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1.
Cell ; 165(2): 434-448, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-26997484

RESUMO

Mutations in the Kv3.3 potassium channel (KCNC3) cause cerebellar neurodegeneration and impair auditory processing. The cytoplasmic C terminus of Kv3.3 contains a proline-rich domain conserved in proteins that activate actin nucleation through Arp2/3. We found that Kv3.3 recruits Arp2/3 to the plasma membrane, resulting in formation of a relatively stable cortical actin filament network resistant to cytochalasin D that inhibits fast barbed end actin assembly. These Kv3.3-associated actin structures are required to prevent very rapid N-type channel inactivation during short depolarizations of the plasma membrane. The effects of Kv3.3 on the actin cytoskeleton are mediated by the binding of the cytoplasmic C terminus of Kv3.3 to Hax-1, an anti-apoptotic protein that regulates actin nucleation through Arp2/3. A human Kv3.3 mutation within a conserved proline-rich domain produces channels that bind Hax-1 but are impaired in recruiting Arp2/3 to the plasma membrane, resulting in growth cones with deficient actin veils in stem cell-derived neurons.


Assuntos
Citoesqueleto de Actina/metabolismo , Proteína 2 Relacionada a Actina/metabolismo , Proteína 3 Relacionada a Actina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Canais de Potássio Shaw/metabolismo , Ataxias Espinocerebelares/metabolismo , Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , Sequência de Aminoácidos , Membrana Celular/metabolismo , Dados de Sequência Molecular , Mutação , Neurônios/metabolismo , Células-Tronco Pluripotentes/metabolismo , Canais de Potássio Shaw/química , Canais de Potássio Shaw/genética , Transdução de Sinais , Proteínas rac de Ligação ao GTP/metabolismo
2.
Stroke ; 54(11): 2842-2850, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37795589

RESUMO

BACKGROUND: Right to left shunt (RLS), including patent foramen ovale, is a recognized risk factor for stroke. RLS/patent foramen ovale diagnosis is made by transthoracic echocardiography (TTE), which is insensitive, transesophageal echocardiography, which is invasive, and transcranial Doppler (TCD), which is noninvasive and accurate but scarce. METHODS: We conducted a prospective, single-arm device clinical trial of robot-assisted TCD (raTCD) versus TTE for RLS diagnosis at 6 clinical sites in patients who presented with an event suspicious for embolic cerebrovascular ischemia from October 6, 2020 to October 20, 2021. raTCD was performed with standard TCD bubble study technique. TTE bubble study was performed per local standards. The primary outcome was rate of RLS detection by raTCD versus TTE. RESULTS: A total of 154 patients were enrolled, 129 evaluable (intent to scan) and 121 subjects had complete data per protocol. In the intent to scan cohort, mean age was 60±15 years, 47% were women, and all qualifying events were diagnosed as ischemic stroke or transient ischemic attack. raTCD was positive for RLS in 82 subjects (64%) and TTE was positive in 26 (20%; absolute difference 43.4% [95% CI, 35.2%-52.0%]; P<0.001). On prespecified secondary analysis, large RLS was detected by raTCD in 35 subjects (27%) versus 13 (10%) by TTE (absolute difference 17.0% [95% CI, 11.5%-24.5%]; P<0.001). There were no serious adverse events. CONCLUSIONS: raTCD was safe and ≈3 times more likely to diagnose RLS than TTE. TTE completely missed or underdiagnosed two thirds of large shunts diagnosed by raTCD. The raTCD device, used by health professionals with no prior TCD training, may allow providers to achieve the known sensitivity of TCD for RLS and patent foramen ovale detection without the need for an experienced operator to perform the test. Pending confirmatory studies, TCD appears to be the superior screen for RLS compared with TTE (funded by NeuraSignal). REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04604015.


Assuntos
Forame Oval Patente , Robótica , Acidente Vascular Cerebral , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ecocardiografia , Ecocardiografia Transesofagiana , Forame Oval Patente/complicações , Estudos Prospectivos , Acidente Vascular Cerebral/etiologia , Ultrassonografia Doppler Transcraniana
3.
Stroke ; 50(1): 143-147, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30580705

