Attention and driving performance in Alzheimer's disease

The present study examined the relationship between visual attention measures and driving performance in healthy older adults and individuals with very mild and mild dementia of the Alzheimer type (DAT). Subjects were administered an on-road driving assessment and three visual attention tasks (visual search, visual monitoring, and useful field of view). The results indicated that error rate and reaction time during visual search were the best predictors of driving performance. Furthermore, visual search performance was predictive of driving performance above and beyond simple dementia severity and several traditional psychometric tests. The results suggest that general cognitive status may be useful for identifying individuals "at risk" for unsafe driving. However, measures of selective attention may serve to better differentiate safe versus unsafe drivers, especially in the DAT population.     

An overview of the older driver

Although MVC rates are not substantially higher among older drivers after adjusting for mileage and may even be lower, the crash risk of the elderly driver remains a matter of increasing public concern. In part this is due to media attention over isolated cases of fatal MVCs involving older drivers, occasionally with a demented driver. This media attention has led to growing apprehension over the issue of elderly drivers. Physicians are likely to be involved increasingly in the evaluation of older drivers, whether they want to or not. The physician's quandary is the competing interests of the patient's well-being (i.e., continued independence), and the public's welfare (i.e., protection from impaired drivers). Unfortunately, there are no certain guidelines to protect the physician from liability for either of these conflicting duties. At issue is the foreseeability of harm from an elderly driver, either to self or to others. What degree of impairment is necessary before a physician is bound to report a patient to authorities? Although there are no clear answers, the best advice is to follow clinical judgment. One suggestion is to consider the diagnosis as suitable evidence. Thus, if the patient has a dementing illness of sufficient severity to warrant documentation in the medical record as a diagnosis, then perhaps the physician should consider advising the patient not to drive; reporting the patient to the appropriate authorities would be left to the physician's discretion after consultation with the patient's family. This might have the added benefit of obliging physicians to think twice before mislabeling patients with benign forgetfullness as demented, an all-too-frequent phenomenon. In this weighty ethical decision, it is critical for physicians to consider the consequences of removal of driving privileges from their elderly patients as well as their duty to protect the public health. Neither should be taken lightly. Above all else, physicians should not forsake their responsibility for advising either patients or the public regarding the driving privilege. To do so would simply relinquish the decision-making to those without clinical training or evaluative skills relevant to driving tasks. The physician's role in the evaluation of the elderly driver should be regarded as a pivotal challenge in the complicated management of the health of the elderly population.     

Simulated car crashes and crash predictors in drivers with Alzheimer disease

BACKGROUND: Alzheimer disease (AD) is the most common cause of dementia and can impair cognitive abilities crucial to the task of driving. Rational decisions about whether such impaired individuals should continue to drive require objective assessments of driver performance. OBJECTIVE: To measure relevant performance factors using high-fidelity driving simulation. DESIGN: We examined the effect of AD on driver collision avoidance using the Iowa Driving Simulator, which provided a high-fidelity, closely controlled environment in which to observe serious errors by at-risk drivers. We determined how such unsafe events are predicted by visual and cognitive factors sensitive to decline in aging and AD. SETTING: The University of Iowa Hospitals and Clinics, Iowa City, and the Iowa Driving Simulator. PARTICIPANTS: Thirty-nine licensed drivers: 21 with AD and 18 controls without dementia. MAIN OUTCOME MEASURES: We determined the number of crashes and related performance errors and analyzed how these occurrences were predicted by visual and cognitive factors. RESULTS: Six participants (29%) with AD experienced crashes vs 0 of 18 control participants (P = .022). Drivers with AD were more than twice as likely to experience close calls (P = .042). Plots of critical control factors in the moments preceding a crash revealed patterns of driver in-attention and error. Strong predictors of crashes included visuospatial impairment, reduction in the useful field of view, and reduced perception of 3-dimensional structure-from-motion. CONCLUSIONS: High-fidelity driving simulation provides a unique new source of performance parameters to standardize the assessment of driver fitness. Detailed observations of crashes and other safety errors provide unbiased evidence to aid in the difficult clinical decision of whether older or medically impaired individuals should continue to drive. The findings are complementary to evidence currently being gathered using techniques from epidemiology and cognitive neuroscience.     

Ethical and Patient Management Issues With Older, Impaired Drivers.

