Cortical Hemodynamic Changes Associated with Status Epilepticus in Critically Ill Patients
Abstract number :
2.462
Submission category :
5. Neuro Imaging / 5B. Functional Imaging
Year :
2022
Submission ID :
2232883
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:28 AM
Authors :
Ali Kassab, MD – Université de Montréal; Dènahin Hinnoutondji Toffa, MD – Neurosciences – CHUM Research Centre; Manon Robert, MSc – Neurosciences – CHUM Research Centre; Frédéric Lesage, PhD – Department of Electrical Engineering – Polytechnique Montréal; Ke Peng, PhD – Neurosciences – CHUM Research Centre; Dang Khoa Nguyen, MD, PhD – Neurosciences – CHUM Research Centre
This is a Late Breaking abstract
Rationale: It is well recognized that status epilepticus (SE) can result in neuronal injury. While the pathophysiological mechanisms leading to brain damage are presumably multifactorial, the abnormal variations of oxygen levels during SE seizures remain a plausible cause. Unfortunately, animal and human studies on brain metabolism and hemodynamics during SE have been conflictual. Functional near-infrared spectroscopy (fNIRS) is a non-invasive imaging technique that measures changes in oxyhemoglobin and deoxyhemoglobin concentrations with a high temporal resolution, which can be used to infer changes in cerebral blood volume (with the sum of the two hemoglobin concentrations) and cerebral blood flow (with the difference of the two concentrations). fNIRS is currently the only modality that can continuously and non-invasively monitor brain hemodynamics over all the superficial cortex in patients with SE. Current use of combined video electroencephalography and fNIRS (vEEG-fNIRS) in critical care seizures and SE have been limited to only a few cases in the pediatric setting. Moreover, there are no long-term whole-head vEEG-fNIRS monitoring reports in critically ill patients, as such recordings remain a considerable clinical and technical challenge.
Methods: In order to assess large-scale cortical hemodynamics during recurrent and/or prolonged seizures, we performed simultaneous whole-head and long-term vEEG-fNIRS recordings in the intensive care unit at our institution and measured hemodynamics changes of 11 critically ill patients admitted with (or later developed) SE.
Results: More than 200h of monitoring and 1000 seizures were recorded (seizure duration: ~ 5s to ~ 2h, and inter-ictal interval: ~ 1s to ~ 45min). We observed that most short-duration seizures (e.g., seizures < 60s - 100s) in a patient were associated with an increase in oxyhemoglobin concentration ([HbO]), cerebral blood volume, and cerebral blood flow, and a decrease in deoxyhemoglobin concentration ([HbR]). However, while a similar increase in [HbO] and a decrease in [HbR] could also be seen at the beginning of long-duration seizures (e.g., > 100s), such hemodynamic change was often followed by a prolonged decline in [HbO] and an increase in [HbR], suggesting an insufficient oxygen supply after the first seconds of the seizure and a brain hypoxic state afterwards.
Conclusions: We observed complex temporal and spatial patterns of the hemodynamic changes induced by seizures, confirming, for the first time in adults, similar observations previously seen only in vitro and in rodents models of SE. vEEG-fNIRS has the potential to offer clinicians a relatively novel, inexpensive, and non-invasive complementary approach to assess cortical hemodynamics during seizures and status epilepticus in the critically ill.
Funding: Canadian Institutes of Health Research (CIHR), National Sciences and Engineering Research Council in partnership with CIHR, Canada Research Chair Program, Fonds de recherche du Québec – Santé, TransMedTech Excellence Scholarship from Canada First Research Fund
Neuro Imaging