RESUMO
BACKGROUND AND PURPOSE: Limited evidence exists on the benefits of organized care for improving risk factor control in patients with stroke or transient ischaemic attack. The effectiveness of an individualized management programme in reducing absolute cardiovascular disease risk in this high-risk population was determined. METHODS: This was a prospective, multicentre, cluster-randomized controlled trial with blinded assessment of outcomes and intention-to-treat analysis. Patients hospitalized for stroke/transient ischaemic attack and aged ≥18 years were recruited from four hospitals. General practices treating recruited patients were randomized to provide either usual care or an individualized management programme comprising nurse-led education and review of care plans by stroke specialists in addition to usual care. The primary outcome was a change in cardiovascular Framingham Risk Score between baseline and 12 months. RESULTS: From January 2010 to November 2013, 156 general practices (280 patients) were randomly assigned to usual care (control) and 159 (283 patients) to the intervention. The median age was 70.1 years; 65% were male. Overall, >80% of participants were prescribed recommended secondary prevention therapies at baseline. The primary efficacy analysis comprised 533 participants, with 30 either dying or lost to follow-up. In adjusted analyses, no significant between-group difference was found in the cardiovascular risk score at 12 months (0.04, 95% confidence interval -1.7, 1.8). CONCLUSIONS: The effectiveness of an organized secondary prevention programme for stroke may be limited in patients from high-performing hospitals with regular post-discharge follow-up and communication with general practices.
Assuntos
Gerenciamento Clínico , Acidente Vascular Cerebral/terapia , Idoso , Idoso de 80 Anos ou mais , Avaliação da Deficiência , Feminino , Humanos , Ataque Isquêmico Transitório/terapia , Masculino , Pessoa de Meia-Idade , Enfermeiras e Enfermeiros , Equipe de Assistência ao Paciente , Educação de Pacientes como Assunto , Médicos , Medicina de Precisão , Estudos Prospectivos , Fatores de Risco , Acidente Vascular Cerebral/mortalidade , Resultado do TratamentoRESUMO
BACKGROUND: Stroke telemedicine is widely used to treat patients with acute stroke in Europe and North America but is seldom used in Australia. The Victorian Stroke Telemedicine (VST) programme aims to enhance acute stroke care in regional Australia. METHODS: Twelve-month pilot prospective, historical-controlled, implementation cohort study. Emergency Department (ED) at a large regional hospital in Victoria. Patients ≥ 18 years of age arriving < 4.5 h in the ED with a possible diagnosis of acute stroke. Telemedicine consultation by a Melbourne-based stroke specialist. Stroke thrombolysis rate, timelines for clinical processes, discharge outcomes. RESULTS: In the initial 12 month VST implementation, 62 patients arrived < 4.5 h of stroke onset (60% male; median age 75 years). Compared to pre-VST data (n = 58; 52% male; median age 77 years), stroke thrombolysis use increased from 17% to 26% (P = 0.26). Clinical process timelines improved including door to computed tomography time (reduced by 29 min, P = 0.006), and door to needle time (reduced by 21 min, P = 0.21). There was no significant increase in deaths (pre-VST 7% vs VST 10%), or symptomatic intracerebral haemorrhage (n = 1 tPA patient). More patients who received tPA were discharged to home or rehabilitation (pre-VST 33% vs VST 80%, P = 0.02), with significantly fewer transfers to other acute care services. CONCLUSIONS: The VST pilot implementation provides evidence that telemedicine can enhance the quality of acute stroke care in a regional hospital. Expanding VST to 16 regional hospitals, Australia's largest telestroke programme, will allow for a more comprehensive clinical and economic analysis.
