Wijdicks and colleagues1 recently presented the Full Outline of UnResponsiveness (FOUR) scale as an alternative to the Glasgow Coma Scale (GCS)2 in the evaluation of consciousness in severely brain-damaged patients. They studied 120 patients in an intensive care setting (mainly neuro-intensive care) and claimed that “the FOUR score detects a locked-in syndrome, as well as the presence of a vegetative state.”1 We fully agree that the FOUR is advantageous in identifying locked-in patients given that it specifically tests for eye movements (...) or blinking on command. This is welcomed given that misdiagnosis of the locked-in syndrome has been shown to occur in more than half of the cases (see Laureys and colleagues3 for review). As for the diagnosis of the vegetative state, the scale explicitly tests for visual pursuit, and hence can disentangle the vegetative state from the minimally conscious state (MCS). The diagnostic criteria for MCS have been proposed4 only recently, but Wijdicks and colleagues1 do not mention the existence of this clinical entity in their article. As for the vegetative state, MCS can be encountered in the acute or subacute setting as a transitional state on the way to further recovery, or it can be a more chronic or even permanent condition. The MCS refers to patients showing inconsistent, albeit clearly discernible, minimal behavioral evidence of consciousness (eg, localization of noxious stimuli, eye fixation or tracking, reproducible movement to command, or nonfunctional verbalization).4 The FOUR scale does not test for all of the behavioral criteria required to diagnose MCS.4 It is known from the literature (see Majerus and colleagues5 for review) that about a third of patients diagnosed with vegetative state are actually in MCS, and this misdiagnosis can lead to major clinical, therapeutic, and ethical consequences. We tested the ability of the newly proposed FOUR scale to correctly diagnose the vegetative state in an acute (intensive care and neurology ward) and chronic (neurorehabilitation) setting.. (shrink)