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1.
Stroke ; 53(4): 1074-1084, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35291822

RESUMO

High blood pressure (BP) is common after ischemic stroke and associated with a poor functional outcome and increased mortality. The conundrum then arises on whether to lower BP to improve outcome or whether this will worsen cerebral perfusion due to aberrant cerebral autoregulation. A number of large trials of BP lowering have failed to change outcome whether treatment was started prehospital in the community or hospital. Hence, nuances on how to manage high BP are likely, including whether different interventions are needed for different causes, the type and timing of the drug, how quickly BP is lowered, and the collateral effects of the drug, including on cerebral perfusion and platelets. Specific scenarios are also important, including when to lower BP before, during, and after intravenous thrombolysis and endovascular therapy/thrombectomy, when it may be necessary to raise BP, and when antihypertensive drugs taken before stroke should be restarted. This narrative review addresses these and other questions. Although further large trials are ongoing, it is increasingly likely that there is no simple answer. Different subgroups of patients may need to have their BP lowered (eg, before or after thrombolysis), left alone, or elevated.


Assuntos
Isquemia Encefálica , Hipertensão , AVC Isquêmico , Acidente Vascular Cerebral , Anti-Hipertensivos , Pressão Sanguínea/fisiologia , Isquemia Encefálica/tratamento farmacológico , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/etiologia , Resultado do Tratamento
2.
Neural Plast ; 2021: 8858394, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34426738

RESUMO

Transcranial direct current stimulation (tDCS) has the potential to improve upper limb motor outcomes after stroke. According to the assumption of interhemispheric inhibition, excessive inhibition from the motor cortex of the unaffected hemisphere to the motor cortex of the affected hemisphere may worsen upper limb motor recovery after stroke. We evaluated the effects of active cathodal tDCS of the primary motor cortex of the unaffected hemisphere (ctDCSM1UH) compared to sham, in subjects within 72 hours to 6 weeks post ischemic stroke. Cathodal tDCS was intended to inhibit the motor cortex of the unaffected hemisphere and hence decrease the inhibition from the unaffected to the affected hemisphere and enhance motor recovery. We hypothesized that motor recovery would be greater in the active than in the sham group. In addition, greater motor recovery in the active group might be associated with bigger improvements in measures in activity and participation in the active than in the sham group. We also explored, for the first time, changes in cognition and sleep after ctDCSM1UH. Thirty subjects were randomized to six sessions of either active or sham ctDCSM1UH as add-on interventions to rehabilitation. The NIH Stroke Scale (NIHSS), Fugl-Meyer Assessment of Motor Recovery after Stroke (FMA), Barthel Index (BI), Stroke Impact Scale (SIS), and Montreal Cognitive Assessment (MoCA) were assessed before, after treatment, and three months later. In the intent-to-treat (ITT) analysis, there were significant GROUP∗TIME interactions reflecting stronger gains in the sham group for scores in NIHSS, FMA, BI, MoCA, and four SIS domains. At three months post intervention, the sham group improved significantly compared to posttreatment in FMA, NIHSS, BI, and three SIS domains while no significant changes occurred in the active group. Also at three months, NIHSS improved significantly in the sham group and worsened significantly in the active group. FMA scores at baseline were higher in the active than in the sham group. After adjustment of analysis according to baseline scores, the between-group differences in FMA changes were no longer statistically significant. Finally, none of the between-group differences in changes in outcomes after treatment were considered clinically relevant. In conclusion, active CtDCSM1UH did not have beneficial effects, compared to sham. These results were consistent with other studies that applied comparable tDCS intensities/current densities or treated subjects with severe upper limb motor impairments during the first weeks post stroke. Dose-finding studies early after stroke are necessary before planning larger clinical trials.


Assuntos
Córtex Motor/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Reabilitação do Acidente Vascular Cerebral/métodos , Acidente Vascular Cerebral/fisiopatologia , Estimulação Transcraniana por Corrente Contínua , Extremidade Superior/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Resultado do Tratamento
3.
Neurocrit Care ; 34(2): 547-556, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32770342

