Large-scale coupling of prefrontal activity patterns as a mechanism for cognitive control in health and disease: evidence from rodent models.

Cognitive control of behavior is crucial for well-being, as allows subject to adapt to changing environments in a goal-directed way. Changes in cognitive control of behavior is observed during cognitive decline in elderly and in pathological mental conditions. Therefore, the recovery of cognitive control may provide a reliable preventive and therapeutic strategy. However, its neural basis is not completely understood. Cognitive control is supported by the prefrontal cortex, structure that integrates relevant information for the appropriate organization of behavior. At neurophysiological level, it is suggested that cognitive control is supported by local and large-scale synchronization of oscillatory activity patterns and neural spiking activity between the prefrontal cortex and distributed neural networks. In this review, we focus mainly on rodent models approaching the neuronal origin of these prefrontal patterns, and the cognitive and behavioral relevance of its coordination with distributed brain systems. We also examine the relationship between cognitive control and neural activity patterns in the prefrontal cortex, and its role in normal cognitive decline and pathological mental conditions. Finally, based on these body of evidence, we propose a common mechanism that may underlie the impaired cognitive control of behavior.

User perceptions about resources based on the Wheelchair Skills Training Program for training indoor and community wheelchair skills in pediatrics: a descriptive qualitative study.

PURPOSE: The Wheelchair Skills Training Program (WSTP) is underutilized in pediatrics for training manual wheelchair skills because the voluminous manual lacks pediatric specificity and no materials adapted for pediatric manual wheelchair users (PMWUs) are available. A set of resources (storybook, posters, training workbook) based on the WSTP has previously been developed for training basic indoor wheelchair skills with five to 15-year-old PMWUs. Occupational therapists (OTs) and PMWUs expressed a need for additional resources addressing higher-level skills. Two new sets of resources teaching indoor and community wheelchair skills were developed. OBJECTIVE: Describe OTs' and PMWUs' satisfaction and perceptions regarding usability, relevance and feasibility in pediatrics with the new resources. METHODS: A descriptive qualitative study was conducted. A focus group and interviews were respectively conducted with a convenience sample of OTs and a criterion sample of PMWUs to document perceptions regarding satisfaction, usability, relevance and feasibility. A deductive approach to data analyses was used following the Framework Method. RESULTS: Six OTs expressed satisfaction regarding both sets of resources feeling more confident using the WSTP (relevance) and perceiving potential time efficiencies when planning training interventions (feasibility). They provided suggestions to improve the usability of the second set. Six PMWUs participated in the interviews, two of which provided feedback on both sets. They were satisfied with the resources recommending them to novice and temporary PMWUs aged from three to 11 years. CONCLUSION: Participants' suggested the resources may contribute to reducing the gap between the evidence supporting the WSTP and its utilization in pediatrics.

Two sets of knowledge transfer resources based on the Wheelchair Skills Training Program (WSTP) are pediatric-friendly materials that could be used in rehabilitation settings to train wheelchair skills among novice and temporary manual wheelchair users.Both sets of knowledge transfer resources may help bridge the gap between the evidence supporting the WSTP and its utilization in pediatrics by responding to clinicians' needs for playful, easy-to-use and condensed materials to use in their interventions.The perspectives of occupational therapists and pediatric manual wheelchair users are important to improve the wheelchair skills training resources so that they align with both knowledge users' needs and preferences.

The French-Canadian WheelCon for manual wheelchair users: paediatric adaptation and preliminary evaluation of its measurement properties.

PURPOSE: To adapt the Wheelchair Use Confidence Scale for Manual Wheelchair Users, French-Canadian Version (WheelCon-M-F) into a paediatric version (WheelCon-M-F-P) and to evaluate its validity. METHODS: A three-phase process was conducted: (1) item adaptation using secondary analysis of focus group data; (2) item refinement using a think-aloud process; and (3) preliminary validation of the WheelCon-M-F-P (i.e. internal consistency, test-retest reliability, standard error of measurement, smallest real difference, ceiling and floor effects, limits of agreement, and relations with other variables). RESULTS: Phase 1: The sample consisted of occupational therapists (n = 9), paediatric manual wheelchair users (PMWUs) (n = 12), and parents of PMWUs (n = 2). Of the 65 WheelCon-M-F items, 35 were removed, 25 modified and 6 were added for the WheelCon-M-F-P. Phase 2: 4 PMWUs helped refine 14 and remove 3 items. Phase 3: 22 PMWUs participated. Cronbach's alpha, test-retest reliability, standard error of measurement, and smallest real difference were 0.846, 0.818, 3.05, and 8.45 respectively. No ceiling or floor effects were demonstrated. Pearson correlations between the WheelCon-M-F-P and the Wheelchair Skills Test Questionnaire (capacity, confidence, and performance), and the Child Occupational Self-Assessment were 0.688, 0.711, 0.584, and 0.687 respectively. CONCLUSIONS: This study provides preliminary evidence of a valid and reliable WheelCon-M-F-P.IMPLICATIONS FOR REHABILITATIONThe Wheelchair Use Confidence Scale for Manual Wheelchair Users, French-Canadian Version (WheelCon-M-F-P) is an outcome measure that can be used clinically with pediatric manual wheelchair users.The WheelCon-M-F-P can help identify modifiable factors associated with wheelchair confidence.Identifying modifiable factors associated with wheelchair confidence can help guide clinicians in establishing a targeted intervention for their pediatric clients.Establishing a targeted intervention can help improve self-efficacy for wheelchair use and social participation of pediatric wheelchair users.

Evaluation of pediatric-specific resources to support utilization of the Wheelchair Skills Training Program by the users of the resources: a descriptive qualitative study.