As the population of America ages, psychologists will be treating more older adults who are, or are at risk of becoming, impaired drivers. Consequently, psychologists will need to address the issue of driving impairment with many of their patients. Although psychologists should generally respect the autonomy of patients to determine the direction and nature of treatment, their concern for patient and public welfare caused by driving impairments may sometimes override respect for patient autonomy. This article suggests ways to protect patient and public welfare while minimizing the infringement on patient autonomy. Relevant clinical features and a decision making process are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chronological age and age-related cognitive deficits are associated with an increase in multiple types of driving errors in late life.

Objective: Older driver research has mostly focused on identifying that small proportion of older drivers who are unsafe. Little is known about how normal cognitive changes in aging affect driving in the wider population of adults who drive regularly. We evaluated the association of cognitive function and age with driving errors. Method: A sample of 266 drivers aged 70 to 88 years were assessed on abilities that decline in normal aging (visual attention, processing speed, inhibition, reaction time, task switching) and the UFOV?, which is a validated screening instrument for older drivers. Participants completed an on-road driving test. Generalized linear models were used to estimate the associations of cognitive factors with specific driving errors and number of errors in self-directed and instructor navigated conditions. Results: All error types increased with chronological age. Reaction time was not associated with driving errors in multivariate analyses. A cognitive factor measuring speeded selective attention and switching was uniquely associated with the most errors types. The UFOV? predicted blind-spot errors and errors on dual carriageways. After adjusting for age, education, and gender, the cognitive factors explained 7% of variance in the total number of errors in the instructor-navigated condition and 4% of variance in the self-navigated condition. Conclusion: We conclude that among older drivers, errors increase with age and are associated with speeded selective attention, particularly when that requires attending to the stimuli in the periphery of the visual field, task switching, errors inhibiting responses, and visual discrimination. These abilities should be the target of cognitive training. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Self-regulation of driving in the context of impaired visual attention: Are there gender differences?

Purpose: To investigate whether older men and women differ in self-regulation of driving in the context of objective visual-attention impairments. Method: Participants were 1,543 drivers aged 75 years or older who participated in a state-wide study. They completed an objective measure of visual attention and self-report measures of driving habits and functional status. Crash records were obtained from the state department of public safety. Results: Overall, women reported greater avoidance of difficult driving situations than did men, and drivers with impaired visual attention reported greater driving avoidance than did nonimpaired drivers. However, men were at least as likely as women to modify their driving in the context of impaired visual attention. Conclusion: Gender disparity in self-restriction of driving may not be due to gender differences in risk taking. It is necessary to consider factors associated with restricted driving among older adults because of their susceptibility to mobility compromise. Interventions for improving visual attention and self-regulation of driving may be effective in extending the years of autonomous driving without jeopardizing the safety of the community. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Treatment of duck hepatitis B virus by antisense poly-2''-O-(2,4-dinitrophenyl)-oligoribonucleotides

This study sought the opinions of a select group of professionals, trained in medicine and law concerning: professional privilege; management of patients who posed risks to society; and the legal charge to impose upon a patient with uncontrolled epilepsy who caused a fatality by driving contrary to medical advice. The second Academic Seminar of the Australian College of Legal Medicine was surveyed to define demographics and opinions. Of 23 respondents, 14 were trained in law and medicine, of whom eight had post graduate medical qualifications and seven had more than basic legal training; 20/23 supported professional privilege in medicine but 18/23 denied its absoluteness; 22/23 felt the doctor had a right to divulge information in the public interest. Only 14/23 (although still a majority opinion) felt this right was a duty and 6/23 refuted the same. When concerned regarding compliance not to drive, 7/23 would discuss it with family/friends in contravention of patient consent, 12/23 would report to the driving authorities where concern became fact, 13/23 would advise the patient that a report would be sent, 4/23 would report without the patient's knowledge and four would threaten but not send the report. In the case of a fatality consequent to non-compliance, 10/23 considered murder and 22/23 considered manslaughter charges to be appropriate. The majority supported professional privilege in the doctor/patient relationship but also supported the right or even a duty to report risks to society. Where a concern arose that a patient with epilepsy may drive contrary to advice, one-third of doctors would discuss with family/friends, without consent, one-half would report the patient to the driving authorities, while almost three-quarters would report the patient if concern was realised. Murder and manslaughter, serious charges, were deemed appropriate for patients who caused death by driving against medical advice.     

An examination of driving records in a dementia clinic

The driving records of 249 persons referred to an outpatient dementia clinic were examined retrospectively to assess the specificity of the association between diagnosed dementia and increased traffic accidents. The clinic patients were divided into two groups: those who met criteria for dementia and those who did not. For each group, control subjects matched on age, gender, and location of residence were randomly selected from the records of all drivers in the province. The dementia sample had approximately 2.5 times the traffic crash rate of their matched control sample. The not-demented sample had approximately 2.2 times the traffic crash rate of their matched control sample. These individuals exhibited a variety of psychiatric, neurological, and medical conditions which could have affected their driving, and multiple medical problems were often present. Further clarification of the characteristics of "high risk" drivers is required if effective strategies for maximizing independence while minimizing the risk of traffic crashes are to be realized.     