RESUMO

BACKGROUND: Small and remote acute ischemic lesions may occur in up to one-third of patients with spontaneous intracerebral hemorrhage (ICH). Possible mechanisms include cerebral embolism, small vessel disease, blood pressure variability and others. The embolic mechanism has not been adequately studied. Using transcranial Doppler (TCD), we assessed the incidence of spontaneous microembolic signals (MESs) in patients with acute ICH. METHODS: Twenty acute ICH patients were prospectively evaluated within 48 h of hospital admission. Clinical and imaging data were collected. Continuous TCD monitoring was performed in both middle cerebral arteries for a one-hour period on days 1, 3 and 7 of hospital admission. Monitoring was performed in the emergency room, ICU or ward, according to patient location. We compared the frequency and risk factors for MES in patients with ICH and in 20 age- and gender-matched controls without history of ischemic or hemorrhagic stroke. RESULTS: The mean age was 57.5 ± 14.1 years, and 60% were male. MESs were detected in 7 patients with ICH and in one control patient without ICH (35% vs 5%, p = 0.048). The frequency of MES on day 1 was 15% (3 of 20 patients), on day 3, 26% (5 of 19 patients) and on day 7, 37.5% (3 of 8 patients). Among patients with ICH, those with MES had a tendency to higher frequencies of dyslipidemia (83% vs 33%, p = 0.13) and lobar location of hemorrhages (71% vs 30%, p = 0.15). Two out of 6 patients with ICH who also underwent MRI had remote DWI lesions, of whom one showed MES on TCD. CONCLUSION: Micro-embolic signals occur in over one-third of patients with ICH. Further research is needed to identify the sources of cerebral microembolism and their relationship with small acute infarcts in ICH.


Assuntos
Hemorragia Cerebral , Embolia Intracraniana , Estudos de Casos e Controles , Hemorragia Cerebral/complicações , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/epidemiologia , Humanos , Embolia Intracraniana/diagnóstico por imagem , Embolia Intracraniana/epidemiologia , Embolia Intracraniana/etiologia , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana
4.
N Engl J Med ; 382(24): 2316-2326, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32521133

RESUMO

BACKGROUND: Randomized trials involving patients with stroke have established that outcomes are improved with the use of thrombectomy for large-vessel occlusion. These trials were performed in high-resource countries and have had limited effects on medical practice in low- and middle-income countries. METHODS: We studied the safety and efficacy of thrombectomy in the public health system of Brazil. In 12 public hospitals, patients with a proximal intracranial occlusion in the anterior circulation that could be treated within 8 hours after the onset of stroke symptoms were randomly assigned in a 1:1 ratio to receive standard care plus mechanical thrombectomy (thrombectomy group) or standard care alone (control group). The primary outcome was the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. RESULTS: A total of 300 patients were enrolled, including 79 who had undergone thrombectomy during an open-label roll-in period. Approximately 70% in the two groups received intravenous alteplase. The trial was stopped early because of efficacy when 221 of a planned 690 patients had undergone randomization (111 to the thrombectomy group and 110 to the control group). The common odds ratio for a better distribution of scores on the modified Rankin scale at 90 days was 2.28 (95% confidence interval [CI], 1.41 to 3.69; P = 0.001), favoring thrombectomy. The percentage of patients with a score on the modified Rankin scale of 0 to 2, signifying an absence of or minor neurologic deficit, was 35.1% in the thrombectomy group and 20.0% in the control group (difference, 15.1 percentage points; 95% CI, 2.6 to 27.6). Asymptomatic intracranial hemorrhage occurred in 51.4% of the patients in the thrombectomy group and 24.5% of those in the control group; symptomatic intracranial hemorrhage occurred in 4.5% of the patients in each group. CONCLUSIONS: In this randomized trial conducted in the public health care system of Brazil, endovascular treatment within 8 hours after the onset of stroke symptoms in conjunction with standard care resulted in better functional outcomes at 90 days than standard care alone. (Funded by the Brazilian Ministry of Health; RESILIENT ClinicalTrials.gov number, NCT02216643.).


Assuntos
Acidente Vascular Cerebral/cirurgia , Trombectomia , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Terapia Combinada , Procedimentos Endovasculares , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Hemorragias Intracranianas/etiologia , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Método Simples-Cego , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/mortalidade , Trombectomia/efeitos adversos , Trombectomia/métodos , Tempo para o Tratamento , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do Tratamento , Adulto Jovem
6.
Continuum (Minneap Minn) ; 26(2): 310-331, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32224754

