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1.
Ann Neurol ; 85(5): 752-764, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30840312

RESUMO

OBJECTIVE: To investigate whether hemodynamic features of symptomatic intracranial atherosclerotic stenosis (sICAS) might correlate with the risk of stroke relapse, using a computational fluid dynamics (CFD) model. METHODS: In a cohort study, we recruited patients with acute ischemic stroke attributed to 50 to 99% ICAS confirmed by computed tomographic angiography (CTA). With CTA-based CFD models, translesional pressure ratio (PR = pressurepoststenotic /pressureprestenotic ) and translesional wall shear stress ratio (WSSR = WSSstenotic - throat /WSSprestenotic ) were obtained in each sICAS lesion. Translesional PR ≤ median was defined as low PR and WSSR ≥4th quartile as high WSSR. All patients received standard medical treatment. The primary outcome was recurrent ischemic stroke in the same territory (SIT) within 1 year. RESULTS: Overall, 245 patients (median age = 61 years, 63.7% males) were analyzed. Median translesional PR was 0.94 (interquartile range [IQR] = 0.87-0.97); median translesional WSSR was 13.3 (IQR = 7.0-26.7). SIT occurred in 20 (8.2%) patients, mostly with multiple infarcts in the border zone and/or cortical regions. In multivariate Cox regression, low PR (adjusted hazard ratio [HR] = 3.16, p = 0.026) and high WSSR (adjusted HR = 3.05, p = 0.014) were independently associated with SIT. Patients with both low PR and high WSSR had significantly higher risk of SIT than those with normal PR and WSSR (risk = 17.5% vs 3.0%, adjusted HR = 7.52, p = 0.004). INTERPRETATION: This work represents a step forward in utilizing computational flow simulation techniques in studying intracranial atherosclerotic disease. It reveals a hemodynamic pattern of sICAS that is more prone to stroke relapse, and supports hypoperfusion and artery-to-artery embolism as common mechanisms of ischemic stroke in such patients. Ann Neurol 2019;85:752-764.

2.
PLoS One ; 13(5): e0196344, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29791452

RESUMO

OBJECTIVE: Repeated testing using the Montreal Cognitive Assessment (MoCA) increases risks for practice effects which may bias measurements of cognitive change. The objective of this study is to develop two alternate versions of the MoCA (Hong Kong version; HK-MoCA) and to investigate the validity and reliability of the alternate versions in patients with DSM-5 Mild Neurocognitive Disorder (Mild NCD) and cognitively healthy controls. METHODS: Concurrent validity and inter-scale agreement were examined by Pearson correlation of the total scores between the original and alternate versions and the Bland-Altman Method. Criterion validity of the two alternate versions in differentiating patients with Mild NCD was tested using receiver operating characteristic curve (ROC) analysis. One-month test-retest and inter-rater reliability were examined in 20 participants. Internal consistency of the alternate versions was measured by the Cronbach's α. RESULTS: 30 controls (age 73.4 [4.5] years, 60% female) and 30 patients (age 75.4 [5.5] years, 73% female) with Mild NCD were recruited. Both alternate versions significantly correlated with the original version (r = 0.79-0.87, p<0.001). Mean differences of 0.17 and -0.40 points were found between the total scores of the alternate with the original versions with a consistent level of agreement observed throughout the range of cognitive abilities. Both alternate versions significantly differentiated patients with Mild NCD from healthy controls (area under ROC 0.922 and 0.724, p<0.001) and showed good one-month test-retest reliability (intra-class correlation [ICC] = 0.92 and 0.82) and inter-rater reliability (ICC = 0.99 and 0.87) and high internal consistency (Cronbach α = 0.79 and 0.75). CONCLUSION: The two alternate versions of the HK-MoCA are useful for Mild NCD screening.


Assuntos
Disfunção Cognitiva/diagnóstico , Testes de Estado Mental e Demência , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Hong Kong , Humanos , Masculino , Testes de Estado Mental e Demência/estatística & dados numéricos , Curva ROC , Reprodutibilidade dos Testes
3.
Int J Geriatr Psychiatry ; 33(5): 729-734, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29292529

RESUMO

BACKGROUND: The Montreal Cognitive Assessment (MoCA) is psychometrically superior over the Mini-mental State Examination (MMSE) for cognitive screening in stroke or transient ischemic attack (TIA). It is free for clinical and research use. The objective of this study is to convert scores from the MMSE to MoCA and MoCA-5-minute protocol (MoCA-5 min) and to examine the ability of the converted scores in detecting cognitive impairment after stroke or TIA. METHODS: A total of 904 patients were randomly divided into training (n = 623) and validation (n = 281) samples matched for demography and cognition. MMSE scores were converted to MoCA and MoCA-5 min using (1) equipercentile method with log-linear smoothing and (2) Poisson regression adjusting for age and education. Receiver operating characteristics curve analysis was used to examine the ability of the converted scores in differentiating patients with cognitive impairment. RESULTS: The mean education was 5.8 (SD = 4.6; ranged 0-20) years. The entire spectrum of MMSE scores was converted to MoCA and MoCA-5 min using equipercentile method. Relationship between MMSE and MoCA scores was confounded by age and education, and a conversion equation with adjustment for age and education was derived. In the validation sample, the converted scores differentiated cognitively impaired patients with area under receiver operating characteristics curve 0.826 to 0.859. CONCLUSION: We provided 2 methods to convert scores from the MMSE to MoCA and MoCA-5 min based on a large sample of patients with stroke or TIA having a wide range of education and cognitive levels. The converted scores differentiated patients with cognitive impairment after stroke or TIA with high accuracy.

