Restorative Neurology and Neuroscience - Volume 24, issue 4-6

Authors: Kerkhoff, G. | Rossetti, Y.

Article Type: Other

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 201-206, 2006

Authors: Jehkonen, M. | Laihosalo, M. | Kettunen, J.E.

Article Type: Research Article

Abstract: Purpose: This study provides an update on recent research findings concerning neglect and its impact on functional outcome. The review covers studies published during the past ten years. Methods: A systematic review was carried out on reports drawn from electronic databases (MEDLINE and PSYCHLIT, January 1996 – August 2005) and identified from the lists of references in these reports. Unpublished reports, articles in other than the English language, and studies with non-human and non-adult …subjects were excluded. The selection criteria were met by 26 articles. Results: 15 of the 26 studies recruited heterogeneous patient groups (patients with right and left and/or unspecified lesions). The results from homogeneous groups (right hemisphere patients) were more consistent, emphasizing neglect as an independent predictor of functional outcome. Studies with homogeneous patient groups used consecutive series of patients, standardized measures of neglect, and a broader concept of functional outcome (both motor and cognitive items) than those with heterogeneous patient groups. Follow-ups longer than one year were very rare. Conclusions: Neglect has a significant negative impact on functional outcome, either as an independent predictive factor or in connection with other variables. The results, however, are inevitably affected by differences in patient samples and in the methods used in assessing neglect and functional outcome. Research focusing on homogeneous patient groups and especially on left hemisphere patients is needed. Neglect should be assessed with a standardized test battery rather than a single test, and functional outcome should be measured with scales consisting of cognitive, social and motor items. Also longer follow-ups are needed to verify the long-term functional outcome of neglect patients. Show more

Keywords: Stroke, neglect, perceptual disorders, daily living

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 209-215, 2006

Authors: Brozzoli, Claudio | Demattè, M. Luisa | Pavani, Francesco | Frassinetti, Francesca | Farnè, Alessandro

Article Type: Research Article

Abstract: Purpose: The interest in human conscious awareness has increasingly propelled the study of neglect, the most striking occurrence of an acquired lack of conscious experience of space. Neglect syndromes commonly arise after unilateral brain damage that spares primary sensory areas nonetheless leading to a lack of conscious stimulus perception. Because of the central role of vision in our everyday life and motor behaviour, most research on neglect has been carried out in the visual domain. Here, …we suggest that a comprehensive perspective on neglect should examine in parallel evidence from all sensory modalities. Methods: We critically reviewed relevant literature on neglect within and between sensory modalities. Results: A number of studies have investigated manifestations of neglect in the tactile and auditory modalities, as well as in the chemical senses, supporting the idea that neglect can arise in various sensory modalities, either separately or concurrently. Moreover, studies on extinction (i.e., failure to report the contralesional stimulus only when this is delivered together with a concurrent one in the ipsilesional side), a deficit to some extent related to neglect, showed strong interactions between sensory modality for the conscious perception of stimuli and representation of space. Conclusions: Examining neglect and extinction by taking into account evidence from all sensory modalities in parallel can provide deeper comprehension of the neglect syndrome mechanisms and possibly more effective multi-sensory based rehabilitation approaches. Show more

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 217-232, 2006

Authors: Snow, Jacqueline C. | Mattingley, Jason B.

Article Type: Research Article

Abstract: In this review we address the question of whether selective attentional mechanisms within the ipsilesional field are intact in unilateral lesion patients with spatial neglect and extinction. We consider how a lesion-induced bias in the neural representation of salience critically disrupts the integration of goal-driven and stimulus-driven prioritization signals. This has important consequences for selectivity both within the 'impaired' contralesional field within the 'intact' ipsilesional field. Examples are drawn from the neuropsychological …literature and recent experiments conducted within our own laboratory. The implications of ipsilesional spatial selection deficits for rehabilitation are discussed. Show more

