121 research outputs found
Influence of dementia on antithrombotic therapy prescribed before stroke in patients with atrial fibrillation.
No full textSecondary prevention of stroke in patients with atrial fibrillation: factors influencing the prescription of oral anticoagulation at discharge.
No full textCholinergic modulation of stimulus-driven attentional capture
No full textDistraction is one of the main problems encountered by people with degenerative diseases that are associated with reduced cortical cholinergic innervations. We examined the effects of donepezil, a cholinesterase inhibitor, on stimulus-driven attentional capture. Reflexive attention shifts to a distractor are usually elicited by abrupt peripheral changes. This bottom-up shift of attention to a salient item is thought to be the result of relatively inflexible hardwired mechanisms. Thirty young male participants were randomly allocated to one of two groups: placebo first/donepezil second session or the opposite. They were asked to locate a target appearing above and below fixation whilst a peripheral distractor moved abruptly (motion-jitter attentional capture condition) or not (baseline condition). A classical attentional capture effect was observed under placebo: moving distractors interfered with the task in slowing down response times as compared to the baseline condition with fixed distractors. Increased interference from moving distractors was found under donepezil. We suggest that attentional capture in our paradigm likely involved low level mechanisms such as automatic reflexive orienting. Peripheral motion-jitter elicited a rapid reflexive orienting response initiated by a cholinergic signal from the brainstem pedunculo-pontine nucleus that activates nicotinic receptors in the superior colliculus
Prestroke dementia in patients with atrial fibrillation: Frequency and associated factors
No full textBackground and purpose: Prestroke dementia is frequent but usually not identified. Non-valvular atrial fibrillation (NVAF) is independently associated with an increased risk for dementia. However, the frequency and determinants of prestroke dementia in patients with NVAF have never been evaluated. Objective: The aim of this study was to determine the frequency of prestroke dementia and associated factors in patients with a previously known NVAF. Methods: This is an ancillary study of Stroke in Atrial Fibrillation Ensemble II (SAFE II), an observational study conducted in patients with a previously known NVAF, consecutively admitted for an acute stroke in French and Italian centers. Prestroke dementia was evaluated by the IQCODE in patients with a reliable informant. Patients were considered as demented before stroke when their IQCODE score was ≥ 104. Results: of 204 patients, 39 (19.1 %; 95 % confidence interval [CI]: 13.7 %-24.5 %) patients met criteria for prestroke dementia. The only variable independently associated with prestroke dementia was increasing age (adjusted odds ratio for 1 year increase in age: 1.10; 95 % CI: 1.04-1.17), and there was a non-significant tendency for previous ischemic stroke or TIA and arterial hypertension. Conclusion: One fifth of stroke patients with a previously known NVAF were already demented before stroke. The main determinant of prestroke dementia is increasing age. A large cohort is necessary to identify other determinants
Influence of dementia on antithrombotic therapy prescribed before stroke in patients with atrial fibrillation
No full textBackground and purpose: Oral anticoagulation (OAC) decreases the risk of stroke in patients with nonvalvular atrial fibrillation (NVAF), but remains underused in practice. The aim of this study was to test the hypothesis that prestroke dementia influenced the nonprescription of OAC before stroke. Methods: This is an ancillary study of Stroke in Atrial Fibrillation Ensemble II, an observational study conducted in patients with a previously known NVAF, consecutively admitted for an acute stroke to French and Italian centers. Prestroke dementia was evaluated by the clinical physician and validated by an Informant Questionnaire for Cognitive Decline in the Elderly score of ≥ 104 in patients with a reliable informant. Results: Of 204 patients, 24 patients met criteria for prestroke dementia according to GP's opinion. The only variables independently associated with OAC before stroke were follow-up by a cardiologist (adjusted OR: 3.33; 95% CI: 1.47-7.53) and a younger age of patients (adjusted OR: 0.94; 95% CI: 0.89-0.99). Variables independently associated with any antithrombotic drug therapy before stroke were follow-up by a general practitioner (adjusted OR: 2.78; 95% CI: 1.09-7.11), and by a cardiologist (adjusted OR: 3.15; 95% CI: 1.48-6.69). Conclusion: In daily practice, the under-prescription of OAC in patients with NVAF mainly depends on co-morbidity and on characteristics of the physician, not on prestroke dementia. Copyright © 2006 S. Karger AG
