients in the reduced left ventricular ejection fraction group (29%) compared with the mid-range one (15.4%, p = 0.005). There were no cases of silent cerebral infarction in the group of preserved left ventricular ejection fraction. In the univariate analysis, an association was identified between silent cerebral infarction and reduced (OR = 8.59; 95%CI: 1.71 - 43.27; p = 0.009) and preserved (OR = 0.05; 95%CI: 0.003-0.817, p = 0.003) left ventricular ejection fraction and diabetes mellitus (OR = 4.28, 95%CI: 1.14-16.15, p = 0.031). In patients with heart failure and without a clinical diagnosis of stroke, reduced and mid-range left ventricular ejection fractions contributed to the occurrence of territorial and lacunar silent cerebral infarction, respectively. The lower the left ventricular ejection fraction, the higher the prevalence of silent cerebral infarction.

Efficacy of alogliptin combined with motor imagery under hyperbaric oxygen in diabetic nephropathy with silent cerebral infarction.

In the present study, we evaluated the curative effect of dipeptidyl peptidase-IV (DPP-IV) inhibitor alogliptin combined with motor imagery under hyperbaric oxygen in diabetic nephropathy (DN) with silent cerebral infarction (SCI). Two-hundred newly diagnosed DN patients with and without SCI were included. The SCI patients were divided into two treatment groups: Alogliptin (A group, n=50) and alogliptin combined with motor imagery under hyperbaric oxygen (B group, n=50). The degrees of neurocognitive dysfunction were evaluated at baseline and after 6 months of treatment. Thromboelastograms (TEGs) mapping were conducted. Serum glycoprotein VI (GPVI) mRNA expression and urine 11-DH-TXB2 levels were determined. Compared to group A patients, the severity of neurofunctional defects, GPVI mRNA expression and 11-DH-TXB2 levels were significantly lower in group B (P<0.05), while comprehensive, MoCA scores were higher in group B. The MoCA subscores of visuospatial/executive function, attention and concentration were significantly higher compared to group A (P<0.05). The sub-scores of computation, abstract thinking, language competence, memory and orientation were also higher in group B but the differences were not significant (P>0.05). TEG indexes were improved in both groups after treatment as manifested by increased R and K values, but there was significant improvement in group B. Intra-group comparisons revealed a time-dependent effect of treatment. In conclusion, the treatment of alogliptin combined with motor imagery under hyperbaric oxygen can better promote thrombolysis absorption, restore brain damage and improve neurocognitive function in DN with silent cerebral infarction.

RBP4/Lp-PLA2/Netrin-1 signaling regulation of cognitive dysfunction in diabetic nephropathy complicated with silent cerebral infarction

Aim To investigate the RBP4/Lp-PLA2/Netrin-1 signal regulation of cognitive function impairment in diabetic nephropathy patients with silent cerebral infarction (SCI). Methods One-hundred patients newly diagnosed with diabetic nephropathy patients were included. The patients were divided into SCI group and NSCI group according to the radiological data. The degrees of cognitive dysfunction were evaluated. Serum RBP4 concentrations were determined by ELISA and protein expressions of Lp-PLA2 and Netrin-1 were determined by Western Blot. Results Compared with NSCI group, the cognitive function of patients in SCI group was impaired, the concentrations of RBP4 and the expressions of Lp-PLA2 and Netrin-1 increased (P<0.05). RBP4 concentrations were positively correlated with the cognitive dysfunction of SCI patients. Moreover, there existed a regression correlation between them. Conclusion RBP4 may be used as a predictive factor of diabetic nephropathy patients complicated with SCI and is positively correlated with cognitive dysfunction. RBP4/Lp-PLA2/Netrin-1 pathway activation may be one of the occurrence mechanisms in diabetic nephropathy complicated with SCI.

Retraction Note to: A study on cognitive impairment and gray matter volume abnormalities in silent cerebral infarction patients.

