The Experts below are selected from a list of 2670 Experts worldwide ranked by ideXlab platform
Yves Rossetti - One of the best experts on this subject based on the ideXlab platform.
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Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation.
Neural plasticity, 2016Co-Authors: Laure Christophe, Eric Chabanat, Ludovic Delporte, Patrice Revol, Pierre Volckmann, Sophie Jacquin-courtois, Yves RossettiAbstract:Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, Prism Adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of Prism Adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during, and following a one-week intense Prism Adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive Prism Adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of Prism Adaptation deserves further investigations.
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Prisms to shift pain away: Physiopathological and therapeutic exploration of CRPS with Prism Adaptation
Annals of Physical and Rehabilitation Medicine, 2016Co-Authors: Laure Christophe, Eric Chabanat, Ludovic Delporte, Patrice Revol, Pierre Volckmann, Sophie Jacquin-courtois, Yves RossettiAbstract:Objective Complex regional pain syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions, with frequent therapeutic failure. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated towards the pain, i.e. neglect of the healthy side. Accordingly, Prism Adaptation has been successfully used to normalize this deviation by some teams, leading to clinical improvement. This study aimed at exploring a CRPS group's spatial references modifications as well as investigating the pathophysiological mechanisms of this manifestation and of the therapeutic effects of Prism Adaptation. Material/Patients and methods On a CRPS patients group ( n = 7), pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect-tests (line-bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during and following a week of Prism Adaptation (twice a day for five days). Results First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, Prism Adaptation intervention durably ameliorated pain and quality of life (effect was maintained 2 weeks after intervention). Discussion/Conclusion Prism Adaptation, which is inexpensive and non-invasive, seems to be a promising tool to use in addition to usual methods to alleviate pain in therapeutic failure situations for CRPS patients. Indeed, our results suggest a sustainable improvement of pain and quality of life. Moreover, these results overturn the neglect-like theory and provide wide physiopathological data on spatial references’ modifications. As for spatial neglect, understanding the therapeutic effects of Prism Adaptation deserves further investigations.
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Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result
Neural plasticity, 2012Co-Authors: Jacques Luaute, G. Rode, S. Jacquin-courtois, D. Boisson, Jacinta O'shea, Laure Christophe, Yves RossettiAbstract:Adaptation to right-deviating Prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of Prism Adaptation on left neglect, the present study evaluated the effect of left-deviating Prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating Prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after Prism Adaptation. These results suggest that the therapeutic effect of Prism Adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for Prism Adaptation both in terms of the side of the visuomanual Adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed.
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Prism Adaptation and the Rehabilitation of Spatial Neglect
Systems Neuroscience and Rehabilitation, 2011Co-Authors: Sophie Jacquin-ciourtois, Gilles Rode, Jacques Luaute, Jacinta O'shea, Alessandro Farnè, Laure Pisella, Patrice Revol, Yves RossettiAbstract:A large proportion of right-hemisphere stroke patients exhibits spatial neglect, a neurological condition characterised by deficits for perceiving, attending, representing, and/or performing actions within their left-sided space. spatial neglect is responsible for many debilitating effects on everyday life, for poor functional recovery, and for decreased ability to benefit from treatment. Prism Adaptation (PA) to a right lateral displacement of the visual field (induced by a simple target-pointing task while wearing base-left wedge Prisms) is known to directionally bias visuo-motor and sensory-motor correspondences and has recently been found to improve various symptoms of neglect. For example, performance on classical pen-and-pencil visuo-motor tests could be improved for at least 2 h following Adaptation. Further effects of PA have also been described for non-motor and non-visual tasks, such as for somatosensory extinction or dichotic listening, for deficits in mental imagery of geographic maps and in number bisection, and even for visuo-constructive disorders. These results suggest that the effects of Prism Adaptation can extend to unexposed sensory systems. The bottom-up approach of visuo-motor Adaptation appears to interact with higher order brain functions related to multisensory integration and can have beneficial effects on sensory processing in different modalities. Lesion studies and functional imaging data point to a cerebello-cortical network in which the cerebellum is crucial for Adaptation and the cortex is involved in functional gains. Prism Adaptation may act not only on the ipsilesional bias characteristic of neglect and also alleviate more generally other spatial cognition deficits due to attentional bias.
