Brief Apnea and Hypoventilation Decreases Seizure Length and Location for Several Hours in a Model of Severe Traumatic Brain Injury with Status Epilepticus and Hemorrhage
Abstract number :
3.465
Submission category :
3. Neurophysiology / 3B. ICU EEG
Year :
2023
Submission ID :
1450
Source :
www.aesnet.org
Presentation date :
12/4/2023 12:00:00 AM
Published date :
Authors :
Presenting Author: Michael Mikaelian, Undergraduate – Massachusetts General Hospital
Beth Costine-Bartell, PhD – Principal Investigator, Massachusetts General Hospital; Ann-Christine Duhaime, MD – Massachusetts General Hospital; Frances Rodriguez Lara, BS – Massachusetts General Hospital
Rationale:
Young children with severe traumatic brain injury (TBI) with acute subdural/subarachnoid hemorrhage often present with seizures and periods of apnea and hypoventilation (A&H). The current standard of care for children with TBI with traumatic seizures is anti-epileptic drugs, but seizures are difficult to treat in the immature brain. Exposure to inhaled 5% CO2 with normoxia stops seizures in epileptic patients but is anxiogenic in conscious patients. In our severe model of TBI, we observed that brief A&H acutely interrupted induced seizures. We aimed to determine if brief A&H followed by normoxia/normocapnia persistently altered the course of seizures in this severe TBI model that results in evolution of wide-spread hypoxic-ischemic injury.
Methods:
Injuries were induced in piglets by cortical impact, mass effect, a placed subdural/subarachnoid hemorrhage, and seizures induced with kainic acid while anesthetized with agents that largely avoid the GABA receptor. Apnea (one minute) and hypoventilation (ten minutes; A&H) was induced before (N = 5) or after (N = 8) seizure. Piglets with severe TBI injuries without A&H served as controls (N = 3). Epidural EEG was recorded with a 6-channel bipolar montage for an average of 18 hours. Seizures were defined as paroxysmal spikes at ≥ 2 Hz for ≥ 10 seconds. Ictal spike trains were defined as paroxysmal spikes at 0.15-1.9 Hz for ≥ 10 seconds.
Results:
Brief A&H after seizure induction reduced seizure duration by 80% from 9.5 ± 5.7 hrs to 2.5 ± 2.4 hrs (Means + SD, P = 0.002) compared to injured piglets without A&H. Brief A&H reduced the time spent in seizure by reducing the amount of seizure in the hemisphere ipsilateral to where injuries and seizure was induced (A&H before or after seizure) while keeping the amount of seizure in the contralateral hemisphere or generalized seizure equivalent among groups. Brief A&H before seizure induction to resulted (P < 0.001) in a greater percentage of piglets having exclusively ipsilateral seizures than other groups. The change in seizure location was cumulative over the 18 hours of recording as seizures in the majority of piglets alternated locations for several hours. Indicators of metabolic acidosis changed over the 24-hour experiment as an effect of the severe brain injury (increased glucose, increased lactate, increased anion gap, decreased pH) while the partial pressure of oxygen and CO2 did not differ over time nor among groups.
Neurophysiology