Driving safety in Parkinson's disease

Parkinson's Disease and Driving Fitness: A Systematic Review of the Existing Guidelines

BACKGROUND

Motor/nonmotor symptomatology and antiparkinsonian drugs deteriorate the driving ability of Parkinson's disease (PD) patients.

OBJECTIVES

Treating neurologists are frequently asked to evaluate driving fitness of their patients and provide evidence-based consultation. Although several guidelines have been published, the exact procedure along with the neurologist's role in this procedure remains obscure.

METHODS

We systematically reviewed the existing guidelines, regarding driving fitness evaluation of PD patients. We searched MEDLINE and Google Scholar and identified 109 articles. After specified inclusion criteria were applied, 15 articles were included (nine national guidelines, five recommendation papers, and one consensus statement).

RESULTS

The treating physician is proposed as the initial evaluator in 8 of 15 articles (neurologist in 2 articles) and may refer patients for a second-line evaluation. The evaluation should include motor, cognitive, and visual assessment (proposed in 15, 13, and 8 articles, respectively). Specific motor tests are proposed in eight articles (cutoff values in four), whereas specific neuropsychological and visual tests are proposed in seven articles each (cutoff values in four and three articles, respectively). Conditional licenses are proposed in 11 of 15 articles, to facilitate driving for PD patients. We summarized our findings on a graphic of the procedure for driving fitness evaluation of PD patients.

CONCLUSIONS

Neurological aspects of driving fitness evaluation of PD patients are recognized in most of the guidelines. Motor, neuropsychological, visual, and sleep assessment and medication review are key components. Clear-cut instructions regarding motor, neuropsychological, and visual tests and relative cutoff values are lacking. Conditional licenses and periodical reevaluation of driving fitness are important safety measures.

Driving Impairment in Movement Disorders

Background

Driving may be adversely affected by any movement disorder, but has been mostly studied in Parkinson's disease (PD). Few studies have addressed driving impairment in patients with Huntington's disease (HD); driving in other movement disorders such as dystonia, blepharospasm and Tourette syndrome (TS) has not been adequately evaluated.

Objectives

The aim of this review is to summarize the findings of driving impairment in movement disorders and evaluate the usefulness of clinical tools in guiding clinicians whether to refer patients for driving assessment.

Methods

A review of literature was performed on PubMed and articles on driving and movement disorders were identified using a Boolean phrase.

Results

We were able to identify 66 articles that fulfilled the target subject: impairment of driving in PD, cervical dystonia, blepharospasm, HD and TS. We also included articles discussing the role of driving rehabilitation in patients with movement disorders.

Conclusions

Driving is often impaired in patients with PD and other movement disorders not only due to motor symptoms but also because of cognitive and behavioral co-morbidities. Certain screening tools may be helpful in guiding the clinician in referring the patients for driving assessment.

Back on the Road: Comparing Cognitive Assessments to Driving Simulators in Moderate to Severe Traumatic Brain Injuries

Objective: To compare established clinical outcome assessments for predicting behind the wheel driving readiness and driving simulator results across age groups and in traumatic brain injury. Methods: Participants included adults who had a traumatic brain injury ranging in age from 31 to 57 years and a non-impaired adult population ranging in age from 18 to 80 years. Physical and cognitive outcomes measures were collected included range of motion and coordination, a “Rules of the Road Test” a “Sign Identification Test,” Trails A and B, and the clock drawing test. Visual measures included the Dynavision D2 system and motor-free visual perceptual test-3 (MVPT-3). Finally, the driving simulators (STIÒ version M300) metro drive assessment was used, which consisted of negotiating several obstacles in a metropolitan area including vehicles abruptly changing lanes, pedestrians crossing streets, and negotiating construction zones. Results: Our findings suggest that the standard paper-pencil cognitive assessments and sign identification test significantly differentiate TBI from a non-impaired population (Trails A, B and Clock drawing test p < 0.001). While the driving simulator did not show as many robust differences with age, the TBI population did have a significantly greater number of road collisions (F3, 78 = 3.5, p = 0.02). We also observed a significant correlation between the cognitive assessments and the simulator variables. Conclusions: Paper-pencil cognitive assessments and the sign identification test highlight greater differences than the STI Driving Simulator between non-impaired and TBI populations. However, the driving simulator may be useful in assessing cognitive ability and training for on the road driving.

Parkinson's disease affects gaze behaviour and performance of drivers

The aim of this study was to investigate the effects of PD and ageing on gaze behaviour and performance of drivers in a simulated task. Ten drivers with PD, ten neurologically healthy older drivers, and ten neurologically healthy younger adult drivers were asked to drive in a car simulator for three minutes, maintaining car speed between 100 and 120 km/h and avoiding collisions. Driver's eye movements were recorded. Drivers with PD had more collisions and spent less time driving within the speed zone than the younger-drivers. Drivers with PD performed an increased number of fixations towards task-irrelevant areas of the visual scene and higher visual entropy, indicating a more random gaze behaviour. Older drivers restricted their visual search to the lane area in order to detect threat-related stimuli. PD led to drops in performance of drivers in the car simulator. Practitioner summary: Parkinson's disease (PD) and ageing process caused a drop in driving performance. Drivers with PD made fewer fixations on task-relevant information and showed higher visual entropy than young adults. Older drivers restricted their visual search to the lane than other areas of interest.

Driving and Parkinson's Disease: A Survey of the Patient's Perspective

BACKGROUND

Parkinson's disease (PD) is a multi-system disorder that can impact on driving ability. Little is known about how these changes in driving ability affect people with PD, making it difficult for clinicians and carers to offer appropriate support.

OBJECTIVE

To assess patient views concerning the effect of PD on their driving ability, the impact of these changes and how they manage them.

METHOD

An online survey was created by a team of clinicians, people with PD, their carers, and representatives from Parkinson's UK. People with PD throughout the United Kingdom were invited to participate through Parkinson's UK's website, newsletter and Parkinson's Excellence Network email list.

RESULTS

805 people with PD took part in the survey. We found that the loss of a driving licence had an adverse impact on employment, socialisation, travel costs and spontaneous lifestyle choices. Multiple changes in driving ability related to PD were described, including that impulse control disorders can have an adverse impact on driving. Changes in driving ability caused people to change their driving practices including taking shorter journeys and being less likely to drive at night. Participants advised managing changes in driving ability through planning, vehicle adaptions, maintaining skills and self-assessment.

