6.3 Remediation of Executive Functioning
6.3.1 Remediation of executive functioning
Executive functions refer to higher-level cognitive functions that are primarily mediated by the frontal lobes. These functions include insight, awareness, judgment, planning, organization, problem solving, multi-tasking and working memory (Lezak, 1983). Executive deficits are particularly relevant following traumatic brain injury from both a pathophysiologic as well as a psychosocial perspective. The frontal lobes tend to be one of the brain areas most likely to be injured following trauma (Greenwald et al., 2003).Frequently bilateral frontal lobe injury occurs following TBI in contrast to typical unilateral insults following vascular injury. Not only direct contusion to the frontal and temporal lobes but also diffuse axonal injury sustained as a result of TBI affects executive functioning. TBI patients often present with cognitive and behavioural deficits in the presence of little physical impairment.
Cicerone et al. (2000) reviewed 14 studies dealing with executive functioning and problem-solving (Table 6.17). Only 3 of the identified studies were classified as a randomized controlled trial or non-randomized cohort study.
In the more current reviews by Cicerone et al. (2005; 2011) 9 and 18 additional studies were identified. Some of these studies were not included in our review as they did not meet our inclusion criteria. Based on the results of the studies in their review, Cicerone et al.(2000) recommended, “training of formal problem-solving strategies and their application to everyday situations and functional activities”.
Table 6.13 Remediation of Executive Functioning
| Cicerone et al., 2000 | |
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Cicerone et al., (2005) |
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| Cicerone et al., 2011 | |
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Executive function deficits are particularly relevant to brain injury survivors who tend to be younger (average age less than 40) and who often desire to re-integrate back into pre-injury life roles. Patients with executive function deficits may have the capacity to be independent for basic activities of daily living where actions tend to be more ingrained and one-dimensional. However, instrumental activities of daily living such as banking, scheduling and household activities require intact executive functions due to the increased cognitive complexity and variability of the tasks. Of particular importance are the advanced tasks such as return to driving and competitive employment which are of increased relevance to the younger age demographic associated with TBI (Miller, et al., 2003).
Within the typical medical and rehabilitation settings, executive function deficits themselves are difficult to identify and evaluate since there is a tendency to focus on other cognitive functions such as memory and attention. The importance of evaluating effective interventions for treating executive dysfunction following brain injury is apparent since impairment can ultimately hinder successful community re-integration. Further to this, it is also important to address the issue of self-awareness which is particularly important in those who sustain moderate to severe TBI. If individuals are not aware they have a problem they are less likely to work on compensating for it.
6.3.2 Group interventions
Although executive function deficits are a common and important impairment post brain injury, there is little overall research directly addressing the impact of rehabilitation on executive function. However, community integration is highly related to executive function and it is possible that programs and interventions aimed at improving community re-integration may in fact be focusing efforts on instrumental activities of daily living for which intact executive functions are required.
Individual Studies
Table 6.14 The Use of Group Therapy to Enhance Executive Function
| Author/ Year/ Country/ Study design/ PEDro and D&B Score |
Methods |
Outcome |
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Ownsworth et al., (2008) |
N=31 Subjects with an ABI agreed to participate. Treatment was designed to last 8 weeks. Each session lasted 3 hours and was conducted 1x each week. There were 3 groups: the intervention group received: Group 1: group based support, Group 2: individual occupation support, Group 3: combined group and individual support interventions. Interventions formats included group based support, individualized occupation based support, and a combined intervention format. The following measures were used to evaluated participants: Canadian Occupational Performance Measure (COPD); Patient Competency Rating Scale (PCRS); Brain Injury Community Rehab Outcome (BR-CRO 39); level of goal attainment was the primary outcome assessed. |
Data was analyzed over three time periods (pre, post and follow-up). When looking at the results of the pre-assessment data for each intervention group, no significant differences were noted on the performance self-ratings, satisfaction self-ratings, relatives’ performance ratings, and relatives’ satisfaction ratings (p>0.05). Looking at the satisfaction self ratings between pre and post assessment, an improvement was noted after each intervention (individual p<0.001; group p<0.025; combined p<0.01). Results indicated that at follow-up an improvement in self-rated satisfaction was noted for the group and combined interventions only (p<0.01). Results from the CPOM indicate that there was no significant difference when looking at the scores from the group intervention pre to post comparison (p<0.028). A significant improvement was noted when looking at the scores for the individual and combined interventions (p<0.01 and p<0.025 respectively). Pre assessment and follow-up assessment for the relatives’ ratings of performance was significant for all three interventions (individual p<0.01; group p<0.01; combined p<0.025). Relatives’ ratings of satisfaction (pre and post) found a significant improvement for the individual (p<0.025) and combined (p<0.01) interventions but not for the group intervention (p<0.117). Pre to post assessment found an improvement for the combined intervention (p<0.025) but not for the other two. A look at the psychosocial outcomes for each intervention group showed few significant differences. Gains made pre to post assessment were not maintained at follow-up; however, gains not significant at post assessment were significant at follow-up. |
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Amos (2002)
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N=32 subjects (24 with ABI, eight without) were randomly assigned into three treatment groups: no treatment, external inhibition and increased stimulus salience. All treatment groups were compared to the normal controls. The Wisconsin Card Sorting Test (WCST) was employed to measure preservative error and random error. |
There were no significant differences in total errors between groups, but groups differed significantly in total number of trials (p= 0.025), perseveration (p= 0.033) and categories achieved (p= 0.001). |
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Parente & Stapleton (1999) |
N=32 A one year measure of TBI subjects with undefined etiologies participating in a group cognitive skills training module were compared to 64 TBI individuals who received services within the same time frame as the cognitive skills group (CSG) clients from the same rehabilitation centre. |
10 of 13 CSG clients who completed the training program by the end of the year had maintained full employment for > 60 days (76%) - versus 58% of the control group. Significance not calculated. |
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Ownsworth et al., (2000) |
N=21 chronic ABI subjects with adequate cognitive skills to communicate needs, understand information, possess an awareness of their difficulties and the motivation to change their lives participated in a 16-week group support program designed to improve self-awareness/regulation skills, and measure change in emotional & behavioral problems as well as psychosocial functioning pre-, post and 6 months following intervention. |
Post-assessment mean score for emotional and behavioural problems was significantly lower (p< 0.001), self-regulation skills improved significantly with no significant change in level of skills at 6 month follow up (p > 0.10), level of psychosocial functioning improved significantly (p < 0.001) with no significant change at 6 month follow up (p > 0.30). |
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Parente et al., (1999) |
N=10 ABI subjects (mean age: 32 yrs; education 13 yrs) were given tasks that trained working memory for 1 hour between pre- and post test measurement (Digit span task, letter/number sequencing tasks from WAIS-III. Control clients matched to treatment group by sex and chronicity. |
No significant differences between Digit Span test. WAIS-III differed significantly pre/post treatment (p< 0.05). |
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Finset et al., (1995) |
N=3 Male participants received team development in memory training with the help of external aids following traumatic brain injury. A modified version of an assignment task as well as a 10-item memory checklist assessed treatment efficacy. |
All three individuals improved on the questions task. Considerable variability of results was revealed on the assignment task, however. |
PEDro = Physiotherapy Evidence Database rating scale score (Moseley et al., 2002).
