Evaluating Recognition Memory in Children Referred for Suspected Obstructive Sleep Apnea

Background: A majority of previous studies showing memory deficits in children with Obstructive Sleep Apnea (OSA) have focused on recall memory tasks and have relied upon subjective measures of sleep (parental reported sleep or actigraphy). The present study uses polysomnography (PSG) to confirm OSA the night following the learning situation. Our objective was to assess the extent of memory deficits in children referred for suspected OSA. Methods: Children with suspected OSA were recruited prior to a night of PSG. Children performed a brief facial recognition memory task: 1) Prior to bedtime in the sleep laboratory, the child was instructed to study faces; 2) In the morning, the child was presented with previously studied faces and foils not seen before. The child was asked to identify which faces they remembered. We assessed memory variables accuracy (%correct) and reaction time (RT, milliseconds) and sleep/respiratory metrics. Results: Twenty-two children (13.1 years+/-2.9) were included. Those with OSA (mixed/obstructive apnea-hypopnea index, MOAHI?1) vs. without OSA (MOAHI<1) had more respiratory-related arousals (p=0.02) but no difference in the oxygen desaturation indices. Regardless of OSA status, children showed greater accuracy in recognizing the faces studied compared to the foils (p=0.001). Pearson correlations revealed no associations between memory performance and respiratory variables (MOAHI, respiratory arousals, desaturations). There were no associations between RT and sleep variables (sleep staging and total sleep time). There was an association between increased sleep and better accuracy in memory performance (r=0.45, p=0.04). Conclusion: Our data suggest that OSA in children may not be associated with deficits in memory performance, when using a brief recognition memory task. We found a modest association between increased sleep duration and higher accuracy in memory performance. Future studies should determine whether sleep quantity in OSA is relevant in preventing a child's susceptibility to impairments in recognition and other types of memory.