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A method to assess the default EEG macrostate and its reactivity to stimulation
Cosmin-Andrei Serban1, Andrei Barborica1, Adina-Maria Roceanu2
1Physics Department, University of Bucharest, Romania; Termobit Prod SRL, Bucharest, Romania; FHC Inc, Bowdoin, ME, USA.
Summary
Routine EEG recordings can detect default mode network (DMN) impairment in stroke patients with impaired consciousness. This method assesses DMN reactivity to light stimulation, aiding bedside monitoring.
Area of Science:
- Neuroscience
- Clinical Neurophysiology
Background:
- The default mode network (DMN) is crucial for consciousness and is typically deactivated by stimulation.
- Impairment of DMN function is observed in various neurological conditions, including stroke.
Purpose of the Study:
- To assess default mode network (DMN) reactivity impairment in stroke patients with impaired consciousness using routine electroencephalography (EEG).
- To evaluate the utility of EEG-based DMN reactivity measures for bedside monitoring.
Main Methods:
- Binocular light flashes were used to stimulate participants (1 Hz, 1-minute epochs).
- EEG data were analyzed using topographic spectral clustering to identify the default EEG macrostate (DEM).
- Default EEG reactivity index (DERI) was calculated by quantifying the decrease in DEM occurrence during stimulation.
Main Results:
- The DEM was localized to posterior DMN hubs.
- Stroke patients exhibited 3-4 times lower DEM frequency and increased theta activity compared to controls.
- A DERI threshold of 0.25 demonstrated >80% sensitivity and specificity in discriminating stroke patients.
Conclusions:
- Routine EEG recordings can effectively detect DMN impairment in comatose stroke patients.
- The DEM and its reactivity are potential biomarkers for monitoring DMN function at the bedside.