CONCLUSION

This study demonstrates the impact that changes in driving ability can have on the lifestyle of people with PD and reveals the strategies that individuals adopt to manage these changes.

Driving in Parkinson's disease: a retrospective study of driving and mobility assessments

BACKGROUND

To guide decision-making about driving ability, some patients with Parkinson's disease (PD) undergo specialist driving assessment. However, decisions about driving safety in most patients need to be made without this definitive test. There is no consensus on what predicts unsafe driving in PD nor a validated prediction tool to guide clinician decision-making and the need to refer for further assessment.

OBJECTIVES

To describe the characteristics of patients with PD assessed at a Driving Mobility Centre and investigate factors that predict driving assessment outcome.

METHODS

Retrospective cohort study of patients with PD assessed between 2012 and 2016. Descriptive analyses and logistic models to determine factors predicting a negative outcome.

RESULTS

There were 86 assessments of patients with PD. The mean age was 70 years (±9.2), 86% were male, median disease duration 7 years (interquartile range 5-12.5 years) and 59% were referred by the Driver and Vehicle Licensing Agency. In total, 62% had a negative 'not drive' outcome. The Rookwood Driving Battery (RDB), depth of vision deficit, usual driving frequency, age, duration license held and response time were all predictors in univariable analysis. The RDB was the best predictor of assessment failure, conditional on other variables in a backward stepwise model (odds ratio 1.29; 95% confidence interval 1.05, 1.60; P = 0.015).

CONCLUSIONS

This is the first study to describe patients with PD undergoing driving assessments in the UK. In this population, RDB performance was the best predictor of outcome. Future prospective studies are required to better determine predictors of driving ability to guide development of prediction tools for implementation into clinical practice.

Differences in visual-spatial working memory and driving behavior between morning-type and evening-type drivers

Circadian rhythms are changes in life activities over a cycle of approximately 24 hours. Studies on chronotypes have found that there are significant differences in physiology, personality, cognitive ability and driving behavior between morning-type and evening-type people. The purpose of this study is to explore the relationship between visual-spatial working memory and driving behavior between morning-type and evening-type drivers in China. A total of 42 Chinese drivers were selected to participate in this study according to their score on the Morningness-Eveningness Questionnaire, including 22 morning-type drivers and 20 evening-type drivers. During the experiment, the participants completed one cognitive task (visual-spatial working memory), two simulated driving tasks (car-following task and pedestrian-crossing task), and the Dula Dangerous Driving Index (DDDI). The results showed that evening-type drivers self-reported more dangerous driving behaviors but had better lateral control on the simulated driving task than morning-type drivers. In addition, evening-type drivers had greater accuracy when performing the visual-spatial working memory task. Moreover, the accuracy on the visual-spatial working memory task positively predicted the percentage of time over the speed limit by 10 mph (POS10) and negatively correlated with the reaction time measure (time to meet pedestrians) in the pedestrian-crossing task. The relationships among chronotype, cognitive ability and driving behavior are also discussed. Understanding the underlying mechanisms could help explain why evening-type drivers perform dangerous driving behaviors more often.

Sleep in Parkinson's disease

Sleep disturbances are common in Parkinson's disease and comprise the entire spectrum of sleep disorders. On the one hand regulation of sleep and wakefulness is affected in Parkinson's disease, leading to the development of disorders, such as insomnia and daytime sleepiness. While on the other hand control of motor activity during sleep is impaired, with subsequent manifestation of parasomnias (mainly REM sleep behavior disorders, but also, albeit more rarely, sleepwalking, and overlap parasomnia). Restless legs syndrome has been reported to be frequent in patients with Parkinson's disease, although there is no consensus on whether it is more frequent in Parkinson's disease than in the general population. The same is true for sleep-related breathing disorders. Regarding the diagnosis of sleep disorders in patients with Parkinson's disease, one of the main challenges is correctly identifying excessive daytime sleepiness as there are many potential confounding factors, for example it is necessary to distinguish sleep-related breathing disorders from medication effects, and to distinguish restless legs syndrome from the concomitant presence of potential mimics specific to Parkinson's disease, such as akathisia, nocturnal leg cramps, nocturnal hypokinesia, early morning dystonia, etc. The correct diagnosis of REM sleep behavior disorder is also not always easy, and video-polysomnography should be performed in order to exclude mimic-like movements at the end of sleep apneas or violent periodic leg movements of sleep. These aspects and specific considerations about diagnosis and treatment of sleep disorders in patients with Parkinson's disease will be reviewed.

Driving in Parkinson Disease

Driving is impaired in most patients with Parkinson disease because of motor, cognitive, and visual dysfunction. Driving impairments in Parkinson disease may increase the risk of crashes and result in early driving cessation with loss of independence. Drivers with Parkinson disease should undergo comprehensive evaluations to determine fitness to drive with periodic follow-up evaluations as needed. Research in rehabilitation of driving and automation to maintain independence of patients with Parkinson disease is in progress.

Relationship between neuropsychological tests and driver's license renewal tests in Parkinson's disease

OBJECTIVE

To determine whether the standard Spanish driving test (ASDE test) was able to identify patients with Parkinson's disease (PD) at risk of unsafe driving and to examine the relationship between the ASDE test and the Useful Field of View (UFOV) as well as with a battery of neuropsychological tests in drivers with PD.

METHODS

Thirty-seven patients with PD and 33 controls matched by age and education level were included in an observational study. All participants were active drivers and patients with PD underwent study procedures after taking the medication in the "on" period. Subjects with a Mini-Mental State Examination (MMSE) score ≤ 24 were excluded. Neuropsychological tests (Repeatable Battery for Neuropsychological Status [RBANS], Trail Making Test [TMT-A and -B], and Block Design test), driving performance tests (ASDE Driver Test and UFOV), and daytime sleepiness (Epworth Sleepiness Scale) were assessed.

