Secondary narcolepsy may be a causative factor of increased daytime sleepiness in obese patients with childhood craniopharyngioma

Prognosis in childhood craniopharyngioma survivors hinges upon late effects such as pituitary deficiency and obesity. Observations indicate that reduced physical activity and increased daytime sleepiness might be risk factors for obesity. We analyzed the degree of daytime sleepiness in 115 childhood craniopharyngioma patients (47% obese) using the Epworth Sleepiness Scale (ESS). Thirty-five (30%) displayed increased daytime sleepiness (ESS score > 10) of whom 14 were obese (26% of obese cohort). Polysomnography (PSG) and Multiple Sleep Latency Tests (MSLT) were conducted with 10 obese patients presenting increased daytime sleepiness, with only two craniopharyngioma patients revealing a sleep related breathing disorder. Four patients had repeated episodes of SOREM (sleep onset rapid eye movement), the classic PSG criterion for narcolepsy. Three patients displayed hypersomnia. All but one patient qualified as acutely obese. We speculate that secondary narcolepsy is an exacerbating condition of childhood craniopharyngioma obesity, supported by recent reports on orexin and narcolepsy which suggest hypothalamic failure in idiopathic narcolepsy.