Cross-over in line bisection among stroke patients / 中华物理医学与康复杂志

ABSTRACT

Objective To explore possible mechanisms of the cross-over observed in stroke patients comple-ting a line bisection test. Methods Twenty-five stroke patients with left neglect and twenty normal subjects were studied.In the ordinary line bisection test,there are two papers presenting 20 mm and 100 mm lines respectively.On each paper,three lines with the same length are presented at the left,middle and right of the paper.In the line im-age test,the two papers are the same as in line bisection test,but here subjects are asked to set endpoints of each re-al line. Results Replicating earlier findings,length cross-over was observed in the patients with neglect.In the hline image test,those patients neglected lines on both sides but with a much larger proportion on the left.The patientsunderestimated long lines as in previous studies,but they also underestimated very short lines in contrast to earlier findings. Conclusion Foveal neglect sparing may explain these observations.For very short lines,the left end of the line falls into foveal vision and the left part of the line was not neglected.As a result,the crossover effect of line length occurs.