The relationship between silent cerebral infarction (SCI) and the integrity of cognitive function is unknown. We intended to investigate whether cognitive impairment is associated with gray matter volume (GMV) in the SCI patients. Sixty-two patients with SCI and 62 age- and gender-matched healthy controls (HC) were evaluated with P300 test, Montreal Cognitive Assessment (MoCA) test, Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HDRS). Whole brain high-resolution T1-weighted images were processed with SPM12b software and analyzed by voxel-based morphometry (VBM). Correlation analysis was performed between the GMV and the scores of MoCA Scale, P300 latency, P300 amplitude, HAMA, HDRS, age, and educational level. The brains of the SCI patients have a significant reduction in GMV in the left superior and inferior frontal gyrus, left superior temporal gyrus, right middle temporal gyrus, and bilateral hippocampus gyrus (p < 0.01, FDR correction). No significant increase of GMV was detected. The GMV of their frontal and temporal lobes is positively correlated with the score of MoCA scale and P300 amplitude (r ≥ 0.62, p < 0.01). The GMV of frontal, temporal, and hippocampus is negatively correlated with P300 latency (r ≤ −0.71, p < 0.05). No significant correlation between the GMV of abnormal brain regions and another two clinical characteristics was found. SCI patients have impaired cognitive function and reduced GMV compared to the HC subjects. The neuropathological basis of such cognitive deficits in SCI patients might be a reduced GMV.

Cognitive impairment and gray matter volume abnormalities in silent cerebral infarction.

To investigate the association between cognitive impairment and gray matter volume (GMV) abnormalities in silent cerebral infarction (SCI) patients, the GMV of 62 pairs of patients and well-matched healthy controls was calculated. All participants underwent a P300 test, a Montreal Cognitive Assessment (MoCA) test. Compared with controls, the patients showed decreased GMV in the left superior frontal gyrus, left inferior frontal gyrus, left superior temporal gyrus, right middle temporal gyrus, and bilateral parahippocampal gyrus; no significantly increasing GMV was found. The volumes of the frontal and temporal lobes were positively correlated with the score of the MoCA scale and P300 amplitudes (r≥0.62, P<0.01). The P300 latency was negatively correlated with the volumes of the frontal lobe, the temporal lobe, and the hippocampus (r≤-0.71, P<0.05). No significant correlations between the GMV of the abnormal brain regions and four clinical characteristics in SCI patients were found, suggesting that cognitive deficiency existed in SCI patients and the reduced GMV might contribute to the pathology of cognitive deficiency in SCI patients.

A study on cognitive impairment and gray matter volume abnormalities in silent cerebral infarction patients.

The relationship between silent cerebral infarction (SCI) and the integrity of cognitive function is unknown. We intended to investigate whether cognitive impairment is associated with gray matter volume (GMV) in the SCI patients. Sixty-two patients with SCI and 62 age- and gender-matched healthy controls (HC) were evaluated with P300 test, Montreal Cognitive Assessment (MoCA) test, Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HDRS). Whole brain high-resolution T1-weighted images were processed with SPM12b software and analyzed by voxel-based morphometry (VBM). Correlation analysis was performed between the GMV and the scores of MoCA Scale, P300 latency, P300 amplitude, HAMA, HDRS, age, and educational level. The brains of the SCI patients have a significant reduction in GMV in the left superior and inferior frontal gyrus, left superior temporal gyrus, right middle temporal gyrus, and bilateral hippocampus gyrus (p < 0.01, FDR correction). No significant increase of GMV was detected. The GMV of their frontal and temporal lobes is positively correlated with the score of MoCA scale and P300 amplitude (r ≥ 0.62, p < 0.01). The GMV of frontal, temporal, and hippocampus is negatively correlated with P300 latency (r ≤ -0.71, p < 0.05). No significant correlation between the GMV of abnormal brain regions and another two clinical characteristics was found. SCI patients have impaired cognitive function and reduced GMV compared to the HC subjects. The neuropathological basis of such cognitive deficits in SCI patients might be a reduced GMV.

Neurologic Outcomes of Preoperative Acute Silent Cerebral Infarction in Patients with Cardiac Surgery

BackgroundAcute cerebral infarction is a major risk factor for postoperative neurologic complications in cardiac surgery. However, the outcomes associated with acute silent cerebral infarction (ASCI) have not been not well established. Few studies have reported the postoperative outcomes of these patients in light of preoperative Diffusion-weighted magnetic resonance imaging (DWI). We studied the postoperative neurologic outcomes of patients with preoperative ASCI detected by DWI.MethodsWe retrospectively studied 32 patients with preoperative ASCI detected by DWI. None of the patients had preoperative neurologic symptoms. The mean age at operation was 68.8±9.5 years. Five patients had previous histories of stroke. Four patients had been diagnosed with infective endocarditis. Single cerebral infarct lesions were detected in 16 patients, double lesions in 13, and multiple lesions (>5) in three. The median size of the infarct lesions was 4 mm (range, 2 to 25 mm). The operations of three of the 32 patients were delayed pending follow-up DWI studies.ResultsThere were two in-hospital mortalities. Neurologic complications also occurred in two patients. One patient developed extensive cerebral infarction unrelated to preoperative infarct lesions. One patient showed sustained delirium over one week but recovered completely without any neurologic deficits. In two patients, postoperative DWI confirmed that no significant changes had occurred in the lesions.ConclusionPatients with preoperative ASCI showed excellent postoperative neurologic outcomes. Preoperative ASCI was not a risk factor for postoperative neurologic deterioration.

