Respiratory-related evoked potentials during sleep in children

Abstract

Study objectives: The respiratory related evoked potential (RREP) has been previously recorded in children and adults during wakefulness and in adults during sleep. However, there have been no data on RREP during sleep in children. We thus examined children during sleep to determine whether early RREP components would be maintained during all sleep

Design and participants: Twelve healthy, nonsnoring children, aged 5-12 years, screened by polysomnography and found to have no sleep disorders were assessed during stage 2 sleep, slow wave sleep, and REM sleep. Brief occlusions were presented via an occlusion valve at the inspiratory port of a non-rebreathing valve as interruptions of inspiration. EEG responses were averaged and assessed for the presence of early and late RREP components.

Results: Robust early components were seen in the majority of subjects in all sleep stages. Late components were also present, although with some apparent differences compared to those previously reported in adults (using the same recording protocol and an almost identical method of stimulus presentation). Specifically, N350 and N550 were less readily differentiated as separate components, and the N550 did not display the clear anterior-posterior amplitude gradient that is ubiquitous in adults.

Conclusion: Cortical processing of respiratory-related information persists throughout sleep in children. The pattern of activation in the late components appear to reflect differences in the structure of the developing brain prior to the process of dendritic pruning associated with adolescence.

Figure 1

Short-latency RREP waveforms for Stage 2 sleep. Fz waveforms are referenced to linked ear leads. The vertical black bar indicates time of the commencement of mask pressure change in response to the occlusion.

Figure 2

Short-latency RREP waveforms for slow wave sleep. Fz waveforms are referenced to linked ears. The vertical black bar indicates time of the commencement of mask pressure change in response to the occlusion.

Figure 3

Short-latency RREP waveforms for REM sleep. Fz waveforms are referenced to linked ears. The vertical black bar indicates time of the commencement of mask pressure change in response to the occlusion.

Figure 4

Long-latency RREP waveforms for Stage 2 sleep. All waveforms are referenced to linked ears. The vertical black bar indicates time of the commencement of ask pressure change in response to the occlusion.

Figure 5

Long-latency RREP waveforms for slow wave sleep. All waveforms are referenced to linked ears. The vertical black bar indicates time of the commencement of mask pressure change in response to the occlusion.

Figure 6

Long-latency RREP waveforms for REM sleep. All waveforms are referenced to linked ears. The vertical black bar indicates time of the commencement of mask pressure change in response to the occlusion.

Figure 7

N550 amplitude presented as a proportion of the amplitude at Fz. Data are presented from the present study, from the seven 19 to 28-year-old male subjects reported in Webster and Colrain and five 23 to 29-year-old female control subjects drawn from Afifi et al. The data from the children in the present study demonstrate the lack of the typical adult pattern of an anterior-posterior gradient in N550 amplitude.