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 233-245, 2006

Authors: Vallar, Giuseppe | Ronchi, Roberta

Article Type: Research Article

Abstract: Purpose: The syndrome of unawareness (anosognosia) for sensory and motor neurological deficits (hemiplegia, hemianaesthesia, and hemianopia), contralateral to the side of a hemispheric lesion, is reviewed. Content: Main topics include: basic historical facts; the types of patient's interview and specific questions used to reveal the deficits; the clinical patterns of presentation; the associations and dissociations of the different anosognosic manifestations, and their relationships with associated disorders of sensory, memory, and executive-intellectual functions; the …hemispheric asymmetry of anosognosia, that, as the syndrome of unilateral spatial neglect, is more frequent and severe after damage to the right cerebral hemisphere; the relationships between spatial neglect and the anosognosias, and their neural correlates; the effects of lateralized sensory stimulations on defective awareness of neurological impairments. Conclusions: The argument is made that anosognosia for sensory and motor neurological deficits should be considered as a multi-component syndrome, including a number of specific disorders that are due to the impairment of discrete monitoring systems, specific for the different supervised functions. The putative causal role of associated deficits of other parts of the sensory-motor or cognitive (e.g., memory, general intelligence) system is critically discussed. These specific control processes may be physically implemented in brain areas anatomically (and functionally) close to those subserving the monitored function. Show more

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 247-257, 2006

Authors: Ishiai, Sumio

Article Type: Research Article

Abstract: Purpose: Eye-fixation patterns, which include ocular searching and fixation, may change with tasks, stimuli, and instructions. This article reviews our studies over 18 years on eye-fixation patterns of neglect patients and aims to elucidate the visuospatial processing of unilateral spatial neglect. Methods: We recorded eye-fixation patterns when patients with neglect bisected a line in various conditions. Results: Patients with neglect rarely searched to the left side when bisecting a line of the …ordinary length (e.g., 200 mm). They persisted in fixating a right-side point, at which they later marked the subjective midpoint. They made no effective comparison between the leftward and rightward extents not only for a whole line but also for its explored right segment. Where they 'favored' to fixate as the subjective midpoint depended strongly upon the location of the right endpoint in space. Their representational image of a line was also estimated with modified line bisection tasks performed on a touch-panel display. Conclusions: For patients with neglect, the representational image of a line may be formed on the basis of the attended segment between the right endpoint and the favored point of fixation. The line bisection task, if combined with recording of eye-fixation, would further contribute to elucidation of the mechanisms underlying neglect. Show more

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 261-271, 2006

Authors: Azouvi, Philippe | Bartolomeo, Paolo | Beis, Jean-Marie | Perennou, Dominic | Pradat-Diehl, Pascale | Rousseaux, Marc

Article Type: Research Article

Abstract: Purpose: The lack of agreement regarding assessment methods is responsible for the variability in the reported rate of occurrence of unilateral neglect (UN) after stroke. In addition, dissociations have been reported between performance on traditional paper-and-pencil tests and UN in everyday life situations. Methods: In this paper, we present the validation studies of a quantitative test battery for UN, including paper-and-pencil tests, an assessment of personal neglect, extinction, and anosognosia, and a behavioural …assessment, the Catherine Bergego Scale (CBS). The battery was given to healthy subjects (n=456–476) and to patients with subacute stroke, either of the right or the left hemisphere. Results: In healthy subjects, a significant effect of age, education duration and acting hand was found in several tasks. In patients with right hemisphere stroke, the most sensitive paper and pencil measure was the starting point in the cancellation task. The whole battery was more sensitive than any single test alone. An important finding was that behavioural assessment was more sensitive than any other single test. Neglect was two to four times less frequent, but also less severe and less consistent after left hemisphere stroke. Conclusion: Assessment of UN should rely on a battery of quantitative and standardised tests. Some patients may show clinically significant UN in everyday life while obtaining a normal performance on paper-and-pencil measures. This underlines the necessity to use a behavioural assessment of UN. Show more

Keywords: Unilateral neglect, assessment, stroke

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 273-285, 2006

Authors: Bublak, Peter | Redel, Petra | Finke, Kathrin

Article Type: Research Article

Abstract: Purpose: The aim was to present evidence that, similarly as in neglect, a combined pattern of spatial and non-spatial deficits of visual attention can also be typically observed in patients suffering from neurodegenerative disorders. Method: Whole and partial report of brief letter arrays, based on Bundesen's 'theory of visual attention' (TVA), was applied in patients suffering from Huntington's disease (HD), mild cognitive impairment (MCI), or Alzheimer's disease (AD). TVA-based parameter estimates were derived reflecting …(a) perceptual processing speed and visual working memory storage capacity as non-spatial aspects of visual attention (determined by whole report performance), and (b) spatial attentional weighting (determined by partial report performance). Results: Processing speed was severely slowed in HD, and also reduced, although to a lesser degree, in MCI and AD patients. In HD and AD patients, but not in MCI patients, a strong leftward bias of spatial attention was observed. Conclusion: Neglect and neurodegenerative diseases both involve a similar constellation of non-spatial and spatial deficits of visual attention. Therefore, by using TVA-based measurement, results from both fields of research may fruitfully inform each other in future studies, thus improving our understanding of the interaction of spatial and non-spatial attention deficits and its behavioral consequences. Show more

