ABSTRACT
INTRODUCTION Excessive sleepiness represents a major, albeit poorly recognized public safety and health problem (1). Countless motor vehicle and work-related accidents directly result from sleepiness. Sleepiness contributes to such accidents via inattention, response slowing, or unexpected lapses into sleep. Sleepiness is the normal physio logical consequence of sleep loss, sleep disruption, or diminished sleep integrity. Sleepiness can also arise from central nervous system alterations produced by brain lesions, medications, or disease. Severe sleepiness is the hallmark symptom of several sleep disorders, including narcolepsy, obstructive sleep apnea, behaviorally induced insufficient sleep syndrome, and idiopathic hypersomnia with or without long sleep time (2). Excessive sleepiness may occur secondary to psychiatric, neurological, medical, and substance abuse conditions. Therefore, a careful evaluation of sleepiness is both clinically relevant and important. Results of such evaluation must be interpreted within the context of sleep schedule, napping, diet, comorbid illnesses, and concurrent medication.
