The value of incorporating personally relevant stimuli into consciousness assessment with the Coma Recovery Scale – Revised: A pilot study
Jonas Stenberg, Alison K. Godbolt, Marika C. Möller
Department of Rehabilitation Medicine, Danderyds Sjukhus AB, SE-182 20 Stockholm, Sweden. E-mail: firstname.lastname@example.org
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.
Patients with a severe brain injury usually emerge from coma and gradually regain some degree of independence. A few patients, however, open their eyes but show no or extremely limited signs of consciousness, a “Disorder of Consciousness”. In this study, we studied whether the use of personally relevant stimuli, which are largely not used in the currently recommended assessment scale, are helpful in assessing the degree of consciousness in these patients. We found that, compared with neutral objects, the patients looked more frequently at a picture of a relative and at their own reflection in a mirror. We conclude that personally relevant stimuli could be helpful in the assessment of consciousness, but that more research is needed.