D&B = Downs and Black (1998) quality assessment scale score.
Discussion
In a current RCT conducted by Ownsworth et al. (2008), they found no significant differences on the performance self-ratings, satisfaction self-ratings, relatives’ performance ratings, and relatives’ satisfaction ratings (p>0.05) for the intervention group. The satisfaction self ratings between pre and post assessment, indicated an improvement after each intervention (individual p<0.001; group p<0.025; combined p<0.01). At follow-up an improvement in self-rated satisfaction was noted for the group and combined interventions only (p<0.01). Results from the CPOM indicate that there were no significant differences when looking at the scores from the group intervention pre to post comparison (p<0.028). Significant improvement was noted when looking at the scores for the individual and combined interventions (p<0.01 and p<0.025 respectively). Pre assessment and follow-up assessment for the relatives’ ratings of performance was significant for all three interventions (individual p<0.01; group p<0.01; combined p<0.025). Relatives’ ratings of satisfaction (pre and post) found a significant improvement for the individual (p<0.025) and combined (p<0.01) interventions but not for the group intervention (p<0.117). A look at the psychosocial outcomes for each intervention group showed few significant differences.
Ownsworthet al. (2000) studied the effect of group therapy aimed at improving self regulation skills as well as psychosocial functioning for brain injury survivors greater than 1 year post injury. Self regulation was evaluated using the self regulation skills interview which examines how brain injury survivors would handle self identified difficulties (Ownsworth et al., 2000). Both self regulation abilities and psychosocial functioning improved following the treatment intervention and improved performance was maintained at 6 month follow up.
Parenteand Stapleton (1999) in a descriptive study compared brain injury survivors who completed a cognitive skills group to comparable controls. The Cognitive skills group interventions included education regarding “thinking skills” such as problem solving, concentration/ attention, decision making, remembering names and faces, study skills, functional mnemonics, prosthetic memory devices, social cognition, organizational skills and goal setting. Other important aspects of the cognitive skills group included computer training, prosthetic aid training, interviewing skills training and focus on a model of clients teaching clients. There was no statistical analysis completed, however, the return to work rate for 13 of 33 participants assigned to the cognitive skills group training was 76% as compared to 58% for the control group. Competitive employment for the intervention group was maintained at 6-month follow up.
Parenteet al. (1999) also studied retraining of working memory post traumatic brain injury. Although working memory would at first glance appear to be a primarily memory related brain function, the authors describe the concept of working memory as involving three main elements. These elements are the articulatory loop which hold verbal information, the visuospatial sketchpad which stores and interprets visual information and the executive system which organizes, prioritizes and allocates information processing resources. In this pilot study, 10 subjects were assigned to the intervention group who completed tasks to enhance working memory functioning between testing sessions. The testing sessions were only 1 hour apart. A control group matched for age, gender and injury type completed the same testing without training. The results showed a significant improvement for the letter number sequencing task for the intervention group, however there was no difference between groups on digit span task performance.
Amos (2002) completed a RCT that evaluated remediating deficits of switching attention in patients with acquired brain injury. 24 patients with ABI were randomly assigned to one of three groups and compared to eight normal controls. Results support that perseverative error and random error are separate functions when switching attention, as suggested by a neural network model. The author notes that external inhibition significantly reduced perseverative error (applying an inappropriate rule continually), while an increase in perceptual salience decreased random error (continually failing to apply an appropriate rule) on the WCST.
Finset et al. (1995) using three single case studies, examined the need for developing team cooperation procedures to treat patients following brain injury. Results indicated that overall, there was a slight tendency, although minimal, toward improvement on the 10-questions task. With the assignment task however, a considerable amount of variability was revealed.
Conclusions
There is conflicting evidence supporting the use of group-based interventions to treat executive dysfunction post ABI.
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Group cognitive interventions may be effective for improving executive function; however more research needs to be completed to determine what that effectiveness is.
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6.3.3 Goal Mangement Training
With regards to cognitive rehabilitation, much of therapy is patient goal directed with both long and short term goals often identified (Carswell et al., 2004). The ability to manage goals is often emphasized as a component of brain injury community reintegration programs and is integral in the completion of instrumental activities of daily living.
