A single blinded randomised controlled pilot trial of prism adaptation for improving self-care in stroke patients with neglect

Abstract

Prism adaptation has been shown to alleviate the symptoms of unilateral spatial neglect following stroke in single case and small group studies. The purposes of this single blinded pilot randomised controlled trial were to determine the feasibility of delivering prism adaptation treatment in a clinically valid sample and to assess its impact on self-care. Thirty seven right hemisphere stroke patients with unilateral spatial neglect were randomised into either prism adaptation (using 10 dioptre, 6 degree prisms) or sham treatment (using plain glasses) groups. Treatment was delivered each weekday for two weeks. Pointing accuracy, without vision of the finger, was recorded each day before treatment. Outcome was measured, by blinded assessors, four days and eight weeks after the end of treatment using the Catherine Bergego Scale (CBS) and the conventional neuropsychological tests from the Behavioural Inattention Test (BIT). Thirty four patients received treatment: 16 with prisms, 18 sham. Mean compliance was 99% and 97%, respectively. Over the treatment days only the prism treated group showed increased leftward bias in open loop pointing to targets on a touch screen. However, despite the group level changes in pointing behaviour no overall effect of the treatment on self-care or BIT were found.

Keywords:

• Stroke
• Hemispatial neglect
• Prism adaptation
• Rehabilitation
• Activities of daily living

Acknowledgments

We would like to thank all the participants for their help with both the intervention and assessments involved in this study, and particularly for their generosity in allowing assessors to observe their personal care; the occupational therapists at University Hospitals Bristol Foundation Trust and North Bristol NHS Trust for their assistance in identifying potential participants; the support staff in the Department of Experimental Psychology who carried out the randomisation process and manufactured boxes for the pointing procedure; Dr Casimir Ludwig who provided the software for presenting targets and recording pointing accuracy; and Dr Paula Kersten, University of Southampton, for converting the CBS data to logits. This study was funded by the Stroke Association.