4.
Stroke ; 49(1): 215-218, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29203690

RESUMO

BACKGROUND AND PURPOSE: Central autonomic dysfunction increases stroke morbidity and mortality. We aimed to investigate whether poststroke autonomic dysfunction graded by Ewing battery can predict clinical outcome. METHODS: In this prospective observational study, we assessed autonomic function of ischemic stroke patients within 7 days from symptom onset by Ewing battery. On the basis of the magnitude of autonomic dysfunction, we stratified patients into significant (definite, severe, or atypical) or minor (normal or early) autonomic function impairment groups and correlated the impairment with the 3-month modified Rankin Scale score (good outcome: modified Rankin Scale score 0≈2; poor outcome: modified Rankin Scale score 3≈6). RESULTS: Among the 150 patients enrolled (mean age, 66.4±9.9 years; 70.7% males), minor autonomic dysfunction was identified in 36 patients (24.0%), and significant autonomic dysfunction was identified in 114 patients (76.0%) based on Ewing battery. In 3 months, a poor functional outcome was found in 32.5% of significant group patients compared with 13.9% in the minor group (P=0.031). Crude odds ratios of the magnitude of autonomic dysfunction and 3-month unfavorable functional outcome after acute ischemic stroke were 2.979 (95% confidence interval, 1.071-8.284; P=0.036). After adjusting for confounding variables with statistical significance between the 2 functional outcome subgroups identified in univariate analysis (including sex and National Institutes of Health Stroke Scale score on admission), the magnitude of autonomic dysfunction still independently predicted an unfavorable outcome, with an odds ratio of 3.263 (95% confidence interval, 1.141-9.335; P=0.027). CONCLUSIONS: Autonomic dysfunction gauged by Ewing battery predicts poor functional outcome after acute ischemic stroke.


Assuntos
Doenças do Sistema Nervoso Autônomo , Sistema Nervoso Autônomo/fisiopatologia , Isquemia Encefálica , Acidente Vascular Cerebral , Idoso , Doenças do Sistema Nervoso Autônomo/etiologia , Doenças do Sistema Nervoso Autônomo/mortalidade , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Isquemia Encefálica/complicações , Isquemia Encefálica/mortalidade , Isquemia Encefálica/fisiopatologia , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/mortalidade , Acidente Vascular Cerebral/fisiopatologia , Taxa de Sobrevida
5.
J Stroke Cerebrovasc Dis ; 26(8): 1760-1765, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28522230

RESUMO

BACKGROUND: Cortical microinfarcts (CMIs) have been correlated to cognitive decline and dementia. It was previously considered only visible on microscope, but was recently reported to be visible on 3.0 Tesla magnetic resonance imaging (MRI) and linked to presence of intracranial stenosis. We aimed to investigate CMIs on 3.0 Tesla MRI in patients with M1 middle cerebral artery (MCA-M1) stenosis. METHODS: Patients with a recent non-cardioembolic ischemic stroke or transient ischemic attack and an atherosclerotic MCA-M1 stenosis were recruited. The severity of MCA stenosis was defined as moderate (50%-69%) or severe (70%-99% or focal flow void) on time-of-flight MR angiography (MRA). The distal to proximal signal intensity ratio (SIR) of MCA stenosis was measured on time-of-flight MRA to represent its hemodynamic significance. The presence of CMI(s) in the ipsilateral hemisphere was assessed on axial T1- or T2-weighted images and T2-weighted fluid-attenuated inversion-recovery images. RESULTS: Overall, 86 patients (mean age: 62.8 years; 77.9% males) were analyzed, 66 (76.7%) and 20 (23.3%), respectively, having moderate and severe MCA-M1 stenoses. The median SIR was .91. Forty-five (52.3%) patients had ipsilateral CMI(s). Multivariate logistic regression showed a history of dyslipidemia (odds ratio [OR] = 6.83, P = .008), and an SIR lower than the median (OR = 4.73, P = .014) were independently associated with presence of CMI(s) in ipsilateral hemisphere to an MCA-M1 stenosis. CONCLUSIONS: Patients with stroke and intracranial stenosis had a high burden of CMI. Except for a history of dyslipidemia, the hemodynamic significance of the arterial stenosis may contribute to the presence of ipsilateral CMI(s) in these patients, which warrants further investigation in prospective, longitudinal studies.