RESUMO

Background and Purpose- Although aggressive medical therapy was superior to stenting in the SAMMPRIS trial (Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis), the stroke rate in the medical arm was still high. The aim of this study was to determine the association between hemodynamic markers (borderzone infarct pattern and impaired collateral flow on baseline imaging) and rates of recurrent stroke in patients treated medically in SAMMPRIS. Methods- This was a post hoc analysis of patients whose qualifying event for SAMMPRIS was an infarct in the territory of a stenotic middle cerebral artery or intracranial carotid artery. Infarcts were adjudicated as involving primarily internal or cortical borderzone territories, the core middle cerebral artery territory, or perforator territories, and collateral flow was assessed according to a standard scale (American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology). Log-rank tests and χ2 tests were performed to assess associations of infarct patterns and collateral flow with rates of recurrent stroke. Results- Of 101 patients who qualified, 14 of 53 (26.4%) with borderzone infarcts, 2 of 24 (8.3%) with core middle cerebral artery infarcts, and 3 of 24 (12.5%) with perforator infarcts had a recurrent stroke in the territory (P=0.14 for comparing the 3 groups, P=0.052 for borderzone versus nonborderzone). Of 82 patients with collateral flow assessment, 30 of 43 (70%) with borderzone infarcts, 7 of 19 (37%) with core middle cerebral artery infarcts, and 11 of 20 (55%) with perforator infarcts had impaired collateral flow distal to the stenosis (P=0.049). Patients with borderzone infarcts and impaired collateral flow had the highest risk of recurrent stroke (37%). Conclusions- Borderzone infarcts and impaired collateral flow identify a subgroup of patients with intracranial stenosis who are at particularly high risk of recurrent stroke on medical treatment. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00576693.

4.
Ann Neurol ; 84(5): 717-728, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30295338

RESUMO

OBJECTIVE: The present study was undertaken to determine the efficacy of coadministration of fingolimod with alteplase in acute ischemic stroke patients in a delayed time window. METHODS: This was a prospective, randomized, open-label, blinded endpoint clinical trial, enrolling patients with internal carotid artery or middle cerebral artery proximal occlusion within 4.5 to 6 hours from symptom onset. Patients were randomly assigned to receive alteplase alone or alteplase with fingolimod. All patients underwent pretreatment and 24-hour noncontrast computed tomography (CT)/perfusion CT/CT angiography. The coprimary endpoints were the decrease of National Institutes of Health Stroke Scale scores over 24 hours and the favorable shift of modified Rankin Scale score (mRS) distribution at day 90. Exploratory outcomes included vessel recanalization, anterograde reperfusion, and retrograde reperfusion of collateral flow. RESULTS: Each treatment group included 23 patients. Compared with alteplase alone, patients receiving fingolimod plus alteplase exhibited better early clinical improvement at 24 hours and a favorable shift of mRS distribution at day 90. In addition, patients who received fingolimod and alteplase exhibited a greater reduction in the perfusion lesion accompanied by suppressed infarct growth by 24 hours. Fingolimod in conjunction with alteplase significantly improved anterograde reperfusion of downstream territory and prevented the failure of retrograde reperfusion from collateral circulation. INTERPRETATION: Fingolimod may enhance the efficacy of alteplase administration in the 4.5- to 6-hour time window in patients with a proximal cerebral arterial occlusion and salvageable penumbral tissue by promoting both anterograde reperfusion and retrograde collateral flow. These findings are instructive for the design of future trials of recanalization therapies in extended time windows. Ann Neurol 2018;84:725-736.


Assuntos
Fibrinolíticos/administração & dosagem , Cloridrato de Fingolimode/administração & dosagem , Imunossupressores/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Ativador de Plasminogênio Tecidual/administração & dosagem , Idoso , Circulação Colateral/efeitos dos fármacos , Quimioterapia Combinada , Feminino , Humanos , Masculino , Recuperação de Função Fisiológica/efeitos dos fármacos , Reperfusão , Acidente Vascular Cerebral/patologia , Tempo para o Tratamento
5.
Curr Opin Neurol ; 36(2): 124, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36862013
6.
Clin Sci (Lond) ; 132(5): 581-593, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29500223

RESUMO

Significant neuroprotective effects of angiotensin II type 2 (AT2) receptor (AT2 receptor) agonists in ischemic stroke have been previously demonstrated in multiple studies. However, the routes of agonist application used in these pre-clinical studies, direct intracerebroventricular (ICV) and systemic administration, are unsuitable for translation into humans; in the latter case because AT2 receptor agonists are blood-brain barrier (BBB) impermeable. To circumvent this problem, in the current study we utilized the nose-to-brain (N2B) route of administration to bypass the BBB and deliver the selective AT2 receptor agonist Compound 21 (C21) to naïve rats or rats that had undergone endothelin 1 (ET-1)-induced ischemic stroke. The results obtained from the present study indicated that C21 applied N2B entered the cerebral cortex and striatum within 30 min in amounts that are therapeutically relevant (8.4-9 nM), regardless of whether BBB was intact or disintegrated. C21 was first applied N2B at 1.5 h after stroke indeed provided neuroprotection, as evidenced by a highly significant, 57% reduction in cerebral infarct size and significant improvements in Bederson and Garcia neurological scores. N2B-administered C21 did not affect blood pressure or heart rate. Thus, these data provide proof-of-principle for the idea that N2B application of an AT2 receptor agonist can exert neuroprotective actions when administered following ischemic stroke. Since N2B delivery of other agents has been shown to be effective in certain human central nervous system diseases, the N2B application of AT2 receptor agonists may become a viable mode of delivering these neuroprotective agents for human ischemic stroke patients.