Facteurs pronostiques à court et moyen terme de l'accident ischémique cérébral (intérêt du dosage de la troponine)
No full textContexte : Les accidents ischémiques cérébraux sont des causes majeures de handicap et de mortalité. La troponine pourrait être un marqueur du pronostic à court et moyen terme qui permettrait d améliorer la prise en charge des patients. Patients et méthodes : De juin 2005 à juin 2006, tout patient présentant un accident ischémique cérébral admis dans les 48 premières heures a été inclus dans l étude. Les éléments cliniques, biologiques et thérapeutiques ont été relevés, ainsi que la mortalité à 3 mois et le pronostic fonctionnel à 8 jours et à 3 mois (Rankin 0-1, Barthel 95-100). Plusieurs analyses univariées ont été effectuées pour déterminer l influence de différents facteurs sur le taux de troponine ainsi que sur le pronostic fonctionnel ou la mortalité. Enfin, des analyses multivariées ont été réalisées pour distinguer les facteurs pronostiques indépendants de mortalité à 3 mois et du bon pronostic fonctionnel à 8 jours et 3 mois. Résultats : 121 patients ont été inclus dans cette étude. Un taux élevé de troponine à l admission semblait avoir une influence péjorative sur la mortalité à 3 mois (0,14 vs 0,03 ng/ml), et sur le pronostic fonctionnel au 8ème jour (Barthel 95-100 et Rankin 0-1: 0,02 vs 0,07 ng/ml) et au 3ème mois (Rankin 0-1: 0,02 vs 0,07 ng/ml). Cependant, les analyses multivariées ne permettaient pas de retenir la troponine comme un facteur pronostique indépendant. A l'inverse, le NIHSS à l admission semblait être à la fois un facteur pronostique indépendant de mortalité à 3 mois (OR=1,27 IC95%=1,07-1,51), et de mauvais pronostic fonctionnel à 8 jours (Barthel 95-100: OR=0,72 IC95%=0,62-0,83; Rankin 0-1: OR=0,75 IC95%=0,67-0,84) et à 3 mois (Barthel 95-100: OR=0,87 IC95%=0,81-0,94; Rankin 0-1: OR=0,83 IC95%=0,76-0,99). Un antécédent d accident ischémique transitoire semblait être un facteur pronostique indépendant de mortalité au 3ème mois (OR=33,9 IC95%=1,04-1108,66), comme le taux de polynucléaires neutrophiles à l admission (OR=1,43 IC95%=1,07-1,92). Enfin, la pratique d une activité physique semblait être un facteur indépendant de meilleur pronostic fonctionnel au 8ème jour (Barthel 95-100 : OR 4,22IC95%=1,24-14,32). Conclusion: le NIHSS doit être impérativement coté à l admission de tout accident ischémique cérébral devant sa valeur pronostique majeure à court et moyen terme. Améliorer la prévention secondaire et encourager la pratique d une activité physique chez tout patient à risque vasculaire pourraient permettre d améliorer le pronostic des accidents ischémiques cérébraux.LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF
Stroke prevention and atrial fibrillation: Reasons leading to an inappropriate management. Main results of the SAFE II study
No full textAims: The aim of the Stroke and Atrial Fibrillation Ensemble (SAFE) II study was to identify the reasons underlying the under-utilization of oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (NVAF). Methods: We investigated from all available sources the reasons why patients hospitalized for a stroke, who had a previously known NVAF, were not receiving OAC beforehand. We interviewed general practitioners (GPs) and cardiologists with a structured questionnaire, to identify the reasons for their therapeutic choice. Results: Of 370 patients, 257 were theoretically eligible for OAC according to guidelines and the presence of contra-indications, but only 82 (22.2%) of them had actually received OAC before. We found that factors independently associated with the prescription of OAC were being followed-up by a cardiologist and having a younger GP. The leading reason evoked by GPs or cardiologists to explain why patients were not treated with OAC was the presence of a 'potential contra-indication', which was often inappropriate, followed by 'there was no indication', 'low compliance' and 'fear of bleeding'. Conclusions: An important reason for not prescribing OAC was the lack of knowledge about trials and guidelines. Medical education about OAC in NVAF should therefore be improved
