In acute brain injury, the need for specific expertise on central nervous pathophysiology is evident. However, even when the primary reason for ICU admission is extracranial, the brain may be affected too, through inadequate substrate and oxygen delivery, blood brain barrier leek, harmful effects of sedatives, and excitotoxicity. The resulting spectrum of brain dysfunction includes delirium, encephalopathy, coma, and non-convulsive seizures. Therefore, all intensive care should integrate neuro-intensive care, with the primary goal to preserve the brain.