Electroencephalographic Microstates During Sleep and Wake in Schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Computational Neuroscience

Background:

• Aberrant functional connectivity is a key feature of schizophrenia.
• Dysconnectivity patterns may differ between wakefulness and sleep.
• Microstate analysis of electroencephalography (EEG) data reveals large-scale brain activity patterns.

Purpose of the Study:

• To investigate sleep-specific brain network dysconnectivity in schizophrenia using microstate analysis.
• To explore the temporal dynamics of brain connectivity during sleep in schizophrenia patients.
• To identify novel sleep-related EEG markers in schizophrenia.

Main Methods:

• Analysis of high-density EEG sleep data from 114 schizophrenia patients and 79 controls.
• Application of polarity-insensitive k-means analysis to extract 6 microstate topographies.
• Comparison of microstate patterns and transition complexity between patient and control groups during wake and sleep.

Main Results:

• Identified 6 microstate topographies, including 4 canonical states.
• Observed a shift from microstates A, B, C to D, E, F upon falling asleep in both groups.
• Found decreased microstate F during wake and microstate E during sleep in schizophrenia patients.
• Noted greater microstate transition complexity in patients during wake, reversing during sleep.

Conclusions:

• Schizophrenia exhibits behavioral state-dependent cortical dysconnectivity.
• These findings highlight previously undescribed sleep-related pathology in schizophrenia.
• The observed patterns are largely independent of established sleep EEG markers like sleep spindles.