Assuntos
Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/diagnóstico por imagem , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Imagem por Ressonância Magnética , Idoso , Velocidade do Fluxo Sanguíneo , Circulação Cerebrovascular , Distribuição de Qui-Quadrado , China/epidemiologia , Estudos Transversais , Dislipidemias/epidemiologia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Incidência , Infarto da Artéria Cerebral Média/epidemiologia , Infarto da Artéria Cerebral Média/fisiopatologia , Modelos Logísticos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Valor Preditivo dos Testes , Fatores de Risco , Índice de Gravidade de Doença
6.
Neuroepidemiology ; 48(1-2): 48-54, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28334718

RESUMO

BACKGROUND: To date, sex difference in outcomes among patients with intracranial atherosclerosis (ICAS) has rarely been discussed in China as well as in the world. This study aimed to estimate the sex difference in outcomes among patients with ICAS in Chinese cerebral ischemia patients. METHODS: We analyzed 1,335 men and women with ICAS who were enrolled in the Chinese Intracranial Atherosclerosis study. They were followed-up for ischemic stroke recurrence, any cause of death, cerebral vascular events (including transient ischemic attack, ischemic and hemorrhagic stroke), combined end points (including cerebral vascular events, angina or myocardial infarction, pulmonary embolism, peripheral vascular events), and unfavorable outcome (modified Rankin scale score of 3-6) at 1 year. RESULTS: During the follow-up period, 59 (13.44%) combined end points were documented in women and 107 (11.94%) in men. Of the combined end points, 47 were recurrent ischemic stroke events (14 in women and 33 in men), and 51 other causes of deaths (24 in women and 27 in men). There were 349 unfavorable end points (117 in women and 232 in men). The cumulative probability of death was higher in women, but after adjusting for age, diabetes mellitus, hypertension, family history of stroke, current smoker, heavy drinking, hyperhomocysteinemia, and heart disease, there was no significant difference. There was also a lack of difference in 1-year ischemic stroke recurrence, cerebral vascular events, combined end points, and unfavorable outcome between women and men at 1 year. CONCLUSIONS: These results suggest no sex difference in outcome among patients with ICAS in Chinese cerebral ischemia patients.


Assuntos
Arteriosclerose Intracraniana/epidemiologia , Avaliação de Resultados da Assistência ao Paciente , Acidente Vascular Cerebral/epidemiologia , Idoso , China , Feminino , Humanos , Arteriosclerose Intracraniana/complicações , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Acidente Vascular Cerebral/complicações
7.
J Neurol Neurosurg Psychiatry ; 88(1): 86-94, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26818728

RESUMO

OBJECTIVE: Acute symptomatic seizure (AS) after ischaemic stroke is defined as a seizure occurring ≤7 days of the stroke. There remains a lack of information on the prognosis of AS after ischaemic stroke and how it should be treated. METHODS: We prospectively recruited patients after their incidents of ischaemic stroke from a population-based stroke registry. Stroke aetiology was defined according to Trial-of-ORG-10172 in acute-stroke treatment (TOAST). Patients were examined for any transient complete-occlusion with recanalisation (TCOR) and haemorrhagic transformation. The seizure outcomes were (1) acute clustering of seizures ≤7 days, (2) seizure recurrence associated with stroke recurrence beyond the 7-day period and (3) unprovoked seizure (US) >7 days. RESULTS: 104 patients (mean age 65 years/55% female) with AS after ischaemic stroke were identified (mean follow-up 6.17 years). Comparison of the group of patients with AS and those without seizures showed that patients with AS had significantly less large-vessel and small-vessel disease but more cardioembolisms (p<0.05) and a higher proportion of TCOR (p<0.01), multiple territory infarcts (p=0.007) and haemorrhagic transformations (p<0.01). Using Kaplan-Meier statistics, the risk of acute clustering of seizures ≤7 days was 22%, with a statistical trend for TCOR as a predictive factor (p=0.06). The risk of seizure recurrence associated with worsening/recurrence of stroke beyond 7 days was 13.5% at 2 years, 16.4% at 4 years and 18% at 8 years. Presence of >2 cardiovascular risk factors (p<0.05) and status epilepticus (P<0.05) are predictive risk factors on Cox regression model. The risk of US was 19% at 2 years, 25% at 4 years and 28% at 8 years with epileptiform EEG as a predictive factor (p<0.05). CONCLUSIONS: Seizure recurrence following AS after ischaemic stroke may appear as acute clustering. Afterwards, seizures may occur as often with a recurrent stroke as without one within 4.2 years. We recommend the use of antiepileptic agents for up to 4 years if the underlying stroke aetiology cannot be fully treated.


Assuntos
Convulsões/diagnóstico , Convulsões/etiologia , Acidente Vascular Cerebral/complicações , Idoso , Idoso de 80 Anos ou mais , Infarto Encefálico/complicações , Estudos de Casos e Controles , Transtornos Cerebrovasculares/complicações , Embolia/complicações , Feminino , Hemorragia/complicações , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Recidiva , Sistema de Registros , Fatores de Risco , Fatores de Tempo
8.
PLoS One ; 11(9): e0162846, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27632159

