Is there a link between a unique body position during sleep in children with Down syndrome and obstructive sleep apnoea?

Abstract

Introduction: Down syndrome (DS) children are reported to assume a unique body during sleep (sitting or crossed-legged flopped forward, with the head on the bed), a phenomenon that is not described in non-DS children (Senthivel et al, 2011). However, the clinical significance of this finding is yet unclear. It could be considered as a mechanism to protect the upper airway in cases with obstructive sleep apnoea (OSA) or represent a form of parasomnia. Aim: To evaluate the prevalence of this unique sleeping position in children with DS, and to investigate whether sleep position is related to OSA. Methods: Body position as observed during full night polysomnography (PSG) was scored as follows: (supine/lateral/ prone/sitting/leaning forward). Sleeping sitting or cross-legged leaning forward was considered a unique sleep position characteristic for DS. The prevalence of this unique body position was evaluated, and correlated to OSA severity and body mass index (BMI). Results: Between January 2013 and January 2015, 53 DS children underwent a PSG. The study group comprised 30 males, age 6,2 (4,5) years, and BMI 19,17 (5,3) kg/m 2 . A diagnosis of OSA (oAHI >2/hr) was established in 69.2% and OSA was severe with an obstructive apnoea/hypopnoea index (oAH) 10,4 (10,7)/hr. Sleeping leaned forward was found in 22,6% and 11.3% slept in a sitting position. We did not find a significant correlation between this unique body position and OSA severity or BMI. Conclusion: 33.9% of DS children assumed a unique body position during PSG. We could not find a correlation between OSA severity or BMI suggesting that these particular body positions may be considered as parasomnia.