Sleep Disorders in Sanfilippo Syndrome: A Polygraphic Study

Abstract

Objective: A high prevalence of sleep disorders is reported in patients affected by Mucopolysaccharidosis III (Sanfilippo syndrome). These disorders have never been investigated by prolonged, objective, and instrumental evaluations. The present work is based on sleep duration and structure in Sanfilippo patients. Study design: The features of sleep/wake cycle in 6 Sanfilippo patients and 6 healthy controls were evaluated by means of sleep diaries and 48 hour ambulatory EEG and polygraphic recordings. Statistical analysis was performed by means of the U-test (Mann-Whitney). Results: Four out of six Sanfilippo patients, the oldest patients in our sample, showed an extremely irregular sleep pattern, with several sleep episodes of inconstant duration, irregularly distributed along 24 hours. The two younger patients showed sleep maintenance insomnia with several nocturnal awakenings. Conclusions: These results suggest that sleep disruption in Sanfilippo syndrome consists of an irregular sleep/wake pattern, which at its onset might appear as a disorder of initiating or maintaining sleep. This could explain why some patients do not respond to conventional hypnotics. The present observation might suggest attempting therapies aimed at resynchronization, such as behavioral treatment, light therapy or melatonin.