What it looks like
No cerebral activity above 2 µV when recorded to a strict technical standard: at least eight scalp electrodes, inter-electrode distances of at least 10 cm, impedances between 100 Ω and 10 kΩ, sensitivity of 2 µV/mm, at least 30 minutes, with no reactivity to intense stimulation. 5
What it means at the bedside
ECI is not specific for death: sedative overdose and hypothermia produce it reversibly. Brain death is a clinical determination. The 2023 AAN/AAP/CNS/SCCM guideline no longer accepts EEG as an ancillary test; requirements differ between countries, so follow your national protocol. 6 In the viewer, raise the sensitivity to 2 µV/mm: what remains is ECG artefact.