Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
Lancet Neurol ; 20(6): 426-436, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34022169

RESUMO

BACKGROUND: Systematic electrocardiogram (ECG) monitoring improves detection of covert atrial fibrillation in stroke survivors but the effect on secondary prevention is unknown. We aimed to assess the effect of systematic ECG monitoring of patients in hospital on the rate of oral anticoagulant use after 12 months. METHODS: In this investigator-initiated, randomised, open-label, parallel-group multicentre study with masked endpoint adjudication, we recruited patients aged at least 18 years with acute ischaemic stroke or transient ischaemic attack without known atrial fibrillation in 38 certified stroke units in Germany. Patients were randomly assigned (1:1) to usual diagnostic procedures for atrial fibrillation detection (control group) or additional Holter-ECG recording for up to 7 days in hospital (intervention group). Patients were stratified by centre using a random permuted block design. The primary outcome was the proportion of patients on oral anticoagulants at 12 months after the index event in the intention-to-treat population. Secondary outcomes included the number of patients with newly diagnosed atrial fibrillation in hospital and the composite of recurrent stroke, major bleeding, myocardial infarction, or death after 6 months, 12 months, and 24 months. This trial was registered with ClinicalTrials.gov, NCT02204267, and is completed and closed for participants. FINDINGS: Between Dec 9, 2014, and Sept 11, 2017, 3465 patients were randomly assigned, 1735 (50·1%) to the intervention group and 1730 (49·9%) to the control group. Oral anticoagulation status was available in 2920 (84·3%) patients at 12 months (1484 [50·8%] in the intervention group and 1436 [49·2%] in the control group). For the primary outcome, at 12 months, 203 (13·7%) of 1484 patients in the intervention group versus 169 (11·8%) of 1436 in the control group were on oral anticoagulants (odds ratio [OR] 1·2 [95% CI 0·9-1·5]; p=0·13). Atrial fibrillation was newly detected in patients in hospital in 97 (5·8%) of 1714 in the intervention group versus 68 (4·0%) of 1717 in the control group (hazard ratio [HR] 1·4 [95% CI 1·0-2·0]; p=0·024). The composite of cardiovascular outcomes and death did not differ between patients randomly assigned to the intervention group versus the control group at 24 months (232 [13·5%] of 1714 vs 249 [14·5%] of 1717; HR 0·9 [0·8-1·1]; p=0·43). Skin reactions due to study ECG electrodes were reported in 56 (3·3%) patients in the intervention group. All-cause death occured in 73 (4·3%) patients in the intervention group and in 103 (6·0%) patients in the control group (OR 0·7 [0·5-0·9]). INTERPRETATION: Systematic core centrally reviewed ECG monitoring is feasible and increases the detection rate of atrial fibrillation in unselected patients hospitalised with acute ischaemic stroke or transient ischaemic attack, if added to usual diagnostic care in certified German stroke units. However, we found no effect of systematic ECG monitoring on the rate of oral anticoagulant use after 12 months and further efforts are needed to improve secondary stroke prevention. FUNDING: Bayer Vital. TRANSLATION: For the German translation of the abstract see Supplementary Materials section.


Assuntos
Fibrilação Atrial/fisiopatologia , Isquemia Encefálica/fisiopatologia , AVC Isquêmico/fisiopatologia , Monitorização Fisiológica/métodos , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/epidemiologia , Eletrocardiografia/métodos , Feminino , Humanos , AVC Isquêmico/diagnóstico , AVC Isquêmico/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco
2.
Arch Cardiovasc Dis ; 111(4): 246-256, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29113786