Assuntos
Encéfalo/metabolismo , Mucosa Nasal/metabolismo , Receptor Tipo 2 de Angiotensina/agonistas , Acidente Vascular Cerebral/prevenção & controle , Sulfonamidas/farmacologia , Tiofenos/farmacologia , Animais , Isquemia Encefálica/complicações , Infarto Cerebral/prevenção & controle , Vias de Administração de Medicamentos , Sistemas de Liberação de Medicamentos/métodos , Humanos , Masculino , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/sangue , Fármacos Neuroprotetores/farmacologia , Ratos Sprague-Dawley , Receptor Tipo 2 de Angiotensina/metabolismo , Acidente Vascular Cerebral/etiologia , Sulfonamidas/administração & dosagem , Sulfonamidas/sangue , Tiofenos/administração & dosagem , Tiofenos/sangue
7.
Cerebellum ; 17(5): 692-697, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29949095

RESUMO

Mutations in the potassium channel gene KCNC3 (Kv3.3) cause the autosomal dominant neurological disease, spinocerebellar ataxia 13 (SCA13). In this study, we expand the genotype-phenotype repertoire of SCA13 by describing the novel KCNC3 deletion p.Pro583_Pro585del highlighting the allelic heterogeneity observed in SCA13 patients. We characterize adult-onset, progressive clinical symptoms of two afflicted kindred and introduce the symptom of profound spasticity not previously associated with the SCA13 phenotype. We also present molecular and electrophysiological characterizations of the mutant protein in mammalian cell culture. Mechanistically, the p.Pro583_Pro585del protein showed normal membrane trafficking with an altered electrophysiological profile, including slower inactivation and decreased sensitivity to the inactivation-accelerating effects of the actin depolymerizer latrunculin B. Taken together, our results highlight the clinical importance of the intracellular C-terminal portion of Kv3.3 and its association with ion channel function.


Assuntos
Espasticidade Muscular/genética , Espasticidade Muscular/fisiopatologia , Deleção de Sequência , Canais de Potássio Shaw/genética , Ataxias Espinocerebelares/congênito , Adulto , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Células CHO , Cricetulus , Feminino , Humanos , Masculino , Toxinas Marinhas/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Espasticidade Muscular/diagnóstico por imagem , Fenótipo , Ataxias Espinocerebelares/diagnóstico por imagem , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/fisiopatologia , Tiazolidinas/farmacologia
8.
Proc Natl Acad Sci U S A ; 112(4): 1155-60, 2015 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-25583472

RESUMO

Cerebral vasospasm (CV) and the resulting delayed cerebral ischemia (DCI) significantly contribute to poor outcomes following aneurysmal subarachnoid hemorrhage (aSAH). Free hemoglobin (Hb) within the subarachnoid space has been implicated in the pathogenesis of CV. Haptoglobin (Hp) binds free pro-oxidant Hb, thereby modulating its harmful effects. Humans can be of three Hp phenotypes: Hp1-1, Hp2-1, or Hp2-2. In several disease states, the Hp2-2 protein has been associated with reduced ability to protect against toxic free Hb. We hypothesized that individuals with the Hp2-2 phenotype would have more CV, DCI, mortality, and worse functional outcomes after aSAH. In a sample of 74 aSAH patients, Hp2-2 phenotype was significantly associated with increased focal moderate (P = 0.014) and severe (P = 0.008) CV and more global CV (P = 0.014) after controlling for covariates. Strong trends toward increased mortality (P = 0.079) and worse functional outcomes were seen for the Hp2-2 patients with modified Rankin scale at 6 wk (P = 0.076) and at 1 y (P = 0.051) and with Glasgow Outcome Scale Extended at discharge (P = 0.091) and at 1 y (P = 0.055). In conclusion, Hp2-2 phenotype is an independent risk factor for the development of both focal and global CV and also predicts poor functional outcomes and mortality after aSAH. Hp phenotyping may serve as a clinically useful tool in the critical care management of aSAH patients by allowing for early prediction of those patients who require increased vigilance due to their inherent genetic risk for the development of CV and resulting DCI and poor outcomes.


Assuntos
Angiografia Cerebral , Genótipo , Haptoglobinas/genética , Hemorragia Subaracnóidea , Vasoespasmo Intracraniano , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/genética , Hemorragia Subaracnóidea/mortalidade , Taxa de Sobrevida , Vasoespasmo Intracraniano/diagnóstico por imagem , Vasoespasmo Intracraniano/genética , Vasoespasmo Intracraniano/mortalidade
9.
South Med J ; 110(7): 466-474, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28679016