RESUMO

BACKGROUND: The objectives of this study are 1) to examine the frequencies of neuropsychiatric symptom clusters in patients with stroke or transient ischemic attack (TIA) by cognitive level and stroke subtype; and 2) to evaluate effect of demographic, clinical, and neuroimaging measures of chronic brain changes and amyloid upon neuropsychiatric symptom clusters. METHODS: Hospital-based, cross-sectional study. 518 patients were administered the Neuropsychiatric Inventory (NPI) 3-6 months post index admission. NPI symptoms were classified into four symptom clusters (Behavioral Problems, Psychosis, Mood Disturbance & Euphoria) derived from a confirmatory factor analysis of the 12 NPI items. Multivariable logistic regression was used to determine independent associations between demographic, clinical and neuroimaging measures of chronic brain changes (white matter changes, old infarcts, whole brain atrophy, medial temporal lobe atrophy [MTLA] and frontal lobe atrophy [FLA]) with the presence of NPI symptoms and all symptom clusters except euphoria. 11C-Pittsburg Compound B Positron Emission Tomography (11C-PiB PET) was performed in 24 patients to measure amyloid retention for Alzheimer's Disease (AD) pathology. RESULTS: 50.6% of the whole sample, including 28.7% cognitively normal and 66.7% of patients with mild cognitive symptoms, had ≥1 NPI symptoms. Frequencies of symptom clusters were largely similar between stroke subtypes. Compared to patients with cardioembolic stroke and intracranial haemorrhage, those with TIA had less frequent mood disturbance. Stroke severity at admission and MTLA were the most robust correlates of symptoms. FLA was associated with behavioral problems cluster only. Frequency of symptom clusters did not differ between patients with and without significant amyloid retention. CONCLUSION: Frequency of neuropsychiatric symptoms increased with level of cognitive impairment but was largely similar between stroke subtypes. Stroke severity and MTLA were associated with neuropsychiatric symptoms. AD pathology appeared to be unrelated to neuropsychiatric manifestations but further studies with larger sample size are required to substantiate this finding.


Assuntos
Amiloide/metabolismo , Vasos Sanguíneos/patologia , Isquemia Encefálica/fisiopatologia , Encéfalo/patologia , Cognição , Acidente Vascular Cerebral/fisiopatologia , Encéfalo/irrigação sanguínea , Isquemia Encefálica/psicologia , Estudos Transversais , Humanos , Acidente Vascular Cerebral/classificação , Acidente Vascular Cerebral/psicologia
9.
Alzheimers Dement ; 12(11): 1167-1176, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27327542

RESUMO

INTRODUCTION: Patients surviving stroke without immediate dementia are at high risk of delayed-onset dementia. Mechanisms underlying delayed-onset dementia are complex and may involve vascular and/or neurodegenerative diseases. METHODS: Dementia-free patients with stroke and/or transient ischemic attack (TIA; n = 919) were studied for 3 years prospectively, excluding those who developed dementia 3 to 6 months after stroke and/or TIA. RESULTS: Forty subjects (4.4%) developed dementia during the study period. Imaging markers of severe small vessel disease (SVD), namely presence of ≥3 lacunes and confluent white matter changes; history of hypertension and diabetes mellitus independently predicted delayed-onset dementia after adjustment for age, gender, and education. Only 6 of 31 (19.4%) subjects with delayed cognitive decline harbored Alzheimer's disease-like Pittsburg compound B (PiB) retention. Most PiB cases (16/25, 64%) had evidence of severe SVD. DISCUSSION: Severe SVD contributes importantly to delayed-onset dementia after stroke and/or TIA. Future clinical trials aiming to prevent delayed-onset dementia after stroke and/or TIA should target this high-risk group.


Assuntos
Demência/etiologia , Ataque Isquêmico Transitório/complicações , Acidente Vascular Cerebral/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Apolipoproteínas E/genética , Encéfalo/diagnóstico por imagem , Demência/diagnóstico por imagem , Feminino , Fluordesoxiglucose F18 , Seguimentos , Humanos , Ataque Isquêmico Transitório/diagnóstico por imagem , Ataque Isquêmico Transitório/psicologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fenantrolinas , Tomografia por Emissão de Pósitrons , Estudos Prospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/psicologia , Fatores de Tempo , Tomografia Computadorizada por Raios X , Adulto Jovem
10.
Cerebrovasc Dis ; 42(3-4): 232-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27173386

RESUMO

BACKGROUND: Intracranial arterial stenosis (ICAS) is a predominant cause of ischemic stroke in Asia. Changes in the signal intensities (SIs) across ICAS lesions on time-of-flight magnetic resonance angiography (TOF-MRA) have been indicated to partially reflect the hemodynamic significance of the lesions, which we aimed to verify by correlating it with cerebral perfusion features provided by CT perfusion (CTP) imaging. METHODS: Ischemic stroke or transient ischemic attack patients with unilateral symptomatic stenosis (≥50%) of intracranial internal carotid artery or middle cerebral artery (MCA) were included in this study. Change of SIs across an ICAS lesion on TOF-MRA was calculated by the distal and proximal SI ratio (SIR). Cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) within the MCA territory of ipsilateral and contralateral hemispheres were evaluated on the CTP images at the basal ganglia level. Relative CBV, CBF and MTT were defined as ratios of the values obtained from ipsilateral and contralateral hemispheres. The relationships between SIR and CTP parameters were analyzed. RESULTS: Fifty subjects (74% male, mean age 62) were recruited. Overall, the mean SIR was 0.77 ± 0.17. SIR of ICAS was significantly, linearly and negatively correlated with ipsilateral CBV (r = -0.335, p = 0.017), ipsilateral MTT (r = -0.301, p = 0.034), and ipsilateral/contralateral MTT ratio (r = -0.443, p = 0.001). CONCLUSIONS: Diminished SIs distal to ICAS on TOF-MRA might be associated with delayed ipsilateral cerebral perfusion. Changes of the SIs across ICAS lesions on TOF-MRA may be a simple marker to reflect cerebral perfusion changes in patients with symptomatic ICAS.


