Abstract
Objective: Deficits in sustained attention are common following traumatic brain injury (TBI), as a result of primary (i.e., neuropathology) and/or secondary factors (i.e., fatigue, sleep disturbance, depressed mood). The extent to which secondary factors play a role in attention deficits is relatively unexamined. Moreover, the Psychomotor Vigilance Task (PVT) is seldom used in TBI assessment despite its sensitivity to secondary factors observed following injury. The primary aim of the current study was to examine the usefulness of the auditory PVT in identifying attentional difficulties in patients with TBI compared with noninjured controls, and also to explore the impact of fatigue, sleep quality, and daytime sleepiness on sustained attention performances. Method: Participants (n = 20 per group) completed the auditory PVT and self-report measures of fatigue, sleep quality, daytime sleepiness, and depression. Results: Compared to controls, patients with TBI had widespread PVT deficits including slower response times, increased response variability and attention lapses, and delayed responding in the slowest 10% of responses. Distribution analyses suggested this was likely due to generalized cognitive slowing. Self-reported secondary factors had varying impacts on aspects of PVT performance, with self-reported fatigue exhibiting a more global impact on attention performance. Conclusions: The auditory PVT is a sensitive measure of sustained attention deficits in patients with TBI, with aspects of performance influenced by fatigue, sleep disturbance, and depression.
Acknowledgments
We thank the Monash Epworth Rehabilitation Research Centre for assistance with participant recruitment. This work was supported by funding from the Transport Accident Commission; Jack Brockhoff Foundation; NHMRC (National Health and Medical Research Council) Centre for Integrated Research and Understanding of Sleep (CIRUS), The University of Sydney; and RACV (Royal Automobile Club of Victoria) Sir Edmund Herring Memorial Scholarship. K.L.S. reports no conflicts of interest. J.L.P. reports that she has received royalties from Psychology Press and Guilford Press for textbooks on traumatic brain injury and received an honorarium, travel, and accommodation support to present a lecture on fatigue and sleep disturbance at the TBI Interagency Conference in Washington, DC, May 2011. S.W.R. reports that he has served as a consultant through his institution to Vanda Pharmaceuticals, Philips Respironics, EdanSafe, The Australian Workers' Union, and National Transport Commission and has through his institution received research grants and/or unrestricted educational grants from Vanda Pharmaceuticals, Takeda Pharmaceuticals North America, Philips Lighting, Philips Respironics, Cephalon, and ResMed Foundation, and reimbursements for conference travel expenses from Vanda Pharmaceuticals. His institution has received equipment donations or other support from Optalert™, Compumedics, and Tyco Healthcare. He has also served as an expert witness and/or consultant to shift work organizations. C.A. reports receiving a research award/prize from Sanofi-Aventis, contract research support from VicRoads, and lecturing fees from Brown Medical School/Rhode Island Hospital and Ausmed. In addition, she has served as consultant to the Rail, Bus and Tram Union to produce a report on best practice management of fatigue in the rail industry, through an agreement with Monash University.