Electrophysiological Signatures of Alpha Coma.

Area of Science:

• Neuroscience
• Quantitative Electroencephalography (qEEG)
• Coma Research

Background:

• Quantitative EEG metrics in coma are challenged by disease heterogeneity.
• Alpha-coma, a pattern of widespread, nonreactive alpha rhythm, is associated with poor prognosis.

Purpose of the Study:

• To quantify electrophysiological features of alpha-coma.
• Compare alpha-coma EEG to awake controls for insights into quantitative EEG analysis in comatose states.

Main Methods:

• Retrospective analysis of 14 alpha-coma patients and 14 age-matched healthy controls.
• EEG data analyzed for power spectra, spectral decay, sample entropy, and functional connectivity.

Main Results:

• Alpha-coma patients showed significantly higher spectral decay (p < 0.001) and sample entropy (p = 0.01) compared to controls.
• No significant difference in alpha power or clustering coefficient was observed.

Conclusions:

• Alpha-coma exhibits increased aperiodic activity and EEG complexity, aligning with other comatose states.
• Increased entropy in alpha-coma contradicts prior literature, suggesting a unique state of widespread cortical dysfunction.
• This highlights that loss of consciousness does not yield consistent cortical measures across all EEG patterns.