[REVIEW] Spatial neglect – Full Text HTML

Abstract

The syndrome of visuospatial neglect is a common consequence of unilateral brain injury. It is most often associated with stroke and is more severe and persistent following right hemisphere damage, with reported frequencies in the acute stage of up to 80%. Neglect is primarily a disorder of attention whereby patients characteristically fail to orientate, to report or to respond to stimuli located on the contralesional side. Neglect is usually caused by large strokes in the middle cerebral artery territory and is heterogeneous, such that most patients do not manifest every feature of the syndrome. A number of treatments may improve neglect, but there is no widely accepted universal approach to therapy. Although most patients recover spontaneously, the evidence suggests that they continue to have significant cognitive impairments, particularly relating to attention.

Introduction

The syndrome of spatial neglect is relatively common. Several pathological processes may cause it, including neurodegenerative disease,1 ,2 neoplasia3 and trauma,4 although it is most common in the context of hemispheric stroke.5 Because of its implications for the understanding of the perception and representation of space, neglect has been of considerable interest to neuroscientists, psychologists and philosophers.6–8 However, it is also very important to clinicians as it may profoundly affect recovery from stroke; indeed, neglect’s negative effects on rehabilitation outcome may be even greater than those of hemiplegia.9 ,10 Neglect may follow right hemisphere stroke in up to 82% of patients5 in the acute stage, but most studies describe rates closer to 50%.11

The terms unilateral neglect, hemineglect and spatial neglect are used interchangeably. They are generally defined as an inability to perceive, report and orient to sensory events towards one side of space, contralateral to the side of the lesion, with or without a primary sensory deficit.12 Neglect is more common and longer-lasting after right hemisphere stroke, most likely because of the right hemisphere’s key role in attentional processes; thus, most of the discussion below refers to neglect for the left side of space.13

Figure 2

Schematic representation of how a visual scene might appear to people with left homonymous hemianopia (middle panel) and left neglect (bottom panel). Whereas hemianopia obeys the midline and affects only the contralesional visual field, neglect affects parts of the ipsilesional field in addition to the contralesional field, such that there is a lateralised bias of attention towards the side of the lesion.

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