High Frequency Oscillations During Sleep in Down Syndrome

Abstract Background Alzheimer's disease (AD) dementia has near full penetrance in adults with Down syndrome (DS) and is strongly linked to late‐onset myoclonic epilepsy syndrome (LOMEDS). However, promising biomarkers of epileptogenicity, such as high frequency oscillations (HFOs>250Hz), have not been studied. This study is the first to use wideband polysomnography in DS to investigate if HFOs occurred and preceded AD dementia and LOMEDS. Method Wideband (0.1‐500Hz, 2048Hz) polysomnography was performed using the international 10‐20 system. HFOs were automatically detected during slow‐wave sleep, followed by manual review. Result Eleven individuals with DS and five age‐matched euploid controls were studied. HFOs were detected in all DS cases but not controls, with a mean rate of 7.4±2.0HFOs/min. HFOs emerged before AD dementia and LOMEDS diagnoses. A trend toward increased HFO rates with age in DS cases warrants further confirmation. Conclusion HFOs are promising biomarkers that may predict symptomatic AD dementia in adults with DS.