The risks of licensing persons with diabetes to drive trucks

The 1990 Americans with Disabilities Act forbids employers to bar disabled persons from jobs unless employers can show the disabled person cannot perform the tasks. The Federal Highway Administration will not license persons with diabetes mellitus to drive commercial motor vehicles in interstate commerce. These individuals may experience severe hypoglycemia, greatly increasing their risk of losing control of the truck. This prohibition is currently being reexamined. We describe the disease process leading to severe hypoglycemia and its physical manifestations. To quantify the risks of licensing persons with diabetes to use insulin, we first estimate the number of potential insulin-using drivers. We estimate that 1420 insulin-using persons would seek licenses in the United States if they were permitted to do so (920 noninsulin dependent and 500 insulin dependent). Next, we estimate the annual incidence of mild and severe hypoglycemia in these populations. The third step is to estimate the number of hypoglycemic episodes while driving. Estimating the likelihood of a crash due to a mild or severe hypoglycemic episode is the fourth step. We estimate that an additional 42 crashes each year would occur if insulin using persons were licensed to drive commercial motor vehicles in interstate commerce (20 from insulin dependent and 22 from non-insulin dependent drivers).     

Do older drivers with visual and cognitive impairments drive less?

OBJECTIVE: To determine whether older drivers with poorer cognitive and/or visual function drive fewer miles or avoid driving in situations that pose higher crash risks, such as at nighttime, in rush hour traffic, or when weather conditions are bad. DESIGN: A cross-sectional data analysis conducted as part of a larger prospective study. SUBJECTS: A total of 3238 drivers aged 65 and older applying for renewal of their driver's license at one of eight participating North Carolina driver's license offices. MEASUREMENTS: Subjects were administered a battery of brief tests of cognitive and visual function, which included the Trail Making Test Parts A and B, the Short Blessed Orientation-Memory-Concentration test, and measures of high and low contrast visual acuity, contrast sensitivity, and peripheral vision. Participants were also asked to complete a brief driving survey containing questions about the number of miles they drove and whether they avoided driving under certain conditions, such as after dark or on busy, multi-lane roadways. Driver age and gender were covariates in the analyses. RESULTS: Results of multivariate logistic regression models show a clear pattern of reduced driving exposure--lower annual miles and greater avoidance of high-risk driving situations--associated with lower levels of cognitive and visual function. In general, the prevalence odds of reduced driving exposure were higher for the cognitive function variables than for the visual function variables, and higher for males than for females. Men who scored in the lowest quartile of performance on one of the cognitive tests were six to seven times more likely to report driving fewer than 3000 miles a year than were men scoring in the highest quartile, and women with low scores were one-and-one-half to two times more likely to report driving less than 3000 miles than women with higher scores. CONCLUSIONS: While the findings of this study are reassuring, they do not guarantee that all drivers with cognitive and visual impairments are limiting their driving exposure appropriately, and geriatricians and other health professionals should be encouraged to evaluate their patients' cognitive and visual fitness for driving and provide counsel where indicated.     

Effects of cardiovascular disease on driving tasks

Heart disease, even in the elderly individual, need not preclude driving; however, safety for the patient and the public is dependent on close cooperation between the patient and the physician. The patient with ischemic heart disease must be in a stable condition wherein the risk of sudden incapacitation is acceptably low. The physician must take into consideration not only the symptom history, but also the potential impact of concomitant illnesses, devices (e.g., pacemakers), and medications. The patient with congestive heart failure must be assessed for functional ability. Where there is doubt about a subjective report, a practical road test may be advisable. Consideration also should be given to limited driving under preset conditions, such as daytime only, or local roads (excluding highways). Many elderly drivers already limit their driving in such a fashion. Finally, it should be realized that a driving permit is a means to independent mobility. Where heart disease precludes driving and personal transportation is not available, physicians should advise and support their patients to obtain paratransport services where communities offer such services for otherwise immobile citizens.     