RESULTS

The PD group performed significantly worse than healthy controls in the ASDE Motor Coordination tests. No significant differences were observed in anticipation speed, multiple reaction time, concentrated attention, and resistance to monotony. All participants successfully completed the UFOV tests. Statistically significant differences between patients with PD and controls were found in processing speed (UFOV1; P =.03) and more patients with PD were found in the categories of higher driving risk levels (P =.03). In addition, patients with PD showed worse scores than healthy controls in visuospatial capacities (Line Orientation), psychomotor speed (Coding and TMT-A), memory (List Recognition, Story Recall), and executive function (TMT-B). The driving tests (ASDE and UFOV) showed a low sensitivity and a high specificity but a higher percentage of patients in the PD group failed in multiple reaction time, concentrated attention, and resistance to monotony. In addition, 18.9% of patients with PD showed a cutoff of 4 for UFOV risk. In the discriminant analysis, Line Orientation (visuospatial/constructive domain) and Figure Recall (delayed memory) were found to be statistically significant with a rate of correct classification of unsafe drivers with PD of 78.2%. In addition, normal results on the Line Orientation item were associated with a 1.5 times higher probability of non-risky driving in the multivariate analysis.

CONCLUSIONS

At early stages of the disease, about 19% of patients with PD showed difficulties that may affect their driving capabilities. Line Orientation and Figure Recall are useful to alert clinicians to the risk of unsafe driving. For this reason, patients with PD should be evaluated for driving abilities more regularly to determine the extent of deficits that may influence driving performance.

Motor vehicle accidents in Parkinson's disease: A questionnaire study

OBJECTIVES

Few studies have investigated the risk factors for motor vehicle accidents (MVA) in individuals with Parkinson's disease (PD) in Japan.

MATERIALS AND METHODS

We sent an anonymous questionnaire to 1417 patients with PD who had received medical care certificates for Intractable Diseases during the 2014 fiscal year from the Aomori Prefectural Government in Japan. Data from patients with PD who previously or currently held a driving license at the time of the survey were analyzed.

RESULTS

Complete datasets were obtained from 384 patients with PD who were either past or present driving license holders. Fifty-seven patients had caused at least one MVA in the last 5 years before the survey. Logistic regression analyses revealed that ergot-dopamine agonist (DA) use and excessive daytime sleepiness (Epworth Sleepiness Scale score ≥ 10) were the best predictors of MVAs. Patients having caused non-sleep-related MVAs had significantly longer disease durations, more frequent ergot-DA use, and higher cognition and communication subscores on the Parkinson's Disease Questionnaire-39 than those without non-sleep-related MVAs (P < .05). The Epworth Sleepiness Scale scores of PD patients with sleep-related MVAs were significantly higher than those of patients without sleep-related MVAs (P < .01).

CONCLUSIONS

Excessive daytime sleepiness and ergot-DA use may be important predictive risk factors for MVAs in PD. Daytime sleepiness appears to be related to sleep-related MVAs in PD, whereas disease progression and ergot-DA use may contribute to non-sleep-related MVAs.

Driving with a neurodegenerative disorder: an overview of the current literature

Driving is important for employment, social activities, and for the feeling of independence. The decision to cease driving affects the quality of life and has been associated with reduced mobility, social isolation, and sadness. Patients with neurodegenerative disorders can experience difficulties while driving due to their cognitive, motor, and behavioral impairments. The aim of this review is to summarize the available literature on changes in driving competence and behavior in patients with neurodegenerative disorders, with a particular focus on Huntington's (HD), Parkinson's (PD), and Alzheimer's disease (AD). A systematic literature search was conducted in the PubMed/Medline database. Studies using on-road or simulated driving assessments were examined in this review. In addition, studies investigating the association between cognitive functioning and driving were included. The review identified 70 studies. Only a few publications were available on HD (n = 7) compared to PD (n = 32) and AD (n = 31). This review revealed that driving is impaired in patients with neurodegenerative disorders on all levels of driving competence. The errors most commonly committed were on the tactical level including lane maintenance and lane changing. Deficits in executive functioning, attention, and visuospatial abilities can partially predict driving competence, and the performance on neuropsychological tests might be useful when discussing potential driving cessation. Currently, there is no gold standard to assess driving ability using clinical measures such as neuropsychological assessments, so more studies are necessary to detect valid screening tools and develop useful and reliable evidence-based guidelines.

Physicians' role in the determination of fitness to drive in patients with Parkinson's disease: systematic review of the assessment tools and a call for national guidelines

BACKGROUND

Physicians are usually at the forefront when the issue of driving ability is raised by Parkinson's disease (PD) patients or their family members, even though few have been formally trained in this area.

OBJECTIVES AND METHODS

To identify relevant literature on driving assessment tools in patients with PD by performing a systematic review on this subject in order to provide background information for physicians on what types of driving assessment are available, and to delineate the role of physicians in providing fitness to drive recommendations.

RESULTS

Of 1,490 abstracts screened, 55 articles fulfilled the selection criteria that investigated assessment of driving ability in PD patients with questionnaires, off-road testing battery, driving simulators, and driving skill tests (on-road tests and naturalistic driving test). Despite different methodology across studies, PD patients were observed to commit more driving errors than controls. Poor driving performance correlated with motor, visual, and cognitive severity. Excessive daytime somnolence was common in PD drivers and the presence of falling asleep while driving was identified to be a significant predictor of car accidents.

CONCLUSION

Although the evidence indicated more driving errors among PD drivers as identified by various assessment tools, the extent on how physicians should be involved in the evaluation process and make related recommendations remain unclear. Driving safety is an important public health issue in PD that needs better-defined specific legal and medical guidelines. National guidelines that establish risk assessment protocols involving multidisciplinary assessments are needed to assist physicians in making appropriate referrals for additional evaluations and recommendations when patients are deemed to be unsafe drivers.

Use of a driving simulator to improve on-road driving performance and cognition in persons with Parkinson's disease: A pilot study

BACKGROUND/AIM

The use of simulators as an assessment and intervention tool for driving is an emerging field in occupational therapy. We investigated the potential usefulness of a driving simulator to improve on-road skills and cognitive functions in drivers with Parkinson's disease (PD).

METHOD

Fifteen participants with PD, and Hoehn and Yahr stages between 2 and 3 participated in this pre-post comparison study. Twelve of the 15 individuals (median age (Q1-Q3), 68 (63.5-72.5); 10 men) completed 10 hours of training in a high-fidelity driving simulator. A practical road test as well as off-road cognitive and simulator tests were administered at pre-training and post-training.

RESULTS

Nine participants, who passed the road test before training, passed at post-training. Furthermore, all three participants who initially failed the on-road test passed after training. Participants' performance improved significantly from pre- to post-training on two cognitive tests: (i) the Montreal Cognitive Assessment and (ii) Dot Cancellation test.

