Abstracts

Patients with epilepsy are at risk for automobile crashes. Cognitive effects of epilepsy and antiepileptic drugs (AEDs) may impair driving performance. Useful Field of View (UFOV) is a sensitive and specific predictor of automobile collisions. We analyzed UFOV in subjects with partial epilepsy. 20 partial epilepsy subjects (aged 21-61 years, mean=41.5) and 50 neurologically normal controls (aged 24-56 years, mean=39.3) participated. Epilepsy syndromes were temporal (n=18; 12 had prior anterior temporal lobectomy) and extratemporal (n=2). UFOV was assessed using the Visual Attention Analyzer, Model 3000 (Visual Resources, Inc.). UFOV Task 1 measures processing speed at central fixation. Task 2 analyzes divided attention between central and peripheral targets. Task 3 involves selective attention between a peripheral target and distracters. Task 4 is a more difficult discrimination task. The dependent measure is a threshold score (ms) for 75% correct target identification. Higher scores indicate poorer performance. UFOV Task scores were added to calculate a UFOV Total score for each subject. UFOV scores were significantly higher on all UFOV tasks in subjects with partial epilepsy (Wilcoxon Rank Sum Test; see Table), indicative of impairments of processing speed, divided attention, and selective attention. UFOV scores are increased in subjects with partial epilepsy compared to neurologically normal individuals, suggesting a greater crash risk in individuals with partial epilepsy. Causes of impaired UFOV scores include reduced processing speed, divided and selective attention impairments, and mild superior quadrantic visual field deficits due to surgical lesions. Our future studies in drivers with epilepsy aim to further differentiate effects of seizures, AEDs, and lesions upon cognitive abilities critical to safe automobile driving.[table1]