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dynamic changes in brain activity during Prism Adaptation
The Journal of Neuroscience, 2009Co-Authors: Jacques Luaute, Mona Spiridon, Yves Rossetti, Gilles Rode, Sophie Schwartz, Dominique Boisson, Patrik VuilleumierAbstract:Prism Adaptation does not only induce short-term sensorimotor plasticity, but also longer-term reorganization in the neural representation of space. We used event-related fMRI to study dynamic changes in brain activity during both early and prolonged exposure to visual Prisms. Participants performed a pointing task before, during, and after Prism exposure. Measures of trial-by-trial pointing errors and corrections allowed parametric analyses of brain activity as a function of performance. We show that during the earliest phase of Prism exposure, anterior intraparietal sulcus was primarily implicated in error detection, whereas parieto-occipital sulcus was implicated in error correction. Cerebellum activity showed progressive increases during Prism exposure, in accordance with a key role for spatial realignment. This time course further suggests that the cerebellum might promote neural changes in superior temporal cortex, which was selectively activated during the later phase of Prism exposure and could mediate the effects of Prism Adaptation on cognitive spatial representations.
Gilles Rode - One of the best experts on this subject based on the ideXlab platform.
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Anatomical predictors of successful Prism Adaptation in chronic visual neglect
Cortex, 2019Co-Authors: Marine Lunven, Gilles Rode, Clemence Bourlon, Christophe Duret, Raffaella Migliaccio, Emmanuel Chevrillon, Michel Thiebaut De Schotten, Paolo BartolomeoAbstract:Visual neglect is a frequent and disabling consequence of right hemisphere damage. Previous work demonstrated a probable role of posterior callosal dysfunction in the chronic persistence of neglect signs. Prism Adaptation is a non-invasive and convenient technique to rehabilitate chronic visual neglect, but it is not effective in all patients. Here we aimed to assess the hypothesis that Prism Adaptation improves left neglect by facilitating compensation through the contribution of the left, undamaged hemisphere. We assessed the relationship between Prism Adaptation effects, cortical thickness and white matter integrity in a group of 14 patients with unilateral right-hemisphere strokes and chronic visual neglect. Results showed that patients who benefitted from Prism Adaptation had thicker cortex in temporo-parietal, prefrontal and cingulate areas of the left, undamaged hemisphere. Additionally, these patients had a higher fractional anisotropy value in the body and genu of the corpus callosum. Results from normal controls show that these callosal regions connect temporo-parietal, sensorimotor and prefrontal areas. Finally, shorter time intervals from the stroke tended to improve patients' response to Prism Adaptation. We concluded that Prism Adaptation may improve left visual neglect by promoting the contribution of the left hemisphere to neglect compensation. These results support current hypotheses on the role of the healthy hemisphere in the compensation for stroke-induced, chronic neuropsychological deficits, and suggest that Prism Adaptation can foster this role by exploiting sensorimotor/prefrontal circuits, especially when applied at early stages post-stroke.
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anatomical predictors of successful Prism Adaptation in chronic visual neglect
bioRxiv, 2018Co-Authors: Marine Lunven, Gilles Rode, Clemence Bourlon, Christophe Duret, Raffaella Migliaccio, Emmanuel Chevrillon, Michel Thiebaut De Schotten, Paolo BartolomeoAbstract:Background and Purpose. To assess the hypothesis that Prism Adaptation improves left neglect after right brain damage by facilitating compensation through the contribution of the left, undamaged hemisphere. Methods. We assessed the relationship between Prism Adaptation effects, cortical thickness and white matter integrity in a group of 14 patients with unilateral right-hemisphere strokes and chronic visual neglect. Results. Patients who benefitted from Prism Adaptation had thicker cortex in temporo-parietal, prefrontal and cingulate areas of the left, undamaged hemisphere. Additionally, these patients had a higher microstructural integrity in the body and genu of the corpus callosum. Results from normal controls show that these callosal regions connect temporo-parietal, sensorimotor and prefrontal areas. Finally, shorter time intervals from the stroke tended to improve the patients9 response to Prism Adaptation. Conclusions. Prism Adaptation appears to improve left visual neglect by promoting the contribution of the left hemisphere to neglect compensation. These results support current hypotheses on the role of the healthy hemisphere in the compensation for stroke-induced, chronic neuropsychological deficits, and suggest that Prism Adaptation can foster this role by exploiting sensorimotor/prefrontal circuits, especially when applied at early stages post-stroke.