RESUMO

OBJECTIVES: Although disparities in stroke care and outcomes have been well documented nationally, state-based registries to monitor acute stroke care in Florida (FL) and Puerto Rico (PR) have not been established. The FL-PR Collaboration to Reduce Stroke Disparities (CReSD) was developed to evaluate race-ethnicity and regional disparities in stroke care performance. The objective of this study was to assess and compare hospital characteristics within a large quality improvement registry to identify characteristics associated with better outcomes for acute ischemic stroke care. METHODS: Trained personnel from 78 FL-PR CReSD hospitals (69 FL, 9 PR) completed a 50-item survey assessing institutional characteristics across seven domains: acute stroke care resource availability, emergency medical services integration, stroke center certification, data collection and use, quality improvement processes, FL-PR CReSD recruitment incentives, and hospital infrastructure. RESULTS: The rate of survey completion was 100%. Differences were observed both within FL and between FL and PR. Years participating in Get With The Guidelines-Stroke (8.9 ± 2.6 years FL vs 4.8 ± 2.4 years PR, P < 0.0001) and proportion of hospitals with any stroke center certification (94.2% FL vs 11.1% PR, P < 0.0001) showed the largest variations. Smaller hospital size, fewer years in Get With The Guidelines-Stroke, and lack of stroke center designation and acute stroke care practice implementation may contribute to poorer outcomes. CONCLUSIONS: Results from our survey indicated variability in hospital- and system-level characteristics in stroke care across hospitals in Florida and Puerto Rico. Identification of these variations, which may explain potential disparities, can help clinicians understand gaps in stroke care and outcomes and targeted interventions to reduce identified disparities can be implemented.


Assuntos
Disparidades em Assistência à Saúde/etnologia , Disparidades em Assistência à Saúde/estatística & dados numéricos , Hospitais Especializados/organização & administração , Colaboração Intersetorial , Acidente Vascular Cerebral/etnologia , Acidente Vascular Cerebral/terapia , Florida , Fidelidade a Diretrizes , Pesquisas sobre Atenção à Saúde , Disparidades em Assistência à Saúde/tendências , Hospitais Especializados/tendências , Humanos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Porto Rico , Melhoria de Qualidade/organização & administração , Melhoria de Qualidade/tendências , Sistema de Registros , Acidente Vascular Cerebral/epidemiologia
10.
Lancet ; 383(9914): 333-41, 2014 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-24168957

RESUMO

BACKGROUND: Early results of the Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis trial showed that, by 30 days, 33 (14·7%) of 224 patients in the stenting group and 13 (5·8%) of 227 patients in the medical group had died or had a stroke (percentages are product limit estimates), but provided insufficient data to establish whether stenting offered any longer-term benefit. Here we report the long-term outcome of patients in this trial. METHODS: We randomly assigned (1:1, stratified by centre with randomly permuted block sizes) 451 patients with recent transient ischaemic attack or stroke related to 70-99% stenosis of a major intracranial artery to aggressive medical management (antiplatelet therapy, intensive management of vascular risk factors, and a lifestyle-modification programme) or aggressive medical management plus stenting with the Wingspan stent. The primary endpoint was any of the following: stroke or death within 30 days after enrolment, ischaemic stroke in the territory of the qualifying artery beyond 30 days of enrolment, or stroke or death within 30 days after a revascularisation procedure of the qualifying lesion during follow-up. Primary endpoint analysis of between-group differences with log-rank test was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT 00576693. FINDINGS: During a median follow-up of 32·4 months, 34 (15%) of 227 patients in the medical group and 52 (23%) of 224 patients in the stenting group had a primary endpoint event. The cumulative probability of the primary endpoints was smaller in the medical group versus the percutaneous transluminal angioplasty and stenting (PTAS) group (p=0·0252). Beyond 30 days, 21 (10%) of 210 patients in the medical group and 19 (10%) of 191 patients in the stenting group had a primary endpoint. The absolute differences in the primary endpoint rates between the two groups were 7·1% at year 1 (95% CI 0·2 to 13·8%; p=0·0428), 6·5% at year 2 (-0·5 to 13·5%; p=0·07) and 9·0% at year 3 (1·5 to 16·5%; p=0·0193). The occurrence of the following adverse events was higher in the PTAS group than in the medical group: any stroke (59 [26%] of 224 patients vs 42 [19%] of 227 patients; p=0·0468) and major haemorrhage (29 [13%]of 224 patients vs 10 [4%] of 227 patients; p=0·0009). INTERPRETATION: The early benefit of aggressive medical management over stenting with the Wingspan stent for high-risk patients with intracranial stenosis persists over extended follow-up. Our findings lend support to the use of aggressive medical management rather than PTAS with the Wingspan system in high-risk patients with atherosclerotic intracranial arterial stenosis. FUNDING: National Institute of Neurological Disorders and Stroke (NINDS) and others.