RESUMO

PURPOSE OF REVIEW: This article reviews the actual indications for mechanical thrombectomy in patients with acute ischemic stroke and how the opportunities for endovascular therapy can be expanded by using the concept of clinical-imaging or perfusion-imaging mismatch (as a surrogate for salvageable tissue) rather than time of ischemia. RECENT FINDINGS: Six randomized controlled trials undoubtedly confirmed the benefits of using endovascular thrombectomy on the clinical outcome of patients with stroke with large vessel occlusion within 6 hours from symptom onset compared with those receiving only standard medical care. In a meta-analysis of individual patient data, the number needed to treat with endovascular thrombectomy to reduce disability by at least one level on the modified Rankin Scale for one patient was 2.6. Recently, the concept of "tissue window" versus time window has proved useful for selecting patients for mechanical thrombectomy up to 24 hours from symptom onset. The DAWN (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention) trial included patients at a median of 12.5 hours from onset and showed the largest effect in functional outcome ever described in any acute stroke treatment trial (35.5% increase in functional independence). In DEFUSE 3 (Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution 3), patients treated with mechanical thrombectomy at a median of 11 hours after onset had a 28% increase in functional independence and an additional 20% absolute reduction in death or severe disability. SUMMARY: For patients with acute ischemic stroke and a large vessel occlusion in the proximal anterior circulation who can be treated within 6 hours of stroke symptom onset, mechanical thrombectomy with a second-generation stent retriever or a catheter aspiration device should be indicated regardless of whether the patient received treatment with intravenous (IV) recombinant tissue plasminogen activator (rtPA) in patients with limited signs of early ischemic changes on neuroimaging. Two clinical trials completely disrupted the time window concept in acute ischemic stroke, showing excellent clinical outcomes in patients treated up to 24 hours from symptom onset. Time of ischemia is, on average, a good biomarker for tissue viability; however, the window of opportunity for treatment varies across different individuals because of a range of compensatory mechanisms. Adjusting time to the adequacy of collateral flow leads to the concept of tissue window, a paradigm shift in stroke reperfusion therapy.


Assuntos
Procedimentos Endovasculares/normas , Fibrinolíticos/administração & dosagem , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/terapia , Avaliação de Processos e Resultados em Cuidados de Saúde , Ensaios Clínicos Controlados Aleatórios como Assunto , Trombectomia/normas , Humanos
7.
J Stroke Cerebrovasc Dis ; 28(6): 1500-1508, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30935810

RESUMO

OBJECTIVE: The role of heparin in acute ischemic stroke is controversial. We investigated the effect of heparin on ischemic lesion growth. METHODS: Data were analyzed on nonthrombolyzed ischemic stroke patients in whom diffusion-weighted imaging (DWI)/perfusion-weighted imaging (PWI) MRI was performed less than 12 hours of last known well and showed a PWI-DWI lesion mismatch, and who underwent follow-up neuroimaging at least 4 days after admission. Lesion growth was assessed by (1) absolute lesion growth and (2) percentage mismatch lost (PML). Univariate and multivariate regression analysis, and propensity score matching, were used to determine the effects of heparin on ischemic lesion growth. RESULTS: Of the 113 patients meeting study criteria, 59 received heparin within 24 hours. Heparin use was associated with ∼5-fold reductions in PML (3.5% versus 19.2%, P = .002) and absolute lesion growth (4.7 versus 20.5 mL, P = .009). In multivariate regression models, heparin independently predicted reduced PML (P = .04) and absolute lesion growth (P = .04) in the entire cohort, and in multiple subgroups (patients with and without proximal artery occlusion; DWI volume greater than 5 mL; cardio-embolic mechanism; DEFUSE-3 target mismatch). In propensity score matching analysis where patients were matched by admission NIHSS, DWI volume and proximal artery occlusion, heparin remained an independent predictor of PML (P = .048) and tended to predict absolute lesion growth (P = .06). Heparin treatment did not predict functional outcome at discharge or 90 days. CONCLUSION: Early heparin treatment in acute ischemic stroke patients with PWI-DWI mismatch attenuates ischemic lesion growth. Clinical trials with careful patient selection are warranted to investigate the potential ischemic protective effects of heparin.


Assuntos
Anticoagulantes/administração & dosagem , Isquemia Encefálica/tratamento farmacológico , Heparina/administração & dosagem , Fármacos Neuroprotetores/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Esquema de Medicação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento
8.
Neurology ; 92(7): e639-e647, 2019 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-30635475

