Functional Outcomes Following Neuropsychological Intervention in Acquired Brain Injury Outpatients With Executive Dysfunction

Executive functions (EF) are higher-order cognitive processes used particularly under novel and complex conditions (Shallice, 1990) and comprise various abilities including devising goals, elucidating alternative solutions, implementing goal-directed behaviors, self-monitoring, and behavior modification and perseverance (Snyder, Nussbaum, & Robins, 2009). According to Sohlberg and Mateer (2001; p.234), EF may be described as cognitive abilities "required to complete goal-directed [behavior] that is not overlearned, automatic, and routine." As a result, executive dysfunction can impair one's ability to function independently (Bolognani et al., 2007). Research has identified a positive relationship between functional ability and EF (Hanks, Rapport, Millis, & Deshpande, 1999). Additionally, differential declines in EF are observed in normal aging after the age of 60 years (Treitz, Heyder, & Daum, 2007). As well, the profile of cognitive impairment in Parkinson's disease is marked by a predominance of executive dysfunction, followed by memory deficits (Emre, 2003; Emre, 2004; Verbaan et al, 2007). In addition to traumatic and acquired brain injuries, executive dysfunction and functional deficits have been observed in individuals with psychiatric illnesses such as ADHD (Attention Deficit Hyperactivity Disorder; e.g., Willcutt, Doyle, Nigg, Faraone, & Pennington, 2005), psychostimulant and opioid abuse (e.g., Verdejo-Garcıa, Lopez-Torrecillas, Aguilar de Arcos, & Perez-Garcıa, 2005; Fernández-Serranoa, Pérez-García, & Verdejo-García, 2011), bipolar disorder (e.g., Frangou, Donaldson, Hadjulis, Landay, & Goldstein, 2005; Maalouf et al., 2010), and geriatric depression (Lockwood, Alexopoulos, van Gorp, 2002). The prominence of executive dysfunction in individuals with acquired brain injury and mental illness, and the associated costs on the healthcare system, highlights a role for cognitive rehabilitation.

Cognitive rehabilitation refers to interventions aiming to enhance or support cognitive abilities following brain injury, with an emphasis on achieving functional changes. It is a structured, goal-oriented, collaborative process between the therapist and the patient (and, where possible, caregivers/family) and is informed by medical and neuropsychological data (Sohlberg & Mateer, 2001). A recent meta-analysis of the effectiveness of cognitive rehabilitation following acquired brain injury revealed a significant effect on global cognitive functioning, with time-since-injury acting as a moderating variable. Attention training following traumatic brain injury (TBI) and language and visuospatial training for aphasia were identified as effective treatments (Rohling, Faust, Beverly, & Damaskis, 2009). In their review of intervention approaches for executive dysfunction, Boelen, Spikman, and Fasotti (2011) describe three approaches used in previous studies. First, compensatory strategies emphasize teaching patients cognitive strategies to offset cognitive deficits. Second, restorative strategies aim to repair cognitive functions. Third, behavioral therapy interventions seek to modify behavior through means such as token economies.

An example of the compensatory approach to executive dysfunction is Goal Management Training (GMT). GMT is a cognitive rehabilitation strategy based on Duncan's (1986) theory of goal neglect resulting in disorganized behavior following frontal lobe injury. It emphasizes strategies for self-monitoring and self-evaluation in everyday life, including pausing, identifying the task at hand, outlining the goals and listing the required steps, completing the task, and evaluating the successful completion of the task.

Given the relationship between disorganized behavior and functional dependence, the use of GMT in patients with executive dysfunction is highly relevant. Levine et al. (2000) compared the effectiveness of GMT and motor skills training (MST) in patients with TBI who were living independently in the community. The GMT group exhibited improved performance on paper and pencil tasks (e.g., proofreading) and slowed speed of task completion suggested increased attention to task demands. Improvements on the MST trained tasks were noted for the MST group. Fish and colleagues (2007) evaluated the effect of a "content-free" cueing strategy (i.e., text messages reading STOP!), the first stage in GMT, to compensate for goal-neglect following brain injury. The authors reported significant improvements in goal-directed behavior with the addition of "content free" cues and conclude that the provision of cues improves goal management by increasing self-monitoring.

GMT has also been evaluated in normal aging, given the relationship between reduced executive functioning, functional difficulties, and aging. Van Hooren and colleagues (2007) evaluated 69 Dutch adults aged 55 years or older for the impact of a structured 12-session GMT program on cognitive functioning, self-reported mood, and self-reported cognitive complaints and failures. Their GMT program included psychoeducation regarding cognitive functioning and functional difficulties and their study design utilized a randomized wait-list control group. The results revealed reduced annoyance, improved management of cognitive failures, and decreased anxiety in the treatment group, relative to controls. No improvement on objective measures of cognitive functioning was noted. In another wait-list controlled study evaluating GMT in normal aging, Levine and colleagues (2007) reported decreased self-report of executive failures and improved performance on simulated real-life tasks in 49 healthy older adults.