Fitness to drive after acquired brain injury: Results from patient cognitive screening and on-road assessment compared to age-adjusted norm values.

Fitness to drive after acquired brain injury or disease is a common question in rehabilitation settings. The aim of the study was to compare age-matched norms with patient cognitive test results used to predict fitness to drive. A second aim was to analyze the contribution from an on-road assessment to a final decision on resumption of driving after an acquired brain injury. Retrospective cognitive test results from four traffic medicine units (n = 333) were compared with results from a healthy norm population (n = 410) in Sweden. Patients were dichotomized according to the final decision as fit or unfit to drive made by the traffic medicine team. The norm group had significantly better results in all age groups for all cognitive tests compared with the patients considered unfit to drive and fit to drive. A binary regression analysis for the patient group showed an explained value for fit to drive/unfit to drive of 88%, including results for the Nordic Stroke Driver Screening Assessment total score, Useful Field of View total score and the final outcome from an on-road assessment. Results from the present study illustrate the importance of using several tests, methods and contexts for the final decision regarding fitness to drive.

Exploring associations between self-regulatory mechanisms and neuropsychological functioning and driver behaviour after brain injury.

The objective of this prospective one-year follow-up study was to explore the associations between self-regulatory mechanisms and neuropsychological tests as well as baseline and follow-up ratings of driver behaviour. The participants were a cohort of subjects with stroke and traumatic brain injury (TBI) who were found fit to drive after a multi-disciplinary driver assessment (baseline). Baseline measures included neuropsychological tests and ratings of self-regulatory mechanisms, i.e., executive functions (Behavior Rating Inventory of Executive Function-Adult Version; BRIEF-A) and impulsive personality traits (UPPS Impulsive Behavior Scale). The participants rated pre-injury driving behaviour on the Driver Behaviour Qestionnaire (DBQ) retrospectively at baseline and after one year of post-injury driving (follow-up). Better performance on neuropsychological tests was significantly associated with more post-injury DBQ Violations. The BRIEF-A main indexes were significantly associated with baseline and follow-up ratings of DBQ Mistakes and follow-up DBQ Inattention. UPPS (lack of) Perseverance was significantly associated with baseline DBQ Inattention, whereas UPPS Urgency was significantly associated with baseline DBQ Inexperience and post-injury DBQ Mistakes. There were no significant changes in DBQ ratings from baseline (pre-injury) to follow-up (post-injury). It was concluded that neuropsychological functioning and self-regulatory mechanisms are related to driver behaviour. Some aspects of driver behaviour do not necessarily change after brain injury, reflecting the influence of premorbid driving behaviour or impaired awareness of deficits on post-injury driving behaviour. Further evidence is required to predict the role of self-regulatory mechanisms on driver behaviour and crashes or near misses.

Behavioural ratings of self-regulatory mechanisms and driving behaviour after an acquired brain injury.

OBJECTIVE: To explore whether measurements of self-regulatory mechanisms and cognition predict driving behaviour after an acquired brain injury (ABI). DESIGN: Consecutive follow-up study. PARTICIPANTS: At baseline participants included 77 persons with stroke and 32 persons with a traumatic brain injury (TBI), all of whom completed a multidisciplinary driving assessment (MDA). A follow-up cohort of 34 persons that succeeded the MDA was included. Baseline measurements: Neuropsychological tests and measurements of self-regulatory mechanisms (BRIEF-A and UPPS Impulsive Behaviour Scale), driving behaviour (DBQ) and pre-injury driving characteristics (mileage, compensatory driving strategies and accident rates). Follow-up measurements: Post-injury driving characteristics were collected by mailed questionnaires from the participants who succeeded the MDA. METHODS: A MDA, which included a medical examination, neuropsychological testing and an on-road driving test, was considered in the decision for or against granting a driver's license. Self-regulatory mechanisms and driving behaviour were examined for research purposes only. RESULTS: At baseline, self-regulatory mechanisms were significantly associated to aberrant driving behaviour, but not with neuropsychological data or with the outcome of the on-road driving test. Aspects of self-regulation were associated to driving behaviour at follow-up. CONCLUSION: It is recommended that self-regulatory measurements should regularly be considered in the driving assessments after ABI.