Assuntos
Acessibilidade aos Serviços de Saúde/organização & administração , Acidente Vascular Cerebral/terapia , Telemedicina/organização & administração , Pesquisa Translacional Biomédica/tendências , Idoso , Austrália/epidemiologia , Feminino , Humanos , Masculino , Projetos Piloto , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos , Acidente Vascular Cerebral/epidemiologia , Terapia Trombolítica/métodos , Resultado do Tratamento , Vitória/epidemiologiaRESUMO
BACKGROUND: Fast diagnosis and delivery of treatment to patients experiencing acute stroke can reduce subsequent disability. While telemedicine can improve rural community access to specialists and facilitate timely diagnosis and treatment decisions, it is not widely used for stroke in Australia. AIM: Identifying the barriers and facilitators to clinician engagement with, and utilisation of, telemedicine consultations could expedite implementation in rural and remote locations. METHODS: Purposive sampling was used to identify and recruit medical and nursing staff varying in telemedicine experience across one hospital department. Twenty-four in-depth, face-to-face interviews were conducted examining aspects surrounding stroke telemedicine uptake. Inductive qualitative thematic analysis was undertaken, and two further researchers verified coding. RESULTS: The main barriers identified were contrasting opinions about the utility of thrombolysis for treating acute stroke, lack of confidence in the telemedicine system, perceived limited need for specialist advice and concerns about receiving advice from an unfamiliar doctor. Facilitators included assistance with diagnosis and treatment, the need for a user-friendly system and access to specialists for complex cases. CONCLUSIONS: Acceptability of telemedicine for acute stroke was multifaceted and closely aligned with regional clinician beliefs about the value of thrombolysis for stroke, highlighting an important area for education. Addressing beliefs about treatment efficacy and other perceived barriers is important for establishing a stroke telemedicine programme.
Assuntos
Atenção à Saúde/organização & administração , Diagnóstico Precoce , População Rural , Acidente Vascular Cerebral/diagnóstico , Telemedicina , Terapia Trombolítica/métodos , Adulto , Austrália/epidemiologia , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Pesquisa Qualitativa , Autocuidado , Acidente Vascular Cerebral/terapia , Terapia Trombolítica/normas , Resultado do TratamentoRESUMO
Emergency medical services (EMS) are vital to ensuring acute stroke patients are transported to thrombolysis and/or stroke unit centres. This 6-month audit of Victorian EMS cases found the majority of suspected acute strokes are transported to appropriate stroke centres. However, there is still room for improvement, in particular, strategies to improve access to stroke services in some rural regions and to ensure patients/relatives are fully informed when requesting transport to a non-stroke service hospital.
Assuntos
Auxiliares de Emergência , Hospitais Especializados , Acidente Vascular Cerebral/diagnóstico , Transporte de Pacientes , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Diagnóstico Precoce , Registros Eletrônicos de Saúde , Auxiliares de Emergência/educação , Feminino , Acessibilidade aos Serviços de Saúde , Unidades Hospitalares , Hospitais Rurais , Hospitais Especializados/estatística & dados numéricos , Hospitais Especializados/provisão & distribuição , Hospitais Urbanos , Humanos , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Terapia Trombolítica/estatística & dados numéricos , Fatores de Tempo , Transporte de Pacientes/estatística & dados numéricos , Triagem , VitóriaRESUMO
BACKGROUND: Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis. METHODS: We added data from ECASS III (821 patients) and EPITHET (100 patients) to a pool of common data elements from six other trials of alteplase for acute stroke (2775 patients). We used multivariate logistic regression to assess the relation of stroke onset to start of treatment (OTT) with treatment on favourable 3-month outcome (defined as modified Rankin score 0-1), mortality, and occurrence and outcome of clinically relevant parenchymal haemorrhage. The presence of an arterial occlusion was inferred from the patient's symptoms and absence of haemorrhage or other causes of ischaemic stroke. Vascular imaging was not a requirement in the trials. All patients with confirmed OTT within 360 min were included in the analysis. FINDINGS: Treatment was started within 360 min of stroke onset in 3670 patients randomly allocated to alteplase (n=1850) or to placebo (n=1820). Odds of a favourable 3-month outcome increased as OTT decreased (p=0.0269) and no benefit of alteplase treatment was seen after around 270 min. Adjusted odds of a favourable 3-month outcome were 2.55 (95% CI 1.44-4.52) for 0-90 min, 1.64 (1.12-2.40) for 91-180 min, 1.34 (1.06-1.68) for 181-270 min, and 1.22 (0.92-1.61) for 271-360 min in favour of the alteplase group. Large parenchymal haemorrhage was seen in 96 (5.2%) of 1850 patients assigned to alteplase and 18 (1.0%) of 1820 controls, with no clear relation to OTT (p=0.4140). Adjusted odds of mortality increased with OTT (p=0.0444) and were 0.78 (0.41-1.48) for 0-90 min, 1.13 (0.70-1.82) for 91-180 min, 1.22 (0.87-1.71) for 181-270 min, and 1.49 (1.00-2.21) for 271-360 min. INTERPRETATION: Patients with ischaemic stroke selected by clinical symptoms and CT benefit from intravenous alteplase when treated up to 4.5 h. To increase benefit to a maximum, every effort should be taken to shorten delay in initiation of treatment. Beyond 4.5 h, risk might outweigh benefit. FUNDING: None.