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Anatomical Predictors Of Recovery From Visual Neglect After Prism Adaptation Therapy
2017Co-Authors: Marine Lunven, Gilles Rode, Clemence Bourlon, Christophe Duret, Raffaella Migliaccio, Emmanuel Chevrillon, Michel Thiebaut De Schotten, Paolo BartolomeoAbstract:Visual neglect is a frequent and disabling consequence of right hemisphere damage. Previous evidence demonstrated a probable role of posterior callosal dysfunction in the chronic persistence of neglect signs. Prism Adaptation is a non-invasive and convenient technique to rehabilitate chronic visual neglect, but it is not effective in all patients. Here we hypothesized that Prism Adaptation improves left neglect by facilitating compensation through the contribution of the left, undamaged hemisphere. To test this hypothesis, we assessed the relationship between Prism Adaptation effects, cortical thickness and white matter integrity in a group of 14 patients with unilateral right-hemisphere strokes and chronic visual neglect. Consistent with our hypothesis, patients who benefitted from Prism Adaptation had a thicker cortex in temporo-parietal, prefrontal and cingulate areas of the left, undamaged hemisphere. Additionally, these patients had higher microstructural integrity of the body and genu of the corpus callosum. These callosal regions connect temporo-parietal, sensorimotor and prefrontal areas. Thus, Prism Adaptation may ameliorate signs of left visual neglect by promoting the contribution of the left hemisphere to neglect compensation. These results support current hypotheses on the role of the healthy hemisphere in the compensation for stroke-induced, chronic neuropsychological deficits, and suggest that Prism Adaptation can foster this role by exploiting sensorimotor/prefrontal circuits for neglect compensation.
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Prism Adaptation and the Rehabilitation of Spatial Neglect
Systems Neuroscience and Rehabilitation, 2011Co-Authors: Sophie Jacquin-ciourtois, Gilles Rode, Jacques Luaute, Jacinta O'shea, Alessandro Farnè, Laure Pisella, Patrice Revol, Yves RossettiAbstract:A large proportion of right-hemisphere stroke patients exhibits spatial neglect, a neurological condition characterised by deficits for perceiving, attending, representing, and/or performing actions within their left-sided space. spatial neglect is responsible for many debilitating effects on everyday life, for poor functional recovery, and for decreased ability to benefit from treatment. Prism Adaptation (PA) to a right lateral displacement of the visual field (induced by a simple target-pointing task while wearing base-left wedge Prisms) is known to directionally bias visuo-motor and sensory-motor correspondences and has recently been found to improve various symptoms of neglect. For example, performance on classical pen-and-pencil visuo-motor tests could be improved for at least 2 h following Adaptation. Further effects of PA have also been described for non-motor and non-visual tasks, such as for somatosensory extinction or dichotic listening, for deficits in mental imagery of geographic maps and in number bisection, and even for visuo-constructive disorders. These results suggest that the effects of Prism Adaptation can extend to unexposed sensory systems. The bottom-up approach of visuo-motor Adaptation appears to interact with higher order brain functions related to multisensory integration and can have beneficial effects on sensory processing in different modalities. Lesion studies and functional imaging data point to a cerebello-cortical network in which the cerebellum is crucial for Adaptation and the cortex is involved in functional gains. Prism Adaptation may act not only on the ipsilesional bias characteristic of neglect and also alleviate more generally other spatial cognition deficits due to attentional bias.
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dynamic changes in brain activity during Prism Adaptation
The Journal of Neuroscience, 2009Co-Authors: Jacques Luaute, Mona Spiridon, Yves Rossetti, Gilles Rode, Sophie Schwartz, Dominique Boisson, Patrik VuilleumierAbstract:Prism Adaptation does not only induce short-term sensorimotor plasticity, but also longer-term reorganization in the neural representation of space. We used event-related fMRI to study dynamic changes in brain activity during both early and prolonged exposure to visual Prisms. Participants performed a pointing task before, during, and after Prism exposure. Measures of trial-by-trial pointing errors and corrections allowed parametric analyses of brain activity as a function of performance. We show that during the earliest phase of Prism exposure, anterior intraparietal sulcus was primarily implicated in error detection, whereas parieto-occipital sulcus was implicated in error correction. Cerebellum activity showed progressive increases during Prism exposure, in accordance with a key role for spatial realignment. This time course further suggests that the cerebellum might promote neural changes in superior temporal cortex, which was selectively activated during the later phase of Prism exposure and could mediate the effects of Prism Adaptation on cognitive spatial representations.
