Occupational performance and information processing in adults with agitation following traumatic brain injury

Abstract

Agitation following traumatic brain injury (TBI) is characterised by a heightened state of activity with disorganised information processing that interferes with learning and achieving functional goals. This thesis outlines a series of studies across four research phases, investigating how occupational performance of adults with TBI is affected by agitated behaviour and information processing difficulties. Clinicians report the presence of agitation interferes with engagement in therapy and achievement of rehabilitation goals. Research Phase One used a retrospective chart review of 80 adults with severe TBI to identify a high incidence of agitated behaviour during inpatient TBI rehabilitation. Agitated behaviour was associated with lengthier rehabilitation admission, prolonged duration of post-traumatic amnesia (PTA), and poor cognitive functioning at discharge. The association between agitation and poor cognition persisted for at least two years after discharge, highlighting the significant impact of agitated behaviour on people’s ability to relearn cognitive skills for daily function. These initial research findings directed subsequent research phases, in which an information processing model was adopted to examine application of cognitive strategies during occupational performance. An emerging occupational therapy assessment, The Perceive, Recall, Plan and Perform (PRPP) System of Task Analysis, was selected as the primary method for evaluating how application of cognitive strategies during occupational performance is affected in agitated patients. Clinical utility of this measure was established in a case study of an adult demonstrating severely agitated behaviour during inpatient TBI rehabilitation, followed by examination of instrument reliability and validity with ten experienced occupational therapists and five adults with agitated behaviour following brain injury. The PRPP System of Task Analysis emerged as a valid and reliable method for determining strategy application deficits during occupational performance of adults with agitated behaviour, in acute stages of TBI rehabilitation. Consistent patterns of processing deficits were related to the Perceive and Recall Quadrants of the PRPP System. The assessment tool forms part of a dynamic, interactive assessment and intervention system. The PRPP System of Intervention was evaluated in the final research phase, using an experimental single case design with replication across eight adults. The effectiveness of PRPP Intervention was examined in comparison to conventional occupational therapy in an ABAB design. Efficacy of the PRPP Intervention was demonstrated, with patients applying significantly more information processing strategies to occupational performance tasks during PRPP Intervention than during conventional occupational therapy sessions. Agitated behaviour concurrently reduced over the period of the study. Relationships between information processing and agitated behaviour are hypothesised.