Assessment of driving performance in patients with relapsing-remitting multiple sclerosis by a driving simulator

Abstract

Objective: To compare the driving performance using a driving simulator with physical and cognitive functions as measured by the Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Functional Composite (MSFC) in patients suffering from the relapsing-remitting form of multiple sclerosis (RRMS).

Methods: 31 RRMS patients (18 women, 13 men, mean age 35.6 +/- 8.3 years, EDSS 2.8 +/- 1.4) were compared with 10 healthy controls (8 men, 2 woman, age 45.1 +/- 7.8 years).

Results: Compared with controls, the accident rate (5.3 +/- 3.8 vs. 1.3 +/- 1.5, p < 0.001) and concentration faults (21.1 +/- 15.5 vs. 7.1 +/- 2.6, p < 0.01) of RRMS patients using the driving simulator were increased. While there was no correlation with the EDSS score, the accident rate was correlated with the MSFC (r = -0.5, p < 0.05). Regarding the three dimensions of the MSFC, accidents were related to the number of correct answers and Z-score in the paced auditory serial addition test (PASAT) as a measure for cognitive function (r = -0.33, p < 0.05).

Conclusion: The current study demonstrates the need to focus also on driving skills in MS patients. The risk of accidents should be evaluated after relapses in particular. However, there are great interindividual differences. In the MSFC, most deficits could be evaluated in the PASAT. As there was a significant correlation between the accident rate in the driving simulator and the PASAT results, accidents seem to be more influenced by cognitive decline than by physical impairment. This indicates that the MSFC is a broader, more dimensional scale than the EDSS and should be preferred in the case of driving assessment. At the present time, the driving simulator seems to be a useful instrument judging driving ability, especially in cases with ambiguous neuropsychological results.