Laure Pisella - One of the best experts on this subject based on the ideXlab platform.
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Prism Adaptation in the healthy brain: the shift in line bisection judgments is long lasting and fluctuates.
Neuropsychologia, 2013Co-Authors: Selene Schintu, Romeo Salemme, Laure Pisella, Stéphane Jacobs, Karen T. Reilly, Alessandro FarnèAbstract:Abstract Rightward Prism Adaptation has been shown to ameliorate visuospatial biases in right brain-damaged patients with neglect, and a single session of Prism Adaptation can lead to improvements that last up to several hours. Leftward Prism Adaptation in neurologically healthy individuals induces neglect-like biases in visuospatial tasks. The duration of these effects in healthy individuals, typically assumed to be ephemeral, has never been investigated. Here we assessed the time-course of the Adaptation-induced modifications in a classical perceptual line bisection task that was repeatedly administered for approximately 40 min after a single session of Adaptation to either a leftward or rightward Prismatic deviation. Consistent with previous reports, only Adaptation to leftward-deviating Prisms induced a visuospatial shift on perceptual line bisection judgments. The typical pattern of pseudoneglect was counteracted by a rightward shift in midline judgments, which became significant between 5 and 10 min after Adaptation, fluctuated between being significant or not several times in the 40 min following Adaptation, and was present as late as 35 min. In contrast, the sensorimotor aftereffect was present immediately after Adaptation to both rightward and leftward deviating Prisms, decayed initially then remained stable until 40 min. These results demonstrate that both the sensorimotor and visuospatial effects last for at least 35 min, but that the visuospatial shift needs time to fully develop and fluctuates. By showing that the effects of Prism Adaptation in the undamaged brain are not ephemeral, these findings reveal the presence of another, so-far neglected dimension in the domain of the cognitive effects induced by Prism Adaptation, namely time. The prolonged duration of the induced visuospatial shift, previously considered to be a feature of Prism Adaptation unique to brain-damaged subjects, also applies to the normal brain.
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Prism Adaptation and the Rehabilitation of Spatial Neglect
Systems Neuroscience and Rehabilitation, 2011Co-Authors: Sophie Jacquin-ciourtois, Gilles Rode, Jacques Luaute, Jacinta O'shea, Alessandro Farnè, Laure Pisella, Patrice Revol, Yves RossettiAbstract:A large proportion of right-hemisphere stroke patients exhibits spatial neglect, a neurological condition characterised by deficits for perceiving, attending, representing, and/or performing actions within their left-sided space. spatial neglect is responsible for many debilitating effects on everyday life, for poor functional recovery, and for decreased ability to benefit from treatment. Prism Adaptation (PA) to a right lateral displacement of the visual field (induced by a simple target-pointing task while wearing base-left wedge Prisms) is known to directionally bias visuo-motor and sensory-motor correspondences and has recently been found to improve various symptoms of neglect. For example, performance on classical pen-and-pencil visuo-motor tests could be improved for at least 2 h following Adaptation. Further effects of PA have also been described for non-motor and non-visual tasks, such as for somatosensory extinction or dichotic listening, for deficits in mental imagery of geographic maps and in number bisection, and even for visuo-constructive disorders. These results suggest that the effects of Prism Adaptation can extend to unexposed sensory systems. The bottom-up approach of visuo-motor Adaptation appears to interact with higher order brain functions related to multisensory integration and can have beneficial effects on sensory processing in different modalities. Lesion studies and functional imaging data point to a cerebello-cortical network in which the cerebellum is crucial for Adaptation and the cortex is involved in functional gains. Prism Adaptation may act not only on the ipsilesional bias characteristic of neglect and also alleviate more generally other spatial cognition deficits due to attentional bias.
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Wheel-chair driving improvement following visuo-manual Prism Adaptation.
Cortex; a journal devoted to the study of the nervous system and behavior, 2007Co-Authors: Sophie Jacquin-courtois, Dominique Boisson, Gilles Rode, Laure Pisella, Yves RossettiAbstract:Prism Adaptation has been used for several years to improve several aspects of unilateral neglect. Parameters ranging from the classical neuropsychological tests to mental imagery or to tactile extinction have been successfully ameliorated following a brief period of Adaptation to wedge Prisms shifting the visual field to the right. However the potential therapeutic implications of this technique depend on the investigation of more functional and ecological parameters. Here we describe a patient with left hemiplegia and unilateral neglect who was impaired during wheel-chair navigation in the clinical unit. Following a brief Adaptation period, this patient showed a sudden improvement of wheel-chair driving as well as of classical tests. The potential implications of Prism Adaptation for the rehabilitation of unilateral neglect are highlighted by the long duration of improvement obtained after a single Adaptation session.
