Peggy P. Barco

Awareness and compensation in postacute head injury rehabilitation

Deficits in awareness caused by brain Injury can be divided into three types: deficits in intellectual awareness, deficits in emergent awareness, and deficits in anticipatory awareness. The presence or absence of an awareness deficit and the type of awareness deficit will determine the kinds of comp

Predicting Road Test Performance in Drivers with Dementia

To develop a cognitive and functional screening battery for the on‐road performance of older drivers with dementia.

Naturalistic validation of an on-road driving test of older drivers.

Objective: The objective was to compare a standardized road test to naturalistic driving by older people who may have cognitive impairment to define improvements that could potentially enhance the validity of road testing in this population. Background: Road testing has been widely adapted as a tool to assess driving competence of older people who may be at risk for unsafe driving because of dementia; however, the validity of this approach has not been rigorously evaluated. Method: For 2 weeks, 80 older drivers (38 healthy elders and 42 with cognitive impairment) who passed a standardized road test were video recorded in their own vehicles. Using a standardized rating scale, 4 hr of video was rated by a driving instructor. The authors examine weighting of individual road test items to form global impressions and to compare road test and naturalistic driving using factor analyses of these two assessments. Results: The road test score was unidimensional, reflecting a major factor related to awareness of signage and traffic behavior. Naturalistic driving reflected two factors related to lane keeping as well as traffic behavior. Conclusion: Maintenance of proper lane is an important dimension of driving safety that appears to be relatively underemphasized during the highly supervised procedures of the standardized road test. Application: Road testing in this population could be improved by standardized designs that emphasize lane keeping and that include self-directed driving. Additional information should be sought from observers in the community as well as crash evidence when advising older drivers who may be cognitively impaired.

Driving Errors in Persons with Dementia

To differentiate driving errors in persons with dementia who fail a performance‐ based road test from errors in persons who pass.

Clinical Utility of the Trail‐Making Test as a Predictor of Driving Performance in Older Adults

To assess the clinical utility of the Trail‐Making Tests (TMTs) as screens for impaired road‐test performance.

Predictors of Return to Driving After Stroke

Objective Although returning to driving is a major concern for many survivors of stroke, predicting who will return to driving after a stroke is often difficult for rehabilitation professionals. The primary aim of this study was to identify patient factors present at admission to an inpatient rehabilitation hospital that can be used to identify which patients who have had acute stroke will and will not return to driving. Design After comparing returners and nonreturners on demographic and clinical characteristics, a logistic regression model with return to driving as the outcome variable was built using the backward stepwise method. Results Thirty-one percent (48/156) of the patients who had been driving before their stroke returned to driving 6 mos after stroke. The final regression model, using Functional Independence Measure cognition and lower extremity Motricity Index scores, predicted the driving outcome with an accuracy of 75% (107/143). Conclusions Patients with lower Functional Independence Measure cognition and lower extremity Motricity Index scores at admission to inpatient rehabilitation are less likely to return to driving at 6 mos. This model could be used by rehabilitation professionals to help counsel patients and their families and focus treatment goals.

Predicting road test performance in drivers with stroke.

OBJECTIVE. The aim of this study was to develop a brief screening battery to predict the on-road performance of drivers who had experienced a stroke. METHOD. We examined 72 people with stroke referred by community physicians to an academic rehabilitation center. The outcome variable was pass or fail on the modified Washington University Road Test. Predictor measures were tests of visual, motor, and cognitive functioning. RESULTS. The best predictive model for failure on the road test included Trail Making Test Part A and the Snellgrove Maze Task(®). CONCLUSION. A screening battery that can be performed in less than 5 min was able to assist in the prediction of road test performance in a sample of drivers with stroke. A probability of failure calculator may be useful for clinicians in their decision to refer clients with stroke for a comprehensive driving evaluation.

Attentional Imbalances following Head Injury

Unilateral left and right hemisphere lesions produce numerous well documented neuropsychological consequences (DeRenzi, 1982). Some of these sequelae are attentional, involving anatomical systems related to the selection of information for conscious detection (Nissen, 1986; Posner & Rafal, 1986). Such attentional deficits can often be demonstrated in tasks involving conflicts between stimuli (Posner & Presti, 1987). For example, patients with left hemisphere lesions have difficulty selecting a verbal input when it conflicts with a simultaneous spatial command. Patients with right hemisphere damage show the reverse pattern (Walker, Friedrich, & Posner, 1983). Similarly, patients with parietal lobe lesions often have great difficulty when an event in the contralesional visual field is in conflict with one in the ipsilesional field. In severe cases these patients may be completely unaware of contralesional targets while in milder cases the target may be detected but with longer latency (DeRenzi, 1982; Posner, Walker, Friedrich & Rafal, 1984).

Amyloid Imaging, Cerebrospinal Fluid Biomarkers Predict Driving Performance Among Cognitively Normal Individuals.

Postmortem brain studies of older drivers killed in car accidents indicate that many had Alzheimer disease (AD) neuropathologic changes. We examined whether AD biomarkers are related to driving performance among cognitively normal older adults. Individuals with normal cognition, aged 65+ years, and driving at least once per week, were recruited. Participants (N=129) took part in clinical assessments, a driving test, and positron emission tomography imaging with Pittsburgh compound B (PIB) and/or cerebrospinal fluid (CSF) collection. General linear models tested whether the number of driving errors differed as a function of each of the biomarker variables (mean cortical binding potential for PIB, and CSF A&bgr;42, tau, ptau181, tau/A&bgr;42, ptau181/A&bgr;42). Higher ratios of CSF tau/A&bgr;42, ptau181/A&bgr;42, and PIB mean cortical binding potential, were associated with more driving errors (P<0.05). Preclinical AD may have subtle cognitive and functional effects, which alone may go unnoticed. However, when combined, these changes may impact complex behaviors such as driving.

Potentially Driver-Impairing (PDI) Medication Use in Medically Impaired Adults Referred for Driving Evaluation

Background: Potentially driver-impairing (PDI) medications have been associated with poorer driving performance and increased risk of motor vehicle collision. Objectives: To describe the frequency of medication use and to determine the association between routine use of PDI medications and performance on driving and cognitive tests. Methods: A total of 225 drivers with medical impairment (mean age 68 ± 12.8 years, 62.2% male) were referred to an occupational therapy–based driving evaluation clinic. Medication lists were reviewed to identify PDI drugs, as defined by a previous study examining medications and crash risk. Outcome variables included road testing on the modified Washington University Road Test and cognitive scores on Trail Making Test Parts A and B, Snellgrove Maze Task, Clock Drawing Task, Driving Health Inventory (DHI) Useful Field of View, DHI Motor Free Visual Perceptual Test, Epworth Sleepiness Scale (ESS), Geriatric Depression Scale, and Functional Assessment Questionnaire. Results: PDI medication use was documented in 68.9% of the sample, with the average subject taking 1.4 PDI drugs. Drivers taking routine PDI medications had a mean ESS score of 7.8 compared to 6.0 in the control group, suggesting increased somnolence (P = .007). Total number of routine medications, regardless of PDI designation, also correlated positively with ESS scores (P = .023). Conclusions: Use of PDI medications was associated with informant ratings of daytime drowsiness on the ESS, which has been linked to motor vehicle crash risk. Further investigation of individual drug classes is warranted using larger sample sizes and a high-powered study design.