Rightward bias in right hemisphere infarct patients with or without thrombolytic treatment and in healthy controls

Abstract

Right hemisphere (RH) infarct patients have a tendency to begin visual scanning from the right side of a given stimulus. Our aim was to find out whether RH patients with (T+) or without (T−) thrombolytic treatment and healthy controls differ in their starting points in three cancellation tasks. Our sample comprised of 77 patients and 62 controls. Thirty-four patients received thrombolysis. Rightward orientation bias was more evident in the T− group than in the T+ group. The T+ group showed a robust tendency to start all cancellation tasks more often on the right side than the controls. Regardless of whether they had visual neglect, patients in the T+ group showed still defective rightward orienting, possibly indicating residual attentional problems. The analyses of starting points in visual cancellation tasks provide additional information on residual symptoms of attention difficulties after stroke.

Keywords:

• Attention
• Cognition
• Neglect
• Rightward bias
• Stroke
• Thrombolysis

Acknowledgments

The authors are grateful to Heidi Losoi, Eija-Inkeri Ruuskanen, and Virpi Ylihärsilä for recruiting the patients and healthy controls for this study. We also thank all the patients and volunteers who participated in the study. The study was supported by grants from the Medical Research Fund of Tampere University Hospital, the Research Fund of the University of Tampere, and the Finnish Cultural Foundation.