Assuntos
Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Angiografia Cerebral/métodos , Circulação Cerebrovascular , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Ataque Isquêmico Transitório/diagnóstico por imagem , Angiografia por Ressonância Magnética , Artéria Cerebral Média/diagnóstico por imagem , Imagem de Perfusão/métodos , Artéria Carótida Interna/fisiopatologia , Estenose das Carótidas/fisiopatologia , Constrição Patológica , Feminino , Humanos , Infarto da Artéria Cerebral Média/fisiopatologia , Ataque Isquêmico Transitório/fisiopatologia , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/fisiopatologia , Valor Preditivo dos Testes , Estudos Prospectivos , Estudos Retrospectivos
11.
Ann Neurol ; 77(3): 478-86, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25557926

RESUMO

OBJECTIVE: Understanding how symptomatic intracranial atherosclerotic disease (ICAD) evolves with current medical therapy may inform secondary stroke prevention. METHODS: In a prospective academic-initiated study, we recruited 50 patients (mean age = 63.4 ± 9.0 years) with acute strokes attributed to high-grade (≥70%) intracranial atherosclerotic stenosis for 3-dimensional rotational angiograms before and after intensive medical therapy for 12 months. Treatment targets included low-density lipoprotein ≤ 70mg/dl, glycosylated hemoglobin (HbA1c) ≤ 6.5%, and systolic blood pressure ≤ 140 mmHg. We analyzed infarct topography and monitored microembolic signal in recurrent strokes. The reference group was a published cohort of 143 ICAD patients. RESULTS: Overall, the stenoses regressed from 79% at baseline (interquartile range [IQR] = 71-87%) to 63% (IQR = 54-74%) in 1 year (p < 0.001). Specifically, the qualifying lesions (n = 49) regressed (stenosis reduced >10%) in 24 patients (49%), remained quiescent (stenosis same or ±10%) in 21 patients (43%), and progressed (stenosis increased >10%) in 4 patients (8%). There was no difference in intensity of risk factor control between groups of diverging clinical or angiographic outcomes. Higher HbA1c at baseline predicted plaque regression at 1 year (odds ratio = 4.4, 95% confidence interval = 1.4-14.5, p = 0.006). Among the 6 patients with recurrent strokes pertaining to the qualifying stenosis, 5 patients had solitary or rosarylike acute infarcts along the internal or anterior border zones, and 2 patients showed microembolic signals in transcranial Doppler ultrasound. INTERPRETATION: A majority of symptomatic high-grade intracranial plaques had regressed or remained quiescent by 12 months under intensive medical therapy. Artery-to-artery thromboembolism with impaired washout at border zones was a common mechanism in stroke recurrence.


Assuntos
Constrição Patológica/tratamento farmacológico , Arteriosclerose Intracraniana/tratamento farmacológico , Placa Aterosclerótica/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológico , Resultado do Tratamento , Idoso , Angiografia Cerebral , Constrição Patológica/complicações , Constrição Patológica/diagnóstico , Feminino , Humanos , Imagem Tridimensional , Arteriosclerose Intracraniana/complicações , Arteriosclerose Intracraniana/diagnóstico , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/diagnóstico , Recidiva , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/etiologia
13.
PLoS One ; 9(5): e97531, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24818753

RESUMO

BACKGROUND: Patients with symptomatic intracranial atherosclerosis (ICAS) of ≥ 70% luminal stenosis are at high risk of stroke recurrence. We aimed to evaluate the relationships between hemodynamics of ICAS revealed by computational fluid dynamics (CFD) models and risk of stroke recurrence in this patient subset. METHODS: Patients with a symptomatic ICAS lesion of 70-99% luminal stenosis were screened and enrolled in this study. CFD models were reconstructed based on baseline computed tomographic angiography (CTA) source images, to reveal hemodynamics of the qualifying symptomatic ICAS lesions. Change of pressures across a lesion was represented by the ratio of post- and pre-stenotic pressures. Change of shear strain rates (SSR) across a lesion was represented by the ratio of SSRs at the stenotic throat and proximal normal vessel segment, similar for the change of flow velocities. Patients were followed up for 1 year. RESULTS: Overall, 32 patients (median age 65; 59.4% males) were recruited. The median pressure, SSR and velocity ratios for the ICAS lesions were 0.40 (-2.46-0.79), 4.5 (2.2-20.6), and 7.4 (5.2-12.5), respectively. SSR ratio (hazard ratio [HR] 1.027; 95% confidence interval [CI], 1.004-1.051; P = 0.023) and velocity ratio (HR 1.029; 95% CI, 1.002-1.056; P = 0.035) were significantly related to recurrent territorial ischemic stroke within 1 year by univariate Cox regression, respectively with the c-statistics of 0.776 (95% CI, 0.594-0.903; P = 0.014) and 0.776 (95% CI, 0.594-0.903; P = 0.002) in receiver operating characteristic analysis. CONCLUSIONS: Hemodynamics of ICAS on CFD models reconstructed from routinely obtained CTA images may predict subsequent stroke recurrence in patients with a symptomatic ICAS lesion of 70-99% luminal stenosis.


