Differentiating the vegetative (VS) from minimally conscious state (MCS) is often one of the most challenging tasks facing clinicians involved in the care of patients with disorders of consciousness (DOC). Whereas VS is characterized by the return of arousal without signs of awareness [
1], MCS is defined by the presence of inconsistent but reproducible goal-directed behaviors (e.g. response to command, verbalizations, visual pursuit, etc.) [
2]. Behavioral assessment remains the "gold standard" for detecting signs of consciousness and, hence, for determining diagnosis [
3]. However, behavioral assessment is complicated by the presence of motor impairment, tracheotomy, fluctuating arousal level or ambiguous and rapidly habituating responses [
4]. Previous studies have shown that 37 to 43% of patients diagnosed with VS demonstrated signs of awareness [
5,
6]. Misdiagnosis can lead to grave consequences, especially in end-of-life decision-making [
7]. Contrary to patients in VS, those in MCS retain some capacity for cognitive processing and activate similar brain networks relatives to controls following painful stimulation; suggesting that they can experience pain [
8,
9]. Moreover, the prognosis of patients in MCS is significantly more favorable relative to those in VS [
10]. End-of-life decisions, therefore, are likely to be influenced by whether one is diagnosed with MCS or VS. In 2002, criteria were proposed to characterize MCS and identify behaviors that signal emergence from this state [
2]. In view of the availability of the MCS criteria, the incidence of misdiagnosis of VS should be lower than the rates reported before these criteria were established [
11]. However, no recent studies have investigated the accuracy of this grave clinical diagnosis. Over the last 15 years, specialized neurobehavioral rating scales have been developed to provide a reliable and valid means of detecting signs of consciousness. There are significant differences among these scales, however, with respect to diagnostic sensitivity [
3]. The Coma Recovery Scale-Revised (CRS-R) was developed specifically to differentiate MCS from VS [
12]. We recently showed that the proportion of patients diagnosed with MCS by the CRS-R was significantly higher as compared to other neurobehavioral scales such as the Glasgow Coma Scale [
13], the Full Outline of UnResponsiveness [
14] and the Wessex Head Injury Matrix [
15]. These results suggest that the type of assessment tool used is crucial to accurate diagnosis [
16,
17]. In this study, we compared consensus-based diagnoses of VS and MCS to those based on the CRS-R, a well-established standardized neurobehavioral rating scale.