Abstracts

Rationale: Seizures while driving in known epilepsy is a well-documented phenomenon with a wide range of medico-legal implications and impact on driving privileges. There is almost no data on patients who have no previous history of epilepsy and experience their first seizure while driving (FSWD). Methods: Out of 311 patients who presented to the Halifax First Seizure Clinic (FSC) between 2008 and 2011, 158 patients were identified who strictly met the criteria of a strict first seizure (FS) or drug-naïve unknown new-onset epilepsy (NOE). A retrospective chart review was conducted. The goal of this study was to assess FSWD with regard of 1) prevalence, 2) clinical presentation, 3) coping strategies, and 4) Time of driving before accident. Results: The prevalence of FSWD while driving was 8.2% (thirteen out of hundred and fifty-eight patients). 11 patients had generalized tonic-clonic seizures, one evolving from a complex partial seizure, three from visual auras. 2 patients had complex partial seizures, one starting with an autonomous seizure. Patients were i) able to actively stop the car (n=4, three of them had visual auras), ii) not able to stop the car resulting in accident (n=7), and iii) passenger was able to pull the car over (n=2). One accident was fatal to the other party. 11 out of 13 patients did drive for less than 1 hour, 2 more than 1 hour. Conclusions: Our results support the theory that FSWD is a frequent and possibly unrecognized phenomenon in FS and NOE patients. It is therefore suggested to better document and evaluate this piece of history since FSWD often lead to accidents. Onset with simple partial seizures seems to give the driver some warning and to help to avoid accidents. Pathophysiological mechanisms remain speculative. While complex mental tasks have been considered to be rather seizure-protective than facilitating seizure, it cannot ruled out that critical visuo-motor tasks while driving may lower seizure threshold in predisposed individuals.