Assuntos
Simulação por Computador , Hidrodinâmica , Arteriosclerose Intracraniana/complicações , Arteriosclerose Intracraniana/fisiopatologia , Acidente Vascular Cerebral/complicações , Idoso , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Recidiva , Estudos Retrospectivos , Medição de Risco
14.
Stroke ; 45(5): 1402-7, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24699055

RESUMO

BACKGROUND AND PURPOSE: We aimed to evaluate the procedural safety, clinical, and angiographic outcome of carotid angioplasty and stenting for high-grade (≥70%) radiation-induced carotid stenosis (RIS) using atherosclerotic stenosis (AS) as a control. METHODS: In this 6-year prospective nonrandomized study, we compared the carotid angioplasty and stenting outcome of 65 consecutive patients (84 vessels) with RIS with that of a control group of 129 consecutive patients (150 vessels) with AS. Study end points were 30-day periprocedural stroke or death, ipsilateral ischemic stroke, technical success, procedural characteristics, instent restenosis (ISR; ≥50%) and symptomatic ISR. RESULTS: The median follow-up was 47.3 months (95% confidence interval, 26.9-61.6). Imaging assessment was available in 74 vessels (RIS) and 120 vessels (AS) in 2 years. Comparing RIS group with AS group, the rates of periprocedural stroke or death were 1.5% (1/65) versus 1.6% (2/129; P=1); ipsilateral ischemic stroke rates were 4.6% (3/65) versus 4.7% (6/129; P=1); the annual risks of ipsilateral ischemic stroke were 1.2% (3 patient/254.7 patient year) versus 1.2% (6 patient/494.2 patient year; P=0.89); technical success rates were both 100%. Stenting of common carotid artery and the use of multiple stents was more common in the RIS group (P=0 in both cases); ISR rates were 25.7% (19/74) versus 4.2% (5/120; P<0.001); symptomatic ISR rates were 6.8% (5/74) versus 0.8% (1/120; P=0.031). CONCLUSIONS: The safety, effectiveness, and technical difficulty of carotid angioplasty and stenting for RIS are comparable with that for AS although it is associated with a higher rate of ISR. CLINICAL TRIAL REGISTRATION: This trial was not registered as enrollment started in 2006.


Assuntos
Angioplastia/métodos , Doenças das Artérias Carótidas/terapia , Estenose das Carótidas/terapia , Lesões por Radiação/etiologia , Lesões por Radiação/terapia , Stents , Idoso , Angioplastia/efeitos adversos , Angioplastia/instrumentação , Isquemia Encefálica/epidemiologia , Isquemia Encefálica/etiologia , Isquemia Encefálica/mortalidade , Doenças das Artérias Carótidas/complicações , Doenças das Artérias Carótidas/mortalidade , Estenose das Carótidas/etiologia , Estenose das Carótidas/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Lesões por Radiação/mortalidade , Índice de Gravidade de Doença , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/mortalidade , Fatores de Tempo , Resultado do Tratamento
15.
Stroke ; 45(3): 663-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24481975

RESUMO

BACKGROUND AND PURPOSE: We aimed to establish the prevalence, characteristics, and outcomes of intracranial atherosclerosis (ICAS) in China by a large, prospective, multicenter study. METHODS: We evaluated 2864 consecutive patients who experienced an acute cerebral ischemia<7 days after symptom onset in 22 Chinese hospitals. All patients underwent magnetic resonance angiography, with measurement of diameter of the main intracranial arteries. ICAS was defined as ≥50% diameter reduction on magnetic resonance angiography. RESULTS: The prevalence of ICAS was 46.6% (1335 patients, including 261 patients with coexisting extracranial carotid stenosis). Patients with ICAS had more severe stroke at admission and stayed longer in hospitals compared with those without intracranial stenosis (median National Institutes of Health Stroke Scale score, 3 versus 5; median length of stay, 14 versus 16 days; both P<0.0001). After 12 months, recurrent stroke occurred in 3.27% of patients with no stenosis, in 3.82% for those with 50% to 69% stenosis, in 5.16% for those with 70% to 99% stenosis, and in 7.27% for those with total occlusion. Cox proportional hazards regression analyses showed that the degree of arterial stenosis, age, family history of stroke, history of cerebral ischemia or heart disease, complete circle of Willis, and National Institutes of Health Stroke Scale score at admission were independent predictors for recurrent stroke at 1 year. The highest rate of recurrence was observed in patients with occlusion with the presence of ≥3 additional risk factors. CONCLUSIONS: ICAS is the most common vascular lesion in patients with cerebrovascular disease in China. Recurrent stroke rate in our study was lower compared with those of previous clinical trials but remains unacceptably high in a subgroup of patients with severe stenosis.