Return to work after acquired brain injury: a patient perspective.

PRIMARY OBJECTIVE: To study significant factors supporting vocational rehabilitation after acquired brain injury from a patient perspective. METHODS: Two focus group interviews were accomplished with former patients. One focus group interview with professional rehabilitation personnel was performed to review the correspondence between patients' and professionals' opinion. SUBJECTS: Fourteen informants with acquired brain injury (ABI) were interviewed. All were working at the time of the focus group interviews. Three occupational therapists and two psychologists participated in the professional group. RESULTS: Two themes were identified as significant for returning to work: Personal and Society factors. Identified meaningful units could be categorized into sub-categories, which were grouped into six main- and 14 sub-categories. The main categories were: Self-continuity, Coping, Social factors, Rehabilitation intervention, Professionalism and Health insurance. Length of treatment time was described as crucial for the rehabilitation process and for utilizing individual resources. CONCLUSIONS: The effects of various synergies and processes form the basis for a successful return to work, which are dependent on, influence and reinforce each other. Society factors support personal factors to be used for returning to work after acquired brain injury. The impact of individual resources and rehabilitation highlights that vocational rehabilitation is inseparable from the individual's capacity, society and the context in which the individual lives.

Interactions with DOM and biofilms affect the fate and bioavailability of insecticides to invertebrate grazers.

We studied the fate and bioavailability of insecticides in short-term experiments (48 h) with different hydrophobicity (3.8 pM carbofuran, 3.0 pM lindane, and 5.3 pM chlorpyrifos) across gradients in dissolved organic matter (low-, medium-, and high-DOM) in freshwater microcosms, mimicking runoff events of pesticides. The effects of biofilms were studied by including treatments with biofilms cultivated under different DOM-concentrations. The presence of biofilms negatively affected chlorpyrifos water concentrations, indicating rapid sorption of this hydrophobic pesticide, while lindane concentrations instead increased and carbofuran concentrations were unaffected. Associations of lindane and chlorpyrifos with biofilms were 1.6-2.0 times higher in low- and high-DOM than in medium-DOM treatments, indicating that sorption was affected not only by the quantity, but also by the quality of DOM. Although the proportion of pesticides recovered in biofilms was consistently less than 1 % of added pesticide, pesticide concentrations in biofilms were on average more than 75- (carbofuran) and 382-times (lindane) higher than those in water. Snail accumulation of all three pesticides was significantly affected by DOM-concentrations and correlated to pesticide hydrophobicity, but the relationships were not straightforward. For example, carbofuran uptake in treatments without biofilms was higher in low-DOM than in medium- and high-DOM treatments, while chlorpyrifos uptake instead increased across the DOM-gradient. Biofilms played a role only for the uptake of chlorpyrifos, which decreased markedly in the presence of biofilms. Bioconcentration factors (BCF) calculated for snails and biofilms differed for the three pesticides and were related to their sorption behaviour (i.e., hydrophobicity). The relative proportion of pesticide uptake through biofilm consumption was consistently less than 2 %, showing that passive uptake was by far the predominant uptake pathway for all three pesticides.

Computerized training of working memory in a group of patients suffering from acquired brain injury.

OBJECTIVE: Study short- and long-term transfer effects of a computerized working memory (WM) training programme for patients suffering from working memory deficits after acquired brain injury. RESEARCH DESIGN: A controlled experimental study with a cross-over design. METHODS: A consecutive sample of 21 subjects. Mean age 43.2 years, time since injury/illness onset 37 months (median). The subjects were randomly selected into two groups where one group served as controls. All subjects trained daily for 5 weeks in a computer WM task program. They were followed-up at 4 and 20 weeks after the training. RESULTS: A significant improvement in the trained WM tasks, significant improvements in neuropsychological WM-test results at 4 and 20 weeks after training compared to baseline. Improvement in the subjects' rated occupational performance and satisfaction with performance in pre-defined occupational problems. Rated quality-of-life did not change. However, rated overall health increased 20 weeks after training. CONCLUSIONS: Structured and intense computerized WM training improves subjects' cognitive functioning as measured by neuropsychological WM-demanding tests, rated occupational performance, satisfaction with performance and rated overall health. The training probably has an impact on the rehabilitation outcome, returning to work, as well as on daily activities for individuals with verified WM impairments.