Driving patterns and medical conditions in older women

OBJECTIVES: To describe driving patterns (e.g., driving frequency) in older women drivers and to evaluate the impact of medical conditions and comorbidity on driving patterns. DESIGN: Cross-sectional examination of the association between medical conditions and driving patterns. SETTING: Population-based cohort from the Pittsburgh Center of the Study of Osteoporotic Fractures (SOF). PARTICIPANTS: A total of 1768 women aged 71 years or older. MAIN MEASUREMENTS: Driving information was obtained through a driving questionnaire, including driving status, weekly mileage, longest trip in the past year, etc. Data for demographics, lifestyle behavior, and medical conditions were collected through the SOF study. RESULTS: Among the participants, 1103 (62.3%) were current drivers, 337 (19.1%) had stopped driving, and 329 (18.6%) had never driven in their lifetime. The proportion reporting driving cessation and decline in driving amount increased with age. The prevalence of most medical conditions was higher among former drivers than in current or never drivers. Even after controlling for age and other demographic variables, fractures, heart disease, diabetes, self-reported poor vision or hearing, as well as comorbidity were found to be associated independently with decreased driving amount, including driving cessation, decline in mileage, and avoiding long trips. CONCLUSION: Both individual medical conditions and comorbidity influence driving patterns in older drivers. Because it is common for older people to have several medical conditions simultaneously, comorbidity might be a more comprehensive measure of medical impact on driving.     

Effects of age, system experience, and navigation technique on driving with an advanced traveler information system

This paper explores the effects of age, system experience, and navigation technique on driving, navigation performance, and safety for drivers who used TravTek, an Advanced Traveler Information System. The first two studies investigated various route guidance configurations on the road in a specially equipped instrumented vehicle with an experimenter present. The third was a naturalistic quasi-experimental field study that collected data unobtrusively from more than 1200 TravTek rental car drivers with no in-vehicle experimenter. The results suggest that with increased experience, drivers become familiar with the system and develop strategies for substantially more efficient and safer use. The results also showed that drivers over age 65 had difficulty driving and navigating concurrently. They compensated by driving slowly and more cautiously. Despite this increased caution, older drivers made more safety-related errors than did younger drivers. The results also showed that older drivers benefited substantially from a well-designed ATIS driver interface.     

Driving after concussion: The acute effect of mild traumatic brain injury on drivers' hazard perception.

Objective: No research has examined whether individuals recovering from a recent mild traumatic brain injury (MTBI) are safe to drive, despite cognitive impairment being a common consequence soon after MTBI. This study examined the acute effect of MTBI on drivers' hazard perception, which is defined as drivers' ability to search the road ahead to rapidly identify potentially dangerous traffic situations. Poorer hazard perception has been associated with higher crash rates in a number of studies. Method: Forty-two patients with MTBI and 43 patients with minor orthopedic injuries were recruited from the emergency department of a large metropolitan hospital within 24 hours of injury. Participants completed a computerized hazard perception test, in which they watched videos of genuine traffic scenes filmed from the driver's point of view. They were required to use the computer mouse to click on potential traffic hazards as early as possible. Results: Participants with MTBI were significantly slower to respond to traffic hazards than participants with minor orthopedic injuries (p = .03, d = .48). Conclusions: This study provides the first indication that within the acute stage postinjury, MTBI is associated with impairment in a crash-related component of driving. This suggests that patients with MTBI should be advised to refrain from driving for at least the first 24 hours' postinjury. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incidence and determinants of poststroke dementia as defined by an informant interview method in a hospital-based stroke registry

BACKGROUND and PURPOSE: Inconsistent information about incidence and determinants of poststroke dementia might be related to patient attrition, partly because of nonapplicability of formal neuropsychological testing to a large proportion of patients registered in a definite setting. METHODS: Using a proxy-informant interview based on ICD-10 criteria, we determined dementia at stroke onset and 1 year after stroke in the 339 patients who survived, were available for follow-up, and were not demented at stroke onset of 635 patients entered over a 1-year period in a stroke registry taken at 2 community hospitals in Florence, Italy. RESULTS: Of the 339 patients, 57 (16.8%) proved to have poststroke dementia. These patients were older, more frequently female, and more often (multivariate odds ratio, 2.35; 95% CI, 1.21 to 4.58) had atrial fibrillation than those without dementia. Aphasia and the clinical features expressing the severity of the stroke event in the acute phase predicted poststroke dementia. CONCLUSIONS: In a hospital-based nonselected series of stroke survivors, despite the use of a method with low sensitivity for defining dementia, our study confirms that dementia is a frequent sequela of stroke and is mainly predicted by stroke severity. Certain determinants could be controlled in the prestroke phase, thus reducing its risk.     