Table 6.15 Goal Management Training in Brain Injury Rehabilitation
| Author/ Year/ Country/ Study design/ PEDro and D&B Score |
Methods |
Outcome |
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Levine et al., (2000) |
N=30 Subjects with moderate to severe ABI as indicated by GCS and PTA were randomized into Goal Management Training (derived from Duncan's theory of goal neglect on disorganized behaviour following TBI) and a Motor Skills Training groups. |
Although both groups improved, GMT was associated with significant gains on everyday paper-and-pencil tasks designed by the authors to mimic problematic tasks for patients with goal neglect (p<0.05). |
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Walker et al., (2005) |
N=11 Individuals (mean time since injury of six years; average age of 30 years; nine men and two women) with severe to extremely severe brain injury (average 11 weeks PTA) participated in a community-based, goal-planning programme over a period of 18 months. The first 9-months of the programme was spent raising funds for a 9-day outdoor adventure course. Following the course, the participants met for 4-months and focused on goal achievement and problem-solving tactics. |
All participants completed the three stages of the programme. 81% of identified goals were achieved. All but one participant achieved at least one goal. There were no significant differences noted between pre-and post-treatment scores on the Depression, Anxiety Stress Scales (DASS), General Well-Being Schedule (GWB), and the European Brain Injury Questionnaire (EBIQ) on the Wilcoxon Signed Ranks Test, although all changes were in direction of improved psychological health. |
PEDro = Physiotherapy Evidence Database rating scale score (Moseley et al. 2002).
D&B = Downs and Black (1998) quality assessment scale score.
Discussion
Levine et al. (2000) completed a RCT comparing a group of patients taking goal management training strategies to a control group who were exposed to only motor skills training. The treatment group improved on paper and pencil everyday tasks as well as meal preparation, which the authors used as an example of task heavily reliant on self-regulation.
Walker et al. (2005) conducted an alternative goal planning, cognitive rehabilitation programme focusing on the development and achievement of goals following brain injury. This single group intervention involved three phases: (1) nine-months of planning and fund-raising for an outdoor adventure course; (2) a nine-day outdoor course; and (3) four-months following the course, the participants focused on goal achievement and problem-solving skills. More than 80% of the identified goals of participants were achieved. No significant pre- and post-treatment differences were noted on psychological measures: Depression, Anxiety Stress Scales (DASS), the General Well-Being Schedule (GWB), and the European Brain Injury Questionnaire (EBIQ). This programme demonstrated a unique and challenging, community-based intervention for group goal management following brain injury.
Conclusions
There is Level 2 evidence, based on a single RCT, that goal management training is effective for improving paper and pencil everyday tasks and meal preparation skills for persons with an ABI.
There is Level 4 evidence, based on a single group intervention, that a goal planning in the form of a leisure activities is effective for achieving identified goals following injury.
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Goal management training is effective for treating some executive function deficits.
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Summary of Executive Function
The current studies support the notion that group cognitive interventions may be effective for improving executive function. Parente and Stapleton (1999) provide some limited evidence that efforts to improve executive function may have potential to improve chances for future competitive employment. There is also some evidence that pharmacological intervention, amantadine, may be effective in improving executive function. Evidence supporting the use of bromocriptine is inconclusive. Ultimately, further research is required to determine which methods are most effective for improving executive function.
6.3.4 Remediation of general cognitive functioning
Intervention for treatment of cognitive deficits post traumatic brain injury tend to be diverse with variability between the interventions themselves and the outcome measures used to document results. For the purposes of this section, interventions were included that either targeted multiple cognitive domains such as attention, memory, information processing speed, executive functions and visuoperceptual function or were non-specific with regards to intended outcome. For example, a general cognitive rehabilitation program would tend to document outcomes across multiple domains.
6.3.4.1 Cognitive Rehabilitation Strategies
Gordon et al. (2006) conducted an extensive review of the traumatic brain injury rehabilitation literature and identified 13 studies dealing with rehabilitative treatments of cognitive deficits (Table 6.16). A comprehensive literature search of MEDLINE, CINAHL, and PsychINFO databases was performed. Gordon et al. (2006) included studies based on several inclusion criteria: more than 20 participants with TBI and 20 controls, the sample was comprised of more than 75% adults, and more than 75% of the participants were individuals with TBI. Several studies have examined the effects of cognitive rehabilitation strategies.
