The value of incorporating personally relevant stimuli into consciousness assessment with the Coma Recovery Scale – Revised: A pilot study

Abstract

OBJECTIVE: To explore whether the use of personally relevant stimuli, for some tasks in the Coma Recovery Scale - Revised (CRS-R), generates more responses in patients with prolonged disorders of consciousness compared with neutral stimuli. DESIGN: Multiple single-case design. SUBJECTS: Three patients with prolonged disorders of consciousness recruited from an inpatient department at a regional brain injury rehabilitation clinic in Stockholm, Sweden. METHODS: Patients were repeatedly assessed with the CRS-R. Randomization tests (bootstrapping) were used to compare the number of responses generated by personally relevant and neutral stimuli on 5 items in the CRS-R. RESULTS: Compared with neutral stimuli, photographs of relatives generated significantly more visual fixations. A mirror generated visual pursuit to a significantly greater extent than other self-relevant stimuli. On other items, no significant differences between neutral and personally relevant stimuli were seen. CONCLUSION: Personally relevant visual stimuli may minimize the risk of missing visual fixation, compared with the neutral stimuli used in the current gold standard behavioural assessment measure (CRS-R). However, due to the single-subject design this conclusion is tentative and more research is needed.