Objective: To assess the relative frequency of occurrence of motor, perceptual, peripersonal, and personal neglect subtypes, the association of neglect and other related deficits (e.g., deficient nonlateralized attention, anosognosia), and the neuroanatomic substrates of neglect in patients with right hemisphere stroke in rehabilitation settings. Methods: The authors assessed 166 rehabilitation inpatients and outpatients with right hemisphere stroke with measures of neglect and neglect subtypes, attention, motor and sensory function, functional disability, and family burden. Detailed lesion analyses were also performed. Results: Neglect was present in 48% of right hemisphere stroke patients. Patients with neglect had more motor impairment, sensory dysfunction, visual extinction, basic (nonlateralized) attention deficit, and anosognosia than did patients without neglect. Personal neglect occurred in 1% and peripersonal neglect in 27%, motor neglect in 17%, and perceptual neglect in 21%. Neglect severity predicted scores on the Functional Independence Measure and Family Burden Questionnaire more accurately than did number of lesioned regions. Conclusions: The neglect syndrome per se, rather than overall stroke severity, predicts poor outcome in right hemisphere stroke. Dissociations between tasks assessing neglect subtypes support the existence of these subtypes. Finally, neglect results from lesions at various loci within a distributed system mediating several aspects of attention and spatiomotor performance.

Humans and monkeys share similar sensory integrated processing of tactile and peri-hand visual inputs for coding peripersonal space surrounding the hand. In monkeys, tool use is known to induce a transient elongation of hand-centred peripersonal space along the tool axis. Here we report evidence that, also in humans, the use of a tool can increase the spatial extent of the representation of peri-hand visual space to incorporate the tool. We investigated this phenomenon in patients with tactile extinction, by using a cross-modal paradigm well suited to reveal visual-tactile integration near patients' hand. In the present study cross-modal extinction was assessed far from patients' ipsilesional hand, at the distal edge of a hand-held rake. We found that cross-modal extinction was more severe after patients used the rake to retrieve distant objects with respect to a condition in which the rake was not used. This evidence of an expansion of peri-hand space lasted only a few minutes after tool use. By contrast, peri-hand space expansion was not observed when motor actions towards distant objects did not involve the tool. These findings show that visual peri-hand space has important dynamic properties in humans; it can be expanded and contracted depending upon tool use.