Table 6.16 Rehabilitative Treatment of Cognitive Deficits
| Gordon et al., (2006) | |
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Individual Studies
Table 6.17 Use of Cognitive Rehabilitation Strategies to Enhance Executive Function
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Author/Year/ Country/Study Design/PEDro & D&B Score |
Methods | Outcome |
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Vas et al., (2011) USA RCT PEDro = 6 D&B=19 |
N=28 Subjects were randomly assigned to 1 of 2 groups: Top down SMART group (exp group) and the information based BHW (control group). A comparison of the benefits of the two groups was conducted. Training was offered for a total of 18 hrs during 12 group sessions over an 8 week period. The first 15 hrs took place over the first 5 week, 10 sessions (2/week). The remaining 2 sessions took place over the remaining 3 weeks (booster sessions). Each SMART session covered various topics which were discussed by participants. Homework assignments were also given to prepare participants for the next session. BHW sessions were designed to be information based sessions covering everything from brain anatomy to health life style and cognitive changes. Reading assignments were also given each week. Pre, Post and Post testing was conducted (3 weeks prior to session beginning, 3 weeks following sessions completing and 6 months post session completion). The examiner was blinded to the group each participant was assigned to. | Following treatment, results indicate that those in the SMART group showed significant improvement on GIST reasoning (p=0.03) on the community integration questionnaire (CIQ) (p=0.02) and the working memory (listening span task) (p<0.001) compared to the BWH group. Pretraining scores were similar for the groups. Those in the SMART group showed significant improvement on 3 executive functions following training (inhibition, nonverbal reasoning, and cognitive flexibility). Overall SMART was found to enhance gist reasoning, of which the benefits were seen in other domains (listening span and increased participation). Six months later the benefits were still evident. |
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Chen et al., (2011) USA RCT PEDro=5 D&B=19 |
N=12 Participants were randomly assigned to 1 of 2 groups and at the end of the 5th week they began the alternative intervention. Two interventions were used: goals training and education. The goals training protocol was based on a goal management training intervention. Participants attending 10 2 hrs sessions of group based training, 3 individual 1hr training sessions and 20 hrs of home practice over 5 weeks.. The education program was a 5 week didactic educational instruction regarding brain injury. | On the domain of attention and executive functions, all (n=12) in goals training showed an increase from pre to post goals training while only 7 of 12 showed an increase from pre to post education. Performance scores increased significantly after the goals training sessions compared to the education sessions. For the group that began in the education session, scores were also found to improve significantly in the post goals training compared to the education training. Tests of motor speed of processing showed no significant differences between the two interventions. |
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Rath et al., (2003) USA RCT PEDro = 2 D&B = 15 |
N=46 Subjects with mild to severe TBI (mean age: 43.6 yrs; mean chronicity: 48.2 mths) with a higher level of functioning were randomized into two groups, the first of which received 1 individualized 2 hr session / week for 24 weeks of a group treatment protocol (emotional self-regulation strategies, problem solving skills) and the second a conventional neuropsychological rehabilitation program. |
Treatment group showed significant improvement in problem-solving (WCST, PSI, PSQ) and emotional self-regulation (PSQ), objective observer ratings of role-play scenarios (PSRPT), visual memory (immediate recall- WMS III: p < 0.001), self-esteem (RSES: p< 0.05), fewer perseverative responses (WCST: p< 0.05), gains in PSI total score (p = 0.005), PSQ Clear Thinking and Self-Regulation (p = 0.01 and p< 0.05), and PSRPT (p< 0.005).
Control improved significantly in the Watson-Glaser Critical Thinking Test (p< 0.05), suffered significantly reduced somatic symptoms (p< 0.005), less severe cognitive symptoms after PCL (p< 0.05), significantly improved emotional self-regulation skills (PSQ Self-Regulation: p< 0.01). Both groups improved on Logical Memory immediate recall, as well as Logical Memory and Visual Memory delayed recall. |
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Dirette et al., (1999) USA RCT PEDro = 4 D&B = 16 |
N=30 TBI subjects with moderate or severe injury as determined by GCS on admission, randomly assigned to remedial (without instruction) and compensatory strategy (verbalization, chunking and pacing) intervention groups receiving a 45-minute session once a week for 4 weeks. | Pre/post-test measured by computer based visual processing, data entry and recording tasks. Weekly measures of 2 computerized matching tasks and the PASAT. Pre/post and weekly tasks significantly improved in both groups (p<0.01). No significant improvement due to intervention (p>0.05). |
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Neistadt et al., (1992) USA RCT PEDro = 6 D&B = 23 |
N=45 Male subjects were randomly allocated to one of two treatment groups: (1) the Adaptive Functional Training; or (2) Remedial Perceptual Skills Training.
The Parquetry Block test, Block design subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the Rabideau Kitchen Evaluation-Revised (RKE-R) was assessed pre- and post-treatment. |
After treatment, the remedial group improved significantly more than the adaptive group on the Parquetry Block test (p= 0.0185), but there were no significant differences on the WAIS-R Block Design subtest.
There was a non-significant tendency in the expected direction to support that the adaptive group would perform better than the remedial group on the RKE-R after treatment. |
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Sohlberg et al., (2000) USA 2000 Pedro = 8 D&B = 22 |
N=14 Those in Condition A (n=7) received 24 hours of attention process training (APT), in 3 one-hour sessions each week for a total of 10 weeks. Attention process training is a cognitive rehab program that has been used to remediate attention deficits following an ABI. Tasks chosen for each subject were specific to his or her needs. Tasks were designed to place increasing demands on complex attentional control and working memory. Those assigned to Condition B (n=7) received a combination of brain injury education, supportive listening and relaxation training. Sessions ran for 10 weeks, one hour per week. All subjects worked directly with a therapist for the length of the study. Following therapy subjects were assessed using various scales (Paced Auditory Serial Addition Task (PASAT), Gordon Diagnostic Vigilance and Distraction, Controlled Oral Word Association Task (COWAT)) and interviews. | Those in the APT group reported significantly more changes following intervention then those in the brain injury education group (p<0.05). The greatest number of changes was reported in attention and memory than in psychosocial functions. Changes in PASAT scores were greater for those who reported more than 2 cognitive changes. Results of the PASAT also found that those with higher levels of vigilance had higher PASAT scores. Those with higher vigilance scores had higher COWAT scores. |
