258 research outputs found

    HIGH-PERFORMANCE MODELING, IDENTIFICATION AND ANALYSIS OF HETEROGENEOUS ABNORMAL NEUROLOGICAL MOVEMENT’S PARAMETERS BASED ON COGNITIVE NEURO FEEDBACK-INFLUENCES

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    The technique is based on a hybrid model of the neuro-system (Brain cortex nodes and tremor-object), which describes on the basis of wave signal propagation the state and behavior of tremor-objects T, namely the segmental de-scription of 3D elements of trajectories of anormal neurological movements of the studied tremor-objects (limb of the hand) taking into account the matrix of cogni-tive influences of groups of cortex neuro-nodes. The rapid analytical solution of the model as a vector function that describes the 3D elements of the trajectories at each movements segment are constructed using the hybrid integral Fourier’s transformations and hybrid spectral function. The main element of the solution is the adaptive infuences matrix  that determines the state parameters of the action of certain groups of brain neuro- cortex. Models and methods of multivariable identification are being developed to investigate their neuro-feedback, which suggest  high-speed parallel computations on multicore computers. This model-ing technology consider as a scientific basis for designing inelidgence information systems of the quality medical diagnostic i of critical neurological diseases.Key words: Computer simulation, Software system, High-performance compu-ting, Tremor diseases, Modeling of objects and processes, Multi-parameter iden-tification

    Designing a comprehensive system for analysis of handwriting biomechanics in relation to neuromotor control of handwriting

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    A comprehensive system for investigation of biomechanical and neuromuscular processes involved with producing handwriting and drawing was developed. The system included a pen-like grip measuring device that enabled the variations of finger grip force associated with writing and drawing to be measured while holding the pen in tripod grip. The pen was integrated with a digitiser tablet for recording x,ycoordinates and pressure of the nib and a motion analysis system for recording the limb and hand kinematics. It was observed that for line drawing in the y-direction of the tablet, finger forces were directly related to pen tip movement and finger forces were modulated in a repeatable and predictable fashion, while this was not the case for line drawing in the x-direction. This was evidence for longstanding assumptions. Wrist rotation was required for production of lines in the x-direction without excessive deviation. For writing tasks, it was observed that no two tasks performed by one subject share an identical writing process, not even when the writing results are (nearly) identical. The neuromuscular control apparatus is highly flexible and works in a coordinated fashion that allows production of nearly equal end-results by means of different mechanical and therefore neuromuscular processes. For spiral drawing, tremor that originates from the fingers, hand and arm was quantified with the transducer pen. Limb joint kinematics were displayed in three dimensions with colour coding of coordinate sample numbers. This method can reveal the origin of some forms of limb tremor. Pen grip force patterns during signature writing were found to be characteristic for subjects, which relate to their individual pen-hand interaction, resulting from fine control of distal joints. Variation between trials of the same subject was observed, revealing adaptations of the computational processes during writing. The potential for signature verification by means of finger force recording was explored.A comprehensive system for investigation of biomechanical and neuromuscular processes involved with producing handwriting and drawing was developed. The system included a pen-like grip measuring device that enabled the variations of finger grip force associated with writing and drawing to be measured while holding the pen in tripod grip. The pen was integrated with a digitiser tablet for recording x,ycoordinates and pressure of the nib and a motion analysis system for recording the limb and hand kinematics. It was observed that for line drawing in the y-direction of the tablet, finger forces were directly related to pen tip movement and finger forces were modulated in a repeatable and predictable fashion, while this was not the case for line drawing in the x-direction. This was evidence for longstanding assumptions. Wrist rotation was required for production of lines in the x-direction without excessive deviation. For writing tasks, it was observed that no two tasks performed by one subject share an identical writing process, not even when the writing results are (nearly) identical. The neuromuscular control apparatus is highly flexible and works in a coordinated fashion that allows production of nearly equal end-results by means of different mechanical and therefore neuromuscular processes. For spiral drawing, tremor that originates from the fingers, hand and arm was quantified with the transducer pen. Limb joint kinematics were displayed in three dimensions with colour coding of coordinate sample numbers. This method can reveal the origin of some forms of limb tremor. Pen grip force patterns during signature writing were found to be characteristic for subjects, which relate to their individual pen-hand interaction, resulting from fine control of distal joints. Variation between trials of the same subject was observed, revealing adaptations of the computational processes during writing. The potential for signature verification by means of finger force recording was explored