RESUMO

OBJECTIVE: To develop a method to distinguish reversible cerebral vasoconstriction syndrome (RCVS) from other large/medium-vessel intracranial arteriopathies. METHODS: We identified consecutive patients from our institutional databases admitted in 2013-2017 with newly diagnosed RCVS (n = 30) or non-RCVS arteriopathy (n = 80). Admission clinical and imaging features were compared. Multivariate logistic regression modeling was used to develop a discriminatory score. Score validity was tested in a separate cohort of patients with RCVS and its closest mimic, primary angiitis of the CNS (PACNS). In addition, key variables were used to develop a bedside approach to distinguish RCVS from non-RCVS arteriopathies. RESULTS: The RCVS group had significantly more women, vasoconstrictive triggers, thunderclap headaches, normal brain imaging results, and better outcomes. Beta coefficients from the multivariate regression model yielding the best c-statistic (0.989) were used to develop the RCVS2 score (range -2 to +10; recurrent/single thunderclap headache; carotid artery involvement; vasoconstrictive trigger; sex; subarachnoid hemorrhage). Score ≥5 had 99% specificity and 90% sensitivity for diagnosing RCVS, and score ≤2 had 100% specificity and 85% sensitivity for excluding RCVS. Scores 3-4 had 86% specificity and 10% sensitivity for diagnosing RCVS. The score showed similar performance to distinguish RCVS from PACNS in the validation cohort. A clinical approach based on recurrent thunderclap headaches, trigger and normal brain scans, or convexity subarachnoid hemorrhage correctly diagnosed 25 of 37 patients with RCVS2 scores 3-4 across the derivation and validation cohorts. CONCLUSION: RCVS can be accurately distinguished from other intracranial arteriopathies upon admission, using widely available clinical and imaging features. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that the RCVS2 score accurately distinguishes patients with RCVS from those with other intracranial arteriopathies.


Assuntos
Doenças Arteriais Intracranianas/diagnóstico , Arteriosclerose Intracraniana/diagnóstico , Doença de Moyamoya/diagnóstico , Transtornos Puerperais/diagnóstico , Vasculite do Sistema Nervoso Central/diagnóstico , Adulto , Angiografia Cerebral , Transtornos Cerebrovasculares/diagnóstico , Angiografia por Tomografia Computadorizada , Diagnóstico Diferencial , Feminino , Transtornos da Cefaleia Primários/etiologia , Humanos , Doenças Arteriais Intracranianas/complicações , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores Sexuais , Hemorragia Subaracnóidea/diagnóstico , Vasoconstrição
10.
Lancet ; 392(10154): 1269-1278, 2018 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-30319114

RESUMO

Along with the rising global burden of disability attributed to stroke, costs of stroke care are rising, providing the impetus to direct our research focus towards effective measures of stroke prevention. In this Series paper, we discuss strategies for reducing the risk of the emergence of disease (primordial prevention), preventing the onset of disease (primary prevention), and preventing the recurrence of disease (secondary prevention). Our focus includes global strategies and campaigns, and measurements of the effectiveness of worldwide preventive interventions, with an emphasis on low-income and middle-income countries. Our findings reveal that effective tobacco control, adequate nutrition, and development of healthy cities are important strategies for primordial prevention, whereas polypill strategies, use of mobile technology (mHealth), along with salt reduction and other dietary interventions, are effective in the primary prevention of stroke. An effective collaboration between various health-care sectors, government policies, and campaigns can successfully implement secondary prevention strategies, through surveillance and registries, such as the WHO's non-communicable diseases programmes, across high-income and low-income countries.


Assuntos
Carga Global da Doença , Acidente Vascular Cerebral/prevenção & controle , Países em Desenvolvimento , Promoção da Saúde , Humanos , Prevenção Primária , Medição de Risco , Fatores de Risco , Prevenção Secundária , Acidente Vascular Cerebral/epidemiologia , Organização Mundial da Saúde
11.
J Stroke Cerebrovasc Dis ; 27(10): 2712-2719, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30033098

RESUMO

OBJECTIVE: To characterize isolated upper extremity (UE) weakness from stroke. METHODS: In our Get with the Guidelines-Stroke dataset (n = 7643), 87 patients (1.14%) had isolated UE weakness and underwent thorough stroke evaluation with diffusion-weighted magnetic resonance imaging and good-quality arterial imaging. We analyzed clinical-imaging features, etiology, management, and outcome. Since isolated UE weakness is typically associated with contralateral hand-knob area infarcts, patients were classified into Group-A (motor strip infarct) or Group-B (non-motor strip infarct). RESULTS: The mean age was 68 years; 66% were male, 72% had hypertension, 22% diabetes, 53% hyperlipidemia, and 16% were smokers. In Group-A (n = 71), 18 patients had single and 53 had multiple infarcts involving the contralateral motor strip. In Group-B (n = 16), 6 patients had contralateral subcortical white matter infarcts, 9 had bihemispheric infarcts and 1 had a brainstem infarct. Compared to Group-B, patients in Group-A more often had carotid artery stenosis or irregular plaque (84.5% versus 50%, P = .006) and large-artery atherosclerosis mechanism (46% versus 19%, P = .05), and less often cardioembolic mechanism (13% versus 44%, P = .008). Among 36 patients with large-artery mechanism, 27 had less than 70% stenosis including 19 with plaque ulceration/thrombus. Recurrent strokes occurred in 10 patients (11.5%), including 5 with mild-moderate carotid stenosis and plaque ulceration/thrombosis, over 1515 days follow-up. CONCLUSION: Stroke mechanism in acute isolated UE weakness is variable. Contralateral motor-strip infarcts are associated with carotid stenosis, often with plaque ulceration ("vulnerable carotid plaque"), and infarcts in other locations with cardioembolism. Recurrent stroke risk is high especially with mild-moderate carotid artery stenosis and plaque ulceration/thrombus.