RESUMO

BACKGROUND: Pulmonary dysfunction and cardiovascular disease are major causes of impaired health status in later life, and co-development of these diseases has been reported. AIM: To better understand the pathobiology involved in the co-development of these diseases. METHODS: We investigated the impact of pulmonary dysfunction on the development of cardiovascular disease among people aged≥50 years in the English longitudinal study of ageing (ELSA). Hazard ratios were estimated by Cox proportional hazards regression models, with and without a time-dependent update of exposure and confounders. Pulmonary function was divided into three categories, with the least affected category as the reference. RESULTS: People with pulmonary dysfunction were at higher risk of developing cardiovascular disease than those with normal pulmonary function: the hazard ratio for pulmonary dysfunction versus healthy in the time-dependent crude analysis of model 1, adjusted for age, body mass index, sex, angina pectoris and heart arrhythmia, was 1.49 (95% confidence interval 1.2-1.9). The effect varied with the precise definition of pulmonary dysfunction and the subtype of the cardiovascular disease, and decreased after correction for some additional confounders but not after correction for inflammatory biomarkers. CONCLUSIONS: A history of pulmonary disease increased the risk of developing cardiovascular disease, but inflammation did not seem to alter the effect of pulmonary dysfunction on cardiovascular disease development. This insight may lead to better understanding and treatment of cardiovascular comorbidities in pulmonary disease; it also indicates that the potentially beneficial effect of targeted anti-inflammatory drugs for pulmonary disease, in terms of reducing cardiovascular risk in these patients, may be limited.


Assuntos
Doenças Cardiovasculares/epidemiologia , Pneumopatias/epidemiologia , Pulmão/fisiopatologia , Fatores Etários , Idoso , Biomarcadores/sangue , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/fisiopatologia , Comorbidade , Inglaterra/epidemiologia , Feminino , Volume Expiratório Forçado , Humanos , Incidência , Mediadores da Inflamação/sangue , Estimativa de Kaplan-Meier , Estudos Longitudinais , Pneumopatias/diagnóstico , Pneumopatias/fisiopatologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Fatores de Risco , Fatores de Tempo , Capacidade Vital
3.
Front Cell Neurosci ; 11: 238, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28860969

RESUMO

Understanding processes performed by an intact visual cortex as the basis for developing methods that enhance or restore visual perception is of great interest to both researchers and medical practitioners. Here, we explore whether contrast sensitivity, a main function of the primary visual cortex (V1), can be improved in healthy subjects by repetitive, noninvasive anodal transcranial direct current stimulation (tDCS). Contrast perception was measured via threshold perimetry directly before and after intervention (tDCS or sham stimulation) on each day over 5 consecutive days (24 subjects, double-blind study). tDCS improved contrast sensitivity from the second day onwards, with significant effects lasting 24 h. After the last stimulation on day 5, the anodal group showed a significantly greater improvement in contrast perception than the sham group (23 vs. 5%). We found significant long-term effects in only the central 2-4° of the visual field 4 weeks after the last stimulation. We suspect a combination of two factors contributes to these lasting effects. First, the V1 area that represents the central retina was located closer to the polarization electrode, resulting in higher current density. Second, the central visual field is represented by a larger cortical area relative to the peripheral visual field (cortical magnification). This is the first study showing that tDCS over V1 enhances contrast perception in healthy subjects for several weeks. This study contributes to the investigation of the causal relationship between the external modulation of neuronal membrane potential and behavior (in our case, visual perception). Because the vast majority of human studies only show temporary effects after single tDCS sessions targeting the visual system, our study underpins the potential for lasting effects of repetitive tDCS-induced modulation of neuronal excitability.

4.
Front Hum Neurosci ; 9: 236, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25972805

RESUMO

Chronic communication impairment is common after stroke, and conventional speech and language therapy (SLT) strategies have limited effectiveness in post-stroke aphasia. Neurorehabilitation with non-invasive brain stimulation techniques (NIBS)-particularly repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS)-may enhance the effects of SLT in selected patients. Applying inhibitory NIBS to specific homologous language regions may induce neural reorganization and reduce interhemispheric competition. This mini review highlights randomized controlled trials (RCTs) and randomized cross-over trials using low-frequency rTMS or cathodal tDCS over the non-lesioned non-language dominant hemisphere and performs an exploratory meta-analysis of those trials considered combinable. Using a random-effects model, a meta-analysis of nine eligible trials involving 215 participants showed a significant mean effect size of 0.51 (95% CI = 0.24-0.79) for the main outcome "accuracy of naming" in language assessment. No heterogeneity was observed (I (2) = 0%). More multicenter RCTs with larger populations and homogenous intervention protocols are required to confirm these and the longer-term effects.

