ORIGINAL ARTICLE EEG spectral analysis of apnoeic events confirms visual scoring in childhood sleep disordered breathing Joel S. C. Yang & Christian L. Nicholas & Gillian M. Nixon & Margot J. Davey & Vicki Anderson & Adrian M. Walker & John Trinder & Rosemary S. C. Horne Received: 26 January 2011 /Revised: 31 March 2011 /Accepted: 4 May 2011 /Published online: 13 May 2011 # Springer-Verlag 2011 Abstract Purpose This study compared electroencephalogram (EEG) spectral analysis with standard visual scoring to assess the validity of clinical classification of arousals at respiratory event termination in children with obstructive sleep apnoea (OSA). Methods Twenty children (six M/14 F) aged 7–12 years, diagnosed with moderate to severe OSA participated in this study. Overnight polysomnography was performed, and sleep stages and arousals visually scored using clinical paediatric measures. The EEG was spectrally analysed in six 5-s epochs across respiratory events, namely two consecutive 5-s epochs pre-event onset and a 5s epoch post-event onset, 5-s before event termination, and two contiguous 5-s epochs post-event termination. EEG spectral power distribution was compared across respiratory events visually categorised as full cortical arousals, subcortical activations, or non-arousals using specialised software (Sleep Research System 5.0). Results There was no difference in power spectra between events in REM and NREM sleep and these were combined. There was a statistically significant fall from pre-arousal baseline values in delta and theta spectral power at respiratory event terminations associated with cortical arousals only. No change in power was detected at respiratory event termina- tions associated with subcortical activations or non-arousals. Conclusions The lack of significant EEG spectral power changes at respiratory event terminations not associated with visually identified cortical arousals indicates undetect- ed micro-arousals are not present. The results support the validity of clinical classifications of arousals at respiratory event termination. Keywords Sleep disordered breathing . Obstructive sleep apnoea . Paediatric . Children . Sleep . Apnoea Introduction Sleep disordered breathing (SDB) is a condition charac- terised by repeated episodes of apnoea and hypopnoea. SDB is common in children, occurring in up to 34% of children [1–4] and ranging in severity from mild (primary snoring) to severe (obstructive sleep apnoea (OSA)). Early studies reported that OSA was associated with behavioural and neurocognitive deficits [5, 6], and it has been suggested that these symptoms could be related to either or both the repeated episodes of hypoxia and the disruption of sleep quality from repeated arousals at respiratory event termina- tion [7]. More recent studies now suggest that children with primary snoring, who do not show any gas exchange abnormalities, also display a wide range of neurocognitive deficits in domains such as intelligence, memory, and attention [8, 9], suggesting that sleep disruption may be J. S. C. Yang : G. M. Nixon : A. M. Walker : R. S. C. Horne (*) The Ritchie Centre, Monash Institute of Medical Research, Monash University, Level 5, Monash Medical Centre, 246 Clayton Rd, Clayton, Melbourne, Victoria, Australia e-mail: rosemary.horne@med.monash.edu.au C. L. Nicholas : J. Trinder Discipline of Psychology, University of Melbourne, Melbourne, Victoria, Australia G. M. Nixon : M. J. Davey Melbourne Children’ s Sleep Centre, Monash Children’ s Programme, Monash Medical Centre, Melbourne, Victoria, Australia V. Anderson Critical Care and Neuroscience, Murdoch Children’ s Research Centre, University of Melbourne, Melbourne, Victoria, Australia Sleep Breath (2012) 16:491–497 DOI 10.1007/s11325-011-0530-0