Keywords: Perceptual disorders, hemispatial neglect, neuropsychology, neuropsychological tests, Huntington's disease, Alzheimer's disease

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 287-301, 2006

Authors: Glocker, D. | Bittl, P. | Kerkhoff, G.

Article Type: Research Article

Abstract: Purpose: Multimodal spatial neglect manifests itself also in nonvisual modalities such as audition, touch and body representation. Yet, quantitative tests for the diagnosis of nonvisual neglect are still quite rare. The purpose of the present paper was to develop and evaluate a novel, simple and sensitive test for the assessment of body representational neglect (BRN) in patients with left or right cerebral hemispheric lesions. Methods: The vest test covers the front part of the trunk. The …blindfolded subject wears the vest and is instructed to pick up all objects from the 24 pockets of the vest (12 on each side) as quickly as possible using the ipsilesional, nonparetic hand. Two samples of healthy control subjects (each N=25) using either their left or their right hand performed the test in identical way to obtain normative data for patients searching with their left hand (i.e. left hemisphere stroke patients) versus their right hand (i.e. right hemisphere stroke patients). The test can be performed within 5~minutes, even with aphasic or apractic stroke patients. Results: Psychometric evaluations in a sample of 50 patients with unilateral stroke (25 leftsided, 25 rightsided) show high objectivity, high internal consistency (Cronbach's alpha=0.96), good retest-reliability (0.79 after 1 week in neglect patients) and good validity as compared with two other measures of BRN or multimodal neglect. Patient examples show that BRN as assessed with the vest test allows the detection of qualitatively and quantitatively different patterns of BRN, and shows double dissociations from visual neglect and from apraxia in left hemisphere stroke patients. Details of the test including instructions and cut-off values are given for users in the appendix of this article. Conclusions: In conclusion, the vest test is a sensitive, quick and reliable test for BRN which complements the assessment of visuo- and audiospatial neglect and allows to measure recovery (spontaneous or treatment-induced) in patients with BRN. Furthermore, it can help to improve our knowledge about the multisensory coding of our body and the surrounding space in the human brain. Show more

Keywords: Stroke, neglect, test, body, human, space

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 303-317, 2006

Authors: Pérennou, Dominic

Article Type: Research Article

Abstract: Purpose: In this paper we analyse the arguments for a strong association between spatial neglect and postural disorders and attempt to better understand the mechanisms which underlie that. Methods: We first provide a general overview of the available tools for a rational assessment of postural control in a clinical context. We then analyse the arguments in favour of a close relationship, although not necessarily causal, between spatial neglect and: 1) body orientation with respect …to gravity (including verticality perception i.e. the visual vertical, the haptic vertical, and the postural vertical); 2) body stabilisation with respect to the base of support; 3) posturographic features of stroke patients; 4) and finally their postural disability in daily life. This second part of the paper is based both on the literature review and on results of our current research. Results: Neglect patients show a dramatic postural disability, due both to problems in body orientation with respect to gravity and to problems in body stabilisation. It might be that these problems are partly caused by a neglect phenomenon bearing on graviceptive (somaesthetic > vestibular) and visual information serving postural control. This could correspond to a kind of postural neglect involving both the bodily and nonbodily domains of spatial neglect. The existence of distorsion(s) in the body scheme are also probably involved, especially to explain the weight-bearing asymmetry in standing, and probably an impaired multisegmental postural coordination leading to an impaired body stabilisation. Conclusion: The present paper explains why neglect patients show longer/worse recovery of postural-walking autonomy than other stroke patients. Show more

Keywords: Spatial cognition, body scheme, subjective vertical, verticality perception, stabilisation, postural control, balance