5.
Restor Neurol Neurosci ; 29(6): 453-61, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22278016

RESUMO

PURPOSE: TDCS can increase excitability in the visual cortex. It is a matter of current debate if tDCS can improve visual performance. Promising parameters to measure detection sensitivity may be those of the signal detection theory ( = SDT), as it allows differentiating between response bias and detection sensitivity changes. The measure of detection sensitivity can be used to predict actual performance under a wide variety of different response criteria. METHODS: Here we test if the SDT can quantify tDCS-induced effects in a visual contrast discrimination task in healthy subjects. RESULTS: Anodal stimulation of the visual cortex improved performance, as calculated by detection sensitivity for stimuli presented in the center of the visual field. More peripheral locations in the visual field were unaffected by anodal stimulation. Cathodal stimulation and sham stimulation of the visual cortex had no consistent effect on detection sensitivity. The response bias was not affected by any type of stimulation. CONCLUSIONS: Neuroplastic changes in the visual cortex induced by anodal tDCS can be measured by SDT, suggesting SDT could prospectively be a useful approach for monitoring restorative tDCS-effects on visual function in patients with central visual deficits.


Assuntos
Mapeamento Encefálico , Detecção de Sinal Psicológico , Córtex Visual/fisiologia , Adulto , Análise de Variância , Eletrodos , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Psicofísica , Tempo de Reação/fisiologia , Estimulação Magnética Transcraniana/métodos , Adulto Jovem
6.
Exp Brain Res ; 207(3-4): 283-90, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21046369

RESUMO

In this study, we aimed to characterize the effect of anodal and cathodal direct current stimulation (tDCS) on contrast sensitivity inside the central 10 degrees of the visual field in healthy subjects. Distinct eccentricities were investigated separately, since at the cortical level, more central regions of the visual field are represented closer to the occipital pole, i.e. closer to the polarizing electrodes, than are the more peripheral regions. Using a double-blind and sham-controlled within-subject design, we measured the effect of stimulation and potential learning effect separately across testing days. Anodal stimulation of the visual cortex compared to sham stimulation yielded a significant increase in contrast sensitivity within 8° of the visual field. A significant increase in contrast sensitivity between the conditions "pre" and "post" anodal stimulation was only obtained for the central positions at eccentricities smaller than 2°. Cathodal stimulation of the visual cortex did not affect contrast sensitivity at either eccentricity. Perceptual learning across testing days was only observed for threshold perimetry before stimulation. Measuring contrast sensitivity changes after tDCS with a standard clinical tool such as threshold perimetry may provide an interesting perspective in assessing therapeutic effects of tDCS in ophthalmological or neurological defects (e.g. with foveal sparing vs. foveal splitting).


Assuntos
Sensibilidades de Contraste/fisiologia , Terapia por Estimulação Elétrica/métodos , Aprendizagem/fisiologia , Córtex Visual/fisiologia , Adulto , Método Duplo-Cego , Feminino , Humanos , Masculino
7.
PLoS One ; 3(9): e3167, 2008 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-18779857

RESUMO

To what extent are the left and right visual hemifields spatially coded in the dorsal frontoparietal attention network? In many experiments with neglect patients, the left hemisphere shows a contralateral hemifield preference, whereas the right hemisphere represents both hemifields. This pattern of spatial coding is often used to explain the right-hemispheric dominance of lesions causing hemispatial neglect. However, pathophysiological mechanisms of hemispatial neglect are controversial because recent experiments on healthy subjects produced conflicting results regarding the spatial coding of visual hemifields. We used an fMRI paradigm that allowed us to distinguish two attentional subprocesses during a visual search task. Either within the left or right hemifield subjects first attended to stationary locations (spatial orienting) and then shifted their attentional focus to search for a target line. Dynamic changes in spatial coding of the left and right hemifields were observed within subregions of the dorsal front-parietal network: During stationary spatial orienting, we found the well-known spatial pattern described above, with a bilateral hemifield representation in the right hemisphere and a contralateral preference in the left hemisphere. However, during search, the right hemisphere had a contralateral preference and the left hemisphere equally represented both hemifields. This finding leads to novel perspectives regarding models of visuospatial attention and hemispatial neglect.


Assuntos
Lobo Frontal/fisiologia , Lobo Parietal/fisiologia , Percepção Espacial/fisiologia , Percepção Visual/fisiologia , Adulto , Comportamento , Percepção de Forma , Lateralidade Funcional/fisiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Memória , Orientação/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Projetos de Pesquisa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...