Assuntos
Arteriopatias Oclusivas/epidemiologia , Arteriopatias Oclusivas/terapia , Transtornos Cerebrovasculares/epidemiologia , Transtornos Cerebrovasculares/terapia , Arteriosclerose Intracraniana/epidemiologia , Arteriosclerose Intracraniana/terapia , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Angiografia Cerebral , China/epidemiologia , Constrição Patológica , Determinação de Ponto Final , Feminino , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Recidiva , Risco , Fatores de Risco
16.
Mediators Inflamm ; 2013: 850714, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24023414

RESUMO

BACKGROUND AND PURPOSE: Inflammation exists in inception, progression, and reperfusion of acute ischemic stroke. Insightful understanding of correlation in inflammatory mediators and stroke severity with intracranial artery stenosis may improve rational stroke therapy. METHODS: We prospectively recruited 977 patients with acute noncardioembolic ischemic stroke with MCA stenosis by MRA as none to mild (<50%), moderate (50-69%), severe (70-99%), or occlusive (100%). The peripheral levels of WBC, homocysteine (HCY), and high sensitivity C-reactive protein (hs-CRP) were recorded. All patients were assessed of 1-year outcome by mRS as favorable (0-2) or poor (3-6). RESULTS: The levels of WBC, HCY, and hs-CRP had no significant differences in patients with categorized MCA stenosis (all P > 0.05). Higher levels of WBC, HCY, and hs-CRP were found in patients with 1-year poor outcome (all P < 0.05), but only hs-CRP is an independent predictor (OR 1.06, 95% CI 1.027-1.093, P = 0.0003). The combination of any two of increased hs-CRP (>3 mg/L), WBC (>6.91 × 10(9)/L), and HCY (>15 µ mol/L) had higher power in predicting 1-year poor outcome than the single elevated mediator. CONCLUSIONS: Elevated hs-CRP independently predicts 1-year poor outcome in acute stroke. The combination of increased hs-CRP, WBC, or HCY had a stronger predictive value in poor outcome than individual elevated mediator.


Assuntos
Isquemia Encefálica/patologia , Constrição Patológica/patologia , Inflamação/sangue , Artéria Cerebral Média/patologia , Acidente Vascular Cerebral/patologia , Idoso , Proteína C-Reativa/metabolismo , Constrição Patológica/diagnóstico , Feminino , Seguimentos , Humanos , Angiografia por Ressonância Magnética , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/diagnóstico , Resultado do Tratamento
17.
Stroke ; 44(2): 401-6, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23306321

RESUMO

BACKGROUND AND PURPOSE: Occlusive radiation vasculopathy (ORV) predisposes head-and-neck cancer survivors to ischemic strokes. METHODS: We analyzed the digital subtraction angiography acquired in 96 patients who had first-ever transient ischemic attack or ischemic strokes attributed to ORV. Another age-matched 115 patients who had no radiotherapy but symptomatic high-grade (>70%) carotid stenoses were enrolled as referent subjects. Digital subtraction angiography was performed within 2 months from stroke onset and delineated carotid and vertebrobasilar circulations from aortic arch up to intracranial branches. Two reviewers blinded to group assignment recorded all vascular lesions, collateral status, and infarct pattern. RESULTS: ORV patients had less atherosclerotic risk factors at presentation. In referent patients, high-grade stenoses were mostly focal at the proximal internal carotid artery. In contrast, high-grade ORV lesions diffusely involved the common carotid artery and internal carotid artery and were more frequently bilateral (54% versus 22%), tandem (23% versus 10%), associated with complete occlusion in one or both carotid arteries (30% versus 9%), vertebral artery (VA) steno-occlusions (28% versus 16%), and external carotid artery stenosis (19% versus 5%) (all P<0.05). With comparable rates of vascular anomaly, ORV patients showed more established collateral circulations through leptomeningeal arteries, anterior communicating artery, posterior communicating artery, suboccipital/costocervical artery, and retrograde flow in ophthalmic artery. In terms of infarct topography, the frequencies of cortical or subcortical watershed infarcts were similar in both groups. CONCLUSIONS: ORV angiographic features and corresponding collaterals are distinct from atherosclerotic patterns at initial stroke presentation. Clinical decompensation, despite more extensive collateralization, may precipitate stroke in ORV.


Assuntos
Angiografia Digital , Infarto Encefálico/diagnóstico , Circulação Colateral/efeitos da radiação , Ataque Isquêmico Transitório/diagnóstico por imagem , Lesões por Radiação/diagnóstico por imagem , Acidente Vascular Cerebral/diagnóstico por imagem , Idoso , Angiografia Digital/métodos , Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/epidemiologia , Estudos de Casos e Controles , Circulação Cerebrovascular/efeitos da radiação , Feminino , Neoplasias de Cabeça e Pescoço/epidemiologia , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Ataque Isquêmico Transitório/epidemiologia , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , Acidente Vascular Cerebral/epidemiologia
18.
Int J Stroke ; 8(8): 645-51, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22759410

