Obstructive sleep apnoea is associated with impaired pictorial memory task acquisition and retention in children

The aim of our study was to evaluate whether obstructive sleep apnoea (OSA) is associated with impaired acquisition and recall of a pictorial-based memory tasks in children. 54 children with OSA and 17 controls matched for age, sex and ethnicity underwent a sleep study (overnight polysomnogram). Before the sleep study subjects completed a 15-min pictorial memory task acquisition consisting of four trials, followed by a free-recall period to assess retention after 10 min and the following morning upon awakening. Children with OSA had a higher obstructive apnoea/hypopnoea index (6.3 +/- 1.5 events.h(-1) TST) than controls (0.6 +/- 0.1 events.h(-1) TST) (p<0.0001). Mean learning scores in controls over the four consecutive trials were incrementally better than in children with OSA for the four-trial set (p<0.0001). Both immediate (p<0.0001) and overnight recall performances were worse among OSA children (p<0.0001), who also exhibited declines in recall performance that was absent in controls (p<0.001). Differences in pictorial task acquisition trajectories suggest that children with OSA require more time and an increased number of learning opportunities to reach immediate and long-term recall performances that are reduced compared with controls. Thus, both acquisition and retention of newly learned material are compromised. These findings confirm and expand on the presence of known cognitive deficits in children with OSA.