Hemispheric contributions to drawing.

The drawings of 69 consecutive stroke patients with single cerebral lesions on CT and of 33 normal controls, were analyzed by two independent observers using a standardized scoring system. The drawings of left brain damaged subjects (LBD) were more impaired overall than those of right brain damaged subjects (RBD). RBD drawings displayed hemispatial neglect and impaired spatial relationships. LBD drawings were simplified and exhibited low level errors of execution. Lesion size correlated significantly with drawing impairment in RBD but not in LBD. No relationship between intrahemispheric lesion location and drawing quality was found. However, severity of hemiparesis correlated significantly with drawing impairment in LBD. Performance on a visuospatial perceptual task correlated better with overall drawing quality for RBD than for LBD. Our data suggest that neglect and a visuospatial deficit impair drawing in RBD while dominant hand paresis and a conceptual impairment which parallels comprehension impairment contribute to LBD drawing disability.