Evaluating the use of prolonged video-EEG monitoring to assess future seizure risk and fitness to drive

Abstract

Objective: The use of prolonged video-electroencephalography monitoring (VEM), rather than routine electroencephalography (EEG), in predicting the risk of future seizures in patients with epilepsy is not well studied. A longer period of monitoring could be more likely to capture either ictal or interictal epileptiform activity. This information may better assist clinical decision making on driving fitness. The goal of this study was to evaluate the use of 6-hour prolonged VEM versus routine EEG in the assessment of future seizure risk and driving fitness for patients with epilepsy.

Methods: Data on consecutive patients referred for 6-hour prolonged VEM were retrospectively analyzed. Criteria were developed that combined EEG findings and clinical factors to determine each patient's fitness to drive. Seizure relapse outcomes were followed over 2 years.

Results: Of 34 patients, 27 were considered safe to drive following prolonged VEM. Five (19%) of these 27 patients had seizure relapses; all had an obvious precipitant(s) identified including sleep deprivation, excessive alcohol, and missed medication doses. Seven of the 34 patients were deemed unsafe to drive. All seven (100%) had seizure relapses, with unprovoked seizures in four patients. The relative risk of seizure in patients deemed unfit to drive was 5.4 (P=0.00015). If only the routine EEG component of the recordings were used with the criteria, the relative risk would have been 3.4 (P=0.037), with nearly double the number of active drivers having seizures. The majority of patients (76%) in this study had idiopathic generalized epilepsy, with a relative seizure risk of 4.0 (P=0.002) for patients deemed unfit to drive in this subgroup. The focal epilepsy group was small (eight patients) and did not quite achieve statistical significance.

Conclusion: Six-hour VEM improves the evaluation of driving fitness by better predicting the risk of subsequent seizure relapse for idiopathic generalized epilepsy and possibly focal epilepsy. Prolonged monitoring is superior to routine EEG. Ongoing avoidance of seizure-provoking factors remains paramount to driving safety.