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Neglect and Prism Adaptation: a new therapeutic tool for spatial cognition disorders.
Restorative neurology and neuroscience, 2006Co-Authors: Gilles Rode, Yves Rossetti, Thomas Klos, Sophie Courtois-jacquin, Laure PisellaAbstract:Purpose: A large proportion of right-hemisphere stroke patients show unilateral neglect, a neurological deficit of perception, attention, representation, and/or performing actions within their left-sided space, inducing many functional debilitating effects on everyday life, and responsible for poor functional recovery and ability to benefit from treatment. This spatial cognition disorder affects the orientation of behaviour with a shift of proprioceptive representations toward the lesion side. Methods: This shift can be reduced after a Prism Adaptation period to a right lateral displacement of visual field (induced by a simple target-pointing task with base-left wedge Prisms). The modification of visuo-motor or sensory-motor correspondences induced by Prism Adaptation involves improvement of different symptoms of neglect. Results: Classical visuo-motor tests could be improved for at least 2h after Adaptation, but also non-motor and non-visual tasks. In addition, cross-modal effects have been described (tactile extinction and dichotic listening), mental imagery tasks (geographic map, number bisection) and even visuo-constructive disorders. These cognitive effects are shown to result from indirect bottom-up effects of the deeper, adaptive realignment component of the reaction to Prisms. Lesion studies and functional imaging data evoke a cerebello-cortical network in which each structure plays a specific role and not all structures are crucial for Adaptation ability. Conclusions: These cognitive effects of Prism Adaptation suggest that Prism Adaptation does not act specifically on the ipsilesional bias characteristic of unilateral neglect but rehabilitates more generally the visuo-spatial functions attributed to the right cortical hemisphere. These results reinforce the idea that the process of Prism Adaptation may activate brain functions related to multisensory integration and higher spatial representations and show a generalization at a functional level. Prism Adaptation therefore appears as a new powerful therapeutic tool for spatial cognition disorders.
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Prism Adaptation in the rehabilitation of patients with visuo-spatial cognitive disorders
Current Opinion in Neurology, 2006Co-Authors: Laure Pisella, Alessandro Farnè, Gilles Rode, Caroline Tilikete, Yves RossettiAbstract:The traditional focus of neurorehabilitaion has been on the patients' attention on their deficit, such that they should become aware of their problems and gain intentional control of compensatory strategies (descending approach). We review Prism Adaptation as one of the approaches that emphasize ascending rather than descending strategies to the rehabilitation of visuo-spatial disorders. The clinical outcome of Prism Adaptation highlights the need for a theoretical reconsideration of some previous stances to neurological rehabilitation.
Alessandro Farnè - One of the best experts on this subject based on the ideXlab platform.
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Studying the neural bases of Prism Adaptation using fMRI: A technical and design challenge
Behavior research methods, 2016Co-Authors: Janet H. Bultitude, Jacinta O'shea, Alessandro Farnè, Romeo Salemme, Danielle Ibarrola, Christian Urquizar, Jacques LuauteAbstract:Prism Adaptation induces rapid recalibration of visuomotor coordination. The neural mechanisms of Prism Adaptation have come under scrutiny since the observations that the technique can alleviate hemispatial neglect following stroke, and can alter spatial cognition in healthy controls. Relative to non-imaging behavioral studies, fMRI investigations of Prism Adaptation face several challenges arising from the confined physical environment of the scanner and the supine position of the participants. Any researcher who wishes to administer Prism Adaptation in an fMRI environment must adjust their procedures enough to enable the experiment to be performed, but not so much that the behavioral task departs too much from true Prism Adaptation. Furthermore, the specific temporal dynamics of behavioral components of Prism Adaptation present additional challenges for measuring their neural correlates. We developed a system for measuring the key features of Prism Adaptation behavior within an fMRI environment. To validate our configuration, we present behavioral (pointing) and head movement data from 11 right-hemisphere lesioned patients and 17 older controls who underwent sham and real Prism Adaptation in an MRI scanner. Most participants could adapt to Prismatic displacement with minimal head movements, and the procedure was well tolerated. We propose recommendations for fMRI studies of Prism Adaptation based on the design-specific constraints and our results.
