Rehabilitation of the central executive of working memory after severe traumatic brain injury: Two single-case studies

Background/objective: A deficit of the central executive of working memory is a frequent finding in patients with severe traumatic brain injury (TBI). The objective of the present study was to assess the efficacy of a rehabilitation programme of the central executive after severe TBI. Method: An experimental single-case design was used in two patients with remote severe TBI suffering from an isolated central executive deficit. Outcome was assessed with specific working memory tests (spans, Brown Peterson, n-back), non-specific cognitive tasks requiring working memory (dual-task, arithmetic solving problem), an ecological questionnaire to assess generalization to everyday life and non-target tasks not requiring working memory, to assess the specificity of the therapy. Results: Performance was stable on two baseline sessions before therapy. For both patients, an improvement was found for target measures, mainly for central executive tasks, and for the questionnaire on attention failures in everyday life. In opposition, no change was found for non-target measures. Discussion: Improvement was not seemingly related to spontaneous recovery, nor to re-test effects. This study suggests that specific cognitive training may improve the central executive of working memory in patients with remote severe TBI.