Assuntos
Fibrinolíticos/administração & dosagem , Acidente Vascular Cerebral/tratamento farmacológico , Ativador de Plasminogênio Tecidual/administração & dosagem , Fibrinolíticos/efeitos adversos , Humanos , Infusões Intravenosas , Injeções Intravenosas , Hemorragias Intracranianas/induzido quimicamente , Ensaios Clínicos Controlados Aleatórios como Assunto , Proteínas Recombinantes/administração & dosagem , Fatores de Tempo , Ativador de Plasminogênio Tecidual/efeitos adversos , Resultado do TratamentoRESUMO
BACKGROUND: Previous data have suggested that diabetes and hyperglycemia predict poor outcome following stroke. We studied the prognostic impact of diabetes and admission blood glucose in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). METHODS: EPITHET was a prospective randomized placebo-controlled trial of intravenous tissue plasminogen activator (tPA) in the 3- to 6-hour time window. A preexisting diagnosis of diabetes was noted and baseline serum glucose was measured. RESULTS: Intravenous tPA attenuated infarct growth in non-diabetics, but not in diabetics (p = 0.029). In the tPA treatment group, admission blood glucose was higher among patients with poor functional outcome (p = 0.002). CONCLUSIONS: Diabetes and hyperglycemia attenuate the effects of tPA on infarct evolution. Future thrombolytic trials should consider randomizing patients by subgroups based on diabetic status and serum glucose levels.
Assuntos
Glicemia/metabolismo , Diabetes Mellitus/diagnóstico , Fibrinolíticos/administração & dosagem , Hiperglicemia/diagnóstico , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica , Ativador de Plasminogênio Tecidual/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Austrália , Diabetes Mellitus/sangue , Esquema de Medicação , Europa (Continente) , Feminino , Humanos , Hiperglicemia/sangue , Hiperglicemia/complicações , Infusões Intravenosas , Modelos Lineares , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Admissão do Paciente , Seleção de Pacientes , Estudos Prospectivos , Recuperação de Função Fisiológica , Medição de Risco , Fatores de Risco , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/fisiopatologia , Resultado do TratamentoRESUMO
BACKGROUND: Recent advances in treatment for stroke give new possibilities for optimizing outcomes. To deliver these prehospital care needs to become more efficient. AIM: To develop a framework to support improved delivery of prehospital care. The recommendations are aimed at clinicians involved in prehospital and emergency health systems who will often not be stroke specialists but need clear guidance as to how to develop and deliver safe and effective care for acute stroke patients. METHODS: Building on the successful implementation program from the Global Resuscitation Alliance and the Resuscitation Academy, the Utstein methodology was used to define a generic chain of survival for Emergency Stroke Care by assembling international expertise in Stroke and Emergency Medical Services (EMS). Ten programs were identified for Acute Stroke Care to improve survival and outcomes, with recommendations for implementation of best practice. CONCLUSIONS: Efficient prehospital systems for acute stroke will be improved through public awareness, optimized prehospital triage and timely diagnostics, and quick and equitable access to acute treatments. Documentation, use of metrics and transparency will help to build a culture of excellence and accountability.