Assuntos
Isquemia Encefálica/etiologia , Córtex Motor/fisiopatologia , Força Muscular , Debilidade Muscular/etiologia , Músculo Esquelético/inervação , Acidente Vascular Cerebral/etiologia , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/terapia , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada , Imagem de Difusão por Ressonância Magnética , Avaliação da Deficiência , Embolia/complicações , Embolia/diagnóstico por imagem , Feminino , Cardiopatias/complicações , Cardiopatias/diagnóstico por imagem , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Atividade Motora , Córtex Motor/diagnóstico por imagem , Debilidade Muscular/diagnóstico , Debilidade Muscular/fisiopatologia , Placa Aterosclerótica , Prognóstico , Recuperação de Função Fisiológica , Estudos Retrospectivos , Fatores de Risco , Ruptura Espontânea , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/terapia , Extremidade Superior
12.
J Neurointerv Surg ; 10(4): 325-329, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28768820

RESUMO

INTRODUCTION: It remains unclear whether patients presenting with large vessel occlusion strokes and mild symptoms benefit from thrombectomy. OBJECTIVE: To compare outcomes of endovascular therapy versus medical management in patients with large vessel occlusion strokes and National Institute of Health Stroke Scale (NIHSS) score ≤5. METHODS: This was a retrospective analysis combining two large prospectively collected datasets including patients with (1) admission NIHSS score ≤5, (2) premorbid modified Rankin Scale (mRS) score 0-2, and (3) middle cerebral-M1/M2, intracranial carotid, anterior cerebral or basilar artery occlusions. Groups receiving (1) endovascular treatment and (2) medical management were compared. The primary and secondary outcome measures were NIHSS shift (discharge NIHSS minus admission NIHSS) and the rates of mRS 0-2 at discharge and 3-6 months, respectively. Univariate, multivariate, and matched analyses were performed. RESULTS: Eighty-eight patients received medical management and 30 thrombectomy. Multivariable analysis indicated thrombectomy was the only predictor of favorable NIHSS shift (ß -3.7, 95% CI -6.0 to -1.5, p=0.02), as well as independence at discharge (ß -21.995% CI -41.4to -20.8, p<0.01) and 3-6-month follow-up (ß -21.1, 95% CI -39.1 to -19.7, p<0.01). A matched analysis (based on age, baseline NIHSS and intravenous tissue plasminogen activator use) produced 26 pairs. Endovascular therapy was statistically associated with lower NIHSS at discharge (p=0.04), favorable NIHSS shift (p=0.03), and increased independence rates at discharge (p=0.03) and 3-6-month follow-up (p=0.04). CONCLUSION: In patients presenting with minimal stroke symptoms (NIHSS score ≤5) and large vessel occlusion strokes, mechanical thrombectomy appears to be associated with a favorable shift of NIHSS at discharge, as well as higher rates of independence at discharge and long-term follow-up. Confirmatory prospective studies are warranted.


Assuntos
Arteriopatias Oclusivas/terapia , Gerenciamento Clínico , Acidente Vascular Cerebral/terapia , Trombectomia/métodos , Idoso , Idoso de 80 Anos ou mais , Arteriopatias Oclusivas/epidemiologia , Estudos de Coortes , Procedimentos Endovasculares/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Acidente Vascular Cerebral/epidemiologia , Ativador de Plasminogênio Tecidual/administração & dosagem , Resultado do Tratamento
13.
J Neurosci ; 37(28): 6797-6809, 2017 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-28607171