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 319-334, 2006

Authors: Pizzamiglio, Luigi | Guariglia, Cecilia | Antonucci, Gabriella | Zoccolotti, Pierluigi

Article Type: Research Article

Abstract: Purpose: The aim of the present paper is to review several studies which assessed the validity of a visuo-spatial training for the rehabilitation of neglect patients. In addition two peripheral stimulations (TENS and Optokinetic Stimulation) have been studied to assess the improvements of neglect disorders when used in combination with the visuo-spatial training. Also we analyzed the potential effect of training for attention on neglect and, viceversa, the effect of visuo-spatial training on attentional impairments. …Methods: the goals have been investigated by both group studies and descriptions of single cases. Results: The visuo-spatial training produced significant improvements on the performance of neglect patients which generalized to every day living situations: the results showed to be stable over time and had positive effects on a variety of other neurological impairments. It was also shown that the improvements are confined to tasks involving spatial exploration of extrapersonal space, but did not extend to other neglect disorders, such as representational and personal neglect. The use of peripheral stimulations, at variance with other studies in the literature, did not add any advantage as compared to the improvements produced by the visuo-spatial training. No transfer between training for neglect and attention was observed. Conclusions: the present review pointed out that neglect disorders can be improved in a clinically meaningful way: the studies described also showed some limitations and proposed the need of further researches in order to extend the improvements to several other aspects of the neglect syndrome. Show more

Keywords: Neglect rehabilitation, attention rehabilitation, sensory stimulation, attention disorders, recovery of functions

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 337-345, 2006

Authors: Rode, Gilles | Klos, Thomas | Courtois-Jacquin, Sophie | Rossetti, Yves | Pisella, Laure

Article Type: Research Article

Abstract: 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. Show more

Keywords: Neglect, prism adaptation, rehabilitation, after-effect, right hemisphere

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 347-356, 2006

Authors: Kerkhoff, G. | Keller, I. | Ritter, V. | Marquardt, C.

Article Type: Research Article

Abstract: Purpose: To evaluate whether repetitive optokinetic stimulation with active pursuit eye movements leads to substantial and greater recovery from visual neglect as compared to conventional visual scanning training. Methods: Two groups of five patients with leftsided hemineglect were consecutively collected and matched for clinical and demographic variables as well as neglect severity. One group received five treatment sessions of repetitive optokinetic stimulation (R-OKS) within one week, while the other group received the same amount …of conventional visual scanning training (VST) using identical visual stimuli and setup. All patients were treated in a single-subject baseline design with treatment-free intervals before (14 days) and after specific neglect therapy (14 days). Dependent variables were the improvements in digit cancellation, visuoperceptual and visuomotor line bisection and visual size distortion during treatment. The transfer of treatment effects was assessed by a paragraph reading test. Results: The results showed superior effects of OKS treatment in all five patients which generalized across all tasks administered and remained stable at follow-up. In contrast, no significant improvements were obtained after VST training in any of these tasks, except in line bisection. Conclusion: We conclude that the presentation of moving visual stimulus displays with active smooth pursuit eye movements can be more efficient than conventional visual scanning training using static visual displays. Show more

Keywords: Brain damage, neglect, visual motion, rehabilitation, therapy, recovery

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 357-369, 2006

Authors: Sturm, W. | Thimm, M. | Küst, J. | Karbe, H. | Fink, G.R.

Article Type: Research Article

Abstract: Purpose: It has been proposed that the right hemisphere alerting network co-activates, either directly or via the brainstem, the spatial attention system in the parietal cortex. The observation that measures of impaired alertness and sustained attention can be used to predict the outcome of neglect might suggest such a relationship, too. The aim of the present study was to investigate the effects of alertness training on hemispatial neglect. Method: A three-week computerised alertness training …was applied to patients with chronic (> 3 months) stable visuospatial hemineglect. Training effects were investigated both in a single case and in a group of 7 patients by means of neuropsychological tests and functional magnetic resonance imaging (fMRI). Results: After the training, the patients showed a significant improvement in a neglect test battery above any natural fluctuation during a three-week baseline phase. Improvements in the neglect tasks were accompanied by an increase of both right and left hemisphere frontal, anterior cingulate and superior parietal activation, areas known to be associated with both alertness and spatial attention. Four weeks after the end of the training, the patients' neglect test performance had mostly returned to baseline. Despite decreases of activation in some of the initially reactivated areas, increases in neural activity bilaterally in frontal areas, in the right anterior cingulate cortex, the right angular gyrus and in the left temporoparietal cortex remained. An Optokinetic Stimulation Training (OKS) in a control group of another 7 neglect patients led to comparable behavioral results. After the training, however, there was a reactivation mainly in posterior parts of both hemispheres suggesting training specific functional reorganization. Conclusion: The limited stability of the behavioral and reactivation results over time demonstrates that a three-week alertness or OKS training alone does not result in long lasting behavioral improvements and stable reactivation patterns in every patient. We rather suggest that combining alertness and spatial attention oriented training procedures might lead to a more stable amelioration of neglect symptoms. Show more