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Ruff et al., (1989) RCT PEDro = 5 D&B = 19 |
N=40 Subjects with severe ABI were randomized into groups comparing the efficacy of neuropsychological treatment (computer assisted selective attention, spatial integration, memory, and problem solving training modules) with a non-structured treatment providing equivalent professional attention and psychosocial support administered in daily sessions over an 8 week period. | Both groups showed significant improvement in neurological functioning (p<0.001). The experimental group achieved greater gains on measures of memory (p=0.03) and error reduction (p=0.06) for visual selective attention. |
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Cicerone et al., (2004) USA Non-RCT D&B = 16 |
N=56 Moderate to severe TBI subjects> 18 years, able to communicate verbally, and accompanied by family member, were divided into a standard neuro-rehabilitation (SRP – 2 hrs/ day; 3x/week focused on executive, meta-cognitive functioning and interpersonal process) control (n=29) and an intensive cognitive rehabilitation (ICRP – 5 hrs / day, 4x/week in small groups emphasizing awareness, compensation, communication skills, family support and work trials) treatment (n=27) group. | Although both groups improved significantly on the CIQ following treatment (p<0.001), IRCP group showed greater improvement when time is factored in (p=0.021) and significant improvements in overall neuro-psychological (NP) functioning (p<0.001). Participants who showed an significant improvement on the CIQ showed a greater improvement on overall NP functioning (P=0.001). |
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Rattok et al., (1992) USA Non-RCT D&B = 17 |
N=59 Severe TBI subjects on whom traditional treatment approaches had failed to stabilize personal and social adjustment were assigned to one of three treatment mixes (balanced, without individualized cognitive remediation, or without small group interpersonal exercises) for 20 consecutive weeks, 5hr / day, 4 days / week. Daily life measures, intra/interpersonal functioning and vocational outcome were taken to compare the effect of treatment mixes. |
All three mixes contributed to improved test scores. Significance achieved by Mix 1 in functional competence (p<0.01), Mix 3 in intra/interpersonal self-appraisal measure (P<0.01). |
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Miotto et al., (2008) United Kingdom Quasi-RCT D&B = 17 |
N=30 individuals with lesions in the frontal lobe were included in the following study. Subjects were placed in one of three groups (with the first half of participants being randomized to a group and the second half being placed into one of the 3 groups). Group 1 (n=10) received the attention and problem solving intervention. Group 2 (n=10) received weekly sessions of attention and problems solving training by 2 psychologists (1 x per week for 90 minutes). Group 2 also received further information and education interventions (an information booklet containing information on brain injury, cognitive, behavioural and social consequences and a list of suggested cognitive exercises. Group 3 received usual treatment (PT, OT etc). | Results indicate that all three groups showed improvement on executive function regardless of the intervention or treatment they received. On assessments 1 and 2 groups 1 and 2 showed significant improvement (P=0.023 and p=0.014 respectively). The change in scores for group 3 did not quite reach significance (p<0.059). Results for the VIP test also showed improvement but again no significant differences were noted between the three groups. A comparison of the results from assessment 2 to assessment 3 did show significant improvement, on each scale; however there were no significant differences between the groups. |
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Turkstra (2008) USA Case-Control D&B = 15 |
N=38 All participants (cases (TBI) n=19, and control (typically developing) n=19) were asked to complete the Reading the Mind in the Eyes Test – assessing the subjects ability to read an individual’s thoughts by looking at his or her eyes; the Video Social Inference Test (VSIT) – video vignettes used to assess social inferences; and the Competing Language Processing Test (CLPT) – a working memory test. All participants completed the tasks listed in random order. A between group comparison was conducted looking at the scores of all the tests. | Results of CLPT (True/False and words recalled) test indicated the controls significantly scored higher than cases (p<0.05, p<0.001 respectively). Scores on the VSIT also found the controls performing significantly better than cases. When looking at the scores on the social inference items, requiring individuals to make predictions on future behaviours, no significant differences were noted between groups (p>0.05). |
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Prigatano et al., (1984) USA Case-Control D&B = 15 |
N=35 Subjects experiencing cognitive and personality disturbances following severe closed head injury were separated into a neuropsychological rehabilitation group and a control group. The control group followed the same testing protocols as the treatment group but without the treatment. The NRP goal was to increase the patients’ awareness and acceptance of their injury, residual deficits through intensive cognitive retraining and compensatory skills development. | NRP treatment group had significantly better pre/post results than the control group (WAIS Performance IQ: p=0.005; WAIS Block Design Scale: p=0.0001; Wechsler Memory Quotient: p=0.03). The control group performed significantly better than treatment group on the Tactual Performance Test with dominant hand (p=0.03). |
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Ownsworth et al., (2006) Australia Single subject intervention D&B = 7 |
N=1 The 36 year old male participated in a 16 week program that targeted error awareness at home (while cooking) and at his volunteer job. Subject was 4 yrs post injury when treatment began. The program was described as a metacognitive contextual intervention. | During the four week baseline period, subject made 21 errors while participating in the cooking task and self-corrected only 15% of the time. During the 16 week treatment period, the subject self-corrected 27% of his errors; however, the maintenance period saw the subject self-correct 46% of his errors. It was noted that the subject would always need a certain amount of prompting and supervision when cooking. |
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Boman et al., (2004) Sweden Pre-Post D&B = 14 |
N=10 Each participated in an individual cognitive training session for 1 hr/3x a week for 3 weeks at home or work. The program included attention process training (APT), generalization for training and teaching of compensatory strategies for self-selected cognitive problems. Identification of cognitive problems in everyday life was also part of the compensatory strategy. Digit Span Test, Claeson-Dahl test; Rivermead Behavioural Memory test (RBMT), Assessment of Motor and Process Skills, European Brain Injury Questionnaire. | For the following: sustained attention, selective attention and alternating attention significant changes (p<0.05, P<0.05, p<0.01 respectively) were noted in the scores of the APT test and Digit Span task between the pre to post training session and the 3 month follow up. Score increases (p<0.05) on the RMBT were found at the 3 month follow up compared to the RMBT scores at the pre-test. When looking at changes in the RBMT score pre to post training, changes were not found. No significant changes were found (pre to post and pre to 3 month follow up) when looking at the scores on the Claeson-Dahl Memory |
