Acute hemianopic patients do not show a contralesional deviation in the line bisection task.

摘要

Sirs: the line bisection task is a common clinical bedside tool for the assessment of spatial neglect and homonymous hemianopia (HH) . When asked to bisect a line, neglect patients show an ipsilesional deviation . In contrast, hemianopic patients (> 90 %) displace their midline contralesionally towards the scotoma [1,3,4].Evidence for this "typical hemianopic line bisection error" came from hemianopic patients in a chronic stage (> 3 months) of brain damage . It is a matter of debate whether their line bisection error (LBE) is due to non-veridical spatial representation or an adaptive attentional shift ("compensatory hyperattention") [1-3].We compared the line bisection task in hemianopic patients as well as hemineglect patients in their acute stage of stroke with healthycontrol subjects. Our objectives were twofold: (i) if adaptive attentional mechanisms are responsible for the LBE in hemianopic patients it may be absent in their acute stage, and if so (ii) is the line bisection task a reliable bedside tool to distinguish hemianopia from hemineglect in the acute stage of stroke?