Keywords: Neglect, spatial attention, functional reactivation, recovery of function, stroke, plasticity

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 371-384, 2006

Authors: Eskes, Gail A. | Butler, Beverly

Article Type: Research Article

Abstract: Purpose: Spatial neglect is common after right-hemisphere stroke and has proven resilient to a number of therapeutic interventions. Both active and experimenter-induced passive movements of the left limb in left hemispace have been shown to ameliorate neglect in subsets of patients by improving performance on tasks requiring attention to the left side of space. However, the high incidence of contralesional hemiparesis and poor motor recovery in neglect makes active limb movement therapies applicable to only a …small subset of patients. The purpose of our studies was to investigate the effects of passive movements of the left hand by functional electrical stimulation (FES), a common and portable motor rehabilitation technique, on performance in a visual scanning task. Methods: The effect of FES-induced passive movement on target detection in a visual scanning task was compared to no movement and active movement conditions and also investigated in scanning tasks in both near and far space. Results: Passive limb movement effects in neglect were variable across and within studies, reference spaces, and individuals, with a subset of positive responders differing from non-responders in regard to constructional deficits and lesion location. Conclusions: The potential viability of FES as a therapy for neglect deserves further investigation and directions for future research in this area are discussed. Show more

Keywords: Limb movement, active, passive, functional electrical stimulation (FES), neglect, stroke

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 385-398, 2006

Authors: Lincoln, N.B. | Bowen, A.

Article Type: Research Article

Abstract: Purpose: The aim was to review the methodological quality of trials to evaluate rehabilitation for spatial neglect and to determine the overall effectiveness of interventions Methods: A systematic literature review and meta-analysis were conducted of trials completed by 2005. Trials identified were independently assessed for methodological quality by two reviewers. Outcomes were analysed as the standardised mean difference and 95% confidence intervals with random effects models. Results: 25 trials of neglect rehabilitation were …identified, 12 randomised controlled trials and 13 controlled clinical trials. The methodological quality was generally poor with only 4 trials achieving an A rating, i.e. low risk of selection bias. The immediate effect of cognitive rehabilitation on disability was small, 0.26 [−0.16, 0.67] and neither this nor the persisting effect 0.61 [−0.42, 1.63] was statistically significant. The most frequently used standardised neglect test (number of single letters correctly cancelled) favoured the experimental group 0.58 [0.10, 1.05] but was not significant. When cancellation errors were measured there was a small immediate effect favouring the experimental group, of borderline statistical significance, −0.65 [−1.28, −0.01] p=0.05, and a significant persisting effect −0.76 [−1.39, −0.13] p=0.02. Cognitive rehabilitation also significantly improved immediate (p=001) and persisting (p=0.02) line bisection performance but these findings are based on only four and one study respectively. Conclusions: The quality of trials identified was poor. Analysis of randomised controlled trials showed some evidence of an effect of intervention on measures of impairment. There was no evidence to support the effects of intervention on measures of disability. Further trials must use methods that reduce bias, have adequate statistical power, and include valid disability outcome measures. Show more

Keywords: Neglect, inattention, meta-analysis, review

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 401-408, 2006

Authors: Luauté, Jacques | Halligan, Peter | Rode, Gilles | Jacquin-Courtois, Sophie | Boisson, Dominique

