CSF hypocretin-1 measurement in pediatric and teenage patients with sleep disorders

Narcolepsy and other sleep disorders are underrecognized in children; therefore, the final diagnosis and initiation of treatment is often delayed. This is due to the fact that the expression of sleep-related symptoms in children is often different from those of adults and polysomnography is generally difficult in children. CSF hypocretin-1 (orexin-A) measurement in adults demonstrated that low levels are highly specific to narcolepsy and this examination is now being established as a new diagnostic tool. In this study, we describe the spectrum of the hypocretin deficiency syndrome by analysis of CSF hypocretin-1 levels and clinical, polysomnography and human leukocyte antigen data in 38 pediatric and teenage patients with various sleep disorders and 120 patients with neurological conditions. The levels of CSF hypocretin-1 were significantly lower in narcolepsy compared to other neurological conditions. The measurement of hypocretin-1 is a useful diagnostic tool in pediatric narcolepsy, especially when other diagnostic information (e.g. polysomnography and human leukocyte antigen) is not sufficient.