Driving, Dementia and Brainscreen

Konstantine K. Zakzanis, Ph.D., C.Psych

Dementia is an acquired syndrome of intellectual impairment produced by brain dysfunction (e.g., Alzheimer’s disease). Its prevalence is rapidly increasing, and adequate care of the burgeoning population of demented individuals require a knowledgeable approach to diagnosis and management.

Operationally, dementia can be defined as an acquired persistent impairment of intellectual function with compromise in at least three of the following spheres of mental activity: language, memory, visuospatial skills, emotion or personality, and cognition (abstraction, calculation, judgment, executive function and so forth). This definition is based on evaluation of disturbances that are readily testable using neuropsychological testing.

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. Recent epidemiological studies demonstrate that the number of senior drivers will increase from just under 500 000 in 1986 to nearly 2 500 000 in 2028. Consequently, the number of drivers with dementia will increase. Although not all drivers with dementia are necessarily dangerous, most are estimated to continue driving well into the disease process. Increasingly, the responsibility for identifying drivers with dementia has fallen on the health care system, a role for which it was never designed nor equipped to handle. The risks associated with the dramatically increasing number of drivers with dementia demand a psychometrically sensitive and efficient screening procedure. At the same time, The Ministry of Transportation does not require any required remedial driver testing until age 80. Nonetheless such testing does not screen for dementia deficits related to driving or any population exhibiting possible deficits under the age of 80.

Given that the mean age of onset is approximately 65 for various dementia syndromes, it is important to stress that 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.

A prerequisite for driving is the integration of high-level cognitive functions with perception and motor function. Ageing, per se, does not necessarily impair driving or increase the crash risk. However, medical conditions, such as cognitive impairment and dementia, as noted, become more prevalent with advancing age and may contribute to poor driving and an increased crash risk. The extent to which driving skills are impaired depends on the cause of dementia, disease severity, other co-morbidities and individual compensation strategies. Dementia often remains undiagnosed and therefore general practitioners (GPs) can find themselves in the difficult situation to disclose a suspicion about cognitive impairment and queries about medical fitness to drive, at the same time. In addition, the literature suggests that cognitive screening tests, most commonly used by GPs, have a limited role in judging whether an older person remains fit to drive.

Diagnosing dementia is not to be equated with absolute driving inability. During the course of dementia, the risk of an accident increases significantly. Detailed observation and regular testing using Brainscreen serve to determine the appropriate time to surrender one’s driving licence. The basis of each decision should be a detailed history of the person and his or her immediate family coupled with objective test resutls. Attention should be paid to incorrect driving practise, unusual behaviour and uncertainty whilst driving as well as involvement in any accidents.

A Brainscreen score below a specific threshold should result in an additional assessment being carried out, e.g. complete and thorough neuropsychological tests, driving simulator or, if necessary on-road tests performed with specialists. Also helpful is the determination of functional status. Limitations in activities of daily living normally indicate an advanced stage of dementia. Due to the progression of the illness, the possibility of surrendering in the driving licence should be addressed as soon as possible. In this context, it is helpful to consider alternative forms of transportation. Individual wishes and needs must to be balanced against general road safety requirements.

In sum, given the rapidly increasing incidence of dementia, it has been called an approaching epidemic and deluge. These alarmist terms appear justified when it is realized that most dementias are found in people over the age of 65 years (or earlier) and that the elderly population is increasing rapidly in both absolute numbers and percentage of the population. All studies to date concur that dementia is a major problem among the elderly and will be an even larger public health concern as the size of the aged population increases. Early identification using Brainscreen and may provide the individual, family of, care giver, and purveyor of benefit with valuable information that can be used to guide decision making regarding fitness to drive throughout the progressive course of the disorder.