42 research outputs found

    Using non-invasive transcranial stimulation to improve motor and cognitive function in Parkinson's disease: A systematic review and meta-analysis

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    Parkinson\u27s disease (PD) is a neurodegenerative disorder affecting motor and cognitive abilities. There is no cure for PD, therefore identifying safe therapies to alleviate symptoms remains a priority. This meta-analysis quantified the effectiveness of repetitive transcranial magnetic stimulation (rTMS) and transcranial electrical stimulation (TES) to improve motor and cognitive dysfunction in PD. PubMed, EMBASE, Web of Science, Google Scholar, Scopus, Library of Congress and Cochrane library were searched. 24 rTMS and 9 TES studies (n = 33) with a sham control group were included for analyses. The Physiotherapy Evidence Database and Cochrane Risk of Bias showed high quality (7.5/10) and low bias with included studies respectively. Our results showed an overall positive effect in favour of rTMS (SMD = 0.394, CI [0.106–0.683], p = 0.007) and TES (SMD = 0.611, CI [0.188–1.035], p = 0.005) compared with sham stimulation on motor function, with no significant differences detected between rTMS and TES (Q [1] = 0.69, p = 0.406). Neither rTMS nor TES improved cognition. No effects for stimulation parameters on motor or cognitive function were observed. To enhance the clinical utility of non-invasive brain stimulation (NBS), individual prescription of stimulation parameters based upon symptomology and resting excitability state should be a priority of future research

    Computational modelling of reinforcement learning and functional neuroimaging of probabilistic reversal for dissociating compulsive behaviours in gambling and cocaine use disorders.

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    Background: Individuals with cocaine use disorder or gambling disorder demonstrate impairments in cognitive flexibility: the ability to adapt to changes in the environment. Flexibility is commonly assessed in a laboratory setting using probabilistic reversal learning, which involves reinforcement learning, the process by which feedback from the environment is used to adjust behavior. Aims: It is poorly understood whether impairments in flexibility differ between individuals with cocaine use and gambling disorders, and how this is instantiated by the brain. We applied computational modelling methods to gain a deeper mechanistic explanation of the latent processes underlying cognitive flexibility across two disorders of compulsivity. Method: We present a re-analysis of probabilistic reversal data from individuals with either gambling disorder (n = 18) or cocaine use disorder (n = 20) and control participants (n = 18), using a hierarchical Bayesian approach. Furthermore, we relate behavioural findings to their underlying neural substrates through an analysis of task-based functional magnetic resonanceimaging (fMRI) data. Results: We observed lower 'stimulus stickiness' in gambling disorder, and report differences in tracking expected values in individuals with gambling disorder compared to controls, with greater activity during reward expected value tracking in the cingulate gyrus and amygdala. In cocaine use disorder, we observed lower responses to positive punishment prediction errors and greater activity following negative punishment prediction errors in the superior frontal gyrus compared to controls. Conclusions: Using a computational approach, we show that individuals with gambling disorder and cocaine use disorder differed in their perseverative tendencies and in how they tracked value neurally, which has implications for psychiatric classification

    Repetitive transcranial magnetic stimulation (rTMS) in autism spectrum disorder: protocol for a multicentre randomised controlled clinical trial

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    Introduction There are no well-established biomedical treatments for the core symptoms of autism spectrum disorder (ASD). A small number of studies suggest that repetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation technique, may improve clinical and cognitive outcomes in ASD. We describe here the protocol for a funded multicentre randomised controlled clinical trial to investigate whether a course of rTMS to the right temporoparietal junction (rTPJ), which has demonstrated abnormal brain activation in ASD, can improve social communication in adolescents and young adults with ASD. Methods and analysis This study will evaluate the safety and efficacy of a 4-week course of intermittent theta burst stimulation (iTBS, a variant of rTMS) in ASD. Participants meeting criteria for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition ASD (n=150, aged 14–40 years) will receive 20 sessions of either active iTBS (600 pulses) or sham iTBS (in which a sham coil mimics the sensation of iTBS, but no active stimulation is delivered) to the rTPJ. Participants will undergo a range of clinical, cognitive, epi/genetic, and neurophysiological assessments before and at multiple time points up to 6 months after iTBS. Safety will be assessed via a structured questionnaire and adverse event reporting. The study will be conducted from November 2020 to October 2024. Ethics and dissemination The study was approved by the Human Research Ethics Committee of Monash Health (Melbourne, Australia) under Australia’s National Mutual Acceptance scheme. The trial will be conducted according to Good Clinical Practice, and findings will be written up for scholarly publication. Trial registration number Australian New Zealand Clinical Trials Registry (ACTRN12620000890932)

