33 research outputs found

    Assessing the Predictive Validity of Simple Dementia Risk Models in Harmonized Stroke Cohorts

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    BACKGROUND AND PURPOSE: Stroke is associated with an increased risk of dementia. To assist in the early identification of individuals at high risk of future dementia, numerous prediction models have been developed for use in the general population. However, it is not known whether such models also provide accurate predictions among stroke patients. Therefore, the aim of this study was to determine whether existing dementia risk prediction models that were developed for use in the general population can also be applied to individuals with a history of stroke to predict poststroke dementia with equivalent predictive validity. METHODS: Data were harmonized from 4 stroke studies (follow-up range, ‚Čą12‚Äď18 months poststroke) from Hong Kong, the United States, the Netherlands, and France. Regression analysis was used to test 3 risk prediction models: the Cardiovascular Risk Factors, Aging and Dementia score, the Australian National University Alzheimer Disease Risk Index, and the Brief Dementia Screening Indicator. Model performance or discrimination accuracy was assessed using the C statistic or area under the curve. Calibration was tested using the Gr√łnnesby and Borgan and the goodness-of-fit tests. RESULTS: The predictive accuracy of the models varied but was generally low compared with the original development cohorts, with the Australian National University Alzheimer Disease Risk Index (C-statistic, 0.66) and the Brief Dementia Screening Indicator (C-statistic, 0.61) both performing better than the Cardiovascular Risk Factors, Aging and Dementia score (area under the curve, 0.53). CONCLUSIONS: Dementia risk prediction models developed for the general population do not perform well in individuals with stroke. Their poor performance could have been due to the need for additional or different predictors related to stroke and vascular risk factors or methodological differences across studies (eg, length of follow-up, age distribution)

    Approche neuropsychologique des troubles émotionnels dans la schizophrénie

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    Stabilized schizophrenia is characterized by cognitive and emotional deficits. Recent works adopted a dynamic view of the relationship between cognition; motivation and emotion in schizophrenia. The objective of this work was to describe the impairments of recognition; subjective feelings and physiological reactions related to emotions in stabilized schizophrenia. The influence of cognitive impairment and apathy on the emotional processes was also explored. In a first study on a group of 23 patients with schizophrenia; we highlighted the introduction of bias in the recognition of emotion in two sensory modalities (visual and auditory). In the next study; we investigated the influence of executive function disorders in the subjective feeling of emotions. With film excerpts; we showed that a disorder in executive functions could lead the introduction of a mixed subjective feeling in schizophrenia. Apathy is a common disorder in schizophrenia and may influence emotional processes. In a third study; we investigated the impact of apathy on physiological reactions induced by emotion. We have shown that the severity of apathy was correlated with a decrease in electrodermal activity during induction of positive emotions. The results of these studies show an impact of cognitive and motivational disturbances in emotional processes in stabilized schizophrenia. This work encourages us to explore the neural bases of the interaction between emotion and cognition in schizophrenia. Clinical applications are also discussed.Les troubles schizophr√©niques stabilis√©s s'accompagnent souvent de d√©ficits cognitifs et √©motionnels. Les plus r√©cents travaux mettent en relation la cognition, la motivation et les √©motions dans la pr√©sentation cliniques des troubles schizophr√©niques. L'objectif de ce travail est de d√©crire les troubles de la reconnaissance des √©motions, du sentiment subjectif et des r√©actions physiologiques li√©es aux √©motions dans les troubles schizophr√©niques stabilis√©s. L'influence des troubles cognitifs et de l'apathie sur les processus √©motionnels est √©galement explor√©e. Dans une premi√®re √©tude, nous avons mis en √©vidence l'introduction de biais dans la reconnaissance des √©motions dans deux modalit√©s sensorielles (visuelle et auditive).Dans l'√©tude suivante, nous nous sommes int√©ress√©s √† l'influence des troubles des fonctions ex√©cutives dans le sentiment subjectif des √©motions. A l'aide d'extrait de films, nous avons montr√© qu'un trouble des fonctions ex√©cutives pouvait entra√ģner l'introduction d'un ressenti √©motionnel nuanc√© dans les troubles schizophr√©niques stabilis√©s. L'apathie est un trouble fr√©quent dans la schizophr√©nie et peut influencer les processus √©motionnels. Dans un troisi√®me travail, nous avons √©tudi√© l'impact de l'apathie sur les r√©actions physiologiques induites par les √©motions. Nous avons montr√© que la s√©v√©rit√© de l'apathie √©tait corr√©l√©e √† une diminution de l'activit√© √©lectrodermale lors de l'induction d'√©motions positives. Les r√©sultats de ces travaux montrent un impact des troubles cognitifs et motivationnels sur les processus √©motionnels dans les troubles schizophr√©niques stabilis√©s. Ces travaux nous encouragent √† explorer les bases c√©r√©brales de l'interaction entre √©motion et cognition dans la schizophr√©nie. Des applications cliniques sont √©galement discut√©es

