Editors' note: Neurologic outcome of postanoxic refractory status epilepticus after aggressive treatment

Abstract

In their prospective observational study of 166 survivors of cardiac arrest with anoxic brain injury, Beretta and colleagues categorized patients according to 1 of 4 mutually exclusive EEG patterns: (1) benign, (2) refractory status epilepticus (RSE), (3) generalized periodic discharges (GPDs), or (4) discontinuous/unreactive. The investigators assessed long-term survival and functional outcome based on a minimum of 5 days of EEG monitoring and other clinical and serologic biomarkers. In response, Dr. Nitin Sethi stresses how EEG patterns may vary with time following anoxic brain injury. Dr. Beretta agrees that EEG patterns are likely to fluctuate with time (and treatment) and, for this reason, classified patients according to the most severe pattern observed. Interrater agreement for each of these EEG categories was high (κ = 0.92). Importantly, patients with discontinuous or unreactive background activity or GPDs had extremely poor outcomes (mortality rates of 85% and 98%, respectively), whereas those with RSE had a 53% chance of long-term survival and 44% chance of a good functional outcome. Dr. Sethi also raises several concerns as to when one should initiate EEG monitoring and at what point one should use this electrophysiological data for neuroprognostication. In this investigation, Dr. Beretta and colleagues found a mean duration of RSE to be 4.7 days and therefore suggested 5 days as a reasonable initial assessment point for prognostication. This information may be helpful in the planning of future clinical trials, especially because a pattern of RSE may be associated with a better prognosis than GPD or discontinuous activity. In their prospective observational study of 166 survivors of cardiac arrest with anoxic brain injury, Beretta and colleagues categorized patients according to 1 of 4 mutually exclusive EEG patterns: (1) benign, (2) refractory status epilepticus (RSE), (3) generalized periodic discharges (GPDs), or (4) discontinuous/unreactive. The investigators assessed long-term survival and functional outcome based on a minimum of 5 days of EEG monitoring and other clinical and serologic biomarkers. In response, Dr. Nitin Sethi stresses how EEG patterns may vary with time following anoxic brain injury. Dr. Beretta agrees that EEG patterns are likely to fluctuate with time (and treatment) and, for this reason, classified patients according to the most severe pattern observed. Interrater agreement for each of these EEG categories was high (κ = 0.92). Importantly, patients with discontinuous or unreactive background activity or GPDs had extremely poor outcomes (mortality rates of 85% and 98%, respectively), whereas those with RSE had a 53% chance of long-term survival and 44% chance of a good functional outcome. Dr. Sethi also raises several concerns as to when one should initiate EEG monitoring and at what point one should use this electrophysiological data for neuroprognostication. In this investigation, Dr. Beretta and colleagues found a mean duration of RSE to be 4.7 days and therefore suggested 5 days as a reasonable initial assessment point for prognostication. This information may be helpful in the planning of future clinical trials, especially because a pattern of RSE may be associated with a better prognosis than GPD or discontinuous activity.