Clinical and echocardiographic predictors of silent cerebral infarctions in patients with persistent atrial fibrillation

Summary Aim. The aims of the study were to evaluate prevalence of silent cerebral infarctions (SCI) and determine their clinical and echocardiographic predictors in patients with atrial fibrillation (AF). Patients and methods. In prospective cross sectional study we examined 134 patients with non-valvular AF. Clinical examination, laboratory tests, transoesophageal, transthoracic echocardiography and multislice computed tomography of the brain were performed for all patients. According to current guidelines, SCI was defined as imaging (≥3 mm) or neuropathological evidence of central nervous system infarction, without a history of acute neurological dysfunction attributable to the lesion. Results. Silent cerebral infarctions were detected in 34.3% (n = 46) of patients, and infarctions ≥ 15 mm (mean diameter 31.3 mm) were detected in 11.2% (n = 15) of patients. Superficial SCIwere found in 12.7%and basal SCI in 21.6% of cases. In multivariate analysis low creatinine clearance &lt; 90 ml/min was independently associated with small basal SCI (p = 0.04). In univariate analysis age ≥ 65 years was significantly associated with basal SCI, p = 0.004, but not with SCI ≥ 15 mm or superficial SCI. The results of multivariate analysis showed that CHA2DS2VASc score was an independent predictor of superficial SCI; low left atrial appendage velocity (LAAV) &lt; 30 cm/s was independently associated both with SCI ≥ 15 mm (p = 0.03) and superficial SCI (p = 0.02). Conclusions. Large and superficial SCI were significantly and independently associated with low LAAV &lt; 30 cm/s and other echocardiographic embolic risk factors and in case of absence of significant large arteries atherosclerosis may be considered as those of cardiac origin. Small basal SCI were associated with age and low creatinine clearance &lt; 90 ml/min which was their independent predictor. CHA2DS2VASc score is useful for assessment of risk of cerebral infarctions even those without history of acute symptoms

Association between atrial fibrillation and silent cerebral infarctions: a systematic review and meta-analysis.

Atrial fibrillation (AF) is a common cause of stroke. Silent cerebral infarctions (SCIs) are known to occur in the presence and absence of AF, but the association between these disorders has not been well-defined. To estimate the association between AF and SCIs and the prevalence of SCIs in stroke-free patients with AF. Searches of MEDLINE, PsycINFO, Cochrane Library, CINAHL, and EMBASE from inception to 8 May 2014 without language restrictions and manual screening of article references. Observational studies involving adults with AF and no clinical history of stroke or prosthetic valves who reported SCIs. Study characteristics and study quality were assessed in duplicate. Eleven studies including 5317 patients with mean ages from 50.0 to 83.6 years reported on the association between AF and SCIs. Autopsy studies were heterogeneous and low-quality; therefore, they were excluded from the meta-analysis of the risk estimates. When computed tomography (CT) and magnetic resonance imaging (MRI) studies were combined, AF was associated with SCIs in patients with no history of symptomatic stroke (odds ratio, 2.62 [95% CI, 1.81 to 3.80]; I(2) = 32.12%; P for heterogeneity = 0.118). This association was independent of AF type (paroxysmal vs. persistent). The results were not altered significantly when the analysis was restricted to studies that met at least 70% of the maximum possible quality score (odds ratio, 3.06 [CI, 2.24 to 4.19]). Seventeen studies reported the prevalence of SCIs. The overall prevalence of SCI lesions on MRI and CT among patients with AF was 40% and 22%, respectively. Most studies were cross-sectional, and autopsy studies were heterogeneous and not sufficiently sensitive to detect small lesions. Atrial fibrillation is associated with more than a 2-fold increase in the odds for SCI. Deane Institute for Integrative Research in Atrial Fibrillation and Stroke, Massachusetts General Hospital.

Elevated mean platelet volume is associated with silent cerebral infarction.