CONCLUSION

This pilot study demonstrates the potential usefulness of a simulator to improve on-road driving and driving-related cognitive skills in PD. Adequately powered randomized controlled trials are needed to further expand this field of study.

Cognitive impairment and dementia in Parkinson's disease: practical issues and management

Cognitive impairment and dementia pose particular challenges in the management of patients with Parkinson's disease (PD). Decision-making capacity can render patients vulnerable in a way that requires careful ethical considerations by clinicians with respect to medical decision making, research participation, and public safety. Clinicians should discuss how future decisions will be made as early in the disease course as possible. Because of cognitive, visual, and motor impairments, PD may be associated with unsafe driving, leading to early driving cessation in many. DBS of the STN and, to a lesser degree, globus pallidus interna (GPi) has consistently been associated with decreased verbal fluency, but significant global cognitive decline is usually not observed in patients who undergo rigorous selection. There are some observations suggesting lesser cognitive decline in GPi DBS than STN DBS, but further research is required. Management of PD dementia (PDD) patients involves both pharmacological and nonpharmacological measures. Patients with PDD should be offered treatment with a cholinesterase inhibitor taking into account expected benefits and potential risks. Treatment with neuroleptics may be necessary to treat psychosis; classical neuroleptics, as well as risperidone and olanzapine, should be avoided. Quetiapine might be considered first-line treatment because it does not need special monitoring, although the strongest evidence for efficacy exists for clozapine. Evidence from randomized, controlled studies in the PDD population is lacking; selective serotonin reuptake inhibitors or serotonin-norepinephrine reuptake inhibitors may be used to treat depressive features. Clonazepam or melatonin may be useful in the treatment of rapid eye movement behavior disorder.

Central corneal thickness and its relationship to Parkinson's disease severity

OBJECTIVE

To investigate the effect of Parkinson's disease (PD) on blink rate (BR), tear breakup time test (TBUT), Schirmer's test, and corneal thickness, and the relationship of these effects with disease severity.

DESIGN

Prospective controlled study.

PARTICIPANTS

Fifty-five eyes from 55 patients with PD and 40 eyes from 40 healthy subjects were analyzed in the study.

METHODS

The patients were divided into 2 groups according to their Hoehn-Yahr (H-Y) scores; patients classified as H-Y 1-2 were designated as the mild group, and those classified as H-Y 3-5 were designated as the moderate group. Subjects were screened for BR, TBUT, and Schirmer's test, and the central corneal thickness (CCT) was measured.

RESULTS

The BR, Schirmer's test, TBUT, and CCT values of the patient group were significantly lower than those of the control group. The BR and TBUT of the mild group were significantly lower than those of the control group, but the decreases in the Schirmer's test values and CCT were not statistically significant. In addition, significant decreases in the BR, TBUT, Schirmer's test scores, and CCT were observed in the patient group as the H-Y score increased.

CONCLUSIONS

A reduced BR and poor tear quality in the early stages of PD, as well as decreased tear production as the disease progresses, can result in reduced CCT. The possibility of a thin cornea should be taken into consideration while measuring the intraocular pressure in patients with severe PD.

Consensus statements on driving in people with Parkinson's disease

Parkinson's disease (PD) is a complex neurodegenerative disorder leading to motor and non-motor impairments, all of which can affect fitness to drive. The literature suggest that on-road and simulated driving performances are impaired in people with PD, as compared to healthy control drivers. Clear associations exist between impaired driving performance and contrast sensitivity, visual processing speed, and psychomotor speed. Prior to this review and expert panel process, no evidence-based guidelines have existed to help occupational therapy practitioners determining fitness to drive in those with PD. Three consensus statements are presented in this work to enable occupational therapy practitioners and other driver rehabilitation specialists to make fitness to drive determinations in people with PD.

Active and passive fatigue in simulated driving: discriminating styles of workload regulation and their safety impacts

Despite the known dangers of driver fatigue, it is a difficult construct to study empirically. Different forms of task-induced fatigue may differ in their effects on driver performance and safety. Desmond and Hancock (2001) defined active and passive fatigue states that reflect different styles of workload regulation. In 2 driving simulator studies we investigated the multidimensional subjective states and safety outcomes associated with active and passive fatigue. Wind gusts were used to induce active fatigue, and full vehicle automation to induce passive fatigue. Drive duration was independently manipulated to track the development of fatigue states over time. Participants were undergraduate students. Study 1 (N = 108) focused on subjective response and associated cognitive stress processes, while Study 2 (N = 168) tested fatigue effects on vehicle control and alertness. In both studies the 2 fatigue manipulations produced different patterns of subjective response reflecting different styles of workload regulation, appraisal, and coping. Active fatigue was associated with distress, overload, and heightened coping efforts, whereas passive fatigue corresponded to large-magnitude declines in task engagement, cognitive underload, and reduced challenge appraisal. Study 2 showed that only passive fatigue reduced alertness, operationalized as speed of braking and steering responses to an emergency event. Passive fatigue also increased crash probability, but did not affect a measure of vehicle control. Findings support theories that see fatigue as an outcome of strategies for managing workload. The distinction between active and passive fatigue is important for assessment of fatigue and for evaluating automated driving systems which may induce dangerous levels of passive fatigue.

Parkinson disease and driving: an evidence-based review

The growing literature on driving in Parkinson disease (PD) has shown that driving is impaired in PD compared to healthy comparison drivers. PD is a complex neurodegenerative disorder leading to motor, cognitive, and visual impairments, all of which can affect fitness to drive. In this review, we examined studies of driving performance (on-road tests and simulators) in PD for outcome measures and their predictors. We searched through various databases and found 25 (of 99) primary studies, all published in English. Using the American Academy of Neurology criteria, a study class of evidence was assigned (I-IV, I indicating the highest level of evidence) and recommendations were made (Level A: predictive or not; B: probably predictive or not; C: possibly predictive or not; U: no recommendations). From available Class II and III studies, we identified various cognitive, visual, and motor measures that met different levels of evidence (usually Level B or C) with respect to predicting on-road and simulated driving performance. Class I studies reporting Level A recommendations for definitive predictors of driving performance in drivers with PD are needed by policy makers and clinicians to develop evidence-based guidelines.

Visuospatial and Attentional Abilities Predict Driving Simulator Performance Among Older HIV-infected Adults

OBJECTIVES

To examine the effects of aging and neuropsychological (NP) impairment on driving simulator performance within a human immunodeficiency virus (HIV)-infected cohort.

