Early cognitive decline in amyotrophic lateral sclerosis and its relation to driving: an observational study

Objective: To determine whether early cognitive function in amyotrophic lateral sclerosis patients predicts future cognitive function and the decision to cease driving. Design: Observational study. Subjects: Patients with amyotrophic lateral sclerosis. Methods: Subjects underwent baseline assessments of cognitive function and driving ability within 4 months of diagnosis, with follow-up evaluation conducted 4 months thereafter. Two hypotheses were tested: (H1) cognitive status remains stable between baseline and follow-up, (H2) patients with baseline cognitive impairment cease driving earlier than those without cognitive changes. Data were analysed using t-tests and regression analysis, with visual inspection of the results. Results: Of 31 subjects tested at baseline, 5 were under 60 years old, 11 were female, 11 were cognitively impaired, and 61% were driving. Over the 4-month period, cognitive function of the subjects (n = 21) did not change significantly. There was no significant association between baseline cognitive function and follow-up driving status. Conclusion: Early cognitive function assessment in amyotrophic lateral sclerosis predicts future cognitive function but not currently the decision to cease driving. Cognitive impairment occurs early in the disease, highlighting the importance of early evaluation and implementation of safety measures related to driving.