Management of EEG Slowing After Cardiac Arrest

Initial Assessment and Monitoring

The American Heart Association recommends promptly performing and interpreting electroencephalography (EEG) for accurate diagnosis of seizures in post-cardiac arrest patients who are not following commands (Class 1, Level of Evidence C-LD) 1
Continuous or repeated EEG monitoring is reasonable for these patients to detect seizures and monitor brain function (Class 2a, Level of Evidence C-LD) 1, 2

The American Heart Association recommends treatment of clinically apparent seizures in adult cardiac arrest survivors (Class 1, Level of Evidence C-LD) 1
Treatment of nonconvulsive seizures (diagnosed by EEG only) is reasonable (Class 2a, Level of Evidence B-R) 1
For electrographic seizures, initiate antiseizure medication therapy 3
A therapeutic trial of a nonsedating antiseizure medication may be reasonable (Class 2b, Level of Evidence C-EO) 1
The same antiseizure medications used for treatment of seizures from other etiologies may be considered (Class 2b, Level of Evidence C-LD) 1, 4

The American Heart Association recommends against using prophylactic antiseizure medications in adult survivors of cardiac arrest (Class 3: No Benefit, Level of Evidence B-R) 1
Seizures occur in 10-35% of patients with cardiac arrest who do not follow commands after ROSC 3
Postanoxic hyperexcitability can manifest as a wide range of electroclinical findings, from overt convulsions to subtle EEG patterns 2
Do not use the presence of myoclonus alone to predict poor neurologic outcomes due to high false-positive rates (FPR 5-11%) 5, 6

Patients with continuous cortical background activity and those who develop epileptiform abnormalities >24 hours after ROSC are more likely to recover 2
Intractable and persistent status epilepticus (more than 72 hours) in the absence of EEG reactivity to external stimuli may indicate poor outcome (Class IIb, LOE B-NR) 5, 6
Avoid early prognostication based solely on EEG findings; the earliest time to prognosticate poor neurologic outcome is 72 hours after cardiac arrest in patients not treated with targeted temperature management 7