Previous studies have discussed the effectiveness or ineffectiveness of prism adaptation for neglect patients. Purpose: The aim of present study was to determine the long-term effect of prism adaptation with activity performance instead of pointing performance on chronic neglect patients. Subjects: Seven patients with chronic unilateral spatial neglect were recruited. Methods: We performed an 8-week intervention using prismatic glasses. Changes in eye movement before and after intervention were measured using an eye mark recorder system. We also assessed intentional spatial bias in terms of center of gravity in the standing position using a tactile sensor scan system. Additionally, regional cerebral blood flow was measured using SPECT (IMP) before and after intervention. Results: Eye movements significantly improved on the neglected side (p < 0.01), and the effects were sustained for up to 6 weeks after the removal of the prism. The center of gravity significantly moved to the left and forward. Furthermore, rCBF showed a significant increase at the parietal cortex, pericalleosal area of the left hemisphere (P < 0.05). Conclusion: These results suggest that intervention using prismatic glasses could improve eye movement on the neglected side and correct intentional spatial bias. Prism intervention might be one valuable method for the activation of the important areas of the brain in neglect patients.

To investigate the sustainability of effect and the changes in basic and instrumental activities of daily living (ADL and IADL) after long-term prism intervention, we carried out a follow-up assessment on five subjects with hemispatial neglect in the chronic stage. Method: At 2-3.5 years after the end of prism intervention, we measured six parameters: 1) eye movement of the neglect side when watching three different video clips, 2) center of gravity as an index of subjective internal midline bias, 3) star and letter cancellation tests, 4) the line bisection test, and ADL scales: 5) Barthel Index and 6) Lawton's IADL scale. In addition, we interviewed and observed the subjects' present ADL performance at home. Results: The eye movement on the neglect side significantly increased compared with that before intervention. The center of gravity was shifted significantly to the left side and forward. The improvement in cancellation and line bisection tests was also observed. All subjects showed improvement in ADL performance. Two of the subjects could return to work after intervention. Conclusion:The results suggested that long-term prism intervention might effectively exert long-lasting effects and bring benefits to ADL performance for subjects with hemispatial neglect.

This study suggests that providing a pedometer during an exercise intervention is an effective addition to an exercise program to improve LEPF.