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 Unpublished reports, articles in other than the English language, and studies with non-human and non-adult …subjects were excluded.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