Assuntos
Angioplastia/métodos , Arteriosclerose Intracraniana/terapia , Inibidores da Agregação Plaquetária/uso terapêutico , Stents , Adulto , Idoso , Idoso de 80 Anos ou mais , Angioplastia/efeitos adversos , Aspirina/uso terapêutico , Estenose das Carótidas/complicações , Estenose das Carótidas/terapia , Clopidogrel , Feminino , Seguimentos , Humanos , Arteriosclerose Intracraniana/complicações , Ataque Isquêmico Transitório/etiologia , Ataque Isquêmico Transitório/prevenção & controle , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/efeitos adversos , Prevenção Secundária , Método Simples-Cego , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Ticlopidina/análogos & derivados , Ticlopidina/uso terapêutico , Resultado do Tratamento
11.
Nat Genet ; 38(4): 447-51, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16501573

RESUMO

Potassium channel mutations have been described in episodic neurological diseases. We report that K+ channel mutations cause disease phenotypes with neurodevelopmental and neurodegenerative features. In a Filipino adult-onset ataxia pedigree, the causative gene maps to 19q13, overlapping the SCA13 disease locus described in a French pedigree with childhood-onset ataxia and cognitive delay. This region contains KCNC3 (also known as Kv3.3), encoding a voltage-gated Shaw channel with enriched cerebellar expression. Sequencing revealed two missense mutations, both of which alter KCNC3 function in Xenopus laevis expression systems. KCNC3(R420H), located in the voltage-sensing domain, had no channel activity when expressed alone and had a dominant-negative effect when co-expressed with the wild-type channel. KCNC3(F448L) shifted the activation curve in the negative direction and slowed channel closing. Thus, KCNC3(R420H) and KCNC3(F448L) are expected to change the output characteristics of fast-spiking cerebellar neurons, in which KCNC channels confer capacity for high-frequency firing. Our results establish a role for KCNC3 in phenotypes ranging from developmental disorders to adult-onset neurodegeneration and suggest voltage-gated K+ channels as candidates for additional neurodegenerative diseases.


Assuntos
Ataxia Cerebelar/genética , Ativação do Canal Iônico , Mutação de Sentido Incorreto , Mutação , Canais de Potássio Shaw/genética , Sequência de Aminoácidos , Animais , Humanos , Dados de Sequência Molecular , Fenótipo , Canais de Potássio Shaw/química , Xenopus laevis
12.
Neurobiol Dis ; 71: 270-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25152487

RESUMO

Spinocerebellar ataxia 13 (SCA13) is an autosomal dominant disease resulting from mutations in KCNC3 (Kv3.3), a voltage-gated potassium channel. The KCNC3(R420H) mutation was first identified as causative for SCA13 in a four-generation Filipino kindred with over 20 affected individuals. Electrophysiological analyses in oocytes previously showed that this mutation did not lead to a functional channel and displayed a dominant negative phenotype. In an effort to identify the molecular basis of this allelic form of SCA13, we first determined that human KCNC3(WT) and KCNC3(R420H) display disparate post-translational modifications, and the mutant protein has reduced complex glycan adducts. Immunohistochemical analyses demonstrated that KCNC3(R420H) was not properly trafficking to the plasma membrane and surface biotinylation demonstrated that KCNC3(R420H) exhibited only 24% as much surface expression as KCNC3(WT). KCNC3(R420H) trafficked through the ER but was retained in the Golgi. KCNC3(R420H) expression results in altered Golgi and cellular morphology. Electron microscopy of KCNC3(R420H) localization further supports retention in the Golgi. These results are specific to the KCNC3(R420H) allele and provide new insight into the molecular basis of disease manifestation in SCA13.


Assuntos
Arginina/genética , Histidina/genética , Líquido Intracelular/metabolismo , Mutação/genética , Canais de Potássio Shaw/genética , Degenerações Espinocerebelares/genética , Animais , Animais Geneticamente Modificados , Biotinilação , Células COS , Caderinas/metabolismo , Chlorocebus aethiops , Citoplasma/genética , Citoplasma/metabolismo , Drosophila , Proteínas de Drosophila/genética , Retículo Endoplasmático/metabolismo , Feminino , Humanos , Masculino , Oócitos , Processamento de Proteína Pós-Traducional , Transporte Proteico , Ataxias Espinocerebelares/congênito , Degenerações Espinocerebelares/metabolismo , Transfecção
13.
N Engl J Med ; 365(11): 993-1003, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21899409

