An aggressive and standardized treatment regimen for refractory status epilepticus (RSE) may be helpful for improving 6-month survival and neurologic outcome, particularly among people with RSE with benign electroencephalography (EEG) patterns within the first 5 days after cardiac arrest, according to a study published in Neurology.

A total of 166 consecutive patients hospitalized with cardiac arrest and subsequent coma at a single center in Italy were enrolled. Patients were stratified according to their EEG patterns observed within the first 5 days following cardiac arrest. These patterns were benign pattern (n=76), RSE pattern (n=36), generalized periodic discharge pattern (n=13), and malignant nonepileptiform pattern (n=41). A treatment protocol comprised of targeted temperature management (ie, 34°C for 24 hours), simplified 4-channel continuous EEG monitoring, on-call neurologic consultations with an epilepsy specialist, and as-needed antiepileptic drug administration was initiated. The primary outcomes of interest included survival and neurologic disability at 6 months following cardiac arrest.

Approximately 22% (n=36) of patients experienced RSE and, if multimodal prognostic indicators were not considered unfavorable, was managed with an aggressive treatment protocol. The RSE events occurred a total of 3±2.3 days following cardiac arrest onset, and these events lasted for 4.7±4.3 days. The benign, RSE, generalized periodic discharge, and malignant nonepileptiform patterns were associated with several different prognostic indicators, including low-flow time, N20 responses, clinical motor seizures, neuron-specific enolase, and neuroimaging.

In the first 5 days following cardiac arrest, the EEG pattern was significantly associated with survival (P =.0001) and neurologic outcome (P <.0001). The greatest change in survival and good neurologic outcome at 6 months was observed in patients with a benign EEG pattern (72.4% and 71.1%, respectively). Comparatively, a moderate reduction in survival and neurologic outcome was observed for RSE patterns (52.8% [odds ratio (OR) 0.43; 95% CI, 0.19-0.97] and 44.4% [OR 0.33; 95% CI, 0.13-0.80], respectively).

A lower proportion of patients with generalized periodic discharge patterns survived (15.4%; OR 0.07; 95% CI, 0.01-0.34) or experienced a good neurologic outcome (0%; OR 0.02; 95% CI, 0.00-0.12) at 6 months. A low proportion of those with malignant nonepileptiform EEG pattern survived (2.4%; OR 0.01; 95% CI, 0.00-0.07) or had good neurologic outcome (0%; OR 0.01; 95% CI, 0.00-0.04).

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The recruitment of patients from a single university hospital and the small sample size may have introduced bias into the study and reduced generalizability of the findings.

“We believe that our findings revealed some important issues in terms of patient selection and intensity and duration of treatment that could inspire the design of future randomized controlled trials comparing aggressive and conservative treatment of postanoxic status epilepticus,” the researchers concluded.

Reference

Beretta S, Coppo A, Bianchi E, et al. Neurologic outcome of postanoxic refractory status epilepticus after aggressive treatment. Neurology. 2018;91(23):e-2153-e2162.