Assuntos
Serviços Médicos de Emergência , Acidente Vascular Cerebral , Serviço Hospitalar de Emergência , Humanos , Acidente Vascular Cerebral/terapia , TriagemAssuntos
Fibrinolíticos , Acidente Vascular Cerebral , Terapia Trombolítica , Gerenciamento Clínico , Fibrinolíticos/farmacologia , Fibrinolíticos/uso terapêutico , Humanos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/terapia , Terapia Trombolítica/métodos , Terapia Trombolítica/tendências , Ativador de Plasminogênio Tecidual/uso terapêuticoRESUMO
The use of tissue-type plasminogen activator (t-PA) in ischaemic stroke outside of experienced stroke centres remains controversial. The aim of this study was to present the initial experience with t-PA in patients with ischaemic stroke at an institution with no prior experience in i.v. stroke thrombolysis and to compare results to published reports. Prospective audit of 888 patients with consecutive stroke and transient ischaemic attack admitted to a 426-bed tertiary referral hospital from March 2003 to October 2005. Main outcome measures were treatment rate, exclusion criteria, protocol violations, intracerebral haemorrhage, disability (modified Rankin scale) and mortality at 3 months. Over the study period, 72 patients received t-PA (11% of ischaemic strokes). The main reason for exclusion was presentation beyond 3 h of onset (44%); if all eligible patients had arrived within 3 h, treatment rate was estimated at 32.5%. Protocol violations occurred in 15 (21%) patients. There were seven (10%) asymptomatic intracerebral haemorrhage and one (1%) non-fatal symptomatic intracerebral haemorrhage. At 3 months, 37% had achieved excellent recovery (modified Rankin scale 0-1) and seven (10%) had died. The delivery and outcomes associated with the use of t-PA were comparable to the results of the National Institute of Neurological Disorders and Stroke trial and meta-analysis of open-labelled studies. With appropriate infrastructure and protocols, previously inexperienced tertiary referral centres can replicate the experience and outcome measures reported by clinical trials of t-PA in patients with stroke.
Assuntos
Isquemia Encefálica/tratamento farmacológico , Hospitais de Ensino , Acidente Vascular Cerebral/tratamento farmacológico , Terapia Trombolítica/estatística & dados numéricos , Ativador de Plasminogênio Tecidual/uso terapêutico , Idoso , Isquemia Encefálica/mortalidade , Feminino , Humanos , Masculino , Estudos Prospectivos , Estudos Retrospectivos , Acidente Vascular Cerebral/mortalidade , Terapia Trombolítica/métodos , Resultado do Tratamento , Vitória/epidemiologiaRESUMO
BACKGROUND AND PURPOSE: The Echoplanar Imaging Thrombolysis Evaluation Trial (EPITHET) tests the hypothesis that perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch predicts the response to thrombolysis. There is no accepted standardized definition of PWI-DWI mismatch. We compared common mismatch definitions in the initial 40 EPITHET patients. METHODS: Raw perfusion images were used to generate maps of time to peak (TTP), mean transit time (MTT), time to peak of the impulse response (Tmax) and first moment transit time (FMT). DWI, apparent diffusion coefficient (ADC), and PWI volumes were measured with planimetric and thresholding techniques. Correlations between mismatch volume (PWIvol-DWIvol) and DWI expansion (T2(Day 90-vol)-DWI(Acute-vol)) were also assessed. RESULTS: Mean age was 68+/-11, time to MRI 4.5+/-0.7 hours, and median National Institutes of Health Stroke Scale (NIHSS) score 11 (range 4 to 23). Tmax and MTT hypoperfusion volumes were significantly lower than those calculated with TTP and FMT maps (P<0.001). Mismatch > or =20% was observed in 89% (Tmax) to 92% (TTP/FMT/MTT) of patients. Application of a +4s (relative to the contralateral hemisphere) PWI threshold reduced the frequency of positive mismatch volumes (TTP 73%/FMT 68%/Tmax 54%/MTT 43%). Mismatch was not significantly different when assessed with ADC maps. Mismatch volume, calculated with all parameters and thresholds, was not significantly correlated with DWI expansion. In contrast, reperfusion was correlated inversely with infarct growth (R=-0.51; P=0.009). CONCLUSIONS: Deconvolution and application of PWI thresholds provide more conservative estimates of tissue at risk and decrease the frequency of mismatch accordingly. The precise definition may not be critical; however, because reperfusion alters tissue fate irrespective of mismatch.
Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Angiografia por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/patologia , Idoso , Isquemia Encefálica/patologia , Artérias Cerebrais/patologia , Infarto Cerebral , Circulação Cerebrovascular , Difusão , Humanos , Processamento de Imagem Assistida por Computador , Pessoa de Meia-Idade , Perfusão , Terapia Trombolítica , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Studies of seizures after stroke have largely been retrospective, with small patient numbers and limited statistical analysis. Much of the doctrine about seizures after stroke is not evidenced based. OBJECTIVE: To determine the incidence, outcome, and risk factors for seizures after stroke. DESIGN: International, multicenter, prospective, analytic inception cohort study conducted for 34 months. PATIENTS AND SETTING: There were 2021 consecutive patients with acute stroke admitted to university teaching hospitals with established stroke units. After exclusion of 124 patients with previous epilepsy or without computed tomographic diagnosis, 1897 were available for analysis. Mean follow-up was 9 months. MAIN OUTCOME MEASURES: Occurrence of 1 or more seizures after stroke, stroke disability, and death after stroke. RESULTS: Seizures occurred in 168 (8.9%) of 1897 patients with stroke (28 [10.6%] of 265 with hemorrhagic and 140 [8.6%] of 1632 with ischemic stroke). On Kaplan-Meier survival analysis, patients with hemorrhagic stroke were at significantly greater risk of seizures (P =.002), with an almost 2-fold increase in risk of seizure after stroke (hazard ratio [HR], 1.85; 95% confidence interval [CI], 1.26-2.73; P =.002). On multivariate analysis, risk factors for seizures after ischemic stroke were cortical location of infarction (HR, 2.09; 95% CI, 1. 19-3.68; P<.01) and stroke disability (HR, 2.10; 95% CI, 1.16-3.82; P<.02). The only risk factor for seizures after hemorrhagic stroke was cortical location (HR, 3.16; 95% CI, 1.35-7.40; P<.008). Recurrent seizures (epilepsy) occurred in 47 (2.5%) of 1897 patients. Late onset of the first seizure was an independent risk factor for epilepsy after ischemic stroke (HR, 12.37; 95% CI, 4.74-32.32; P<. 001) but not after hemorrhagic stroke. CONCLUSIONS: Seizures occur more commonly with hemorrhagic stroke than with ischemic stroke. Only a small minority later develop epilepsy. Patients with a disabling cortical infarct or a cortical hemorrhage are more likely to have seizures after stroke; those with late-onset seizures are at greater risk of epilepsy.
Assuntos
Convulsões/etiologia , Acidente Vascular Cerebral/complicações , Idoso , Análise de Variância , Isquemia Encefálica/complicações , Hemorragia Cerebral/complicações , Infarto Cerebral/complicações , Feminino , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco , Convulsões/epidemiologia , Convulsões/terapia , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/mortalidade , Resultado do TratamentoRESUMO
Although the general guidelines for do-not-resuscitate (DNR) orders apply to acute stroke patients, few data are available to aid decision-making. With a view to developing specific guidelines for use in patients with acute stroke, we decided to evaluate the clinical factors associated with DNR orders at our university teaching hospital. We prospectively studied 450 consecutive patients with acute hemispheric strokes (237 men and 213 women, mean age 75 +/- 12 years). Thirty-six patients (8%) had intracerebral hemorrhage (ICH) and 414 (92%) had ischemic strokes. Overall inhospital mortality was 26%. DNR status was given to 31% of all patients at some time during their admission (83% of those died). DNR decision-making was closely associated with the severity of the neurologic deficit (Canadian Neurological Scale score < or = 5); the patient's incapacity for informed DNR decision-making; age (> 60 years); and devastating ICH unsuitable for surgery (p < 0.001). Fifty-three percent of DNR orders were given on admission (first 24 hours of the hospital stay), 35% during the first week of the hospital stay, due to brain damage, and 12% at any time between days 8 and 44 due to systemic complications. Once DNR status was given, 53% of patients continued to receive normal nutrition and 60% still received medical or surgical treatment. Although the current practice of DNR orders in patients with acute stroke is generally satisfactory, some criteria (eg, age and operable ICH) need revision.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Encefalopatias , Transtornos Cerebrovasculares/terapia , Ordens quanto à Conduta (Ética Médica) , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Transtornos Cerebrovasculares/mortalidade , Transtornos Cerebrovasculares/fisiopatologia , Tomada de Decisões , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de DoençaRESUMO
We studied six patients after intracerebral hemorrhage (ICH) and eight controls using positron emission tomography (PET) with to determine whether a zone of tissue hypoxia, possibly representing "penumbral" tissue, exists surrounding an intracerebral hemorrhage. None of the stroke patients, studied 24 to 43 hours after symptom onset, nor any of the controls exhibited areas of tissue hypoxia on 18F-fluoromisonidazole PET images. These findings may have implications for the treatment of intracerebral hemorrhage with neuroprotective strategies.