METHODS

Participants included 79 HIV-infected adults (n = 58 > age 50, n = 21 ≤ 40) who completed a NP battery and a personnel computer-based driving simulator task. Outcome variables included total completion time (time) and number of city blocks to complete the task (blocks).

RESULTS

Compared to the younger group, the older group was less efficient in their route finding (blocks over optimum: 25.9 [20.1] vs 14.4 [16.9]; P = .02) and took longer to complete the task (time: 1297.6 [577.6] vs 804.4 [458.5] seconds; P = .001). Regression models within the older adult group indicated that visuospatial abilities (blocks: b = -0.40, P <.001; time: b = -0.40, P = .001) and attention (blocks: b = -0.49, P = .001; time: b = -0.42, P = .006) independently predicted simulator performance. The NP-impaired group performed more poorly on both time and blocks, compared to the NP normal group.

CONCLUSIONS

Older HIV-infected adults may be at risk of driving-related functional compromise secondary to HIV-associated neurocognitive decline.

Relationships between cognitive functions and driving behavior in Parkinson's disease

Alterations in cognitive functions in Parkinson's disease (PD) have been reported even in mild stages of the disease. These functions may play a role in complex daily activities, such as driving. This article provides an overview on the relationships between cognitive functions and driving behavior in PD in driving simulator and on-road studies. The role of attention, executive functions, visual memory, visuospatial construction and information processing speed is discussed. In driving simulator studies, driving performances were correlated with several neuropsychological measures, especially those of Trail Making Test (TMT), Brixton and Symbol Digit Modalities Test. In on-road studies, TMT, Useful Field Of View and Block Design tests appear as good predictors of driving performances. Most of these tests are also relevant to driving in Alzheimer's disease and traumatic brain injury.

Usefulness of Screening Tools for Predicting Driving Performance in People With Parkinson’s Disease

OBJECTIVE. We used screening tests administered by a certified driving rehabilitation specialist and by Parkinson’s disease (PD) specialty neurologists to develop a model to predict on-road outcomes for patients with PD.

METHOD. We administered a battery of screening tests to 41 patients with PD and 41 age-matched control participants before on-road testing. We used statistical models to predict actual on-road performance.

RESULTS. The PD group had a higher failure rate, indicating more on-road errors. For the PD participants, the Useful Field of View (UFOV) Subtest 2 and Rapid Pace Walk were responsible for most of the variance in the on-road test. The model accurately categorized pass–fail outcomes for 81% of PD patients.

CONCLUSION. Clinical screening batteries may be predictive of driving performance in PD. The UFOV Subtest 2, administered in approximately 15 min, may be the single most useful clinical test for such predictions.

Real-life driving outcomes in Parkinson disease

OBJECTIVE

To determine the incidence of and risk factors for driving outcomes in drivers with Parkinson disease (PD).

METHODS

In a prospective cohort study, we ascertained the time until driving cessation, a crash, or a traffic citation using self-report and state Department of Transportation records in 106 licensed, active drivers with PD and 130 controls.

RESULTS

Drivers with PD stopped driving earlier than controls, hazard ratio (95% confidence interval) = 7.09 (3.66-13.75), p < 0.001. Cumulative incidence of driving cessation at 2 years after baseline was 17.6% (11.5%-26.5%) for PD and 3.1% (1.2%-8.1%) for controls. No significant differences between groups on times to first crash or citation were detected. However, the number of observed crashes was low. Cox proportional hazards models showed that significant baseline risk factors for driving cessation in PD were older age, preference to be driven by somebody else, positive crash history, use of compensatory strategies, low driving exposure, impairments in visual perception (especially visual processing speed and attention) and cognitive abilities, parkinsonism (especially activities of daily living score and total daily dose of antiparkinsonian medications), and higher error counts on a road test. Within PD, crashes were associated with poorer postural stability and history of driving citations, and citations were associated with younger age and road errors at baseline.

CONCLUSIONS

Drivers with PD are at a higher risk of driving cessation than elderly control drivers. A battery evaluating motor and nonmotor aspects of PD, driving record, and performance can be useful in assessing future driving outcomes in PD.

Impact of external cue validity on driving performance in Parkinson's disease

This study sought to investigate the impact of external cue validity on simulated driving performance in 19 Parkinson's disease (PD) patients and 19 healthy age-matched controls. Braking points and distance between deceleration point and braking point were analysed for red traffic signals preceded either by Valid Cues (correctly predicting signal), Invalid Cues (incorrectly predicting signal), and No Cues. Results showed that PD drivers braked significantly later and travelled significantly further between deceleration and braking points compared with controls for Invalid and No-Cue conditions. No significant group differences were observed for driving performance in response to Valid Cues. The benefit of Valid Cues relative to Invalid Cues and No Cues was significantly greater for PD drivers compared with controls. Trail Making Test (B-A) scores correlated with driving performance for PDs only. These results highlight the importance of external cues and higher cognitive functioning for driving performance in mild to moderate PD.

Useful field of view as a reliable screening measure of driving performance in people with Parkinson's disease: results of a pilot study

PURPOSE

To determine the correlations of the Useful Field of View (UFOV), compared to other clinical tests of Parkinson's disease (PD); vision; and cognition with measures of on-road driving assessments and to quantify the UFOV's ability to indicate passing/failing an on-road test in people with PD.

METHODS

Nineteen randomly selected people with idiopathic PD, mean age = 74.8 (6.1), 14 (73.7%) men, 18 (94.7%) Caucasians, were age-matched to 104 controls without PD. The controls had a mean age of 75.4 (6.4), 59 (56.7%) men, 96 (92.3%) Caucasians. Both groups were referred for a driving evaluation after institutional review board approval.

RESULTS

Compared to neuropsychological and clinical tests of vision and cognition, the UFOV showed the strongest correlations (r > .75, p < 0.05) with measures of failing a standardized road test and number of driving errors. Among PD patients, the UFOV Risk Index score of 3 (range 1-5) was established as the optimal cutoff value for passing the on-road test, with sensitivity 87 percent and specificity 82 percent, AUC = 92 percent (SE 0.61, p = .002). Similarly, the UFOV 2 (divided attention) optimum cutoff value is 223 ms (range 16-500 ms), sensitivity 87.5 percent, specificity 81.8 percent, AUC = 91 percent (SE 0.73, p = .003). The UFOV 3 (selected attention) optimal cutoff value is 273 ms (range 16-500 ms), sensitivity 75 percent, specificity 72.7 percent, AUC = 87 percent (SE 0.81, p = .007).