RESUMO

BACKGROUND AND PURPOSE: Studies mostly use the analysis of heart rate variability to measure cardiovascular autonomic regulation in ischemic stroke. Besides power spectral analysis of heart rate variability, this study sought to determine whether autonomic function was impaired during different phases in ischemic stroke by Ewing's battery of autonomic function tests. METHODS: Ninety-four patients with ischemic stroke (34 patients in acute phase and 60 patients in chronic phase, average six-months after stroke onset) and thirty-seven elderly controls were recruited. Ewing's battery autonomic function tests and power spectral analysis of heart rate variability were performed in all the subjects. RESULTS: From power spectral analysis of heart rate variability, stroke patients of both acute and chronic phases had significantly lower low frequency power spectral density than controls. From Ewing's battery of autonomic function tests, patients in acute phase showed impairment in two parasympathetic tests (Valsalva ratio: P = 0·002; heart rate response to deep breathing: P < 0·001) and those in chronic phase showed impairment in all parasympathetic tests (all P < 0·05) in comparison with controls. CONCLUSIONS: The comprehensive assessment indicates that autonomic dysfunction occurs in acute phase of ischemic stroke and may persist up to six-months after stroke. Parasympathetic dysfunction rather than sympathetic dysfunction is predominant after ischemic stroke.


Assuntos
Doenças do Sistema Nervoso Autônomo/etiologia , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Idoso , Feminino , Humanos , Masculino
19.
Hong Kong Med J ; 18(2): 92-8, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22477731

RESUMO

OBJECTIVE: To investigate the safety and efficacy of stroke thrombolysis in a local hospital. DESIGN: Historical cohort study. SETTING: A tertiary hospital in Hong Kong. PATIENTS: The outcome of acute ischaemic stroke patients treated with intravenous tissue plasminogen activator between October 2008 and May 2011 was compared to those admitted during the same period who were thrombolysis-eligible, but treated conservatively due to unavailability of the thrombolysis service after-hours. INTERVENTIONS: Intravenous tissue plasminogen activator. MAIN OUTCOME MEASURES: Primary outcome was functional independence (modified Rankin Scale score of 2 or below) at 3 months. Safety outcomes were symptomatic intracranial haemorrhage and 3-month mortality. Secondary outcomes were hospital length of stay, direct home discharge, and nursing home discharge. RESULTS: A total of 48 thrombolysis and 63 non-thrombolysis patients were identified. Fifty-two percent of the thrombolysis group achieved functional independence compared to 24% of non-thrombolysis group (P=0.003), without significant increase in mortality (15% vs 13%, P=0.51) or symptomatic intracranial haemorrhage (4% vs 2%, P=0.58). Twenty-nine percent of the thrombolysis group patients were discharged home directly, versus 6% of non-thrombolysis group (P<0.001). Mean length of stay was shorter for the thrombolysis group (25 vs 35 days; P=0.034). A similar percentage from each group was discharged to nursing homes. CONCLUSION: Implementation of the stroke thrombolysis service in Hong Kong appeared safe and efficacious. Patients who received thrombolysis had better outcomes compared to non-thrombolysis cohort. Further studies are needed to investigate the economics of stroke thrombolysis in Hong Kong, which may help to improve funding for provision of this service.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/mortalidade , Estudos de Coortes , Feminino , Hong Kong , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/mortalidade , Terapia Trombolítica/efeitos adversos
20.
Stroke ; 43(6): 1532-6, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22535273

RESUMO

BACKGROUND AND PURPOSE: Cerebral microbleeds (CMBs) on MRI gradient echo images are hemosiderin deposits, which may predict intracerebral hemorrhage (ICH). The risk of ICH in patients with CMBs could be exacerbated by the use of antithrombotics. The purpose of our study is to prospectively evaluate the risk of ICH in patients with ischemic stroke who receive dual antiplatelet therapy for endovascular intervention. METHODS: We analyzed MRI of 133 patients admitted consecutively for intra- and extracranial stenting for symptomatic large artery atherosclerosis who received aspirin and clopidogrel. Quantity and location of CMBs were recorded by neuroradiologists independent from the angioplasty team. The primary end point was symptomatic ICH as evident in CT of the brain within 12 weeks of procedure. RESULTS: CMBs were identified in 23 patients. Mean number of CMBs was 2.3 ± 1.6. Four patients had >5 CMBs. Forty-seven patients had intracranial stents, 84 patients had extracranial stents, and 2 patients had both intracranial and extracranial stents. There was no difference in risk of symptomatic ICH between those with (4.3%) and without CMBs (5.5%) patient with CMBs (P=1.000). CONCLUSIONS: The presence of a small number of CMBs does not cause a large increase in the short-term risk of symptomatic ICH in patients with ischemic stroke who undergo endovascular intervention with dual antiplatelet therapy. The risk of ICH in patients with ≥ 5 CMBs, however, remains unclear. Further studies with a larger sample size of patients with multiple CMBs are needed.


Assuntos
Aspirina/administração & dosagem , Isquemia Encefálica/terapia , Hemorragia Cerebral/etiologia , Procedimentos Endovasculares , Inibidores da Agregação de Plaquetas/administração & dosagem , Acidente Vascular Cerebral/terapia , Ticlopidina/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Aspirina/efeitos adversos , Aterosclerose/terapia , Isquemia Encefálica/complicações , Clopidogrel , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação de Plaquetas/efeitos adversos , Estudos Retrospectivos , Fatores de Risco , Acidente Vascular Cerebral/complicações , Ticlopidina/administração & dosagem , Ticlopidina/efeitos adversos
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