The adolescent pattern of sleep spindle development revealed by HD-EEG polysomnography

Abstract

Sleep spindles are developmentally relevant cortical oscillatory patterns; however, they have mostly been studied by considering the entire spindle frequency range (11 to 15 Hz) without a distinction between the functionally and topographically different slow and fast spindles, using relatively few electrodes and analysing wide age-ranges. Here, we employ HD-EEG polysomnography in three age-groups between 12 to 20 years of age, with an equal distribution between the two genders, and analyse the adolescent developmental pattern of the four major parameters of slow and fast sleep spindles. Most of our findings corroborate those very few previous studies that also make a distinction between slow and fast spindles in their developmental analysis. We find spindle frequency increasing with age, although spindle density change is not obvious in our study. We confirm the declining tendencies for amplitude and duration, although within narrower, more specific age-windows than previously. Spindle frequency seems to be higher in females in the oldest age-group. Based on the pattern of our findings, we suggest that HD-EEG, specifically targeting slow and fast spindle ranges and relatively narrow age-ranges would advance the understanding of both adolescent development and the functional relevance of sleep spindles in general.

Mapping Typical and Altered Neurodevelopment with Sleep Macro- and Micro-Architecture

“…Interestingly, such a pattern appears to be opposite of the aging effect in aging adults (50s to 80s) where the SS and FS frequencies tend to diverge with SS becoming slower and FS faster (Djonlagic et al, 2020). A recent study that studied spindles in three groups of adolescents found that both slow and fast spindles frequency was increased with age (Bocskai et al, 2022). However, in that study, slow and fast spindles were distinguished only using topographical differences (all spindles detected in frontal channels were declared slow and all spindles in centro-parietal channels fast).…”