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Biomedical subjects

Peter Halligan

Publications and source records attributed to Peter Halligan.

5 recordsLinked to original sources
PubMed2006

Visuo-spatial neglect: a systematic review of current interventions and their effectiveness.

Left visuo-spatial neglect is a well-recognized predictor of poor functional outcome following right hemisphere stroke. Over the past 60 years, 18 different methods have been described and evaluated aimed at reducing the effects of this impairment. Although there are some grounds for optimism particularly in terms of short-term impairment-based effects, the range and degree of disability borne by many patients remain high and the clinical effectiveness of the different methods viewed in terms of long-lasting functional improvement (i.e. improvement of disabilities or handicap) is not clear. A systematic review of the available clinically relevant literature, using comparative and stringent levels of evidence, indicates that visual scanning training (VST), trunk rotation (TR) or repeated neck muscle vibrations (NMV) when associated with an extensive training program, mental imagery training, video feedback training and prism adaptation (PA) can be recommended for the rehabilitation of patients with left neglect. More studies however are needed to determine the optimal paradigm of limb activation (LA) eliciting a sustained functional improvement. Sensory stimulations alone and Fresnel prisms do not appear to be functionally relevant. For the other methods, the actual literature is not sufficient to conclude whether or not a long-term functional improvement can be achieved.

Functional Laterality↗
PubMed2006

Prism adaptation first among equals in alleviating left neglect: a review.

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.

Adaptation, Physiological↗
PubMed2004

Neglected attention in apparent spatial compression.

Halligan and Marshall [Cortex 27 (1991) 623] devised a new test to evaluate the hypothesis that in visual neglect, left space is systematically compressed rightwards. In the critical condition of the original study, rows of horizontally arranged numbers with a target arrow pointing to one of them from the opposite margin of the display were presented. When asked to verbally identify the number indicated by the arrow, a right brain-damaged patient with left neglect and hemianopia often indicated a number to the right of the target. The more the target was located on the left, the greater the response shift rightward, as if rightward compression were linearly proportional to the co-ordinates of Euclidian space. However, a possible alternative account could be that the patient's attention was attracted by the numbers located to the right of the target digit, thus biasing her responses toward numbers on the right. To explore this hypothesis, we asked normal participants and patients with right hemisphere lesions, with and without neglect or hemianopia, to mark on the margin of a sheet the approximate location indicated by an arrow situated on the opposite margin. In three different conditions, the arrow indicated either one of several numbers or lines in a row, or a blank location on the sheet margin. Only patients with left neglect, and especially those with associated hemianopia, deviated rightward, and then crucially only on those conditions where visible targets were present, consistent with the attentional bias account.

Adult↗
PubMed2003

New wine in old bottles: the WHO ICF as an explanatory model of human behaviour.

The World Health Organization's International Classification of Functioning (WHO ICF) is a good but incomplete framework for describing the situation of someone with long-term ill health. Several deficiencies exist for which improvements are suggested. The WHO needs to integrate the ICF with the ICD-10 to form a comprehensive system of classification of illness. Words are needed for normality at the level of organ and person, and the words 'histology' and 'physiology', and 'anatomy' and 'capacity' are suggested for the two levels respectively. A fourth context, that of time, is needed to understand fully a person's situation. The classification framework needs to take more account of the patient. It needs to recognize two separate perspectives, that of the subject and that of external observers and it needs to recognize two other specific person-centred phenomena: free will and quality of life. With changes and additions to take account of these deficiencies, the WHO ICF can be used as a powerful analytic and explanatory model of human experience and behaviour in any situation, not only in illness and disease.

Activities of Daily Living↗