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Brett & Laatsch (1998) USA Pre-Post D&B = 11 |
N=10 TBI high school students (14-18 years, chronicity 1-16 years) with borderline or above intelligence who participated in an individualized, bi-weekly session (40 minutes) of computer administered Rehabilitation Therapy (CRT) based on a 3 level developmental model of cognitive rehabilitation. Pre and post treatment evaluations measured General intellectual functioning, self-esteem, concentration/sensory processing, memory and problem solving. | Significant improvement in memory skills (WRAML screen: p=0.025); no significant differences found in any other measure. |
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Harrington & Levandowski (1987) USA Pre-Post D&B = 15 |
N=18 TBI adults (mean age 32.25 years, mean chronicity: 2.9 yrs) with a confirmed neurological diagnosis by qualified physician enrolled in a community college head-injury recovery program. Patients received a 2 year structured retraining program consisting of five sequential modules in a neurodevelopmental hierarchy. | Pre/post treatment testing consisting of all 269 items of the Luria-Nebraska Neuropsychological battery. Collective analysis yielded significant t-test values on all scales except tactile. Visual scale most frequently improved, along with reading, math, memory and motor skills (no p values indicated). |
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Serino et al., (2007) Italy Case Series D&B=16 |
N=9 Individuals with a mean GCS of 10 were selected for participation in the following study. All had severe working memory (WM) deficits and underwent working memory training (WMT).The WMT was based on the repeated administration of the Paced Auditory Serial Addition Test (PASAT). A long sequence of numbers is presented and patients were asked to add each new number to the number preceding it and say the sum out loud (e.g., 5 6 “respond 11”, 6 “respond 12” 3 “respond 9”).Two additional tests (the Months tasks and the Word tasks) were also administered in a similar way. During the Months task, a sequence of months names was presented auditorily to the participants, one at a time. Patients were asked to say out loud which month came first (eg: January & June, January comes first etc). Administration of the Words test was similar. During general stimulus training (GST) patients were provided with a description and an explanation of their cognitive impairments in an effort to increase their awareness of their deficits and disabilities. The GST and the WMT were each 4 sessions/week, for 4 weeks. To vary tasks and their level of difficulty, in the interstimulus interval was varied. | Study results indicate the greatest improvement in performance occurred from the intermediate to the final sessions (p<0.0005) after the WMT. Improvement from the initial to intermediate sessions did not show any significant improvement in working memory (p<0.46) after GST. Working memory (p<0.05), divided attention (p<0.05), executive function (p<0.05), and long term memory (p<0.05) for subjects were significantly improved in the final session compared to the intermediate session. The same was not noted on the speed processing and sustained attention tasks (p>0.05). Working memory training tasks were also found to improve scores on various psychosocial outcomes. |
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Laatsch et al., (1999) USA Case series D&B = 8 |
N=5 Individuals with mild to moderate TBI between 18 and 65, 2-48 months post injury received a mean of 15.8 (range 6-36) individualized cognitive rehabilitation sessions (CRT – meta-cognitive approach). Progress was measured by a battery of NP tests prior to, at completion and 3-12 months post treatment. |
NP measures: WAIS-R, WMS-R, CVLT, RCFT, SCWT, WCST or ACT, SPECT image.
CRT was found to be effective in improving both NP and everyday functioning. All patients were able to be more productive in their lives following treatment. |
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Ben-Yishay et al., (1987) USA Case Series D&B = 7 |
N=94 TBI subjects who had reached a neurological plateau at program entry participated in a two phase outpatient day program involving intensive, systematic, holistic remedial interventions (Phase 1 – 20 weeks) and individualized, guided occupational trails culminating in a vocational placement (Phase 2 – 3-9 months). | At the end of phase 2, 84% of previously unemployable patients had attained the ability to engage in productive endeavors. Over three years, a tendency emerged for patients to fall from the competitive employability level (63% to 50% by year 3). |
PEDro = Physiotherapy Evidence Database rating scale score (Moseley et al., 2002).
D&B = Downs and Black (1998) quality assessment scale score.
Discussion
In a RCT conducted by Vase et al. (2011), 28 individuals who had sustained a TBI and were at least 2 years post injury, were assigned to one of two groups: the Strategic Memory and Reasoning Training (SMART) group or the Brain Health Workshop (BHW) group. Each groups received 15 hours of training over an eight week period. Those in the SMART group were given information about brain injuries, were asked to read pieces of literature on brain injury and were given homework assignments to be completed for the next meeting. The SMART sessions were built around three strategies: strategic attention, integration (combining important facts to form higher order abstracted meaning) and innovation (derive multiple abstract interpretations). Those in the BHW group participated in information sessions. Sessions for the BHW groups included an introduction to brain anatomy, functions of the brain, neuroplasticity, and the effects of lifestyle on the brain (diets, exercises and cognitive changes following a TBI). Study results indicate that those assigned to the SMART group showed significant improvement on gist reasoning and measures of executive function.
Chen et al. (2011) in a recent study, randomized a group of individuals (n=24) who had sustained a TBI, into one of two groups: a goals training group (n=12) and an education group (n=12). Those in the goals training program (the experimental condition) was based on a goal management training program. Participants attended ten 2 hour sessions of group based training, 3 individual 1 hour training sessions and 20 hours of home practice over 5 weeks. The control group attended a five week didactic educational instruction regarding brain injury. Following training, performance on tests of attention and executive control increased for 100% of participants in the experimental condition, while only 58% in the education groups showed an increase in test scores. On tests looking at learning and memory performance scores increased for 92% (11/12) of those in the goals training program and 33% (4/12) in the education program.
In a randomized controlled trial by Dirette et al. (1999) although there were significant improvements on post intervention results for both intervention and control groups, there was no overall difference between groups when the experimental group was taught to use compensation strategies including verbalization, chunking and pacing. In this study, the authors did note that control participants spontaneously relied upon compensatory strategies, which may have accounted for improvement.
