Hypersomnia is characterized by recurrent episodes of excessive daytime sleepiness (EDS) or prolonged nighttime sleep that affects the everyday life of the patient. Clinical surveys have reported EDS as a complaint in up to 68% of normal high-school children. Causes of EDS are divided into three categories: insufficient nighttime sleep, fragmented nighttime sleep, and an increased need of sleep. Pediatric daytime sleepiness scale (PDSS) is a recently introduced validated measure for assessing sleepiness in children. Management of disorders that may coexist with hypersomnia of central origin such as obstructive sleep apnea, psychiatric disorders, medications, and circadian rhythm disorders will require specific therapeutic interventions, but need to be done for optimal outcome in children with narcolepsy. The general approach to the treatment of childhood narcolepsy and other hypersomnias of central origin is based on the adult experience.

This chapter reviews the psychometric properties, validation, and strengths and weaknesses of the most common measurement tools used for the subjective evaluation of sleepiness. Subjective measures of sleepiness described in the chapter include visual analogue scales (VAS), Stanford sleepiness scale (SSS), Karolinska sleepiness scale (KSS), Epworth sleepiness scale (ESS) pediatric sleep questionnaire, sleepiness subscale (PSQ-SS) and pediatric daytime sleepiness scale (PDSS). Children present with a variety of sleep disorders associated with excessive sleepiness. Subjective sleepiness is critical as it is often the initial symptom of underlying sleep pathology, and a major presenting complaint that clinicians must understand and address. More work is needed on potential cultural and racial differences in subjective sleepiness and in relation to specific types of measurement. It has been shown that subjective sleepiness is accompanied by EEG changes including selective slowing of specific frequency bands.