Driving Performance and Its Correlation with Neuropsychological Tests in Senior Drivers with Cognitive Impairment in Japan

Alterations in driving ability and their relationship with morphometric magnetic resonance imaging indicators in patients with amnestic mild cognitive impairment and Alzheimer's disease

BACKGROUND

Drivers with dementia are at a higher risk of motor vehicle accidents. The characteristics of driving behaviour of patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD) have not been fully elucidated. We investigated driving ability and its relationship with cognitive function and magnetic resonance imaging (MRI) morphometry indicators.

METHODS

The driving abilities of 19 patients with AD and 11 with amnestic MCI (aMCI) were evaluated using a driving simulator. The association between each driving ability parameter and the Mini-Mental State Examination (MMSE) score or voxel-based specific regional analysis system for AD (VSRAD) was assessed.

RESULTS

Patients with AD made a significantly higher number of operational errors than those with aMCI in attention allocation in the complex task test (P = 0.0008). The number of operational errors in attention allocation in the complex task test significantly and negatively correlated with MMSE scores in all participants (r = -0.4354, P = 0.0162). The decision time in the selective reaction test significantly and positively correlated with the severity and extent of medial temporal structural atrophy (r = 0.4807, P = 0.0372; r = 0.4862, P = 0.0348; respectively).

CONCLUSION

An increase in the operational errors for attention allocation in the complex task test could be a potential indicator of progression from aMCI to AD. Atrophy of the medial temporal structures could be a potential predictor of impaired judgement in driving performance in aMCI and AD. A driving simulator could be useful for evaluating the driving abilities of individuals with aMCI and AD.

Speedometer-reading performance of senior drivers with cognitive impairment: a comparison of analogue and digital speedometers

BACKGROUND

With the deterioration of cognitive functions, the capability to obtain information with speed, one of the essential elements needed to perform safe driving, may be impacted. We aimed to compare the legibility of analogue and digital speedometers for senior drivers with cognitive impairment, and examined the demographic, cognitive, and driving-related variables that predict their speedometer-reading performance.

METHODS

A total of 50 senior drivers with cognitive impairment were investigated and asked to complete an office-based speedometer-reading test using an iPad. Two general types of speedometers (analogue and digital) were tested in this study.

RESULTS

The age of the participants ranged from 61 to 92 years (mean (SD), 79.10 (6.973)), and 29 were male. The mean (SD) score of the Mini-Mental State Examination was 22.48 (6.089). The median (Q_L , Q_U ) scores of the analogue and digital speedometer-reading tests were 4 (4, 5.25) and 6 (6), respectively. Based on the result of the Wilcoxon signed-rank test, the score of the digital speedometer-reading test was significantly higher than that of the analogue one (Z = 4.399, P < 0.001). The results of multiple linear regression analyses show that the scores of the Mini-Mental State Examination (β = 0.358, P = 0.025), and the trail-making test-A (β = -0.443, P = 0.006) predicted the digital speedometer-reading performance, and they together explain 54.7% of the total variance.

CONCLUSIONS

A digital speedometer was found to be easier for absolute value reading for senior drivers with cognitive impairment, compared to an analogue speedometer. Senior drivers with subjective cognitive decline may also have impairments in obtaining the speed information through an analogue speedometer. General cognitive function and attention may influence the speed-reading performance on the digital speedometer.