    Overall prognosis of preschool autism spectrum disorder diagnoses

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    © 2017 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. This is a protocol for a Cochrane Review (Prognosis). The objectives are as follows: The primary objective of this review is to synthesise the available evidence on the proportion of individuals who have a diagnosis of autism spectrum disorder at baseline and at follow-up one or more years later. The secondary objectives of this review are to: investigate whether there are differences in the proportions of individuals with autism spectrum disorder who maintain a diagnosis at follow-up dependent on use of the different classification systems (i.e. DSM or ICD criteria) and their revisions; and investigate the proportion of individuals with autism spectrum disorder who maintain diagnosis at follow-up in important subgroups of individuals, including those of different ages and those with different language levels (verbal/non-verbal; standard score ≤ 70 or > 70), IQs (≤ 70 or > 70), adaptive behaviour (standard score ≤ 70 or > 70), and different diagnostic subgroups (Asperger's syndrome/disorder, autistic disorder, childhood autism, PDD-NOS, atypical autism, PDD and autism spectrum disorder). We will investigate potential sources of heterogeneity that may impact outcomes such as differences in study participation, study design, length of follow-up, participant attrition and participant outcome measurement factors. We will use internationally recognised standards for systematic reviews to guide the review

    Trait and neurobiological underpinnings of negative emotion regulation in gambling disorder

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    Background and Aims Gambling disorder is characterized by poor regulation of negative emotions and impulsive behaviours. This study aimed to (1) compare gambling disorder patients (GDPs) and healthy controls (HCs) in self-report and brain activation measures of emotion regulation; and (2) establish its relationship with negative emotion-driven impulsivity. Design Two cross-sectional case–control studies including GDPs and HCs. Setting and Participants GDPs and HCs were recruited from specialized gambling clinics in Andalusia (Spain), where they were following out-patient treatment, and from the community, respectively. Study 1 included 41 GDPs and 45 HCs [All males; Mage = 35.22, 33.22; standard deviation (SD) = 11.16, 8.18; respectively]. Study 2 included 17 GDPs and 21 HCs (16/20 males; Mage = 32.94, 31.00; SD = 7.77, 4.60; respectively). Measurements In study 1, we compared both groups on suppression and re-appraisal emotion regulation strategies [Emotion Regulation Questionnaire (ERQ)]. In study 2, we compared GDPs with HCs on brain activation associated with down-regulation of negative emotions in a cognitive re-appraisal task, measured with functional magnetic resonance imaging (fMRI). In both studies, we correlated the measures of emotion regulation with mood-related impulsivity indicated by negative urgency (UPPS-P impulsive behaviour scale). Findings GDPs relative to HCs showed higher levels of emotional suppression [F = 4.525; P = 0.036; means difference MHCs–MGDPs = −2.433, 95% confidence interval (CI) = −4.706, −0.159] and higher activation of the premotor cortex and middle frontal gyrus during negative emotion regulation in the fMRI task [P ≤ 0.005, cluster size (CS) > 50 voxels]. Negative urgency correlated positively with emotional suppression (r = 0.399, 95% CI = 0.104, 0.629, one-tailed P = 0.005) and middle frontal gyrus activation during negative emotion regulation (P ≤ 0.005, CS > 50) in GDPs. Conclusions Gambling disorder is associated with greater use of emotional suppression and stronger pre-motor cortex and middle frontal gyrus activation for regulating negative emotions, compared with healthy controls. Emotional suppression use and middle frontal gyrus activation during negative emotion regulation are linked with negative emotion-driven impulsivity in this disorder.Depto. de Personalidad, Evaluación y Psicología ClínicaFac. de PsicologíaTRUEpu

    A single- and paired-pulse TMS-EEG investigation of the N100 and long interval cortical inhibition in autism spectrum disorder

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    Abstract not availableMelissa Kirkovski, Aron T. Hill, Nigel C.Rogasch, Takashi Saeki, Bernadette M. Fitzgibbon, Joel Yang, Michael Do, Peter H.Donaldson, Natalia Albein-Urios, Paul B.Fitzgerald, Peter G. Enticot
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