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Prism Adaptation in the healthy brain: the shift in line bisection judgments is long lasting and fluctuates.
Neuropsychologia, 2013Co-Authors: Selene Schintu, Romeo Salemme, Laure Pisella, Stéphane Jacobs, Karen T. Reilly, Alessandro FarnèAbstract:Abstract Rightward Prism Adaptation has been shown to ameliorate visuospatial biases in right brain-damaged patients with neglect, and a single session of Prism Adaptation can lead to improvements that last up to several hours. Leftward Prism Adaptation in neurologically healthy individuals induces neglect-like biases in visuospatial tasks. The duration of these effects in healthy individuals, typically assumed to be ephemeral, has never been investigated. Here we assessed the time-course of the Adaptation-induced modifications in a classical perceptual line bisection task that was repeatedly administered for approximately 40 min after a single session of Adaptation to either a leftward or rightward Prismatic deviation. Consistent with previous reports, only Adaptation to leftward-deviating Prisms induced a visuospatial shift on perceptual line bisection judgments. The typical pattern of pseudoneglect was counteracted by a rightward shift in midline judgments, which became significant between 5 and 10 min after Adaptation, fluctuated between being significant or not several times in the 40 min following Adaptation, and was present as late as 35 min. In contrast, the sensorimotor aftereffect was present immediately after Adaptation to both rightward and leftward deviating Prisms, decayed initially then remained stable until 40 min. These results demonstrate that both the sensorimotor and visuospatial effects last for at least 35 min, but that the visuospatial shift needs time to fully develop and fluctuates. By showing that the effects of Prism Adaptation in the undamaged brain are not ephemeral, these findings reveal the presence of another, so-far neglected dimension in the domain of the cognitive effects induced by Prism Adaptation, namely time. The prolonged duration of the induced visuospatial shift, previously considered to be a feature of Prism Adaptation unique to brain-damaged subjects, also applies to the normal brain.
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Prism Adaptation and the Rehabilitation of Spatial Neglect
Systems Neuroscience and Rehabilitation, 2011Co-Authors: Sophie Jacquin-ciourtois, Gilles Rode, Jacques Luaute, Jacinta O'shea, Alessandro Farnè, Laure Pisella, Patrice Revol, Yves RossettiAbstract:A large proportion of right-hemisphere stroke patients exhibits spatial neglect, a neurological condition characterised by deficits for perceiving, attending, representing, and/or performing actions within their left-sided space. spatial neglect is responsible for many debilitating effects on everyday life, for poor functional recovery, and for decreased ability to benefit from treatment. Prism Adaptation (PA) to a right lateral displacement of the visual field (induced by a simple target-pointing task while wearing base-left wedge Prisms) is known to directionally bias visuo-motor and sensory-motor correspondences and has recently been found to improve various symptoms of neglect. For example, performance on classical pen-and-pencil visuo-motor tests could be improved for at least 2 h following Adaptation. Further effects of PA have also been described for non-motor and non-visual tasks, such as for somatosensory extinction or dichotic listening, for deficits in mental imagery of geographic maps and in number bisection, and even for visuo-constructive disorders. These results suggest that the effects of Prism Adaptation can extend to unexposed sensory systems. The bottom-up approach of visuo-motor Adaptation appears to interact with higher order brain functions related to multisensory integration and can have beneficial effects on sensory processing in different modalities. Lesion studies and functional imaging data point to a cerebello-cortical network in which the cerebellum is crucial for Adaptation and the cortex is involved in functional gains. Prism Adaptation may act not only on the ipsilesional bias characteristic of neglect and also alleviate more generally other spatial cognition deficits due to attentional bias.
-
Prism Adaptation in the rehabilitation of patients with visuo-spatial cognitive disorders
Current Opinion in Neurology, 2006Co-Authors: Laure Pisella, Alessandro Farnè, Gilles Rode, Caroline Tilikete, Yves RossettiAbstract:The traditional focus of neurorehabilitaion has been on the patients' attention on their deficit, such that they should become aware of their problems and gain intentional control of compensatory strategies (descending approach). We review Prism Adaptation as one of the approaches that emphasize ascending rather than descending strategies to the rehabilitation of visuo-spatial disorders. The clinical outcome of Prism Adaptation highlights the need for a theoretical reconsideration of some previous stances to neurological rehabilitation.