CONCLUSION

In this pilot study among PD patients, the UFOV may be a superior screening measure (compared to other measures of disease, cognition, and vision) for predicting on-road driving performance but its rigor must be verified in a larger sample of people with PD.

Driving under low-contrast visibility conditions in Parkinson disease

OBJECTIVE

To assess driving performance in Parkinson disease (PD) under low-contrast visibility conditions.

METHODS

Licensed, active drivers with mild to moderate PD (n = 67, aged 66.2 +/- 9.0 years, median Hoehn-Yahr stage = 2) and controls (n = 51, aged 64.0 +/- 7.2 years) drove in a driving simulator under high- (clear sky) and low-contrast visibility (fog) conditions, leading up to an intersection where an incurring vehicle posed a crash risk in fog.

RESULTS

Drivers with PD had higher SD of lateral position (SDLP) and lane violation counts (LVC) than controls during fog (p < 0.001). Transition from high- to low-contrast visibility condition increased SDLP and LVC more in PD than in controls (p < 0.01). A larger proportion of drivers with PD crashed at the intersection in fog (76.1% vs 37.3%, p < 0.0001). The time to first reaction in response to incursion was longer in drivers with PD compared with controls (median 2.5 vs 2.0 seconds, p < 0.0001). Within the PD group, the strongest predictors of poor driving outcomes under low-contrast visibility conditions were worse scores on measures of visual processing speed and attention, motion perception, contrast sensitivity, visuospatial construction, motor speed, and activities of daily living score.

CONCLUSIONS

During driving simulation under low-contrast visibility conditions, drivers with Parkinson disease (PD) had poorer vehicle control and were at higher risk for crashes, which were primarily predicted by decreased visual perception and cognition; motor dysfunction also contributed. Our results suggest that drivers with PD may be at risk for unsafe driving in low-contrast visibility conditions such as during fog or twilight.

Driving and neurodegenerative diseases

The proportion of elderly people in the general population is rising, resulting in greater numbers of drivers with neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. These neurodegenerative disorders impair cognition, visual perception, and motor function, leading to reduced driver fitness and greater crash risk. Yet neither medical diagnosis nor age alone is reliable enough to predict driver safety or crashes or to revoke the driving privileges of these individuals. Driving research utilizes tools such as questionnaires about driving habits and history, driving simulators, standardized road tests utilizing instrumented vehicles, and state driving records. Research challenges include outlining the evolution of driving safety, understanding the mechanisms of driving impairment, and developing a reliable and efficient standardized test battery for prediction of driver safety in neurodegenerative disorders. This information will enable healthcare providers to advise their patients with neurodegenerative disorders with more certainty, affect policy, and help develop rehabilitative measures for driving.

Driving cessation and self-reported car crashes in older drivers: the impact of cognitive impairment and dementia in a population-based study

The complexity of driving activity has incited numerous developed countries to initiate evaluative procedures in elderly people, varying according to first evaluation age, frequency, and screening tools. The objective of this paper is to improve the knowledge of the driving cessation process regarding factors associated with crash involvement. Driving cessation and self-reported crashes during the past 5 years were analyzed with multivariate models, in a cross-sectional study including a population-based sample of 1051 drivers aged 65 years and more. Visual trouble, Parkinson disease, dementia, and stroke history were associated with driving cessation. Future dementia was associated with self-reported crashes only. Attentional and executive deficits were associated with both outcomes. The detection of attentional and executive deficits should be included in driving evaluation procedures to improve awareness of these deficits by older drivers.

Visual and cognitive predictors of driving safety in Parkinson's disease patients

This study assessed the clinical utility of contrast sensitivity (CS) relative to attention, executive function, and visuospatial abilities for predicting driving safety in participants with Parkinson's disease (PD). Twenty-five, non-demented PD patients completed measures of contrast sensitivity, visuospatial skills, executive functions, and attention. All PD participants also underwent a formal on-road driving evaluation. Of the 25 participants, 11 received a marginal or unsafe rating on the road test. Poorer driving performance was associated with worse performance on measures of CS, visuospatial constructions, set shifting, and attention. While impaired driving was associated with a range of cognitive and visual abilities, only a composite measure of executive functioning and visuospatial abilities, and not CS or attentional skills, predicted driving performance. These findings suggest that neuropsychological tests, which are multifactorial in nature and require visual perception and visual spatial judgments are the most useful screening measures for hazardous driving in PD patients.

Parkinson's disease and driving ability

OBJECTIVES

To explore the driving problems associated with Parkinson's disease (PD) and to ascertain whether any clinical features or tests predict driver safety.

METHODS

The driving ability of 154 individuals with PD referred to a driving assessment centre was determined by a combination of clinical tests, reaction times on a test rig and an in-car driving test.

RESULTS

The majority of cases (104, 66%) were able to continue driving although 46 individuals required an automatic transmission and 10 others needed car modifications. Ability to drive was predicted by the severity of physical disease, age, presence of other associated medical conditions, particularly dementia, duration of disease, brake reaction, time on a test rig and score on a driving test (all p<0.001). The level of drug treatment and the length of driving history were not correlated. Discriminant analysis revealed that the most important features in distinguishing safety to drive were severe physical disease (Hoehn and Yahr stage 3), reaction time, moderate disease associated with another medical condition and high score on car testing.

CONCLUSIONS

Most individuals with PD are safe to drive, although many benefit from car modifications or from using an automatic transmission. A combination of clinical tests and in-car driving assessment will establish safety to drive, and a number of clinical correlates can be shown to predict the likely outcome and may assist in the decision process. This is the largest series of consecutive patients seen at a driving assessment centre reported to date, and the first to devise a scoring system for on-road driving assessment.