Improved self-awareness and coping strategies for patients with acquired brain injury--a group therapy programme.

PRIMARY OBJECTIVE: This study evaluates the effects of a group therapy programme for anticipatory self-awareness and coping strategies. DESIGN: The study includes methodological triangulation using three methods to gather data: an overall self-report questionnaire, Self Regulation Skills Interview (SRSI) and focus group interview. SUBJECTS: Twenty-one individuals with acquired brain injury participated in a group therapy programme. METHODS: A self-report questionnaire developed and used especially for evaluation of the described intervention was used at the end of the last session of the group therapy programme. The Self Regulation Skills Interview-SRSI, was used within 2 weeks before and after the subjects participated in one group program. Three Focus groups were used as a third method for data collection. The Focus group interviews were accomplished 1 month after each group programme. RESULTS: The individuals increased their self-awareness and strategy behaviour significantly. Participating in the group therapy programme had had an effect on their life and work situation and on their self-confidence. CONCLUSIONS: A structured group therapy programme helps patients with acquired brain injury understand the consequences of their neuropsychological deficits, helps them improve awareness of their impairments and helps them develop coping strategies.

Effects of extracellular polymeric and humic substances on chlorpyrifos bioavailability to Chironomus riparius.

The role of sediment organic matter quality and quantity for chlorpyrifos bioavailability was studied in experiments with Chironomus riparius larvae and with four types of organic matter; (1) commercially available extracellular polymeric substances (EPS), (2) EPS produced by sediment microbes, (3) commercially available humic substances and, (4) humic substances extracted from a boreal lake. The effects of each type of organic matter were assessed at three concentrations. We used a (14)C-tracer approach to quantify uptake of chlorpyrifos in the larvae, and the partitioning of the insecticide within the microcosm. Carbon-normalised larval uptake was reduced both by EPS and humic substances. However, the reduction in uptake was much greater for EPS than for humic substances: uptake was reduced by 94 and 88% for commercial and complex EPS, and by 59 and 57% for commercial and complex humic substances, respectively. We also found differences in chlorpyrifos uptake, and sediment concentrations between treatments with commercially available and complex polymers, suggesting that minor differences in the quality of relatively simple organic molecules can affect contaminant behaviour in ecotoxicological studies. Passive uptake in dead controls was 40% of that in living larvae. Therefore, both passive and digestive uptake were important processes for chlorpyrifos uptake by larvae. Our results show that both EPS and humic substances affect chlorpyrifos bioavailability to sediment biota negatively and contribute to the understanding of the processes that regulate organic contaminant bioavailability in aquatic environments.

Factors influencing driving 10 years after brain injury.

OBJECTIVE: To study long-term consequences of brain injury on health status, driving characteristics and car accidents. To study whether driving 10 years after brain injury was retrospectively related to cognitive functioning and on-road driving performance 10 years before. RESEARCH DESIGN: A semi-structured telephone interview with 38 patients with sequelae of brain injury and 49 healthy controls was used. RESULTS: Hypertension, heart disease and vascular disorder were the most frequently reported diseases. The patients reported fatigue, irritability, memory and initiative problems. Concentration and vision problems influenced their driving. Patients had more car accidents reported to an insurance company during the observation period than control subjects. Present driving was retrospectively significantly related to neuropsychological test results but not to on-road test outcome 10 years before. Car accidents were not related to neuropsychological test results or to on-road test outcome 10 years back. Half of the dropouts were stroke patients and they performed significantly worse on the neuropsychological tests but not on the on-road test 10 years before. CONCLUSION: Neuropsychological tests focusing on information processing speed and attention is a useful screening tool for predicting driving competence. Stroke patients are vulnerable if they continue to drive and need to be evaluated for their driving capacity to drive.

