Comparaison des potentiels évoqués cognitifs de patients présentant des tics chroniques simples ou complexes

Les tics affectent 1% des individus et sont associés avec une diminution de la qualité de vie. L’importante hétérogénéité phénoménologique retrouvée chez ceux-ci représente un obstacle majeur pour l’évaluation et le traitement de ces symptômes, et explique potentiellement la présence de données neurobiologiques contradictoires. Certaines variables rarement contrôlées, comme la complexité des tics et la demande motrice des tâches pourraient expliquer l’hétérogénéité de ces résultats. Une meilleure compréhension des processus cognitifs affectés pourrait être atteinte par l’étude de la chronométrie des événements cérébraux. Ainsi, notre objectif était d’évaluer l’impact de la complexité des tics et du type de réponse sur les potentiels électrocorticaux liés à l’inhibition, à l’attention et à la mémoire de patients tics. Nous avons comparé 12 patients présentant des tics simples avec 12 patients atteints de tics complexes, qui furent appariés à 15 participants contrôles sains. Deux tâches oddball furent accomplies, dont l’une exigeait une réponse motrice et l’autre une réponse non-motrice (compter le nombre de stimuli). Durant ces tâches, nous avons enregistré des composantes électrocorticales indexant des processus d’attention (P200), d’inhibition (N200) et de mémoire (P300). Pour la tâche non-motrice, nos résultats révélèrent une N200 plus ample chez les deux groupes de patients tics et une P300 réduite seulement chez ceux avec des tics simples. Quant à la tâche motrice, les deux groupes de patients tics présentaient une P300 réduite. Selon nos résultats, la complexité des tics et la demande motrice des tâches peuvent affecter les mécanismes neuronaux sous-tendant les différentes étapes du traitement de l’information.Tic disorders affect up to 1% of individuals worldwide and are associated with social stigma. A major obstacle to these disorders’ evaluation and treatment is the large heterogeneity of phenotypes, which could explain the important number of conflicting neurobiological data. Certain variables, like tic complexity and tasks’ cognitive demand, could explain these heterogeneous results. We propose that a better understanding of cognitive impairments often seen in tic disorders could be obtained by studying the chronometry of electrocortical activity underlying inhibition, attention, memory and motor processes. Our aim was to evaluate the impact of tic complexity as well as task response demand on tic patients’ electrocortical profiles. Thus, we compared 12 patients exhibiting simple tics to 12 patients showing complex tics, and matched them to 15 healthy control participants. All participants performed two Oddball tasks in which one required a motor response (button press) and the other a non-motor response (counting). During both tasks, electrophysiological components were recorded, serving as indices of processes underlying attention (P200), inhibition (N200) and memory (P300). Our results revealed that for the non-motor task, both groups of tics patients had an enhanced N200, while only those with simple tics showed a reduced P300. For the motor task, both groups of tics patients exhibited a decreased P300. According to our results, both tic complexity and motor demand can affect neural mechanisms of the processing stream. Conflicting results found in previous studies might have been confounded by tic complexity as well as task motor requirements

Dye Sensitization of Nanocrystalline Titanium Dioxide with Osmium and Ruthenium Polypyridyl Complexes

A series of osmium polypyridyl complexes having various ground-state reduction potentials has been synthesized and used to sensitize nanoporous titanium dioxide electrodes to solar illumination. The spectral response and current vs potential properties of electrodes modified with these dyes have been compared with the behavior of their ruthenium analogues. The trends can be explained by the differences in absorption spectra and ground-state redox potentials. The osmium complexes appear to be promising candidates for further optimization in operating photoelectrochemical cells for solar energy conversion applications. Of the materials studied, all complexes having ground-state redox potentials in methanol more positive than ∼0.4 V vs aqueous SCE were able to sustain oxidation of I-/I_3- with a high steady-state quantum yield. For electrodes with very low dye coverages, the open-circuit voltage was mainly determined by the rate of reduction of I_2, whereas for high dye coverages, the open-circuit voltage depended on the nature of the complex and on the dye loading level