Article Type: Research Article

Abstract: Purpose: The current paper was designed to provide a critical overview on the different methods proposed for the rehabilitation of left spatial neglect. Methods: On the basis of a previous systematic review of the literature, we analyzed all articles available aiming at reducing left spatial neglect which included a long term functional assessment. Results: The aim of most early rehabilitation approaches, such as visuo-scanning training, was to re-orient visual scanning toward the neglected …side. This review confirmed the utility of this method for rehabilitation purposes. More recent – theory driven – procedures, also based on a training approach, include limb activation, mental imagery training and video-feedback training. Although there is ground for optimism, the functional effectiveness of these methods still relies on few single-case studies. Newer methods have tried to stimulate automatic orientation of gaze or attention towards neglected space in a bottom-up fashion. Sensory stimulations can remove most of the classical signs of left neglect but their effects are short-lived. Such stimulations are not functionally relevant for rehabilitation except for trunk rotation or repeated neck muscle vibrations if they are associated with an extensive training program. A more promising intervention is prism adaptation given the growing evidence of relatively long-term functional gains from comparatively short term usage. Conclusion: Overall, there is now evidence for several clinically relevant long-term benefits in the case of visual scanning training, mental imagery training, video feedback training, neck muscle vibration and trunk rotation if associated with visual scanning training and prism adaptation. However, the amount of evidence is still limited to a small number of relevant published articles and it is mandatory to continue the research in this field. In this review, the possible routes for new rehabilitation procedures are discussed on the basis of the actual knowledge regarding the neuro-cognitive mechanisms underlying the therapeutic effect of prism adaptation. Show more

Keywords: Left neglect, stroke, rehabilitation, prism adaptation, review

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 409-418, 2006

Authors: Michel, Carine

Article Type: Research Article

Abstract: Hemispatial neglect is a neurological deficit of perception, attention, representation, and/or performing actions within the left-sided space. The condition also produces many functional debilitating effects on everyday life, and is associated with poor functional recovery and inability to benefit from treatment. Numerous methods of rehabilitation (sensory stimulations or active training) have been proposed to alleviate neglect condition. It has been recently shown that visuo-manual adaptation to rightward optical shift leads to profound …and enduring improvements of neglect symptoms. Based on the different methods commonly used in the rehabilitation of neglect, several techniques have been employed to simulate neglect symptoms in healthy subjects with a view to better understand the physiopathology of neglect. The present paper reviews studies of neglect-like behaviour in healthy individuals and in particular the use of prism adaptation as a procedure for simulating various symptoms of clinical neglect in normals. Neglect-like symptoms following prism adaptation offer insights as to the mechanisms of spatial neglect and provide an understanding of the interaction between low level sensorimotor processes and spatial cognition. Implications for the functional mechanisms and the anatomical substrates of prism adaptation are discussed in terms of inter-sensory plasticity and sensorimotor coordination and the way these may affect higher-level representations of space. Show more

Keywords: Simulation of neglect, healthy subjects, prism adaptation, space representation, plasticity

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 419-430, 2006

Authors: Ansuini, Caterina | Pierno, Andrea Cristiano | Lusher, Dean | Castiello, Umberto

Article Type: Research Article

Abstract: Purpose: The aims of the present article were the following: (i) to provide some evidence of the potential of virtual reality (VR) for the assessment, training and recovery of hemispatial neglect; (ii) to present data from our laboratory which seem to confirm that the clinical manifestation of neglect can be improved by using VR techniques; and (iii) to ascertain the neural bases of this improvement. Methods: We used a VR device (DataGlove) interfaced with a specially …designed computer program which allowed neglect patients to reach and grasp a real object while simultaneously observing the grasping of a virtual object located within a virtual environment by a virtual hand. The virtual hand was commanded in real time by their real hand. Results: After a period of training, hemispatial neglect patients coded the visual stimuli within the neglected space in an identical fashion as those presented within the preserved portions of space. However it was also found that only patients with lesions that spared the inferior parietal/superior temporal regions were able to benefit from the virtual reality training. Conclusions: It was concluded that using VR it is possible to re-create links between the affected and the nonaffected space in neglect patients. Furthermore, that specific regions may play a crucial role in the recovery of space that underlies the improvement of neglect patients when trained with virtual reality. The implications of these results for determining the neural bases of a higher order attentional and/or spatial representation, and for the treatment of patients with unilateral neglect are discussed. Show more

Keywords: Visual neglect, rehabilitation, virtual reality, reach-to-grasp, space remapping

Citation: Restorative Neurology and Neuroscience, vol. 24, no. 4-6, pp. 431-441, 2006