RESUMO

BACKGROUND: Atherosclerotic intracranial arterial stenosis is an important cause of stroke that is increasingly being treated with percutaneous transluminal angioplasty and stenting (PTAS) to prevent recurrent stroke. However, PTAS has not been compared with medical management in a randomized trial. METHODS: We randomly assigned patients who had a recent transient ischemic attack or stroke attributed to stenosis of 70 to 99% of the diameter of a major intracranial artery to aggressive medical management alone or aggressive medical management plus PTAS with the use of the Wingspan stent system. The primary end point was stroke or death within 30 days after enrollment or after a revascularization procedure for the qualifying lesion during the follow-up period or stroke in the territory of the qualifying artery beyond 30 days. RESULTS: Enrollment was stopped after 451 patients underwent randomization, because the 30-day rate of stroke or death was 14.7% in the PTAS group (nonfatal stroke, 12.5%; fatal stroke, 2.2%) and 5.8% in the medical-management group (nonfatal stroke, 5.3%; non-stroke-related death, 0.4%) (P=0.002). Beyond 30 days, stroke in the same territory occurred in 13 patients in each group. Currently, the mean duration of follow-up, which is ongoing, is 11.9 months. The probability of the occurrence of a primary end-point event over time differed significantly between the two treatment groups (P=0.009), with 1-year rates of the primary end point of 20.0% in the PTAS group and 12.2% in the medical-management group. CONCLUSIONS: In patients with intracranial arterial stenosis, aggressive medical management was superior to PTAS with the use of the Wingspan stent system, both because the risk of early stroke after PTAS was high and because the risk of stroke with aggressive medical therapy alone was lower than expected. (Funded by the National Institute of Neurological Disorders and Stroke and others; SAMMPRIS ClinicalTrials.gov number, NCT00576693.).


Assuntos
Arteriosclerose Intracraniana/terapia , Ataque Isquêmico Transitório/terapia , Stents , Acidente Vascular Cerebral/prevenção & controle , Idoso , Anti-Hipertensivos/uso terapêutico , Aspirina/uso terapêutico , Clopidogrel , Terapia Combinada , Feminino , Seguimentos , Comportamentos Relacionados com a Saúde , Humanos , Arteriosclerose Intracraniana/tratamento farmacológico , Hemorragias Intracranianas/epidemiologia , Hemorragias Intracranianas/etiologia , Ataque Isquêmico Transitório/tratamento farmacológico , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/uso terapêutico , Stents/efeitos adversos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/terapia , Ticlopidina/análogos & derivados , Ticlopidina/uso terapêutico
14.
BMC Neurol ; 14: 62, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24678735

RESUMO

BACKGROUND: Takayasu arteritis (TA) is an idiopathic large-vessel vasculitis that can result in significant morbidity and mortality secondary to progressive stenosis and occlusion. Monitoring disease progression is crucial to preventing relapse, but is often complicated by the lack of clinical symptoms in the setting of active disease. Although acute phase reactants such as ESR and CRP are generally used as an indicator of inflammation and disease activity, mounting evidence suggests that these markers cannot reliably distinguish active from inactive TA. CASE PRESENTATION: We report a 24-year-old Hispanic female with a 5-year history of TA who presented with stroke-like symptoms and evidence of left MCA occlusion on imaging, despite a history of decreasing inflammatory markers. CTA revealed complete occlusion of the left common carotid artery, left subclavian, and left MCA from their origins. It also revealed a striking compensatory circulation supplying the left anterior circulation as well as the left subclavian as a response to progressive stenosis. CONCLUSION: Monitoring ESR and CRP levels alone may not be a reliable method to evaluate disease progression in patients with TA, and should be taken in context with both patient's clinical picture and the imaging. We recommend that serial imaging be performed regularly in the setting of active disease to monitor progression and allow for immediate therapy in response to evidence of disease advancement, with a relaxation of the imaging interval once the disease is presumed inactive.


Assuntos
Biomarcadores/sangue , Mediadores da Inflamação/sangue , Arterite de Takayasu/diagnóstico , Sedimentação Sanguínea , Proteína C-Reativa/análise , Estenose das Carótidas/etiologia , Estenose das Carótidas/terapia , Circulação Colateral/fisiologia , Feminino , Humanos , Isquemia/etiologia , Monitorização Fisiológica , Acidente Vascular Cerebral/etiologia , Arterite de Takayasu/fisiopatologia , Adulto Jovem
15.
J Stroke Cerebrovasc Dis ; 23(1): 17-24, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22818388

RESUMO

BACKGROUND: Health care disparities exist between demographic groups with stroke. We examined whether patients of particular ethnicity or income levels experienced reduced access to or delays in receiving stroke care. METHODS: We studied all admissions for ischemic stroke in the Nationwide Inpatient Sample (NIS) database between 2002 and 2008. We used statistical models to determine whether median income or race were associated with intravenous (i.v.) thrombolysis treatment, in-hospital mortality, discharge disposition, hospital charges, and LOS in high- or low-volume hospitals. RESULTS: There were a total of 477,474 patients with ischemic stroke: 10,781 (2.3%) received i.v. thrombolysis, and 380,400 (79.7%) were treated in high-volume hospitals. Race (P < .0001) and median income (P < .001) were significant predictors of receiving i.v. thrombolysis, and minorities and low-income patients were less likely to receive i.v. thrombolysis. Median income was a predictor of access to high-volume hospitals (P < .0001), with wealthier patients more likely to be treated in high-volume hospitals, which had lower mortality rates (P = .0002). Patients in high-volume hospitals were 1.84 times more likely to receive i.v. thrombolysis (P < .0001). CONCLUSIONS: African Americans, Hispanics, and low median income patients are less likely to receive i.v. thrombolysis for ischemic stroke. Low median income patients are less likely to be treated at high-volume hospitals. High-volume hospitals have lower mortality rates and a higher likelihood of treating patients with i.v. thrombolysis. There is evidence for an influence of socioeconomic status and racial disparity in the treatment of ischemic stroke.