Sediment microbes and biofilms increase the bioavailability of chlorpyrifos in Chironomus riparius (Chironomidae, Diptera).

In a microcosm study, the importance of different sources of organic matter (humic acids, sterile sediment, sediment, and a microbial extract) for the bioavailability of the hydrophobic pesticide chlorpyrifos to Chironomus riparius larvae was quantified. In the last two treatments biofilms were allowed to grow before (14)C-chlorpyrifos addition. Chlorpyrifos accumulation was quantified after 25 h of exposure and after 21 h of depuration. Larval accumulation was twice as high in the microbial extract treatment (447+/-79 microg/kg ww larvae) and 1.7 times higher in the sediment treatment (371+/-33 microg/kg). After depuration, chlorpyrifos accumulation in larval tissue showed even higher differences; 3.1 times higher tissue concentrations in the microbial extract treatment (218+/-21 microg/kg) and 2.2 times higher in the sediment treatment (156+/-35 microg/kg). In contrast, chlorpyrifos accumulation in the humic acid and sterile sediment did not differ from that in controls. These results show that living microbes and biofilms, by creating a microenvironment and providing food for larvae, markedly increase the bioavailability of chlorpyrifos to Chironomus riparius.

Neurocognitive impairment and driving performance after coronary artery bypass surgery.

OBJECTIVE: Neurocognitive impairment is common after cardiac surgery but few studies have examined the relationship between postoperative neuropsychological test performance and everyday behavior. The influence of postoperative cognitive impairment on car driving has previously not been investigated. The purpose of this study was to evaluate neurocognitive function and driving performance after coronary artery bypass grafting (CABG). METHODS: Twenty-seven patients who underwent coronary artery bypass grafting with standard cardiopulmonary bypass technique and 20 patients scheduled for percutaneous coronary intervention (PCI) under local anesthesia (control group) were enrolled in this prospective study conducted from April 1999 to September 2000. Complete data were obtained in 23 and 19 patients, respectively. The patients underwent neuropsychological examination with a test battery including 12 tests, a standardized on-road driving test and a test in an advanced driving simulator before and 4-6 weeks after intervention. RESULTS: More patients in the coronary artery bypass grafting group (n=11, 48%) than in the percutaneous coronary intervention group (n=2, 10%) showed a cognitive decline after intervention (P=0.01). In the on-road driving test, patients who underwent coronary artery bypass grafting deteriorated after surgery in the cognitive demanding parts like traffic behavior (P=0.01) and attention (P=0.04). Patients who underwent percutaneous intervention deteriorated in maneuvering of the vehicle (P=0.04). No deterioration was detected in the simulator in any of the groups after intervention. Patients with a cognitive decline after intervention also tended to drop in the on-road driving scores to a larger extent than did patients without a cognitive decline. CONCLUSION: This study indicates that cognitive functions important for safe driving may be influenced after cardiac surgery.

Driving after brain injury: self-awareness and coping at the tactical level of control.

OBJECTIVE: To study whether metacognition is a prerequisite for coping at the tactical level of driving. RESEARCH DESIGN: A consecutive series of 30 drivers with acquired brain injury were assessed concerning cognitive functions and driving performance. In addition the drivers assessed their driving performance through self-rating. RESULTS: On average the drivers had cognitive impairments compared to a healthy reference group. The group that passed the driving test and the group that failed the driving test did not differ in terms of cognitive functions. Neither did they differ in their self-ratings of driving performance. However, the group that failed the driving test significantly over-estimated their performances as compared to the assessments made by the professional driving inspector, while the group that passed the test made more accurate self-ratings. CONCLUSIONS: One interpretation of these results is that the group that made a more realistic evaluation of their driving performance were more aware of their cognitive capacity compared to those who failed the driving test. They seemed to have a better ability to adjust their driving behaviour at a tactical level. Thus, the subject's metacognition, awareness of his/her own cognitive capacity, is important for coping with cognitive impairments at tactical driving.