RESUMO

Alzheimer's disease (AD) is characterized by progressive cognitive decline, increasingly attributed to neuronal dysfunction induced by amyloid-ß oligomers (AßOs). Although the impact of AßOs on neurons has been extensively studied, only recently have the possible effects of AßOs on astrocytes begun to be investigated. Given the key roles of astrocytes in synapse formation, plasticity, and function, we sought to investigate the impact of AßOs on astrocytes, and to determine whether this impact is related to the deleterious actions of AßOs on synapses. We found that AßOs interact with astrocytes, cause astrocyte activation and trigger abnormal generation of reactive oxygen species, which is accompanied by impairment of astrocyte neuroprotective potential in vitro We further show that both murine and human astrocyte conditioned media (CM) increase synapse density, reduce AßOs binding, and prevent AßO-induced synapse loss in cultured hippocampal neurons. Both a neutralizing anti-transforming growth factor-ß1 (TGF-ß1) antibody and siRNA-mediated knockdown of TGF-ß1, previously identified as an important synaptogenic factor secreted by astrocytes, abrogated the protective action of astrocyte CM against AßO-induced synapse loss. Notably, TGF-ß1 prevented hippocampal dendritic spine loss and memory impairment in mice that received an intracerebroventricular infusion of AßOs. Results suggest that astrocyte-derived TGF-ß1 is part of an endogenous mechanism that protects synapses against AßOs. By demonstrating that AßOs decrease astrocyte ability to protect synapses, our results unravel a new mechanism underlying the synaptotoxic action of AßOs in AD.SIGNIFICANCE STATEMENT Alzheimer's disease is characterized by progressive cognitive decline, mainly attributed to synaptotoxicity of the amyloid-ß oligomers (AßOs). Here, we investigated the impact of AßOs in astrocytes, a less known subject. We show that astrocytes prevent synapse loss induced by AßOs, via production of transforming growth factor-ß1 (TGF-ß1). We found that AßOs trigger morphological and functional alterations in astrocytes, and impair their neuroprotective potential. Notably, TGF-ß1 reduced hippocampal dendritic spine loss and memory impairment in mice that received intracerebroventricular infusions of AßOs. Our results describe a new mechanism underlying the toxicity of AßOs and indicate novel therapeutic targets for Alzheimer's disease, mainly focused on TGF-ß1 and astrocytes.


Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Astrócitos/metabolismo , Sinapses/metabolismo , Sinapses/patologia , Fator de Crescimento Transformador beta1/metabolismo , Peptídeos beta-Amiloides , Animais , Células Cultivadas , Humanos , Masculino , Camundongos , Espécies Reativas de Oxigênio/metabolismo
14.
Stroke ; 48(5): 1278-1284, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28411260

RESUMO

BACKGROUND AND PURPOSE: The Emergency Medical Services field triage to stroke centers has gained considerable complexity with the recent demonstration of clinical benefit of endovascular treatment for acute ischemic stroke. We sought to describe a new smartphone freeware application designed to assist Emergency Medical Services professionals with the field assessment and destination triage of patients with acute ischemic stroke. METHODS: Review of the application's platform and its development as well as the different variables, assessments, algorithms, and assumptions involved. RESULTS: The FAST-ED (Field Assessment Stroke Triage for Emergency Destination) application is based on a built-in automated decision-making algorithm that relies on (1) a brief series of questions assessing patient's age, anticoagulant usage, time last known normal, motor weakness, gaze deviation, aphasia, and hemineglect; (2) a database of all regional stroke centers according to their capability to provide endovascular treatment; and (3) Global Positioning System technology with real-time traffic information to compute the patient's eligibility for intravenous tissue-type plasminogen activator or endovascular treatment as well as the distances/transportation times to the different neighboring stroke centers in order to assist Emergency Medical Services professionals with the decision about the most suitable destination for any given patient with acute ischemic stroke. CONCLUSIONS: The FAST-ED smartphone application has great potential to improve the triage of patients with acute ischemic stroke, as it seems capable to optimize resources, reduce hospital arrivals times, and maximize the use of both intravenous tissue-type plasminogen activator and endovascular treatment ultimately leading to better clinical outcomes. Future field studies are needed to properly evaluate the impact of this tool in stroke outcomes and resource utilization.