BACKGROUND: Children's ability to engage in meaningful activities is positively influenced by their ability to move independently. Preliminary evidence in children suggests that wheelchair skills training improves wheelchair skills, which are important for independent mobility. The Wheelchair Skills Training Program is a standardized program to teach wheelchair skills. However, it is underutilized in pediatric rehabilitation settings. To increase its utilization, 3 pediatric-specific Wheelchair Skills Training Program resources related to indoor skills were developed (i.e., a storybook, four instructional posters, and a training workbook). This study aimed to describe occupational therapists' (OTs) and pediatric manual wheelchair users' (PMWUs) perceived satisfaction with the storybook, instructional posters and training workbook, and to explore their perceptions regarding the usability, relevance, and feasibility of these resources in pediatric rehabilitation settings. METHODS: A descriptive qualitative design was used. Convenience samples of OTs and PMWUs were recruited in a rehabilitation center and affiliated schools. A focus group with OTs and semi-structured interviews with PMWUs were conducted by videoconference to obtain participants' feedback on the resource prototypes and suggestions for improvement. Data were deductively analyzed using the Framework method. RESULTS: Eight OTs and 5 PMWUs expressed general satisfaction with the resources, describing them as usable, relevant, and feasible to integrate into wheelchair skills training with novice wheelchair users and younger children. All OTs and 3 PMWUs expressed the desire to use the resources for wheelchair skills training. Two PMWUs perceived the resources were not relevant to them because they already mastered the skills. The participants suggested minor modifications for improving the resources (e.g., more action in the story, increased precision of illustrations related to the characters' position in the wheelchair). CONCLUSION: OTs and PMWUs were satisfied with the resources, perceiving them to be applicable for training wheelchair skills among young children and novice wheelchair users. The resources represent a concrete solution to facilitate the use of the Wheelchair Skills Training Program in pediatric rehabilitation settings. Additional resources are needed to better reach older and more experienced PMWUs (i.e., of intermediate and advanced skill levels).

Effects of Early Life Exposure to Sex Hormones on Neurochemical and Behavioral Responses to Psychostimulants in Adulthood: Implications in Drug Addiction.

Early life exposure to sex hormones affects several brain areas involved in regulating locomotor and motivation behaviors. Our group has shown that neonatal exposure to testosterone propionate (TP) or estradiol valerate (EV) affected the brain dopamine (DA) system in adulthood. Here, we studied the long-lasting effects of neonatal exposure to sex hormones on behavioral and neurochemical responses to amphetamine (AMPH) and methylphenidate (MPD). Our results show that AMPH-induced locomotor activity was higher in female than male control rats. The conditioned place preference (CPP) to AMPH was only observed in EV male rats. In EV female rats, AMPH did not increase locomotor activity, but MPD-induced CPP was observed in control, EV and TP female rats. Using in vivo brain microdialysis, we observed that AMPH-induced extracellular DA levels were lower in nucleus accumbens (NAcc) of EV and TP female rats than control rats. In addition, MPD did not increase NAcc extracellular DA levels in EV rats. Using in vivo fast-scan cyclic voltammetry in striatum, MPD-induced DA reuptake was higher in EV than control rats. In summary, our results show that early life exposure to sex hormones modulates mesolimbic and nigrostriatal DA neurons producing opposite neurochemical effects induced by psychostimulant drugs in NAcc or striatum.

Neonatal programming with testosterone propionate reduces dopamine transporter expression in nucleus accumbens and methylphenidate-induced locomotor activity in adult female rats.

Research in programming is focused on the study of stimuli that alters sensitive periods in development, such as prenatal and neonatal stages, that can produce long-term deleterious effects. These effects can occur in various organs or tissues such as the brain, affecting brain circuits and related behaviors. Our laboratory has demonstrated that neonatal programming with sex hormones affects the mesocorticolimbic circuitry, increasing the synthesis and release of dopamine (DA) in striatum and nucleus accumbens (NAcc). However, the behavioral response to psychostimulant drugs such as methylphenidate and the possible mechanism(s) involved have not been studied in adult rats exposed to sex hormones during the first hours of life. Thus, the aim of this study was to examine the locomotor activity induced by methylphenidate (5mg/kg i.p.) and the expression of the DA transporter (DAT) in NAcc of adult rats exposed to a single dose of testosterone propionate (TP: 1mg/50µLs.c.) or estradiol valerate (EV: 0.1mg/50µLs.c.) at postnatal day 1. Our results demonstrated that adult female rats treated with TP have a lower methylphenidate-induced locomotor activity compared to control and EV-treated adult female rats. This reduction in locomotor activity is related with a lower NAcc DAT expression. However, neither methylphenidate-induced locomotor activity nor NAcc DAT expression was affected in EV or TP-treated adult male rats. Our results suggest that early exposure to sex hormones affects long-term dopaminergic brain areas involved in the response to psychostimulants, which could be a vulnerability factor to favor the escalating doses of drugs of abuse.

Delirium no paciente idoso / Delirium in elderly patient

Delirium é um distúrbio mental agudo, de etiologia orgânica, precipitado por qualquer condição que leve a alterações no metabolismo cerebral, sendo bastante freqüente entre pacientes idosos hospitalizados. Seu desenvolvimento inicia uma série de eventos que pode culminar com perda de independência, aumento de morbidade e de mortalidade, além de aumentar o tempo e custos de internação e de cuidados após alta hospitalar. Trata-se de uma condição potencialmente previsível e tratável, porém pouco reconhecida e, conseqüentemente, subdiagnosticada.O presente artigo tem como finalidade apresentar, de forma simplificada, o diagnóstico e o manejo do delirium no paciente idoso.