Neurophysiological patterns reflecting vulnerability to delirium subtypes: a resting-state EEG and event-related
Monique S Boord1,2, Daniel Feuerriegel3, Scott W Coussens1
1Cognitive Ageing and Impairment Neurosciences Laboratory, Justice and Society, University of South Australia, Adelaide, 5072, South Australia, Australia.
Brain Communications
|September 12, 2024
Summary
Pre-operative brain activity in older adults undergoing cardiac surgery can predict delirium risk. Specific EEG markers identified potential differences in neural function linked to delirium subtypes, even weeks before the procedure.
Area of Science:
- Neuroscience
- Geriatrics
- Cognitive Science
Background:
- Delirium is a common acute neurocognitive disorder in older adults, increasing dementia and mortality risk.
- Understanding delirium pathophysiology requires insight into brain vulnerability and acute stressors.
- Neurophysiological markers of delirium vulnerability are not well-defined.
Purpose of the Study:
- Identify pre-operative electroencephalography (EEG) and event-related potential (ERP) markers for incident delirium and its subtypes in older adults undergoing elective cardiac procedures.
- Investigate the neurophysiology of delirium vulnerability prior to surgery.
Main Methods:
- Prospective observational study of 58 older adults (mean age 75.6 years) undergoing elective cardiac procedures.
- Collected resting-state EEG (eyes open/closed) and auditory oddball paradigm data pre-operatively.
- Analyzed EEG spectral properties (power, frequency, bandwidth, aperiodic offsets/exponents) and ERPs (component amplitudes).
Main Results:
- Incident delirium occurred in 21 participants (10 hypoactive, 6 mixed, 5 hyperactive).
- Hyperactive delirium linked to higher pre-operative eyes open/closed aperiodic offsets.
- Mixed delirium associated with larger pre-operative ERP component amplitudes (first positive, third positive) to auditory stimuli.
Conclusions:
- Evidence suggests pre-operative neurophysiological markers predict delirium risk weeks before cardiac procedures in older adults.
- Findings indicate pre-operative neural excitation/inhibition imbalance associated with different delirium subtypes.
- Further large-scale investigation is warranted despite COVID-19 related limitations impacting study power.