    Retention of a novel visuomotor gain in patients with Parkinson's disease is context-specific

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    Hypometria or reduced movement amplitude is a major concern in Parkinson's disease (PD) since it impairs multiple functional activities of daily living, including fine motor control tasks, such as handwriting. Recent research using virtual or computer-based environments, wherein visual information about hand movement is altered and dissociated from perception (e.g., position sense or kinesthesia) of hand movement itself, has shown increases in handwriting size in patients with PD. In fact, preliminary findings in our laboratory have shown that gradual alterations in visual feedback of movement facilitate adaptation of handwriting size in patients with PD, plausibly by recruiting neural networks other than the basal ganglia, such as those in cerebellum. The purpose of this study was to determine whether these adaptive effects persist after a week following visuomotor training in patients with PD and can favorably transfer to other functional writing and drawing tasks. Thirteen patients with Parkinson's disease and twelve healthy, age-matched subjects practiced handwriting either under gradually manipulated (intervention) or intact (placebo) visual display of handwriting size. The results from this study show for the first time, that these adaptive effects may persist for at least up to a week in PD; however, a single training session seemed inadequate to transfer these acquired changes to paper-pen writing and drawing. Additionally, experimental manipulation of task demands during training also helped maintain movement quality in patients with PD as against the placebo group. These findings have important implications in designing rehabilitative interventions to enhance functional sensorimotor performance in patients with PD

    Proteomics and network analysis identify common and specific pathways of neurodegeneration

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    Neurodegenerative disorders, such as Parkinson's disease (PD), Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS) are multi-factorial in nature, involving several genetic mutations (in coding or regulatory regions) and epigenetic and environmental factors. The main clinical manifestation (movement disorders, cognitive impairment and/or psychiatric disturbances) depends on the neuron population being primarily affected. Complex and multifactorial neurodegenerative diseases can be investigated using a holistic approach that can give a global view about the pathogenetic process and shed light on specific and generic pathways of neurodegeneration. Proteomics offers a global molecular snapshot of proteins and consequently of processes that may influence neuronal death. The proteome in fact provides a dynamic view of what is happening in the system under investigation, because the expression of proteins, their abundance, their localization in tissues or cells, the type and amount of their post-translational changes depend from the environment and from the cellular physiological state. Therefore, all the projects presented in this thesis, by combining bioinformatics tools with proteomics, aimed at highlighting biochemical processes shared by different neurodegenerative diseases and diseasespecific pathways, which may justify the degeneration of dopaminergic neurons in PD. Finally, a focus on the mitochondrial interactome and proteome intended to elucidate important specific steps of the degenerative process in PD

    Next move in movement disorders (NEMO):Developing a computer-aided classification tool for hyperkinetic movement disorders

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    Introduction: Our aim is to develop a novel approach to hyperkinetic movement disorder classification, that combines clinical information, electromyography, accelerometry and video in a computer-aided classification tool. We see this as the next step towards rapid and accurate phenotype classification, the cornerstone of both the diagnostic and treatment process. Methods and analysis: The Next Move in Movement Disorders (NEMO) study is a cross-sectional study at Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen. It comprises patients with single and mixed phenotype movement disorders. Single phenotype groups will first include dystonia, myoclonus and tremor, and then chorea, tics, ataxia and spasticity. Mixed phenotypes are myoclonus-dystonia, dystonic tremor, myoclonus ataxia and jerky/tremulous functional movement disorders. Groups will contain 20 patients, or 40 healthy participants. The gold standard for inclusion consists of interobserver agreement on the phenotype among three independent clinical experts. Electromyography, accelerometry and three-dimensional video data will be recorded during performance of a set of movement tasks, chosen by a team of specialists to elicit movement disorders. These data will serve as input for the machine learning algorithm. Labels for supervised learning are provided by the expert-based classification, allowing the algorithm to learn to predict what the output label should be when given new input data. Methods using manually engineered features based on existing clinical knowledge will be used, as well as deep learning methods which can detect relevant and possibly new features. Finally, we will employ visual analytics to visualise how the classification algorithm arrives at its decision. Ethics and dissemination: Ethical approval has been obtained from the relevant local ethics committee. The NEMO study is designed to pioneer the application of machine learning of movement disorders. We expect to publish articles in multiple related fields of research and patients will be informed of important results via patient associations and press releases

