Introduction to the JFK Coma Recovery Scale-Revised (CRS-R)

Description and Purpose of the JFK Coma Recovery Scale-Revised (CRS-R)
The JFK Coma Recovery Scale was initially described by Giacino and colleagues in 1991. The scale was restructured by Giacino and Kalmar and republished in 2004 as the JFK Coma Recovery Scale-Revised (Giacino, Kalmar and Whyte, 2004). The purpose of the scale is to assist with differential diagnosis, prognostic assessment and treatment planning in patients with disorders of consciousness. The scale consists of 23 items that comprise six subscales addressing auditory, visual, motor, oromotor, communication and arousal functions. CRS-R subscales are comprised of heirachically-arranged items associated with brain stem, subcortical and cortical processes. The lowest item on each subscale represents reflexive activity while the highest items represent cognitively-mediated behaviors. Scoring is standardized and is based on the presence or absence of operationally-defined behavioral responses to specific sensory stimuli. Adequate interrater and test-retest reliability have been demonstrated and concurrent validity has been established relative to the Disability Rating Scale. A recently-published review of behavioral assessment methods completed by European researchers recommended use of the CRS-R as a "new promising tool" for evaluation of consciousness after severe brain injury (Majerus, et al., 2005). Spanish, Italian, German, French, Dutch and Norwegian translations of the CRS-R are available.

Clinical and Research Applications
The diagnostic utility of the CRS-R was investigated by Giacino, Kalmar and Whyte in 2004. Eighty patients were assigned a diagnosis of VS or MCS following completion of the CRS-R and the DRS. In 51 of the 80 patients assessed, both scales produced a diagnosis of MCS. An additional 19 patients received a diagnosis of VS on both measures. The overall rate of agreement in diagnosis was 87%. There were no cases in which the DRS found evidence of MCS while the CRS-R did not. Conversely, there were 10 cases in which the CRS-R profile supported a diagnosis of MCS while the DRS findings were indicative of VS. In all 10 of these cases, the CRS-R detected evidence of visual pursuit, a diagnostic feature of MCS that is not represented on the DRS.

Schnakers and associates (in press) compared the diagnostic accuracy of the CRS-R to the GCS and the Full Outline of UnResponsiveness scale (FOUR). The FOUR is a recently developed scale that was designed to differentiate VS from the locked-in syndrome, however, it does not assess all of the behaviors associated with MCS. Sixty patients (GCS<8), primarily with traumatic, anoxic-ishemic and vascular etiologies, were prospectively evaluated with the FOUR, GCS and CRS-R in randomized order. Based on the GCS evaluation, 29 patients were diagnosed with VS. The FOUR indicated that 4 of these 29 patients were in MCS as visual pursuit was detected in these cases. Of the remaining 25 patients diagnosed with VS on the GCS and the FOUR, the CRS-R identified 7 additional patients in MCS based on the presence of visual fixation, a diagnostic feature of MCS that is not assessed on either the GCS or the FOUR.

The CRS-R has been utilized in TBI outcomes research and in large-scale epidemiologic studies. A 2005 Australian study of patients who were in MCS for at least one month after TBI used the CRS-R to document long-term outcome. Results showed that duration of time in MCS did not predict psychosocial outcome at 2-5 years post-injury and that a large percentage of MCS patients eventually regained functional independence. The governments of Belgium and Italy are currently using the CRS-R to investigate the incidence, prevalence, functional outcome and costs of care in patients diagnosed with VS and MCS.

Readers may also be interested in earlier research using the original version of the CRS. Giacino and Kalmar (1997) employed the CRS to estimate the incidence of selected neurobehavioral signs in patients admitted to rehabilitation with a diagnosis of either VS or MCS. Visual pursuit and motor agitation were observed significantly more frequently in the MCS group. Among patients in the VS group, 73% (8/11) of those who demonstrated pursuit recovered consciousness within the first 12 months post-injury, as compared to 45% (20/44) of those who did not evidence this behavior.

The prognostic utility of the CRS was investigated in a number of additional studies. Giacino et al. (1991) found that CRS change scores obtained during the initial four weeks of inpatient rehabilitation correlated more strongly with functional outcome at one year than did GCS change scores, after controlling for the influence of injury severity and length of time post-injury. In a second study (Giacino and Kalmar, 1997) focusing on the influence of diagnosis on functional outcome, level of functional disability on the DRS was found to be significantly lower at 12 months post-injury in patients diagnosed with MCS on admission to rehabilitation (mean time post-injury=9 weeks), relative to those in VS. This difference was most pronounced for patients with traumatic versus non-traumatic brain injuries. In those with traumatic injuries, 50% of patients in MCS had no to moderate disability at 12 months, while only 3% of patients in VS recovered to this level of function. Thompson et al. (1999) used the CRS to study the relationship between time to recovery of consciousness and degree of cognitive improvement from admission to discharge on the Functional Independence Measure. Principal components analysis indicated that time to recovery of consciousness (based on CRS subscale scores) accounted for 60% of the variability in cognitive change and correctly classified 22 of 25 patients on this index.

Information regarding the CRS-R was contributed by JFK-Johnson Rehabilitation Institute. Please contact Joseph Giacino, Ph.D., at for more information.

If you find the information in the COMBI useful, please mention it when citing sources of information. The information on the CRS may be cited as:

Giacino, J & Kalmar, K. (2006). Coma Recovery Scale-Revised. The Center for Outcome Measurement in Brain Injury. http://www.tbims.org/combi/crs ( accessed ).