Hemodynamic Changes Associated with Sirpids: A Combined Eeg-fnirs Study
Abstract number :
3.486
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2024
Submission ID :
1547
Source :
www.aesnet.org
Presentation date :
12/9/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Lyna-Nour Hamidi, MD, MSc – Centre de recherche du centre hospitalier de l'Université de Montréal (CRCHUM)
Dang Nguyen, MD, PhD, FRCPC – CRCHUM, Department of Neuroscience of the Université de Montréal
Ali Kassab, MD, MSc, PhD – Centre de recherche du centre hospitalier de l'Université de Montréal (CRCHUM)
Ke Peng, BEng, MSc, PhD – Department of Electrical and Computer Engineering, Price Faculty of Engineering
Rationale: Stimulus-induced rhythmic, periodic, or ictal-like discharges (SIRPIDs) are a common type of EEG pattern observed among critically ill patients suffering from acute neurological insults. The pathophysiology of SIRPIDs remains debated, along with the decision to treat them. Functional near-infrared spectroscopy (fNIRS), a non-invasive and portable neuroimaging modality, has the potential to unravel the hemodynamic changes associated with SIRPIDS and possibly guide management.
Methods: In this exploratory study, 6 comatose patients (4 men; mean age of 56; range from 32 to 81 years) underwent prolonged simultaneous EEG-fNIRS in the intensive care unit. Reasons of admission included cardiorespiratory arrest (n = 2), metabolic encephalopathy (n = 3), and idiopathic (n = 1). A stimulation protocol was administered, comprising of auditory, tactile, and nociceptive stimuli, with rest periods in between. Each task was repeated 2 to 3 times. SIRPIDs were marked and correlated with stimulus administration. For each patient, the frequency of the SIRPIDs was calculated by taking the reciprocal of the averaged inter-discharge intervals. fNIRS data were analyzed with a modified version of the open-source MATLAB toolbox HomER2. A hemodynamic response function (HRF) to SIRPIDs was estimated for each patient showing the associated oxygenated hemoglobin (HbO) and deoxygenated hemoglobin (HbR) concentration changes.
Results: SIRPIDs were successfully recorded in all 6 patients. We found an overall increase in HbO and decrease in HbR from baseline elicited by lower frequency SIRPIDs (e.g., 0.3Hz, see Fig.1). However, for patients with higher frequency SIRPIDs (e.g., 0.9Hz), a decrease in HbO was observed following the discharges, implying potentially disrupted neurovascular coupling and insufficient oxygen supply in the underlying brain tissue.
Conclusions: Our results showed that at least some SIRPIDs may behave similarly to ictal events. These findings suggest that treatment with antiseizure medications might be beneficial, particularly for critically ill patients presenting with high frequency SIRPIDs.
Funding: None
Neuro Imaging