High-density EEG power topography and connectivity during confusional arousal
Anna Castelnovo1, Julian Amacker2, Massimo Maiolo3
1Sleep Medicine Unit, Neurocenter of Southern Switzerland, Ospedale Civico, Lugano, Switzerland; Faculty of Biomedical Sciences, University of Southern Switzerland, Lugano, Switzerland; University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.
Summary
Disorders of Arousal (DOA) involve abnormal behaviors during sleep with reduced awareness. High-density EEG revealed widespread brain activity changes during confusional arousal episodes, suggesting a partial re-emergence of consciousness.
Area of Science:
- Neuroscience
- Sleep Medicine
- Computational Neuroscience
Background:
- Disorders of Arousal (DOA) are characterized by abnormal behaviors during non-REM sleep with reduced awareness.
- Previous studies using low-density EEG showed mixed sleep and wake frequencies during DOA.
- Limited understanding of whole-brain neural dynamics during these events exists.
Observation:
- High-density EEG (hd-EEG) and v-PSG were used in a child with sleepwalking.
- 256-channel hd-EEG captured neural activity during confusional arousal episodes and baseline sleep.
- Source power and functional connectivity were analyzed during and before episodes.
Findings:
- Confusional arousal episodes showed increased slow wave activity (SWA) and theta, alpha, beta, gamma power, with decreased sigma power.
- Specific brain regions (Brodmann areas 7, 39, 40) were relatively spared from increased SWA.
- Functional connectivity analysis revealed increased complexity and outflow from prefrontal and temporal regions during episodes, even preceding motor onset.
Implications:
- DOA may represent peculiar brain states with a partial re-emergence of consciousness.
- HD-EEG provides detailed insights into the neural underpinnings of DOA.
- Findings contribute to understanding the neurobiology of sleep disorders and consciousness.
