Vocational Multitasking Ability in TBI
Authors:   , Tessier Jillian M. , Schultheis Maria T. 
Published: July 2021

A non-trivial subset of individuals with TBI report cognitive deficits and difficulty with vocational functioning that persist for many years post-injury. Prior domain-specific approaches to measuring the relationship between cognitive deficits and vocational functioning in traumatic brain injury (TBI) have yielded mixed results. Therefore, current research must consider a more complex cognitive construct that integrates multiple cognitive domains, such as multitasking. Qualitative reports suggest that multitasking difficulty may impact vocational functioning after TBI. Experimentally assessing multitasking ability requires a performance-based assessment that approximates naturalistic environments. To date, one such assessment, the vocational multitasking test (VMT) has been developed and tested with multiple sclerosis (MS). This performance-based assessment has not yet been examined with TBI. Thus, the main aim of this study is to examine the VMT with a previously untested clinical population of TBI. Cognitive deficits in TBI may also be compounded by sleep disturbance, which is exceedingly common after TBI. In individuals with TBI, sleep disturbance impacts the cognitive domains that underpin multitasking, including memory, executive functioning, and attention. There is some research to suggest that sleep disturbance may also impact vocational functioning after TBI. However, this link has not yet been extensively studied. The current study consisted of three specific aims: 1) evaluate the psychometric properties of the VMT in a previously untested clinical population, 2) examine VMT performance in TBI compared to healthy controls (HC), and evaluate its relationship to vocational functioning, and 3) examine sleep disturbance and its relationship to VMT performance in TBI. In a sample of 5 individuals with TBI, 3 had sustained a mild TBI (mTBI) and 2 had sustained a severe TBI. VMT performance was related to measures of immediate and delayed verbal memory, problem solving, inhibition and switching, and processing speed in the TBI sample. Participants with mTBI and postconcussive symptoms (PCS) had difficulty returning to work (RTW), without measured cognitive impairment, while participants with severe TBI had cognitive impairment and difficulty with RTW. However, VMT performance was not related to vocational functioning in the TBI group. Individuals with TBI endorsed poorer sleep quality and marginally greater insomnia severity compared to the HC group, with no difference in sleepiness. Sleep variables were not related to VMT performance. Conclusions from the current study are limited by the small and unequal sample sizes. However, results indicate that RTW remains a challenge after TBI across the severity spectrum, and the VMT is a feasible task for these participants to complete. Results continue to support Morse's (2014) findings that VMT performance requires cognitive domains that underpin multitasking ability. If future studies demonstrate that VMT performance is related to vocational functioning, the VMT could be used as a rehabilitation tool for TBI.