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Prism Adaptation in the rehabilitation of patients with visuo-spatial cognitive disorders
Current opinion in neurology, 2006Co-Authors: Laure Pisella, Alessandro Farnè, Gilles Rode, Caroline Tilikete, Yves RossettiAbstract:Purpose of review The traditional focus of neurorehabilitaion has been on the patients’ attention on their deficit, such that they should become aware of their problems and gain intentional control of compensatory strategies (descending approach). We review Prism Adaptation as one of the approaches that emphasizes ascending rather than descending strategies to the rehabilitation of visuo-spatial disorders. The clinical outcome of Prism Adaptation highlights the need for a theoretical reconsideration of some previous stances to neurological rehabilitation. Recent findings Recent years have given rise to a growing body of experimental studies showing that the descending strategy is not always optimal, especially when higher-level cognition is affected by the patients’ condition. Ascending approaches have, for example, used visuo-manual Adaptation for the rehabilitation of visuo-spatial deficits. A simple task of pointing to visual targets while wearing Prismatic goggles can produce remarkable improvements of various aspects of unilateral neglect. Summary The neural mechanisms underpinning visuo-manual plasticity can be viewed as a powerful rehabilitation tool that produces straightforward effects not only on visual and motor parameters, but on visuo-spatial, attentional and higher cognitive neurological functions. The use of Prism Adaptation therapy in neglect and other visuo-spatial disorders has just started to reveal its potential, both at a practical and theoretical level.
Jacques Luaute - One of the best experts on this subject based on the ideXlab platform.
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Studying the neural bases of Prism Adaptation using fMRI: A technical and design challenge
Behavior research methods, 2016Co-Authors: Janet H. Bultitude, Jacinta O'shea, Alessandro Farnè, Romeo Salemme, Danielle Ibarrola, Christian Urquizar, Jacques LuauteAbstract:Prism Adaptation induces rapid recalibration of visuomotor coordination. The neural mechanisms of Prism Adaptation have come under scrutiny since the observations that the technique can alleviate hemispatial neglect following stroke, and can alter spatial cognition in healthy controls. Relative to non-imaging behavioral studies, fMRI investigations of Prism Adaptation face several challenges arising from the confined physical environment of the scanner and the supine position of the participants. Any researcher who wishes to administer Prism Adaptation in an fMRI environment must adjust their procedures enough to enable the experiment to be performed, but not so much that the behavioral task departs too much from true Prism Adaptation. Furthermore, the specific temporal dynamics of behavioral components of Prism Adaptation present additional challenges for measuring their neural correlates. We developed a system for measuring the key features of Prism Adaptation behavior within an fMRI environment. To validate our configuration, we present behavioral (pointing) and head movement data from 11 right-hemisphere lesioned patients and 17 older controls who underwent sham and real Prism Adaptation in an MRI scanner. Most participants could adapt to Prismatic displacement with minimal head movements, and the procedure was well tolerated. We propose recommendations for fMRI studies of Prism Adaptation based on the design-specific constraints and our results.
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Left-Deviating Prism Adaptation in Left Neglect Patient: Reflexions on a Negative Result
Neural plasticity, 2012Co-Authors: Jacques Luaute, G. Rode, S. Jacquin-courtois, D. Boisson, Jacinta O'shea, Laure Christophe, Yves RossettiAbstract:Adaptation to right-deviating Prisms is a promising intervention for the rehabilitation of patients with left spatial neglect. In order to test the lateral specificity of Prism Adaptation on left neglect, the present study evaluated the effect of left-deviating Prism on straight-ahead pointing movements and on several classical neuropsychological tests in a group of five right brain-damaged patients with left spatial neglect. A group of healthy subjects was also included for comparison purposes. After a single session of exposing simple manual pointing to left-deviating Prisms, contrary to healthy controls, none of the patients showed a reliable change of the straight-ahead pointing movement in the dark. No significant modification of attentional paper-and-pencil tasks was either observed immediately or 2 hours after Prism Adaptation. These results suggest that the therapeutic effect of Prism Adaptation on left spatial neglect relies on a specific lateralized mechanism. Evidence for a directional effect for Prism Adaptation both in terms of the side of the visuomanual Adaptation and therefore possibly in terms of the side of brain affected by the stimulation is discussed.
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Prism Adaptation enhances activity of intact fronto-parietal areas in both hemispheres in neglect patients.