Assuntos
Isquemia Encefálica/terapia , Disparidades em Assistência à Saúde/estatística & dados numéricos , Renda/estatística & dados numéricos , Grupos Minoritários/estatística & dados numéricos , Acidente Vascular Cerebral/terapia , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/epidemiologia , Bases de Dados Factuais , Feminino , Preços Hospitalares/estatística & dados numéricos , Mortalidade Hospitalar , Hospitais/estatística & dados numéricos , Humanos , Pacientes Internados , Classificação Internacional de Doenças , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Pacientes , Classe Social , Fatores Socioeconômicos , Acidente Vascular Cerebral/epidemiologia , Terapia Trombolítica/estatística & dados numéricos , Resultado do Tratamento , Estados Unidos/epidemiologia
16.
Stroke ; 44(12): 3452-7, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24149008

RESUMO

BACKGROUND AND PURPOSE: Spontaneous swallowing frequency has been described as an index of dysphagia in various health conditions. This study evaluated the potential of spontaneous swallow frequency analysis as a screening protocol for dysphagia in acute stroke. METHODS: In a cohort of 63 acute stroke cases, swallow frequency rates (swallows per minute [SPM]) were compared with stroke and swallow severity indices, age, time from stroke to assessment, and consciousness level. Mean differences in SPM were compared between patients with versus without clinically significant dysphagia. Receiver operating characteristic curve analysis was used to identify the optimal threshold in SPM, which was compared with a validated clinical dysphagia examination for identification of dysphagia cases. Time series analysis was used to identify the minimally adequate time period to complete spontaneous swallow frequency analysis. RESULTS: SPM correlated significantly with stroke and swallow severity indices but not with age, time from stroke onset, or consciousness level. Patients with dysphagia demonstrated significantly lower SPM rates. SPM differed by dysphagia severity. Receiver operating characteristic curve analysis yielded a threshold of SPM≤0.40 that identified dysphagia (per the criterion referent) with 0.96 sensitivity, 0.68 specificity, and 0.96 negative predictive value. Time series analysis indicated that a 5- to 10-minute sampling window was sufficient to calculate spontaneous swallow frequency to identify dysphagia cases in acute stroke. CONCLUSIONS: Spontaneous swallowing frequency presents high potential to screen for dysphagia in acute stroke without the need for trained, available personnel.


Assuntos
Transtornos de Deglutição/diagnóstico , Deglutição/fisiologia , Acidente Vascular Cerebral/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Acidente Vascular Cerebral/fisiopatologia , Fatores de Tempo
17.
Stroke ; 44(11): 3154-60, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23963330

RESUMO

BACKGROUND AND PURPOSE: Dysphagia can lead to pneumonia and subsequent death after acute stroke. However, no prospective study has demonstrated reduced pneumonia prevalence after implementation of a dysphagia screen. METHODS: We performed a single-center prospective interrupted time series trial of a quality initiative to improve dysphagia screening. Subjects included all patients with ischemic or hemorrhagic stroke admitted to our institution over 42 months with a 31-month (n=1686) preintervention and an 11-month (n=648) postintervention period. The intervention consisted of a dysphagia protocol with a nurse-administered bedside dysphagia screen and a reflexive rapid clinical swallow evaluation by a speech pathologist. RESULTS: The dysphagia initiative increased the percentage of patients with stroke screened from 39.3% to 74.2% (P<0.001). Furthermore, this initiative coincided with a drop in hospital-acquired pneumonia from 6.5% to 2.8% among patients with stroke (P<0.001). Patients admitted postinitiative had 57% lower odds of pneumonia, after controlling for multiple confounds (odds ratio=0.43; confidence interval, 0.255-0.711; P=0.0011). The best predictors of pneumonia were stroke type (P<0.0001), oral intake status (P<0.0001), dysphagia screening status (P=0.0037), and hospitalization before the beginning of the quality improvement initiative (P=0.0449). CONCLUSIONS: A quality improvement initiative using a nurse-administered bedside screen with rapid bedside swallow evaluation by a speech pathologist improves screening compliance and correlates with decreased prevalence of pneumonia among patients with stroke.