Assuntos
Hemorragia Cerebral/diagnóstico por imagem , Hipóxia Encefálica/diagnóstico por imagem , Misonidazol/análogos & derivados , Radiossensibilizantes , Tomografia Computadorizada de Emissão , Idoso , Idoso de 80 Anos ou mais , Feminino , Radioisótopos de Flúor , Humanos , Masculino , Sensibilidade e Especificidade , Acidente Vascular Cerebral/diagnóstico por imagemRESUMO
OBJECTIVE: To show that PET with 18F-fluoromisonidazole (18F-FMISO) can detect peri-infarct hypoxic tissue in patients after ischemic stroke. BACKGROUND: PET with (15)O-labeled oxygen and water is the only established method for identifying the ischemic penumbra in humans. We used PET with 18F-FMISO in patients after ischemic stroke to identify hypoxic but viable peri-infarct tissue likely to represent the ischemic penumbra, and to determine how long hypoxic tissues persist after stroke. METHODS: Patients with acute hemispheric ischemic stroke were studied using PET with 18F-FMISO either within 48 hours or 6 to 11 days after stroke onset. The final infarct was defined by CT performed 6 to 11 days after stroke. Tracer uptake was assessed objectively by calculating the mean activity in the contralateral (normal) hemisphere, then identifying pixels with activity greater than 3 SDs above the mean in both hemispheres. Positive studies were those with high-activity pixels ipsilateral to the infarct. RESULTS: Fifteen patients were studied; 13 within 48 hours of stroke, 8 at 6 to 11 days, and 6 during both time periods. Hypoxic tissue was detected in 9 of the 13 patients studied within 48 hours of stroke, generally distributed in the peripheries of the infarct and adjacent peri-infarct tissues. None of the 8 patients studied 6 to 11 days after stroke exhibited increased 18F-FMISO activity. All 6 patients studied both early and late exhibited areas of increased activity during the early but not the late study. CONCLUSIONS: PET with 18F-FMISO can detect peri-infarct hypoxic tissue after acute ischemic stroke. The distribution of hypoxic tissue suggests that it may represent the ischemic penumbra. Hypoxic tissues do not persist to the subacute phase of stroke (6 to 11 days).
Assuntos
Transtornos Cerebrovasculares/diagnóstico por imagem , Hipóxia Encefálica/diagnóstico por imagem , Misonidazol/análogos & derivados , Radiossensibilizantes , Tomografia Computadorizada de Emissão , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Radioisótopos de Flúor , Humanos , Masculino , Tomografia Computadorizada por Raios XRESUMO
RATIONALE AND OBJECTIVES: The authors present phantom validation of a method for computing pulsatile flow waveforms in arterial vessels from high-frame-rate biplane x-ray angiograms. METHODS: The three-dimensional course of a blood vessel is constructed from biplane digital x-ray angiograms. A parametric image of contrast mass versus time and true three-dimensional path length is generated. Adjacent contrast mass-distance profiles are matched to compute instantaneous velocity, which is multiplied by cross-sectional area to yield volume flow. An electromagnetic flowmeter was used to validate flow estimates in a phantom consisting of 150-mm tubes 3, 4, and 6 mm in diameter, orientated 15 degrees, 30 degrees, and 35 degrees to the imaging plane, with flow rates and waveforms expected in vivo. RESULTS: Mean and peak flows were accurate to within 9% and 10%, respectively, for velocities of less than 1 meter/second at a frame rate of 25 frames per second. CONCLUSIONS: A practical method for computing highly pulsatile flow waveforms in vivo in tortuous vessels is presented.