Rath et al. (2003) completed an RCT comparing two cognitive rehabilitation therapies: conventional (cognitive remediation and psychosocial components) versus an innovative rehabilitation approach focusing on emotional self regulation and clear thinking. Outcomes were measured across multiple domains of cognition including attention, memory, reasoning, psychosocial functioning, and problem solving measures. Significant changes comparing baseline to post intervention outcomes were seen for each group, however, the improvements were different for the interventions. No between-group comparisons were made.
Neistadt (1992) divided 45 patients into one of two groups: a remedial group who received individual training with parquetry block assembly,and an adaptive group who received functional skills training over a six-week period. Outcomes for the effect of treatment for constructional test performance revealed that the remedial group improved significantly more than the adaptive group on the Parquetry Block test. However, there were no significant differences on the WAIS-R Block Design subtest after treatment. Outcomes for the effect of treatment on functional test performance revealed a trend as predicted, although non-significant, toward the functional group improving more than the perceptual skills group. Training-specific learning appears to be an effective approach to rehabilitation as demonstrated by the treatment effect.
Cicerone et al. (2004) compared an intensive cognitive rehabilitation program to a standard rehabilitation program. This intensive program included individual and group therapy 4 days per week for 5 hours per day for a total of 16 weeks. The main outcome for this study was community integration post injury. The treatment group had a significantly better outcome compared to the control group. With regards to cognitive outcomes, analysis was not performed on the control group due to incomplete data; however, there was a significant improvement on post intervention composite neuropsychological scores for the treatment group who on average were greater than two years post injury at the start of the intervention.
Ruff et al. (1989) in an RCT compared an active treatment based group focusing on attention, spatial integration, memory and problem solving to a control group that focused on computer and video games, coping skills, health, discussion forum, independent living and art. Both groups improved significantly, however, the treatment group experienced relative gains on memory testing and selective attention, suggesting that focusing on these specific elements has the potential to improve them.
In another RCT conducted by Sohlberg et al. (2000) they found that those who were assigned to the attention process training group (APT) (n=7), showed improved performance on cognitive function and executive attention tasks compared to than those in the brain education therapy group (n=7). Results of the Paced Auditory Serial Addition Task(PASAT) found those with higher PASAT scores were related to higher levels of vigilance. Improvement in PASAT scores was greater after APT than in brain education, suggesting subjects benefited more from APT than from the brain education program. Similar results were also found when looking at the scores of the Controlled Oral Word Association Task (COWAT- a measure of frontal function). Those with higher vigilance scores had higher COWAT scores. Self-reports of those receiving only brain education, indicate an improvement in psychosocial function.
In an effort to improve the central executive system of working memory, Serino et al. (2007) invited nine subjects to participate in a working memory training (WTM) program. Treatment was based on the repeated administration of the Paced Auditory Serial Addition Test (PASAT), and two tasks derived from the PASAT and Months and Words Task.The difficulty of each task was varied. The results of the working memory test were compared to a general stimulus training (GST) program which was also provided to all subjects. The GST used the same material used for the WST tasks; however, when this material was used in the GST the tasks only required basic level attentional demands. The results indicate the GST had no significant impact on the performance of subjects compared to the WMT. Results from the WMT showed improvements in working memory, divided attention, executive functions, and long term memory. These results support the use of WST in recovering the central executive system impairments.
Laatsch et al. (1999) examined individual cognitive rehabilitation therapy using a metacognitive approach with the five participants with mild to moderate traumatic brain injury receiving between six to 36 one-hour sessions. The results demonstrated improvement in cognition for tests of intelligence, memory, processing speed and problem solving, however statistical results were not reported. The results also demonstrate a statistical significant increase in cerebral blood flow on SPECT imaging following cognitive rehabilitation intervention.
Harrington and Levandowski (1987) demonstrated overall cognitive improvement in 18 TBI survivors following a two-year structured cognitive retraining program which consisted of 5 sequential instructional modules focusing on 1) orientation, attention/concentration and psycho-motor skills 2) perceptual cognitive processing 3) perceptual-cognitive integration 4) logical reasoning and problem solving and 5) a transitional community module. Pre- post comparisons demonstrated significant improvement on all elements of the Luria-Nebraska Neuropsychogical battery except for tactile functioning.
Brett and Laatsch (1998) studied the effects of a cognitive rehabilitation therapy program for TBI survivors in a high school setting. The intervention included biweekly 40-minute sessions for a total of 20 weeks. Cognitive therapy focused on alertness, attention, concentration, perception and memory as well as problem solving. Only memory demonstrated a statistically significant improvement post intervention whereas general intellectual functioning, concentration and problem solving did not demonstrate significant improvement.
Rattok et al. (1992) compared three cognitive rehabilitation programs which were similar in intensity, but varied in the emphasis of type of retraining format. This non-randomized controlled trial addressed cognitive retraining in the domains of attention, personal counseling, individual cognitive remediation and interpersonal communication exercises. All treatment mixes were equally effective with regards to level of vocational attainment.
In a quasi-experimental study conducted by Miotto et al. (2008) 30 patients were placed (15 were randomly assigned to a group) in one of three groups: group 1 (n=10) received the attention and problem solving intervention; group 2 (n=10) received weekly sessions of attention and problems solving training by 2 psychologists (1 x per week for 90 minutes) along with information and education interventions and a list of suggested cognitive exercises; while group 3 received usual treatment (PT, OT etc). Results indicate that all three groups showed improvement on executive function regardless of the intervention or treatment they received. Groups 1 and 2 showed significant improvement (p=0.023 and p=0.014 respectively) on assessment one and two, whereas the change in scores for group 3 did not quite reach significance (p<0.059). Results for the VIP test also showed improvement but again no significant differences were noted between the three groups. A comparison of the results from assessment 2 to assessment 3 did show significant improvement, on each scale; however there were no significant differences between the groups. Overall although improvement was noted for groups 1 and 2, group 3 also showed signs of improvement without any added intervention.
