Poster No:
572
Submission Type:
Late-Breaking Abstract Submission
Authors:
Evelyn Alvarez1, Francisco J. Parada2, Gabriela Cruz3, Rodrigo Gutierrez4, Abraham Gajardo4
Institutions:
1Universidad Diego Portales, Santiago, Metropolitana, 2Universidad Diego Portales, Santiago, Chile, 3University of Glasgow, Glasgow, United Kingdom, 4Universidad de Chile, Santiago, Metropolitana
First Author:
Co-Author(s):
Introduction:
Sepsis, a life-threatening organ dysfunction caused by a dysregulated host response to infection, is associated with delirium (Atterton, 2020), an acute brain dysfunction that leads to adverse outcomes. The pathophysiology involves neuroinflammation, altered cerebral perfusion, and neurotransmission disturbances (Sharshar, 2004, Tokuda, 2023). EEG reveals altered brain connectivity in septic delirium, including reduced alpha/beta bands and increased theta/delta activity (Fleischmann, 2019; Urdanibia-Centelles, 2021). Microstate analysis, which examines temporal dynamics of brain networks, offers insights into neural activity during rest (Khanna, 2015; Kleinert, 2024). This study explores EEG microstates in septic patients with delirium during the acute phase, aiming to identify specific patterns and improve the understanding of neurophysiological mechanisms, potentially enhancing diagnosis and treatment.
Methods:
This prospective observational study, following STROBE guidelines (Vanderbrouke, 2009), analyzed patient records from the Clinical Hospital of the University of Chile (June-October 2023). Patients aged over 18 who met SEPSIS-3 criteria for renal, abdominal, or respiratory sepsis were included. Patients with COVID-19, chronic liver disease, severe cardiovascular instability, cognitive impairment, or receiving end-of-life care were excluded. Data collected included sociodemographics, clinical information (SOFA, APACHE II), EEG evaluations (for the first three days), SAS, and CAM-ICU for delirium. EEG utilized a 16-channel Biosemi system (10-20 configuration, 2048 Hz) during eyes-open (5 minutes) and eyes-closed (3 minutes) states. Microstate analysis (EEGLAB) involved bandpass filtering (2-20 Hz), GFP calculation, and group-average maps (5 clusters: A, B, C, D, E). The metrics evaluated included duration, occurrence, coverage, and transition probabilities (Nagabhushan, 2024). Patients were categorized as D+ (with delirium) or D- (without). Statistical analysis employed chi-square and Mann-Whitney U tests.
Results:
The study included 21 septic patients, with 12 (57.14%) presenting abdominal sepsis, 7 (33.3%) renal sepsis, and 2 (9.5%) respiratory sepsis. Ten patients were classified as D+ (with delirium symptoms) and 11 as D- (without delirium symptoms). Sociodemographic data revealed that D+ patients had lower levels of consciousness at hospital admission (SAS 3.5; Glasgow Scale 13.2) and higher CRP levels (275.83) compared to D- patients.
Regarding microstate analysis, no significant differences were found in duration, occurrence, or coverage during both eyes-open and eyes-closed conditions. However, mean global field power (GFP) during the eyes-open condition was notably higher in D+ patients. Significant differences were observed in transition probabilities, particularly from microstate C to microstate D and from microstate C to microstate E.
Conclusions:
The study reveals altered EEG microstate dynamics in sepsis-induced delirium, with higher global field power (GFP) in D+ patients during eyes-open conditions and significant changes in transition probabilities (C to D and C to E). These findings suggest disrupted neural network integration, potentially reflecting impaired attention and awareness regulation. While microstate duration and occurrence remained stable, transition abnormalities highlight their sensitivity to delirium-related neurophysiological changes. This supports EEG microstate analysis as a tool for understanding delirium mechanisms, with potential applications in early detection and monitoring. Further research is needed to validate these findings and explore their clinical utility.
Disorders of the Nervous System:
Psychiatric (eg. Depression, Anxiety, Schizophrenia) 1
Novel Imaging Acquisition Methods:
EEG 2
Keywords:
Electroencephaolography (EEG)
Other - Delirium, Microstate
1|2Indicates the priority used for review
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Please indicate below if your study was a "resting state" or "task-activation” study.
Resting state
Healthy subjects only or patients (note that patient studies may also involve healthy subjects):
Patients
Was this research conducted in the United States?
No
Were any human subjects research approved by the relevant Institutional Review Board or ethics panel?
NOTE: Any human subjects studies without IRB approval will be automatically rejected.
Yes
Were any animal research approved by the relevant IACUC or other animal research panel?
NOTE: Any animal studies without IACUC approval will be automatically rejected.
Not applicable
Please indicate which methods were used in your research:
EEG/ERP
Neuropsychological testing
Provide references using APA citation style.
Atterton, B., Paulino, M. C., Povoa, P., & Martin-Loeches, I. (2020). Sepsis Associated Delirium. Medicina , 56(5). https://doi.org/10.3390/medicina56050240
Fleischmann, R., Traenkner, S., Kraft, A., Schmidt, S., Schreiber, S. J., & Brandt, S. A. (2019). Delirium is associated with frequency band specific dysconnectivity in intrinsic connectivity networks: preliminary evidence from a large retrospective pilot case-control study. Pilot and Feasibility Studies, 5, 2.
Khanna, A., Pascual-Leone, A., Michel, C. M., & Farzan, F. (2015). Microstates in resting-state EEG: current status and future directions. Neuroscience and Biobehavioral Reviews, 49, 105–113.
Kleinert, T., Koenig, T., Nash, K., & Wascher, E. (2024). On the Reliability of the EEG Microstate Approach. Brain Topography, 37(2), 271–286.
Nagabhushan Kalburgi, S., Kleinert, T., Aryan, D., Nash, K., Schiller, B., & Koenig, T. (2024). MICROSTATELAB: The EEGLAB Toolbox for Resting-State Microstate Analysis. Brain Topography, 37(4), 621–645.
Sharshar, T., Annane, D., de la Grandmaison, G. L., Brouland, J. P., Hopkinson, N. S., & Françoise, G. (2004). The neuropathology of septic shock. Brain Pathology , 14(1), 21–33.
Tokuda, R., Nakamura, K., Takatani, Y., Tanaka, C., Kondo, Y., Ohbe, H., Kamijo, H., Otake, K., Nakamura, A., Ishikura, H., Kawazoe, Y., & J-Stad Japan Sepsis Treatment And Diagnosis Study Group. (2023). Sepsis-Associated Delirium: A Narrative Review. Journal of Clinical Medicine Research, 12(4). https://doi.org/10.3390/jcm12041273
Urdanibia-Centelles, O., Nielsen, R. M., Rostrup, E., Vedel-Larsen, E., Thomsen, K., Nikolic, M., Johnsen, B., Møller, K., Lauritzen, M., & Benedek, K. (2021). Automatic continuous EEG signal analysis for diagnosis of delirium in patients with sepsis. Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology, 132(9), 2075–2082.
Vandenbroucke, J. P., Von Elm, E., Altman, D. G., Gøtzsche, P. C., Mulrow, C. D., Pocock, S. J., Poole, C., Schlesselman, J. J., Egger, M., & Iniciativa STROBE. (2009). [Strengthening the reporting of observational studies in epidemiology (STROBE): explanation and elaboration]. Gaceta sanitaria / S.E.S.P.A.S, 23(2), 158.
No