Progress in intensive care has led to an increase in the number of patients who survive severe brain injury and, therefore, the number of patients with impaired consciousness. Behavioral assessment remains the gold standard to monitor the level of consciousness. However, about one-third of patients diagnosed with a vegetative state are actually conscious (or in a minimally conscious state). We compared the ability of the famous Glasgow Coma Scale (GCS) and other standardized behavioral scales to correctly diagnose the vegetative state in an acute (intensive care and neurology ward) and chronic (neuro-rehabilitation) setting.
Sixty postcomatose patients (that is, GCS > 8) were prospectively assessed using the GCS, the Full Outline of UnResponsiveness (FOUR) and the Coma Recovery Scale-Revised (CRS-R) in randomized order. The mean age was 50 years (range 18–86); 39 were men. Etiology was traumatic in 24 patients.
Overall, 29 patients (16 acute and 13 chronic patients) were considered as being in a vegetative state based on the GCS. The FOUR identified four out of these 29 patients (1/16 acute and 3/13 chronic patients) as not being vegetative considering the presence of visual pursuit. The CRS-R identified an additional seven patients (4/16 acute and 3/13 chronic patients) showing visual fixation meeting the criteria for a minimally conscious state set forth by the Aspen Workgroup. Therefore, the GCS diagnosed a total of 38% (11/29) of conscious patients (5/16 acute and 6/13 chronic patients) as being in a vegetative state.
Using the GCS can lead one to misdiagnose conscious patients. This misdiagnosis can lead to major clinical, therapeutic and ethical consequences. Using additional sensitive tools such as the CRS-R can avoid this kind of situation.