Assuntos
Infecção Hospitalar/epidemiologia , Transtornos de Deglutição/diagnóstico , Pneumonia/epidemiologia , Pneumonia/prevenção & controle , Acidente Vascular Cerebral/complicações , Idoso , Isquemia Encefálica/complicações , Isquemia Encefálica/terapia , Infecção Hospitalar/prevenção & controle , Deglutição , Feminino , Humanos , Hemorragias Intracranianas/complicações , Hemorragias Intracranianas/terapia , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Estudos Prospectivos , Qualidade da Assistência à Saúde , Acidente Vascular Cerebral/terapia , Inquéritos e Questionários
18.
Cerebellum ; 12(6): 932-6, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23912307

RESUMO

The p.Arg420His allelic form of spinocerebellar ataxia type 13 has been reported in a large Filipino kindred, as well as three European index cases, one with an affected offspring. Haplotype analysis has confirmed independent mutational events. All individuals share adult-onset, predominantly cerebellar signs and a slowly progressive course. However, a comprehensive phenotypic description has yet to be published on SCA13(p.Arg420His). In this study, we present the results of a detailed neurological clinical and diagnostic testing on 21 mutation-positive members of a four-generation Filipino family to further define this disease, aiding diagnosis and prognosis.


Assuntos
Arginina/genética , Histidina/genética , Mutação/genética , Canais de Potássio Shaw/genética , Degenerações Espinocerebelares/genética , Degenerações Espinocerebelares/fisiopatologia , Adulto , Cerebelo/patologia , Saúde da Família , Feminino , Ligação Genética , Genótipo , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fenótipo , Filipinas , Ataxias Espinocerebelares/congênito , Degenerações Espinocerebelares/patologia
19.
Stroke ; 43(10): 2682-8, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22984008

RESUMO

BACKGROUND AND PURPOSE: Enrollment in the Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) trial was halted due to the high risk of stroke or death within 30 days of enrollment in the percutaneous transluminal angioplasty and stenting arm relative to the medical arm. This analysis focuses on the patient and procedural factors that may have been associated with periprocedural cerebrovascular events in the trial. METHODS: Bivariate and multivariate analyses were performed to evaluate whether patient and procedural variables were associated with cerebral ischemic or hemorrhagic events occurring within 30 days of enrollment (termed periprocedural) in the percutaneous transluminal angioplasty and stenting arm. RESULTS: Of 224 patients randomized to percutaneous transluminal angioplasty and stenting, 213 underwent angioplasty alone (n=5) or with stenting (n=208). Of these, 13 had hemorrhagic strokes (7 parenchymal, 6 subarachnoid), 19 had ischemic stroke, and 2 had cerebral infarcts with temporary signs within the periprocedural period. Ischemic events were categorized as perforator occlusions (13), embolic (4), mixed perforator and embolic (2), and delayed stent occlusion (2). Multivariate analyses showed that higher percent stenosis, lower modified Rankin score, and clopidogrel load associated with an activated clotting time above the target range were associated (P ≤ 0.05) with hemorrhagic stroke. Nonsmoking, basilar artery stenosis, diabetes, and older age were associated (P ≤ 0.05) with ischemic events. CONCLUSIONS: Periprocedural strokes in SAMMPRIS had multiple causes with the most common being perforator occlusion. Although risk factors for periprocedural strokes could be identified, excluding patients with these features from undergoing percutaneous transluminal angioplasty and stenting to lower the procedural risk would limit percutaneous transluminal angioplasty and stenting to a small subset of patients. Moreover, given the small number of events, the present data should be used for hypothesis generation rather than to guide patient selection in clinical practice. Clinical Trial Registration Information- URL: http://clinicaltrials.gov. Unique Identifier: NCT00576693.


Assuntos
Angioplastia/efeitos adversos , Constrição Patológica/cirurgia , Período Perioperatório , Stents/efeitos adversos , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controle , Idoso , Angioplastia/instrumentação , Angioplastia/métodos , Constrição Patológica/complicações , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Recidiva , Fatores de Risco , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Resultado do Tratamento
20.
Neurosurg Focus ; 32(2): E1, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22296678

RESUMO

The overall incidence of neurological complications due to infective endocarditis is as high as 40%, with embolic infarcts more common than hemorrhagic strokes. The standard of care for typical strokes does not apply to infective endocarditis because there is a substantial risk of hemorrhage with thrombolysis. In the last decade there have been multiple case reports of intravenous and intraarterial thrombolysis with successful outcomes for acute strokes with related infective endocarditis, but successful endovascular interventions for acute strokes associated with infective endocarditis are rarely reported. To the authors' knowledge, this report is the first case in the literature to use a mechanical retrieval device in successful vegetation retrieval in an infective endocarditis acute stroke. Although an interventional approach for treatment of acute stroke related to infective endocarditis is a promising option, it is controversial and a cautious clinical decision should be made on a case-by-case basis. The authors conclude that this approach can be tested in a case series with matched controls, because this condition is rare and a randomized clinical trial is not a realistic option.


Assuntos
Endocardite/complicações , Endocardite/cirurgia , Procedimentos Endovasculares/métodos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/cirurgia , Idoso , Endocardite/diagnóstico , Feminino , Humanos , Acidente Vascular Cerebral/diagnóstico
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