Assuntos
Algoritmos , Angiografia Digital , Processamento de Imagem Assistida por Computador , Velocidade do Fluxo Sanguíneo/fisiologia , Vasos Sanguíneos , Humanos , Modelos Cardiovasculares , Modelos Estruturais , Fluxo Pulsátil/fisiologiaRESUMO
Over the last 10 years, snowboarding has become established as a popular and legitimate alpine sport. However, at present, there are few epidemiological studies examining the spectrum of injuries associated with this new sport. Snowboarders are typically male (male: female ratio of 3:1) and in their early twenties. They have an injury rate of 4 to 6 per 1000 visits, which is comparable to that which occurs with skiing. However, in contrast to skiing, in which only 34% of those injured are beginners, the majority (60%) of snowboarders injured are beginners. This is a reflection of the participant profile of this developing sport. 57% of injuries occur in the lower limbs, and 30% in the upper limbs. The most common injuries are simple sprains (31 to 53%), particularly of the ankles (23 to 26%) and knees (12 to 23%), followed by fractures (24 to 27%) and contusions (12%). Compared with skiing injuries, snowboarders have 2.4 times as many fractures, particularly of the upper limbs (constituting 21 vs 35% of upper limb injuries), fewer knee injuries (23 vs 44% of lower limb injuries), but more ankle injuries (23 vs 6% of lower limb injuries). Snowboarding knee injuries are less severe than those associated with skiing. Fracture of the lateral process of the talus is an unusual and uncommon snowboarding injury that can be misdiagnosed as a severe ankle sprain. Ankle injuries are more common with soft shell boots, whereas knee injuries and distal tibia fractures are more common with hard shell boots.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Esqui/lesões , Adulto , Traumatismos do Tornozelo/epidemiologia , Traumatismos do Braço/epidemiologia , Traumatismos em Atletas/epidemiologia , Feminino , Fraturas Ósseas/epidemiologia , Humanos , Traumatismos do Joelho/epidemiologia , Masculino , Esqui/classificação , Vitória/epidemiologiaRESUMO
Single-photon emission computed tomography (SPECT) and transcranial Doppler sonography (TCD) may help to determine a target group of patients with maximum therapeutic response for tissue rescue after acute stroke. As previously described, the cerebral perfusion index represents a combination of these techniques, and is calculated by multiplying assigned values for TCD and SPECT perfusion patterns. The three grades of cerebral perfusion index (1-5, 6-12, 15-20) may predict short-term outcome if the index is based on SPECT and TCD performed within the first 6 hours after stroke. A total of 30 consecutive patients were studied (18 with middle cerebral artery stroke and 12 with transient ischemic attack or minor stroke). Neurological deficit was scored using the Canadian Neurological Scale. SPECT and TCD were performed 4 +/- 2 hours after the onset. Forty-five minutes were required to perform both tests, evaluate the results, and calculate the cerebral perfusion index. The mean score (+/- standard deviation) of the neurological deficit on admission was 84 +/- 20 in patients with transient ischemic attack/minor stroke and 54 +/- 33 in patients with stroke (p < 0.009). The volume of ischemic lesion was measured on computed tomography scans performed more than 3 days after the ictus. Patients with transient ischemic attack/minor stroke had lesion volumes of 8 +/- 7 cm3 compared to 72 +/- 26 cm3 for those with stroke (p < 0.0001). The mean cerebral perfusion index in the transient ischemic attack group was 18 +/- 4, while in the stroke group it was 4 +/- 1 (p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Isquemia Encefálica/fisiopatologia , Circulação Cerebrovascular/fisiologia , Doença Aguda , Idoso , Isquemia Encefálica/diagnóstico por imagem , Infarto Cerebral/diagnóstico por imagem , Infarto Cerebral/fisiopatologia , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/fisiopatologia , Ecoencefalografia , Feminino , Humanos , Ataque Isquêmico Transitório/diagnóstico por imagem , Ataque Isquêmico Transitório/fisiopatologia , Masculino , Exame Neurológico , Compostos de Organotecnécio , Oximas , Estudos Prospectivos , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Ultrassonografia Doppler TranscranianaRESUMO