The presence of silent cerebral infarction (SCI) increases the risk of transient ischaemia attack, symptomatic stroke, cardiovascular disease and dementia. Mean platelet volume (MPV) is a surrogate marker of activated platelets and is considered a link between inflammation and thrombosis. In addition, MPV is a risk predictor for cardiovascular disease, stroke and overall vascular mortality. The purpose of the study was to assess the MPV levels in SCI patients. A cross-sectional study was conducted to evaluate the association between MPV and SCI in 2215 subjects (1385 men and 830 women). The participants with SCI had higher MPV levels than those without SCI (10.4 ± 1.3 fL vs. 9.2 ± 1.2 fL; P < 0.001). Moreover, the subjects with a high MPV had a higher prevalence of SCI. Multivariate logistic regression analyses revealed that the odds ratios and 95% confidence intervals for SCI according to MPV quartiles were 1.000, 2.131 (1.319-3.444), 3.015 (1.896-4.794), 7.822 (4.874-12.554) respectively (P < 0.001). MPV is a novel index for SCI regardless of classical cardiovascular risk factors.

Abstract 3392: Silent Cerebral Infarctions in Healthy Subjects with Right-Left Shunt on Transcranial Doppler

Background: In healthy elderly people, silent cerebral infarction (SCI) and white matter lesions are common, but little is known about their relevance. In the present study, we evaluated the association between SCI located outside the perforating artery territory and paradoxical embolism detected by agitated saline transcranial Doppler (TCD) monitoring in healthy subjects. We also compared the frequency and amount of paradoxical embolism between healthy subjects with SCI and acute stroke patients with presumed cryptogenic embolism. Methods: This study is a prospective observational study undertaken from January 2009 to January 2011 by a university health promotion center and from January 2008 to January 2010 by a university stroke center. We defined SCI as evidence on MRI of one or more infarcts, without a history of a (corresponding) stroke or TIA; brain infarction was defined as a focal hyperintensity lesion 3 mm or large in diameter in the fluid-attenuation inversion recovery (FLAIR) images. We also evaluated neuroimaing indicators of microangiopathy, SCI within perforator territory and leukoaraiosis (LA), in all subjects. Results: Among 1103 consecutive healthy adults who underwent MRI, 347 (31%) had one or more SCI. After excluding subjects with poor temporal window, refusal or having SCI within only striatocapsular area, 253 subjects underwent agitated saline TCD monitoring and 128 (51%) had right-to-left shunts (RLS). Similarly, 145 out of 234 patients (62%) with presumed cryptogenic embolic stroke showed RLS. However, RLS was less frequently observed in stroke patients with determined mechanisms (34 out of 94 patients (38%)) than healthy subjects with SCI (p=0.017). Moreover, the number of SCI within perforator territory and the degree of LA were inversely correlated with the amount of RLS in healthy subjects. Conclusion: Our results suggest that paradoxical embolism plays an important role in the development of SCI outside the perforating artery territory in apparently healthy adult.

Monocyte chemoattractant protein‐1 is associated with silent cerebral infarction in patients on haemodialysis

In patients with chronic renal failure undergoing haemodialysis (HD), silent cerebral infarctions (SCI) are associated with high mortality. Levels of monocyte chemoattractant protein-1 (MCP-1) increase with renal dysfunction and may be a novel predictor for cerebrovascular events. We tested the hypothesis that increased MCP-1 concentration correlate with the occurrence of SCI in HD patients. Using cranial magnetic resonance imaging (MRI) findings, 52 Japanese patients undergoing HD were divided into two groups: with SCI (61 ± 7 years, mean ± SD, n= 28) and without SCI (60 ± 6 years, n= 24). The gender, metabolic profiles and MCP-1 concentration were compared between the two groups. The level of MCP-1 was higher in the with-SCI group than in the without-SCI group (P < 0.0001). The proportion of smokers was higher in the with-SCI group (P < 0.05) than in the without-SCI group. Plasma level of high-density lipoprotein cholesterol was lower, while uric acid level was higher, in the with-SCI group (P < 0.05 and P < 0.05 respectively) compared to the without-SCI group. Multiple logistic regression analysis identified MCP-1 level as being significantly associated with the presence of SCI (odds ratio 1.48, 95% confidence interval = 1.10-5.75, P < 0.0001). This study indicates that patients with chronic renal failure who are maintained on HD exhibit an increased prevalence of SCI, and that MCP-1 is significantly associated with the presence of SCI in HD patients.