Assuntos
Isquemia Encefálica/diagnóstico , Tomada de Decisão Clínica/métodos , Sistemas de Apoio a Decisões Clínicas/instrumentação , Acidente Vascular Cerebral/diagnóstico , Triagem/métodos , Algoritmos , Sistemas de Informação Geográfica/instrumentação , Humanos , Smartphone , Transporte de Pacientes/métodos
15.
J Biol Chem ; 292(18): 7395-7406, 2017 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-28302722

RESUMO

AMP-activated kinase (AMPK) is a key player in energy sensing and metabolic reprogramming under cellular energy restriction. Several studies have linked impaired AMPK function to peripheral metabolic diseases such as diabetes. However, the impact of neurological disorders, such as Alzheimer disease (AD), on AMPK function and downstream effects of altered AMPK activity on neuronal metabolism have been investigated only recently. Here, we report the impact of Aß oligomers (AßOs), synaptotoxins that accumulate in AD brains, on neuronal AMPK activity. Short-term exposure of cultured rat hippocampal neurons or ex vivo human cortical slices to AßOs transiently decreased intracellular ATP levels and AMPK activity, as evaluated by its phosphorylation at threonine residue 172 (AMPK-Thr(P)172). The AßO-dependent reduction in AMPK-Thr(P)172 levels was mediated by glutamate receptors of the N-methyl-d-aspartate (NMDA) subtype and resulted in removal of glucose transporters (GLUTs) from the surfaces of dendritic processes in hippocampal neurons. Importantly, insulin prevented the AßO-induced inhibition of AMPK. Our results establish a novel toxic impact of AßOs on neuronal metabolism and suggest that AßO-induced, NMDA receptor-mediated AMPK inhibition may play a key role in early brain metabolic defects in AD.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Hipocampo/metabolismo , Neurônios/metabolismo , Fragmentos de Peptídeos/metabolismo , Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Proteínas Quinases Ativadas por AMP/genética , Trifosfato de Adenosina/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Proteínas Facilitadoras de Transporte de Glucose/genética , Proteínas Facilitadoras de Transporte de Glucose/metabolismo , Hipocampo/patologia , Humanos , Insulina/farmacologia , Neurônios/patologia , Fragmentos de Peptídeos/genética , Ratos , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo
17.
Stroke ; 47(8): 1997-2002, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27364531

RESUMO

BACKGROUND AND PURPOSE: Patients with large vessel occlusion strokes (LVOS) may be better served by direct transfer to endovascular capable centers avoiding hazardous delays between primary and comprehensive stroke centers. However, accurate stroke field triage remains challenging. We aimed to develop a simple field scale to identify LVOS. METHODS: The Field Assessment Stroke Triage for Emergency Destination (FAST-ED) scale was based on items of the National Institutes of Health Stroke Scale (NIHSS) with higher predictive value for LVOS and tested in the Screening Technology and Outcomes Project in Stroke (STOPStroke) cohort, in which patients underwent computed tomographic angiography within the first 24 hours of stroke onset. LVOS were defined by total occlusions involving the intracranial internal carotid artery, middle cerebral artery-M1, middle cerebral artery-2, or basilar arteries. Patients with partial, bihemispheric, and anterior+posterior circulation occlusions were excluded. Receiver operating characteristic curve, sensitivity, specificity, positive predictive value, and negative predictive value of FAST-ED were compared with the NIHSS, Rapid Arterial Occlusion Evaluation (RACE) scale, and Cincinnati Prehospital Stroke Severity (CPSS) scale. RESULTS: LVO was detected in 240 of the 727 qualifying patients (33%). FAST-ED had comparable accuracy to predict LVO to the NIHSS and higher accuracy than RACE and CPSS (area under the receiver operating characteristic curve: FAST-ED=0.81 as reference; NIHSS=0.80, P=0.28; RACE=0.77, P=0.02; and CPSS=0.75, P=0.002). A FAST-ED ≥4 had sensitivity of 0.60, specificity of 0.89, positive predictive value of 0.72, and negative predictive value of 0.82 versus RACE ≥5 of 0.55, 0.87, 0.68, and 0.79, and CPSS ≥2 of 0.56, 0.85, 0.65, and 0.78, respectively. CONCLUSIONS: FAST-ED is a simple scale that if successfully validated in the field, it may be used by medical emergency professionals to identify LVOS in the prehospital setting enabling rapid triage of patients.


Assuntos
Arteriopatias Oclusivas/diagnóstico , Isquemia Encefálica/diagnóstico , Encéfalo/diagnóstico por imagem , Serviços Médicos de Emergência , Acidente Vascular Cerebral/diagnóstico , Triagem/métodos , Idoso , Idoso de 80 Anos ou mais , Arteriopatias Oclusivas/diagnóstico por imagem , Isquemia Encefálica/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico por imagem
18.
J Enzyme Inhib Med Chem ; 31(6): 1464-70, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26928712

RESUMO

Acetylcholinesterase inhibitors and compounds that trigger Aß amyloid oligomerization and fibrillization represent an opportunity to discover new drug candidates to treat Alzheimer's disease. In this work, we synthesized nine new acylhydrazones and a known one, both employing 3-carboethoxy-4-quinolone derivatives as starting materials with chemical yields ranging from 63% to 90%. We evaluated the effect of these compounds on the acetylcholinesterase (AChE) activity and the fibrillization of Aß42 peptide. Except for one acylhydrazone, the compounds exhibited good inhibitory effect on AChE (1.2 µM < IC50 values < 17 µM). They also showed a significant decrease in the thioflavin-T fluorescence emission, suggesting an inhibitory effect on the Aß42 fibril formation.


