Acute neglect rehabilitation using repetitive prism adaptation: a randomized placebo-controlled trial

At present, prism adaptation is probably the most promising rehabilitation procedure for hemi-neglect. However, randomised controlled trials are lacking and no data are available on the effectiveness of prism adaptation in the treatment of acute neglect.

We followed sixteen neglect patients using a randomised controlled design in which six patients received four-day-in-a-row placebo treatment (CG) and ten patients received four-day-in-a row experimental treatment with 10 degrees rightward deviating prisms (EG) during their stay on the stroke unit. We examined whether patients in the EG improved faster than the CG by administering three neglect tasks (Schenkenberg Line Bisection, Letter Cancellation, Gainotti Scene Copying) immediately before and after each treatment. Second, we examined whether patients in the EG demonstrated a better long-term outcome at one month post-treatment (Behavioural Inattention Test).

Patients in the EG improved faster on spatial tasks (line bisection, cancellation) than the CG but not on visuo-construction. Patients in the EG showed no differences with the CG in neglect outcome at one month post-treatment.

Four consecutive prism sessions produced beneficial effects in patients with acute neglect. However, prism effects were either short-term, or placebo treatment with repeated pointing and/or repeated neglect testing was more helpful than we anticipated. Our results emphasize the importance of a placebo condition and a follow-up in rehabilitation studies.