Neuropsychological Function and Driving Ability in People with Parkinson's Disease

In this study the association between cognitive symptoms of PD and driving performance was investigated by examining the correlation between neuropsychological test performance and driving simulator behavior. Eighteen participants with PD and 18 healthy participants in a matched comparison group completed a range of neuropsychological measures. These data were correlated with driving simulator performance results from an earlier study. Significant correlations were found between several measures of neuropsychological test performance and driving behavior in participants with PD. In contrast, few significant correlations were obtained in the comparison group. Results suggest that executive difficulties in people with PD such as working memory, planning and set shifting are associated with reduced tactical level driving performance such as speed adaptation and complex curve navigation. Impaired information processing, visual attention and visual perception in people with PD appears associated with reduced operational level driving performance, such as reacting to road obstacles and maintaining constant lane position. Few correlations were found between measures of physical mobility and psychomotor speed with driving measures. Overall, this study highlights the important role of cognitive function in driving performance within the PD population. Comprehensive assessment of cognitive function should be included when assessing driving competency in people with PD.

Predictors of driving assessment outcome in Parkinson's disease

This study evaluated selected clinical and functional tests as predictors of driving safety outcomes in Parkinson's disease (PD) patients. A total of 25 PD patients and 21 age-matched controls, all regular drivers, underwent neurological evaluation and assessment of cognitive, visual, and motor function and a standardized, on-road driving assessment. The capacity of the tests to predict pass/fail driving outcomes was determined by selecting a subset with the highest predictive value from each domain and then subjecting these subsets to discriminant function analysis. Accuracy, sensitivity, specificity, and positive and negative predictive values were determined. Three relatively simple tests from the larger battery predicted passes with relatively high sensitivity (PD, 72.7%; controls, 93.8%; both combined, 85.2%); and moderate specificity (PD, 64.3%; controls, 60.0%; both combined. 63.2%). These tests assessed motor performance (Purdue Pegboard test), contrast sensitivity (Pelli-Robson test), and cognitive function (verbal version of Symbol Digit Modalities test). Adding time since diagnosis for the PD group increased sensitivity to 90.9% and specificity to 71.4%. These simple tests confer more objectivity and predictive power to clinical recommendations for driving, they reflect distinct functions that are necessary for safe driving, and they may be especially useful when on-road assessments are not feasible.

Impaired visual search in drivers with Parkinson's disease

OBJECTIVE

To assess the ability for visual search and recognition of roadside targets and safety errors during a landmark and traffic sign identification task in drivers with Parkinson's disease (PD).

METHODS

Seventy-nine drivers with PD and 151 neurologically normal older adults underwent a battery of visual, cognitive, and motor tests. The drivers were asked to report sightings of specific landmarks and traffic signs along a four-lane commercial strip during an experimental drive in an instrumented vehicle.

RESULTS

The drivers with PD identified significantly fewer landmarks and traffic signs, and they committed more at-fault safety errors during the task than control subjects, even after adjusting for baseline errors. Within the PD group, the most important predictors of landmark and traffic sign identification rate were performances on Useful Field of View (visual speed of processing and attention) and Complex Figure Test-Copy (visuospatial abilities). Trail Making Test (B-A), a measure of cognitive flexibility independent of motor function, was the only independent predictor of at-fault safety errors in drivers with PD.

INTERPRETATION

The cognitive and visual deficits associated with PD resulted in impaired visual search while driving, and the increased cognitive load during this task worsened their driving safety.

Effect of a concurrent task on driving performance in people with Parkinson's disease

Numerous studies previously have reported reduced driving performance in people with Parkinson's disease (PD). Few studies to date, however, have examined how specific cognitive difficulties associated with PD impact on specific aspects of driving performance in this population. In this study, the impact of a concurrent task on driving performance was examined. A simulator was used to measure the driving behavior of 18 current drivers with PD and 18 matched controls. The presence of a concurrent task was manipulated between conditions. Results showed that, although groups were similarly affected by the concurrent task on most driving measures, participants with PD were disproportionately affected on operational level driving behavior. It also appears that participants with PD sacrificed concurrent task performance to maintain driving performance. These results further support the hypothesis that cognitive difficulties associated with PD compromise driving performance in this population, even in the mild to moderate stages of the disease.

Neuropsychological deficits associated with driving performance in Parkinson's and Alzheimer's disease

Neuropsychological and motor deficits in Parkinson's disease that may contribute to driving impairment were examined in a cohort study comparing patients with Parkinson's disease (PD) to patients with Alzheimer's disease (AD) and to healthy elderly controls. Nondemented individuals with Parkinson's disease [Hoehn & Yahr (H&Y) stage I-III], patients with Alzheimer's disease [Clinical Demetia Rating scale (CDR) range 0-1], and elderly controls, who were actively driving, completed a neuropsychological battery and a standardized road test administered by a professional driving instructor. On-road driving ability was rated on number of driving errors and a global rating of safe, marginal, or unsafe. Overall, Alzheimer's patients were more impaired drivers than Parkinson's patients. Parkinson's patients distinguished themselves from other drivers by a head-turning deficiency. Drivers with neuropsychological impairment were more likely to be unsafe drivers in both disease groups compared to controls. Compared to controls, unsafe drivers with Alzheimer's disease were impaired across all neuropsychological measures except finger tapping. Driving performance in Parkinson's patients was related to disease severity (H&Y), neuropsychological measures [Rey Osterreith Complex Figure (ROCF), Trails B, Hopkins Verbal List Learning Test (HVLT)-delay], and specific motor symptoms (axial rigidity, postural instability), but not to the Unified Parkinson Disease Rating Scale (UPDRS) motor score. Multifactorial measures (ROCF, Trails B) were useful in distinguishing safe from unsafe drivers in both patient groups.

Neuropsychological deficits associated with driving performance in Parkinson's and Alzheimer's disease

Neuropsychological and motor deficits in Parkinson's disease that may contribute to driving impairment were examined in a cohort study comparing patients with Parkinson's disease (PD) to patients with Alzheimer's disease (AD) and to healthy elderly controls. Nondemented individuals with Parkinson's disease [Hoehn & Yahr (H&Y) stage I-III], patients with Alzheimer's disease [Clinical Demetia Rating scale (CDR) range 0-1], and elderly controls, who were actively driving, completed a neuropsychological battery and a standardized road test administered by a professional driving instructor. On-road driving ability was rated on number of driving errors and a global rating of safe, marginal, or unsafe. Overall, Alzheimer's patients were more impaired drivers than Parkinson's patients. Parkinson's patients distinguished themselves from other drivers by a head-turning deficiency. Drivers with neuropsychological impairment were more likely to be unsafe drivers in both disease groups compared to controls. Compared to controls, unsafe drivers with Alzheimer's disease were impaired across all neuropsychological measures except finger tapping. Driving performance in Parkinson's patients was related to disease severity (H&Y), neuropsychological measures [Rey Osterreith Complex Figure (ROCF), Trails B, Hopkins Verbal List Learning Test (HVLT)-delay], and specific motor symptoms (axial rigidity, postural instability), but not to the Unified Parkinson Disease Rating Scale (UPDRS) motor score. Multifactorial measures (ROCF, Trails B) were useful in distinguishing safe from unsafe drivers in both patient groups.