Assuntos
4-Quinolonas/química , Acetilcolinesterase/efeitos dos fármacos , Peptídeos beta-Amiloides/efeitos dos fármacos , Inibidores da Colinesterase/farmacologia , Hidrazonas/farmacologia , Fragmentos de Peptídeos/efeitos dos fármacos , Peptídeos beta-Amiloides/química , Hidrazonas/química , Fragmentos de Peptídeos/química , Análise Espectral/métodos
19.
J Stroke Cerebrovasc Dis ; 24(9): e271-3, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26198371

RESUMO

BACKGROUND: Vasospasm has been rarely described as a complication associated with craniopharyngioma surgery. Herein we describe a patient who developed symptomatic vasospasm and delayed cerebral ischemia after transsphenoidal surgery for a craniopharyngioma. CASE REPORT: A 67-year-old woman became drowsy 2 weeks after a transsphenoidal resection of a craniopharyngioma. A head computed tomography (CT) was unremarkable except for postoperative findings. Electroencephalogram and laboratory studies were within the normal limits. A repeated CT scan 48 hours after the initial symptoms showed bilateral infarcts in the territory of the anterior cerebral arteries (ACA). Transcranial Doppler (TCD) showed increased blood flow velocities in both anterior cerebral arteries (169 cm/second in the left ACA and 145 cm/second in the right ACA) and right middle cerebral artery (164 cm/second) compatible with vasospasm. A CT angiography confirmed the findings. She was treated with induced hypertension and her level of consciousness improved. TCD velocities normalized after 2 weeks. CONCLUSION: Cerebral vasospasm should be considered in the differential diagnosis of patients with altered neurologic status in the postoperative period following a craniopharyngioma resection.


Assuntos
Isquemia Encefálica/etiologia , Craniofaringioma/cirurgia , Procedimentos Neurocirúrgicos/efeitos adversos , Neoplasias Hipofisárias/cirurgia , Complicações Pós-Operatórias/fisiopatologia , Vasoespasmo Intracraniano/etiologia , Idoso , Angiografia Cerebral , Feminino , Humanos , Tomografia Computadorizada por Raios X
20.
J Stroke Cerebrovasc Dis ; 24(9): e275-8, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26198372

RESUMO

BACKGROUND: Subarachnoid hemorrhage (SAH) associated with anticoagulation is a rare event. About 30% of in-hospital patients with aneurysmal SAH develop delayed cerebral ischemia (DCI); however, the occurrence of vasospasm and DCI in patients with nonaneurysmal SAH is still controversial. METHODS: This study is a case report of a patient experiencing an anticoagulation-induced SAH complicated by vasospasm and DCI. RESULTS: A 38-year-old woman presented to our hospital with a sudden onset of severe headache. Head computed tomography (CT) showed bleeding in the posterior fossa subarachnoid space. There was no aneurysm in the CT angiography. The International Normalized Ratio at hospital admission was 9. Anticoagulation was held, and she was treated with fresh frozen plasma (15 mg/kg) and parenteral vitamin K. The patient remained in the intensive care unit and had daily transcranial Doppler (TCD) monitorization. TCD examination detected increased blood flow velocities in the basilar and vertebral arteries, meeting criteria for definitive vasospasm. CT angiography confirmed the presence of posterior circulation vasospasm. Magnetic resonance (MR) imaging 2 weeks after the bleeding showed a small area of restricted diffusion in the left superior cerebellar artery territory. MR angiography showed resolution of the vasospasm at this time point and TCD velocities normalized. CONCLUSIONS: In conclusion, this case report suggests that vasospasm and consequent DCI is a possible mechanism of secondary lesion after anticoagulation-induced SAH. To our knowledge, this is the first report of vasospasm and DCI due to warfarin-associated SAH.


Assuntos
Isquemia Encefálica/etiologia , Hemorragia Subaracnóidea/complicações , Vasoespasmo Intracraniano/etiologia , Adulto , Anticoagulantes/efeitos adversos , Feminino , Humanos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Hemorragia Subaracnóidea/induzido quimicamente , Ultrassonografia Doppler Transcraniana , Varfarina/efeitos adversos
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