Alternate finger tapping test in patients with migraine

Out of 2494 subjects screened in a Nigerian community, 28 patients with dementia were identified. Alzheimer's disease was diagnosed in 18 patients (64.3%), 16 of whom had probable Alzheimer's disease. Eight patients (28.6%) had vascular dementia while one patient each had parkinsonism with dementia and depression with dementia. Patients with Alzheimer's disease were significantly older, predominantly females and illiterates. Cognitive deficit commonly took the form of memory and judgment impairment while financial mismanagement was the most frequent impaired activity of daily living. More than half of the cases had mild disease on severity rating and were comprised mainly of Alzheimer's disease subjects. These results confirm the higher frequency of Alzheimer's disease over the other types as reported in other communities.     

Different storage and retrieval deficits in normal aging and mild cognitive impairment: A multinomial modeling analysis.

The authors compared patients with mild cognitive impairment with healthy older adults and young control participants in a free recall test in order to locate potential qualitative differences in normal and pathological memory decline. Analysis with an extended multitrial version of W. H. Batchelder and D. M. Riefer's (1980) pair-clustering model revealed globally decelerated learning and an additional retrieval deficit in patients with mild cognitive impairment but not in healthy older adults. Results thus suggest differences in memory decline between normal and pathological aging that may be useful for the detection of risk groups for dementia, and they illustrate the value of model-based disentangling of processes and of multitrial tests for early detection of dementia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychopathology in younger versus older persons with very mild and mild dementia of the Alzheimer type

OBJECTIVE: The psychopathology associated with early-onset dementia of the Alzheimer type was investigated by comparing the prevalence of psychiatric symptoms in younger subjects (mean age = 59 years) who had very mild or mild dementia with that in older adults (mean age = 72) whose dementia was of equivalent severity. METHOD: Nondemented comparison subjects and persons with very mild or mild dementia of the Alzheimer type were recruited to participate in longitudinal studies. All subjects met strict inclusion and exclusion criteria. Information pertaining to personality changes, affective symptoms, and psychotic symptoms was included in the 90-minute semistructured, physician-administered interview, which was used to assign a clinical dementia rating according to published guidelines. The younger group were age 64 or younger and consisted of 20 nondemented subjects, 11 subjects with very mild dementia, and 18 subjects with mild dementia. The older group, described previously, were 64-83 years old and consisted of 83 nondemented subjects, 41 persons with very mild dementia, and 68 subjects with mild dementia. RESULTS: The psychopathology in the younger subjects was similar to that in the older group. Personality changes occurred in over 80% of the younger persons with very mild illness. Psychotic symptoms were present in over 40% of the younger persons with mild illness but were rare in the group with very mild dementia. CONCLUSIONS: Similar patterns of psychopathology in younger and more elderly persons with dementia of the Alzheimer type support the suggestion that these changes are direct effects of the illness on the CNS. Increased attention to documenting these noncognitive symptoms and studying various treatments is urgently needed.     

Metabolic encephalopathy as a complication of renal failure: mechanisms and mediators

Among patients with end-stage renal disease, nervous system dysfunction remains a major cause of disability. Patients with chronic renal failure who have not yet received dialysis may develop symptoms ranging from mild sensorial clouding to delirium and coma. Dialysis itself is associated with at least three distinct disorders of the CNS: dialysis disequilibrium syndrome; dialysis dementia; and progressive intellectual dysfunction. Peripheral neuropathy is also a major cause of disability in uremic subjects. It is believed that aluminum contributes to the pathogenesis of dialysis dementia. Biochemically, brain calcium is elevated in patients with renal failure, probably because of actions of parathyroid hormone on the brain. The diagnosis of dialysis disequilibrium syndrome, intellectual dysfunction, dialysis dementia, and uremic neuropathy can be made by the characteristic clinical pictures of these syndromes and the exclusion of other causes of nervous system dysfunction.     

The duration of response to norgestimate and ethinyl estradiol in the treatment of acne vulgaris

Cost drivers in the treatment of full-thickness pressure sores were identified from the literature, Medicare data tapes and interviews with health-care providers. The following were identified as cost drivers in pressure sore treatment: nursing time related to wound care; nursing time devoted to patient position changes; dressing products; patient support devices; antibiotics; room charges for nursing home care; doctor visits for nursing home and home care patients; surgical debridement for nursing home and home care patients; hospital admissions for medical treatment for pressure sores; admissions for surgical treatment for pressure sores; and additional costs for hospital stays when patients who are admitted for other diagnoses develop sores. These cost drivers may be useful to health-care providers in developing cost-effective strategies for treating and preventing pressure sores.