Cortex; a journal devoted to the study of the nervous system and behavior, 2011Co-Authors: Arnaud Saj, Jacques Luaute, Yann Cojan, Roland Vocat, Patrik VuilleumierAbstract:Unilateral spatial neglect involves a failure to report or orient to stimuli in the contralesional (left) space due to right brain damage, with severe handicap in everyday activities and poor rehabilitation outcome. Because behavioral studies suggest that Prism Adaptation may reduce spatial neglect, we investigated the neural mechanisms underlying Prism effects on visuo-spatial processing in neglect patients. We used functional magnetic resonance imaging (fMRI) to examine the effect of (right-deviating) Prisms on seven patients with left neglect, by comparing brain activity while they performed three different spatial tasks on the same visual stimuli (bisection, search, and memory), before and after a single Prism-Adaptation session. Following Prism Adaptation, fMRI data showed increased activation in bilateral parietal, frontal, and occipital cortex during bisection and visual search, but not during the memory task. These increases were associated with significant behavioral improvement in the same two tasks. Changes in neural activity and behavior were seen only after Prism Adaptation, but not attributable to mere task repetition. These results show for the first time the neural substrates underlying the therapeutic benefits of Prism Adaptation, and demonstrate that visuo-motor Adaptation induced by Prism exposure can restore activation in bilateral brain networks controlling spatial attention and awareness. This bilateral recruitment of fronto-parietal networks may counteract the pathological biases produced by unilateral right hemisphere damage, consistent with recent proposals that neglect may reflect lateralized deficits induced by bilateral hemispheric dysfunction.
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Prism Adaptation and the Rehabilitation of Spatial Neglect
Systems Neuroscience and Rehabilitation, 2011Co-Authors: Sophie Jacquin-ciourtois, Gilles Rode, Jacques Luaute, Jacinta O'shea, Alessandro Farnè, Laure Pisella, Patrice Revol, Yves RossettiAbstract:A large proportion of right-hemisphere stroke patients exhibits spatial neglect, a neurological condition characterised by deficits for perceiving, attending, representing, and/or performing actions within their left-sided space. spatial neglect is responsible for many debilitating effects on everyday life, for poor functional recovery, and for decreased ability to benefit from treatment. Prism Adaptation (PA) to a right lateral displacement of the visual field (induced by a simple target-pointing task while wearing base-left wedge Prisms) is known to directionally bias visuo-motor and sensory-motor correspondences and has recently been found to improve various symptoms of neglect. For example, performance on classical pen-and-pencil visuo-motor tests could be improved for at least 2 h following Adaptation. Further effects of PA have also been described for non-motor and non-visual tasks, such as for somatosensory extinction or dichotic listening, for deficits in mental imagery of geographic maps and in number bisection, and even for visuo-constructive disorders. These results suggest that the effects of Prism Adaptation can extend to unexposed sensory systems. The bottom-up approach of visuo-motor Adaptation appears to interact with higher order brain functions related to multisensory integration and can have beneficial effects on sensory processing in different modalities. Lesion studies and functional imaging data point to a cerebello-cortical network in which the cerebellum is crucial for Adaptation and the cortex is involved in functional gains. Prism Adaptation may act not only on the ipsilesional bias characteristic of neglect and also alleviate more generally other spatial cognition deficits due to attentional bias.
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dynamic changes in brain activity during Prism Adaptation
The Journal of Neuroscience, 2009Co-Authors: Jacques Luaute, Mona Spiridon, Yves Rossetti, Gilles Rode, Sophie Schwartz, Dominique Boisson, Patrik VuilleumierAbstract:Prism Adaptation does not only induce short-term sensorimotor plasticity, but also longer-term reorganization in the neural representation of space. We used event-related fMRI to study dynamic changes in brain activity during both early and prolonged exposure to visual Prisms. Participants performed a pointing task before, during, and after Prism exposure. Measures of trial-by-trial pointing errors and corrections allowed parametric analyses of brain activity as a function of performance. We show that during the earliest phase of Prism exposure, anterior intraparietal sulcus was primarily implicated in error detection, whereas parieto-occipital sulcus was implicated in error correction. Cerebellum activity showed progressive increases during Prism exposure, in accordance with a key role for spatial realignment. This time course further suggests that the cerebellum might promote neural changes in superior temporal cortex, which was selectively activated during the later phase of Prism exposure and could mediate the effects of Prism Adaptation on cognitive spatial representations.