The value of EEG monitoring after cardiac arrest treated with hypothermia

The prognostic value of EEG in comatose patients after cardiac arrest (CA) has been an important clinical issue for decades. Research started in the 1960s with the classic study by Hockaday et al.1 in which EEG predicted outcome with a not-so-great reliability of about 80%. At present, the management of post-CA patients often involves the induction of therapeutic hypothermia (TH). TH, a neuroprotective strategy, improves clinical outcomes in comatose patients after witnessed out-of-hospital CA from ventricular fibrillation in randomized controlled trials,2 and it is standard of care for these patients. How to prognosticate outcome in post-CA patients treated with hypothermia has become a very active area of research, in particular regarding the value of EEG monitoring. In this issue of Neurology ®, Rossetti et al.3 add valuable information to this growing body of literature. Rossetti et al. evaluated the prognostic value of EEG findings during TH. They used elevated serum levels of neuron-specific enolase (NSE) as a surrogate marker of irreversible brain damage. They hypothesized that “malignant” EEG patterns were indicative of neuronal damage or death and sought support for this idea by correlating EEG with high NSE levels. The results of their study confirm …