Useful Field of View Impairment in Partial Epilepsy

Abstract

Patients with epilepsy are at elevated risk for automobile crashes. Most collisions in drivers with epilepsy are not seizure-related, but may instead result from cognitive effects of epilepsy and antiepileptic drugs (AEDs) upon driving performance. The Useful Field of View (UFOV) score has demonstrated good sensitivity and specificity for predicting automobile crashes. The goal in this pilot study was to assess impairments in the UFOV in subjects with partial epilepsy. Participants included 20 subjects with partial epilepsy. Neurologically normal control subjects of comparable age also participated. UFOV was assessed in all participants using the Visual Attention Analyzer, Model 3000 (Visual Resources, Inc.). UFOV Task scores were added to calculate a UFOV Total score for each subject. UFOV scores were higher on all UFOV tasks in subjects with partial epilepsy compared to neurologically normal individuals of similar age (p<0.05, Wilcoxon Rank Sum Test), suggesting a greater crash risk in individuals with partial epilepsy, even in the absence of an epileptic seizure. Causes of impaired UFOV scores include processing speed reduction, divided and selective attention impairments, and mild postoperative visual field deficits. The authors' ongoing studies in drivers with epilepsy are aimed at further differentiating potential effects of seizures, antiepileptic drugs, and surgical lesions upon cognitive abilities that are critical to safe automobile driving.