Interfacial anchor properties of tryptophan residues in transmembrane peptides can dominate over hydrophobic matching effects in peptide-lipid interactions
No full textMembrane model systems consisting of phosphatidylcholines and hydrophobic -helical peptides with tryptophan flanking residues, a characteristic motif for transmembrane protein segments, were used to investigate the contribution of tryptophans to peptide-lipid interactions. Peptides of different lengths and with the flanking tryptophans at different positions in the sequence were incorporated in relatively thick or thin lipid bilayers. The organization of the systems was assessed by NMR methods and by hydrogen/deuterium exchange in combination with mass spectrometry. Previously, it was found that relatively short peptides induce nonlamellar phases and that relatively long analogues order the lipid acyl chains in response to peptide-bilayer mismatch. Here it is shown that these effects do not correlate with the total hydrophobic peptide length, but instead with the length of the stretch between the flanking tryptophan residues. The tryptophan indole ring was consistently found to be positioned near the lipid carbonyl moieties, regardless of the peptide-lipid combination, as indicated by magic angle spinning NMR measurements. These observations suggest that the lipid adaptations are not primarily directed to avoid a peptide-lipid hydrophobic mismatch, but instead to prevent displacement of the tryptophan side chains from the polar-apolar interface. In contrast, long lysine-flanked analogues fully associate with a bilayer without significant lipid adaptations, and hydrogen/deuterium exchange experiments indicate that this is achieved by simply exposing more (hydrophobic) residues to the lipid headgroup region. The results highlight the specific properties that are imposed on transmembrane protein segments by flanking tryptophan residues
Atherogenic Dyslipidemia in Patients With Transient Ischemic Attack
No full textBackground and Purpose-There is mounting evidence that atherogenic dyslipidemia (ie, low high-density lipoprotein cholesterol combined with high triglyceride concentrations) is an independent predictor of high cardiovascular risk and possibly of stroke. Methods-All patients included in the SOS-TIA cohort underwent an initial standardized evaluation, including medical history, physical examination, routine blood biochemistry, and diagnostic testing, and were followed for 1 year. Lipid profile was evaluated under fasting conditions. Atherogenic dyslipidemia was defined as high-density lipoprotein cholesterol blood concentration = 150 mg/dL. Results-Among 1471 consecutive patients with transient ischemic attack (TIA) or minor stroke, overall prevalence of atherogenic dyslipidemia was 5.8%, but varied from 4.6% to 11.1%, depending on final diagnosis (possible TIA or TIA with a cerebral ischemic lesion, respectively). Prevalence of atherogenic dyslipidemia was independently associated with male sex, diabetes, and body mass index, but not with ABCD2 score. Atherogenic dyslipidemia also strongly associated with symptomatic intracranial stenosis >= 50% (adjusted odds ratio, 2.77; 95% CI, 1.38-5.55), but not with symptomatic extracranial stenosis >= 50% (adjusted odds ratio, 1.20; 95% CI, 0.64-2.26). Despite appropriate secondary prevention treatment, 90-day stroke risk was greater in patients with versus without atherogenic dyslipidemia (4.8% versus 1.7%; P=0.04). Conclusions-The atherogenic dyslipidemia phenotype in patients with TIA may be associated with intracranial artery stenosis and higher risk of early recurrent stroke. Additional data are needed to confirm these findings and to assess the best way to reduce important residual risk in such patients. (Stroke. 2011;42:2131-2137.
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