Single-photon emission computed tomography (SPECT) with 99mtechnetium-hexamethylpropylamineoxime (HMPAO) noninvasively shows brain perfusion in patients after acute stroke. However, the clinical significance of the increased HMPAO uptake remains unclear. In this study, consecutive patients with hemispheric hemorrhagic and ischemic stroke admitted to the hospital were evaluated prospectively. The increased uptake of HMPAO was determined by visual analysis of SPECT images. The pathogenic mechanism of ischemic stroke was determined using the clinical and computed tomography (CT) criteria including the Toronto Embolic Scale. Of the 500 consecutive patients with acute hemispheric stroke, SPECT was performed in 458 at a mean time 5 +/- 7 days after the onset of symptoms. A strong association was found between SPECT perfusion patterns and pathogenic subtypes of stroke (p < 0.0001). Thus, in 95% of patients with intracerebral hemorrhage the focal absence of perfusion was found, and 26% of lacunar infarctions presented with a normal SPECT appearance. The mean volume of lacunar lesions that did not produce significant abnormalities on SPECT was 2.5 +/- 1.2 ml. Increased HMPAO uptake was associated with a cardioembolic mechanism of stroke: High and mixed perfusion patterns were present subacutely in 29% of patients with cardioembolic stroke, compared to 15% of patients with other types of ischemic stroke (p < or = 0.0006). The increased uptake of HMPAO on SPECT as determined by visual analysis is associated with a cardioembolic mechanism of cerebral ischemia, which could be explained by glutathione-mediated trapping of the tracer during reperfusion and later in newly developed granulation tissue. HMPAO-SPECT may help in early management decisions since it indicates stroke pathogenesis and evolution.
Assuntos
Encéfalo/metabolismo , Transtornos Cerebrovasculares/metabolismo , Compostos de Organotecnécio/farmacocinética , Oximas/farmacocinética , Tomografia Computadorizada de Emissão de Fóton Único , Doença Aguda , Idoso , Encéfalo/diagnóstico por imagem , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/metabolismo , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/metabolismo , Circulação Cerebrovascular , Transtornos Cerebrovasculares/diagnóstico por imagem , Feminino , Glutationa/metabolismo , Tecido de Granulação/diagnóstico por imagem , Humanos , Embolia e Trombose Intracraniana/diagnóstico por imagem , Embolia e Trombose Intracraniana/metabolismo , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reperfusão , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada por Raios XRESUMO
Single-photon emission computed tomography (SPECT) and transcranial Doppler (TCD) ultrasound are of good prognostic value in acute stroke, and combined they may be an accurate way to determine a target group of patients with maximum therapeutic response. Seventy consecutive patients were studied (42 with middle cerebral artery strokes, 18 with transient ischemic attacks {TIAs}; 10 were excluded due to failure of insonation). Two SPECT studies were performed at 2.1 +/- 1.2 and 13.8 +/- 3.1 days after onset. Serial TCD studies were done at 10 hours and at the time of the SPECT studies. Neurological deficit was scored on admission and 2 weeks later (using the Canadian Neurological Scale). Cerebral perfusion index (CPI) was derived by multiplying the values for TCD and SPECT patterns. Positive correlation was obtained in all 16 patients in whom cerebral angiography was performed within the first 3 days after onset. The occlusive TCD pattern and absence of perfusion on SPECT were common in the stroke group (19/42 patients) and were never seen in those with TIAs. A normal TCD pattern and normal perfusion on SPECT were more common in the patients with TIAs (9/18 vs 8/42, p = 0.02; 5/10 vs 1/40, p = 0.0003). The occlusive TCD and SPECT patterns were associated with the highest mean infarction volume (147 +/- 87 vs 19 +/- 21, p less than 0.0001) and all nonocclusive TCD and SPECT patterns were associated with the better short-term outcome (43.2 +/- 33.9 vs 92.4 +/- 20.2, p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)