Validity, Reliability, and Differential Item Functioning of English and French Versions of the 10-Item Connor-Davidson Resilience Scale in Systemic Sclerosis: A Scleroderma Patient-Centered Intervention Network Cohort Study

Objective Some individuals with systemic sclerosis (SSc) report positive mental health, despite severe disease manifestations, which may be associated with resilience, but no resilience measure has been validated in SSc. This study was undertaken to assess the validity, reliability, and differential item functioning (DIF) between English- and French-language versions of the 10-item Connor-Davidson Resilience Scale (CD-RISC-10) in SSc. Methods Eligible participants were enrolled in the Scleroderma Patient-centered Intervention Network Cohort and completed the CD-RISC-10 between August 2022 and January 2023. We used confirmatory factor analysis (CFA) to evaluate the CD-RISC-10 factor structure and conducted DIF analysis across languages with Multiple Indicators Multiple Causes models. We tested convergent validity with another measure of resilience and measures of self-esteem and depression and anxiety symptoms. We assessed internal consistency and test–retest reliability using Cronbach\u27s alpha and intraclass correlation coefficient (ICC). Results A total of 962 participants were included in this analysis. CFA supported a single-factor structure (Tucker–Lewis index = 0.99, comparative fit index = 0.99, root mean square error of approximation = 0.08 [90% confidence interval (90% CI) 0.07, 0.09]). We found no meaningful DIF. Internal consistency was high (α = 0.93 [95% CI 0.92, 0.94]), and we found that correlations with other measures of psychological functioning were moderate to large (|r| = 0.57–0.78) and confirmed study hypotheses. The scale showed good 1–2-week test–retest reliability (ICC 0.80 [95% CI 0.75, 0.85]) in a subsample of 230 participants. Conclusion The CD-RISC-10 is a valid and reliable measure of resilience in SSc, with score comparability across English and French versions

P300 Source Localization Contrasts in Body-Focused Repetitive Behaviors and Tic Disorders

Tic disorders (TD) and body-focused repetitive behaviors (BFRB) have similar phenotypes that can be challenging to distinguish in clinical settings. Both disorders show high rates of comorbid psychiatric conditions, dysfunctional basal ganglia activity, atypical cortical functioning in the prefrontal and motor cortical regions, and cognitive deficits. Clinicians frequently confound the two disorders and it is important to find reliable objective methods to discriminate TD and BFRB. Neuropsychological tests and event-related potential (ERP) studies have yielded inconsistent results regarding a possible context updating deficit in TD and BFRB patients. However, most previous studies did not control for the presence of comorbid psychiatric condition and medication status, which might have confounded the findings reported to date. Hence, we aimed to investigate the psychophysiology of working memory using ERP in carefully screened TD and BFRB patients excluding those with psychiatric comorbidity and those taking psychoactive medication. The current study compared 12 TD patients, 12 BRFB patients, and 15 healthy control participants using a motor oddball task (button press). The P300 component was analyzed as an index of working memory functioning. Results showed that BFRB patients had decreased P300 oddball effect amplitudes over the right hemisphere compared to the TD and control groups. Clinical groups presented different scalp distributions compared to controls, which could represent a potential endophenotype candidate of BFRB and TD

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Charge Transport Properties of BO-Chelated Azadipyrromethenes

Intramolecular BO-chelated azadipyrromethenes are promising organic semiconductors. Here, we evaluated the electron and hole mobility of a series of BO-chelated azadipyrromethenes using the Space Charge Limited Current(SCLC) method. In order to determine the mobility of the material, Mott Gurney\u27s law was applied using the film thickness and slope of the J1/2 versus voltage plot in the SCLC graph. The best electron mobility observed for BO-chelated materials is 4.64—10-6 cm2V-1s-1 and the best hole mobility is 7.38—10-4 cm2V-1s-1. These results suggest that BO-chelated materials are promising p-type semiconductors for electronic applications.https://commons.case.edu/intersections-fa20/1028/thumbnail.jp