    Modulatory effects of happy mood on performance monitoring: Insights from error-related brain potentials

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    International audienceGoal-adaptive behavior requires the rapid detection of conflicts between actions and intentions or goals. Although many studies have focused in the past on the influence of negative affect on this cognitive control process (and more specifically, on error monitoring), little is known about the possible modulatory effects of positive affect on it. To address this question, we used a standard (positive) mood induction procedure (based on guided imagery) and asked participants to carry out a speeded go/no-go task while high-density electroencephalography was recorded concurrently. As a control condition, we used a group with neutral mood. Event-related potential results showed that the error-related negativity (ERN) component, reflecting early error detection within the dorsal anterior cingulate cortex, was not influenced by happy mood. In contrast, the subsequent error positivity (Pe) component, related to the appraisal of the motivational significance of errors, was reliably smaller in the happy than in the neutral mood group. Complementing source localization analyses showed that this effect was explained by decreased activation within the posterior cingulate and insular cortices. These results were obtained in the absence of group differences regarding behavioral performance and tonic arousal. These findings suggest that happy mood likely decreases and changes the motivational significance of worse-than-expected events (Pe), while leaving their earlier automatic detection (ERN) unaltered. We discuss these new results in terms of dynamic changes in the complex interplay of performance monitoring with motivation

    Emotional processing in Parkinson's disease: a systematic review.

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    International audienceParkinson's disease provides a useful model for studying the neural substrates of emotional processing. The striato-thalamo-cortical circuits, like the mesolimbic dopamine system that modulates their function, are thought to be involved in emotional processing. As Parkinson's disease is histopathologically characterized by the selective, progressive, and chronic degeneration of the nigrostriatal and mesocorticolimbic dopamine systems, it can therefore serve as a model for assessing the functional role of these circuits in humans. In the present review, we begin by providing a synopsis of the emotional disturbances observed in Parkinson's disease. We then discuss the functional roles of the striato-thalamo-cortical and mesolimbic circuits, ending with the conclusion that both these pathways are indeed involved in emotional processing

    The nucleus accumbens: a target for deep brain stimulation in resistant major depressive disorder

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    International audienceObjectiveThis review aimed to investigate the therapeutic potential of Deep Brain Stimulation (DBS) for treating resistant Major Depressive Disorder (MDD). We explored the role of Nucleus accumbens (Nac) as a target for treatment.MethodWe made a systematic review of all studies examining the mechanisms of action of high frequency brain stimulation and the pathophysiology of MDD. We also reported all the studies exploring the therapeutic potential of DBS in MDD.ResultsAs a central relay-structure, the Nac seems to play a central role in MDD symptomatology. We investigated its role as a primary target for DBS in depressed patients. Anatomically the Nac is at the centre of the interactions between dopaminergic, serotoninergic and glutamatergic systems. Functionally, the Nac is involved in both normal and abnormal reward processes and in anhedonia and loss of motivation. Due to its central location between the emotional system, the cognitive system and motor control system, the Nac seems to have a central role in mood and feeling regulation.ConclusionAccording to encouraging recent studies, DBS seems to be a promising technique in resistant MDD treatment

    Pallidal stimulation in advanced Parkinson's patients with contraindications for subthalamic stimulation.

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    International audienceThe aim of this study was to evaluate the efficacy and safety of bilateral pallidal (GPi) deep brain stimulation (DBS) 6 months after surgery in advanced parkinsonian patients whose dopa-resistant axial motor signs or cognitive decline constituted contraindications for subthalamic nucleus (STN) DBS. Seventeen patients with a mean age of 59.3 ¬Ī 7.1 years (range, 45-70), mean disease duration of 12.5 ¬Ī 4.3 years (range, 7-20), and contraindications for STN DBS, underwent bilateral GPi DBS. They were evaluated before surgery and 6 months afterward, in accordance with Core Assessment Program for Intracerebral Transplantation recommendations. There were mean improvements of 41.1% in the UPDRS III motor score in the off-dopa condition and 20.3% in the activities of daily living score. Motor fluctuations were reduced by 22.9% and dyskinesias by 68.6%. Axial motor signs improved in the off-dopa condition by 34.2%. Neuropsychological performances remained unchanged at the 6-month assessment. Bilateral GPi DBS is both safe and effective in advanced parkinsonian patients with untreatable motor fluctuations, for whom STN DBS is contraindicated due to dopa-resistant axial motor signs or cognitive decline. As such, it should be regarded as a viable option for these patients
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