Turkstra (2008), in a between groups comparison study (n=38) found those with a TBI did not perform as well as those without an injury on various cognitive/communication tests. Results of CLPT (True/False and words recalled) and the VSIT test indicated that the controls significantly scored higher than the clinical group. No significant differences were noted between groups (p>0.05), when looking at the scores on the social inference items.
In the single subject intervention study conducted by Ownsworth et al. (2006), they found that by exposing their subject to systematic feedback they were able to reduce the number of errors made while engaging in cooking tasks and volunteer work. During the baseline phase the subject was videotaped performing various tasks. Upon viewing the tapes, it was noted the subject made 21 errors but during the treatment phase of the study a 46% decline in errors was noted. This reduction in errors was noted during both the cooking tasks and volunteer work completed by the subject.
Boman et al. (2004) in a study of 10 individuals with mild or moderate TBI, after completing 1 hour of an individual cognitive training 3 times a week for 3 weeks, significant improvement was noted on the attention processing training test in sustained attention (p<0.05), selective attention (p<0.05), and alternating attention (p<0.01) pre to post training and at 3 month follow-up. Scores on the RBMT were also seen to have significantly increased at the 3 month follow-up compared to pre test scores (p<0.05). Changes on the Claeson-Dahl Memory test did not increase pre to post to 3 month follow-up.
Ben-Yishay et al. (1987) reported a single group intervention of 101 patients with traumatic brain injury who entered into a comprehensive out patient day program consisting of two phases. At the end of the program, 84% were competitively employable, however over the intervening three years, this declined to only 50% remaining employed. Although no controls are available for this study, there is some evidence to support that a day program is effective for returning brain injury survivors to competitive employment.
Prigatano et al. (1984) in one of the earlier studies examining neuropsychological functioning found that an out-patient neuropsycholgical rehabilitation program provided significant benefit compared to a control group not receiving further rehabilitation. This comprehensive, intensive program emphasized increased awareness and acceptance of injury and residual deficits, intensive cognitive retraining and compensatory skills development. There was improvement in neuropsychological performance in the treatment group compared to the control group. Emotional distress was noted to substantially decrease in the treatment group.
Salazar et al. (2000) in a RCT of 120 moderate to severe TBI patients studied the efficacy of an intensive, eight-week, in-patient cognitive rehabilitation program compared to a limited home rehabilitation program with weekly telephone contact from a psychiatric nurse. Overall there were no differences between groups with regards to return to work or fitness for duty at one-year. There were also no differences in cognitive, behavioral or quality of life outcomes.
Cicerone et al. (2000) had concluded that comprehensive-holistic cognitive rehabilitation should be recommended as a practice guideline for patients with either a stroke or acquired brain injury. Since completion of this review, further quality studies have been published supporting a general cognitive therapy approach following acquired brain injury. In the studies by Dirette et al. (1999) Rath et al. (2003) and Cicerone et al. (2004) comparisons of specific strategies using experimental techniques (randomized and non-randomized) are attempted. All groups demonstrated benefit from the interventions and in the studies by Rath et al. (2003) and Cicerone et al. (2004) there were overall trends to improvement for the experimental groups. The study by Salazar et al. (Salazar et al., 2000) provides contradictory results to these other studies in that no benefit was demonstrated for an intensive in-patient rehabilitation program versus a limited home based rehabilitation program. This study was a RCT and challenges the trend of studies demonstrating the benefit of intensive cognitive rehabilitation programs. Comparison of cognitive rehabilitation strategies against a non-intervention group has been generally considered unethical supporting the general held belief that cognitive rehabilitation is effective, therefore trials such as these comparing different cognitive therapy strategies remain necessary to optimize rehabilitation outcomes.
Although there are differences in the delivery techniques of cognitive rehabilitation therapy, most studies when considering within-group comparisons demonstrated an overall improvement in cognitive abilities across multiple cognitive domains. The majority of the studies included patients greater than one-year post injury, which would assist in controlling for the effects of spontaneous recovery. There are limitations in most studies in that typically a time series design is used with pre- and post-intervention testing where the subject acts as their own control. The primary limitation with regards to brain injury rehabilitation is time-dependent confounding. Two factors contribute to this including anticipated spontaneous recovery as well as the consideration of the practice/ learning effect of repeat neuropsychology testing which may lead to higher scores.
Analysis of findings from the current review as well as those from Cicerone et al. (2005) and Gordon et al. (2006) all suggest that future studies need to control for patient characteristics (e.g., level of impairment needs to be clearly defined, not just severity of injury), spontaneous recovery and practice effects on outcome measures used. Studies should not just rely on psychometric tests but should consider functional outcome measures and long-term effects of treatment interventions should be monitored through follow-up.
Conclusions
There is conflicting evidence as to the effectiveness of cognitive rehabilitation programs focusing on memory strategies and selective attention.
There is Level 4 evidence that general cognitive rehabilitation therapy post acquired brain injury is effective for improving cognition. Although there are variable strategies and protocols for cognitive rehabilitation, all comprehensive interventions appear to provide benefit.
There is Level 4 evidence that working memory training is effective in recovering the central executive system of working memory.
There is Level 4 evidence that an outpatient day program is effective for assisting brain injury survivors in returning to competitive employment.
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Programs focusing on memory strategies and selective attention post ABI have not been shown to be effective.
Outpatient day programs are effective in helping survivors of a brain injury return to competitive employment.
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