    2016 IMSAloquium, Student Investigation Showcase

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    Welcome to the twenty-eighth year of the Student Inquiry and Research Program (SIR)! This is a program that is as old as IMSA. The SIR program represents our unending dedication to enabling our students to learn what it is to be an innovator and to make contributions to what is known on Earth.https://digitalcommons.imsa.edu/archives_sir/1026/thumbnail.jp

    Eye Movements and Attention Are Related to Impaired Hand Motor Control in Older Adults

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    Visual information is critical for many goal-directed movements and changes in visual information influence hand motor performance in older adults. Knowledge of eye movements during hand motor tasks would provide greater insight into impaired hand function in older adults. This dissertation examined age-related changes in eye movements and the association with hand motor impairments in older adults. Given that attention plays a role in motor performance and declines with age, the relationship between attentional processes and hand motor control was also assessed. A total of 23 young (age 20 – 38) and 28 older (age 65 – 90) adults were recruited. Eye movements were recorded during common hand tasks including pegboard tests of manual dexterity, Archimedes spiral tracing, and a pinch force-matching task. Measures of the subsystems of attention and a dual task were performed. Results provide evidence for decreased ability to control gaze location and altered visual strategies during hand tasks in older adults, and hand motor performance decrements may be associated with these age-related changes in eye movements. Findings also illustrate a relationship between attentional processes and pegboard performance impairments in older adults. This dissertation contributes novel findings regarding age-associated impairments in hand motor control as they relate to eye movements, offering more insight into decreased function and loss of independence in older adults

    2013 IMSAloquium, Student Investigation Showcase

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    This year, we are proudly celebrating the twenty-fifth anniversary of IMSA’s Student Inquiry and Research (SIR) Program. Our first IMSAloquium, then called Presentation Day, was held in 1989 with only ten presentations; this year we are nearing two hundred.https://digitalcommons.imsa.edu/archives_sir/1005/thumbnail.jp

    Neuroimaging of fetal cell therapy in Parkinson’s disease

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    Parkinson’s disease is the second most common neurodegenerative disease characterised by the elevated formation of α-synuclein-immunopositive intraneuronal proteinaceous inclusions (Lewy pathology) and the progressive loss of neuromelanin-laden dopaminergic cells of the substantia nigra pars compacta, resulting in the loss of striatal dopaminergic terminals and emergence of cardinal motor features including bradykinesia, rigidity, tremor and postural instability. Dopaminomimetic agents provide effective symptomatic relief in the early stages of illness, yet due to the inherently progressive nature of the disease and the induction of debilitating side effects their efficacy is eventually lost. Cellular restorative strategies involving intrastriatal transplantation of human fetal ventral mesencephalic (hfVM) tissue gained traction from the early 1990’s, when several multi-disciplinary teams reported drastic motoric improvements concomitant with graft-derived dopaminergic re-innervation. However, outcomes of double-blind randomised controlled trials and the presentation of novel dyskinetic movements persisting in the “off-state” called for substantial revision of cell delivery strategies. The current thesis utilises positron emission tomography to examine the effects of hfVM implantation under the Transeuro protocol on dopaminergic ([18F]FDOPA, [11C]PE2I) and serotonergic ([11C]DASB) systems in patients with Parkinson’s disease and elucidate the neural underpinnings of its clinical impact. The main findings are; 1) implanted hfVM tissue led to increases in putamenal dopamine synthesis and storage capacity, dopamine and serotonin transporter density as compared to non-transplanted patients; 2) modification to surgical procedures provided inhomogenous and inconsistent re-innervation; 3) hfVM transplantation was associated with clinical improvements in measures of bradykinesia, rigidity and tremor; 4) graft-related changes in posterior putamenal dopamine and serotonin transporter density predicted symptomatic relief of bradykinesia and tremor; 5) heterogeneity of posterior putamenal re-innervation may impact upon potential clinical benefit; 6) graft-induced dyskinesia was associated with greater post-operative increases in dopamine transporter expression in the anterior putamen; 7) there was no evidence that graft-induced dyskinesia was related to serotonergic hyperinnervation. The novel findings presented in this thesis have major implications for cell-based restorative strategies beyond the hfVM era and will likely foster informed [re]consideration of many aspects of therapeutic delivery and trial design. For its ability to provide mechanistic insight in vivo, neuroimaging may continue to play a central role in the optimisation of future interventions.Open Acces
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