Abstracts

Rationale: Loss of driving privileges is emblematic of the disadvantages faced by people with epilepsy (PWE) and a chief concern impacting their quality of life. The identification of seizure specific risk factors predisposing PWE to have motor vehicle accidents (MVA) would help physicians and regulators give fair and effective advice in regards to driving with epilepsy. No single study has looked at various seizure-associated features and their impact on MVA risk in PWE. Study of the role of reliable auras in MVA in PWE has produced conflicting results. The objective of our study is to evaluate factors related to seizures that potentially impair driving leading to MVA in people with medically refractory epilepsy. Methods: We utilized the Multicenter Study of Epilepsy Surgery database to identify our study population. As part of evaluation, patients were asked if they ever had seizures while driving. Those who responded "yes" were then asked if they ever had a seizure that caused an accident while driving. We divided patients who reported having seizures while driving into two groups: those who had seizures while driving that led to a MVA ("Accident" group) and those who had seizures while driving but did not lead to a MVA ("No Accident" group). We then compared different variables between the two groups that could potentially increase the risk of MVA. Results: 215 of 553 (38.9%) patients reported having seizure(s) while driving; 74 in the "No Accident" group and 141 in the "Accident" group. The two groups had similar demographic and clinical features including age, sex, seizure localization and AED history. Presence of a reliable aura did not differ between the two groups overall (OR = 0.89, 95% CI 0.49 - 1.61, p = 0.76) or when analyzed based on associated seizure type or aura duration (p > 0.05). We found that patients who had history of complex partial seizures (CPS) (OR = 2.83; 95% CI 1.14-7.09; p = 0.029) or reported having at least one CPS per month in last 3 months (OR = 2.52, 95% CI 1.22-5.21, p = 0.01) had much greater odds of being involved in MVA due to a seizure. Surprisingly having generalized tonic clonic seizures did not affect chances of having MVA (OR = 0.69; 95% CI 0.36-1.3, p>0.05), which may be because our patient population primarily had localization related epilepsy. Longer seizures (≥3 minutes) were not found to affect MVA risk (p > 0.05) but patients with longer post-ictal period (≥1 minutes) had higher likelihood of MVA due to seizures (OR = 2.53; 95% CI 1.04 - 6.19; p = 0.05). Motor impairments like convulsions and serious disruptive automatism also did not differ significantly between the two groups (p > 0.05). Conclusions: The American Academy of Neurology and American Epilepsy Society have proposed using "consistent and prolonged auras" as favorable modifier when considering eligibility of driver license among PWE. Our findings question the assumed protective benefit of reliable auras against MVAs. We have found that CPS and longer post-ictal state are the most salient features of seizures increasing risk of accidents and suggests that impairment of consciousness may be a key factor.