[Evaluation of the capacity to drive in patients diagnosed of mild cognitive impairment and dementia].

INTRODUCTION: Mild cognitive impairment (MCI) and dementia involve cognitive changes that may influence driving capacity.

OBJECTIVES: a) To study if the tests used for renewing the driver's licence are appropriate; b) to study the MCI patient's driving capacity according to ASDE Driver-Test and Useful Field of View (UFOV) test; c) to study mild dementia (MD) patient's driving capacity according to ASDE and UFOV tests; d) to determine which neuropsychological tests may be useful to make decisions on driving capacity in MCI and MD; e) to study the difference in the evaluation of each neuropsychological test between patients who are able to drive and those who are not, in each MCI subgroups, and f) we will establish the correlation between the neuropsychological tests and driving tests used for licence renewal.

METHOD: A total of 184 people were included: 92 MCI, 55 MD and 40 healthy controls. Cognitive functioning was evaluated by Repeatable Battery Assessment for Neuropsychological Status (RBANS), Trail Making Test (TMT) and Kohs' Block Design. Driving capacity was assessed by ASDE and UFOV test.

RESULTS: We established the cut-off points for ASDE and UFOV tests. Sensitivity and specificity for the MD on the ASDE test was 86% and 95%, respectively for concentrated attention and monotony resistance subtest. The UFOV test sensitivity was 88%, specificity 81%. For MCI, both tests showed a sensitivity and specificity lower than 70 %. According to the performance on the test only a half of the MCI group could drive. They showed different driving profiles according to MCI subtype. Neuropsychological tests showing the best correlations with performance on driving test were: Kohs' Block Design, Immediate Memory, Delayed Memory and TMT-A.

CONCLUSIONS: a) People with MD should not drive; b) both ASDE and UFOV tests can detect driving difficulties in people with dementia; c) according to the UFOV and ASDE, half of those diagnosed of MCI should not drive; d) there are significant differences in memory test (RBANS) between Amnesic MCI patients who are able to drive and those who are not (according to ASDE/UFOV tests); e) there are significant differences in TMT-A between multiple functions MCI patients who are able to drive and those who are not (according to ASDE/UFOV tests), and f) the neuropsychological tests that correlate with the driving test were: Kohs' Block Design, Immediate Memory, Delayed Memory and TMT-A.