La conduite automobile chez les sujets âgés

Impairment of cognitive performance is associated with an excess risk of accidents. Adaptation of driving behavior in subjects with benign cognitive disorders reduces risk of automobile accidents. Cessation of driving or at least not driving alone limits the excess accident risk for drivers with dementia. Alterations in visual field and acuity increase risk of traffic accidents. Drugs affecting vigilance and neurological, cardiovascular and osteoarticular disorders increase accident risk. Screening for these disorders in the elderly is a necessary public safety measure.

Quantitative assessment of driving performance in Parkinson's disease

OBJECTIVES

The primary aim of this study was to determine how Parkinson's disease (PD) affects driving performance. It also examined whether changes in driver safety were related to specific clinical disease markers or an individual's self rating of driving ability.

METHODS

The driving performance of 25 patients with idiopathic PD and 21 age matched controls was assessed on a standardised open road route by an occupational therapist and driving instructor, to provide overall safety ratings and specific driving error scores.

RESULTS

The drivers with PD were rated as significantly less safe (p<0.05) than controls, and more than half of the drivers with PD would not have passed a state based driving test. The driver safety ratings were more strongly related to disease duration (r = -0.60) than to their on time Unified Parkinson's Disease Rating Scale (r = -0.24). Drivers with PD made significantly more errors than the control group during manoeuvres that involved changing lanes and lane keeping, monitoring their blind spot, reversing, car parking, and traffic light controlled intersections. The driving instructor also had to intervene to avoid an incident significantly more often for drivers with PD than for controls. Interestingly, driver safety ratings were unrelated to an individual's rating of their own driving performance, and this was the case for all participants.

CONCLUSIONS

As a group, drivers with PD are less safe to drive than age matched controls. Standard clinical markers cannot reliably predict driver safety. Further studies are required to ascertain whether the identified driving difficulties can be ameliorated.

Driving in Parkinson's disease: Mobility, accidents, and sudden onset of sleep at the wheel

Only few studies have addressed driving ability in Parkinson's disease (PD) to date. However, studies investigating accident proneness of PD patients are urgently needed in the light of motor disability in PD and--particularly--the report of "sleep attacks" at the wheel. We sent a questionnaire about sudden onset of sleep (SOS) and driving behavior to 12,000 PD patients. Subsequently, of 6,620 complete data sets, 361 patients were interviewed by phone. A total of 82% of those 6,620 patients held a driving license, and 60% of them still participated in traffic. Of the patients holding a driving license, 15% had been involved in and 11% had caused at least one accident during the past 5 years. The risk of causing accidents was significantly increased for patients who felt moderately impaired by PD, had an increased Epworth Sleepiness Scale (ESS) score, and had experienced SOS while driving. Sleep attacks at the wheel usually occurred in easy driving situations and resulted in typical fatigue-related accidents. Those having retired from driving had a more advanced (subjective) disease severity, higher age, more frequently female gender, an increased ESS score, and a longer disease duration. The study revealed SOS and daytime sleepiness as critical factors for traffic safety in addition to motor disabilities of PD patients. The results suggest that real sleep attacks without any prior sleepiness are rare. However, our data underline the importance of mobility for patients and the need for further studies addressing the ability to drive in PD.

Impact of internal versus external cueing on driving performance in people with Parkinson's disease

Numerous aspects of driving performance seem compromised in people with Parkinson's disease (PD). Measures of cognitive impairment consistently correlate with poor driving simulator performance in this population; however, the effects of specific cognitive difficulties on discrete aspects of driving behavior have not been investigated thoroughly. Previous studies have demonstrated that people with PD exhibit difficulties internally cueing cognitive processes. This study examined the impact of impaired internal cueing on specific driving behaviors. A simulator measured the driving behavior of 18 current drivers in the mild-to-moderate stages of PD and 18 matched controls. Participants navigated through different driving conditions where the opportunity to use internal and external cues was manipulated. People with PD exhibited difficulties using internal cues to regulate driving behavior around traffic signals and curves. Instead of using internal cues, participants with PD were more reliant on external cues to regulate driving behavior. They were also less able to adapt their driving behavior to suit driving conditions. Because all participants with PD were current drivers in the mild-to-moderate stages of the disease, findings challenge the widely-held assumption that cognitive difficulties only impact on driving performance in the moderate-to-severe stages of PD.

The effects of cognitive abilities on driving in people with Parkinson's disease

OBJECTIVE

The aim was to develop a cognitive screening procedure, which could be used to identify cognitive problems in patients with Parkinson's disease, which might affect their safety to drive.

DESIGN

Two group comparison of those found safe to drive and those found unsafe.

SETTING

People living in the community who were attending an outpatient Movement Disorders clinic or who had been referred to a Regional Mobility Centre.

PARTICIPANTS

Fifty-one people with Parkinson's disease who were driving or who wished to resume driving. The 41 men and 10 women were aged 44 - 85 years (mean 64.4 SD 9.1).

MAIN MEASURES

Webster's Rating Scale, Unified Parkinson's Disease Rating Scale motor examination, Stroke Drivers Screening Assessment, Adult Memory and Information Processing Battery, Stroop, Paced Auditory Serial Addition Task and a Tapping task.

RESULTS

The unsafe drivers were significantly more disabled, as assessed on Webster's Scale, than those who were found safe to drive. There were no significant differences in the cognitive abilities of safe and unsafe drivers. The most common faults, which caused drivers to be judged unsafe, were lack of observations to the side at junctions, poor positioning on the road and poor driving on roundabouts. There were significant correlations (p < 0.05) between driving ability and performance on the SDSA Dot Cancellation task and the AMIPB Story Recall and Information Processing A.

CONCLUSIONS

Cognitive abilities were not found to be associated with fitness to drive in people with Parkinson's disease. Webster's Rating Scale differentiated between safe and unsafe drivers. This could be used to determine who to refer to a mobility centre for advice on fitness to drive.