Behavioral recovery in disorders of consciousness: a prospective study with the Spanish version of the Coma Recovery Scale-Revised.

OBJECTIVE: To describe the clinical characteristics and short-term pattern of evolution of a sample of patients within 1 year after acquiring a brain injury that led to a vegetative state (VS) or a minimally conscious state (MCS). DESIGN: Cohort study. SETTING: Inpatient brain injury rehabilitation program. PARTICIPANTS: Patients with acquired brain injury (N=32; 47% traumatic, 37.5% hemorrhagic, 15.5% anoxic) who were in a VS or an MCS according to Coma Recovery Scale-Revised (CRS-R) scores. INTERVENTION: Integrative multisensory program comprising daily physical rehabilitation procedures and multimodal sensory stimulation. MAIN OUTCOME MEASURE: All patients were assessed with a Spanish version of the CRS-R at admission and then monthly for at least 6 months or until emergence from MCS. RESULTS: At the time of admission, 12 patients were diagnosed as being in a VS and 20 as being in an MCS. Eight patients were able to emerge from their MCS during follow-up. Seven of these 8 patients were diagnosed as being in an MCS at inclusion, and only 1 was diagnosed as being in a VS. Emergence from an MCS was mostly associated with improvement in both the communication and motor function scales (n=4). Lesser chronicity (P=.01) and the presence of more than visual behavioral responses at admission (P=.05) were both significant predictors of emergence from an MCS. CONCLUSIONS: The CRS-R seems appropriate for establishing an immediate prognosis in this population. A quick referral of these patients for specialized assessment and rehabilitation facilities is recommended.

A voxel-based analysis of FDG-PET in traumatic brain injury: regional metabolism and relationship between the thalamus and cortical areas.

The objective was to study the correlations and the differences in glucose metabolism between the thalamus and cortical structures in a sample of severe traumatic brain injury (TBI) patients with different neurological outcomes. We studied 49 patients who had suffered a severe TBI and 10 healthy control subjects using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET). The patients were divided into three groups: a vegetative or minimally-conscious state (MCS&VS) group (n=17), which included patients who were in a vegetative or a minimally conscious state; an In-post-traumatic amnesia (In-PTA) group (n=12), which included patients in PTA; and an Out-PTA group (n=20), which included patients who had recovered from PTA. SPM5 software was used to determine the metabolic differences between the groups. FDG-PET images were normalized and four regions of interest were generated around the thalamus, precuneus, and the frontal and temporal lobes. The groups were parameterized using Student's t-test. Principal component analysis was used to obtain an intensity-estimated-value per subject to correlate the function between the structures. Differences in glucose metabolism in all structures were related to the neurological outcome, and the most severe patients showed the most severe hypometabolism. We also found a significant correlation between the cortico-thalamo-cortical metabolism in all groups. Voxel-based analysis suggests a functional correlation between these four areas, and decreased metabolism was associated with less favorable outcomes. Higher levels of activation of the cortico-cortical connections appear to be related to better neurological condition. Differences in the thalamo-cortical correlations between patients and controls may be related to traumatic dysfunction due to focal or diffuse lesions.

Voxel-based statistical analysis of thalamic glucose metabolism in traumatic brain injury: relationship with consciousness and cognition.

OBJECTIVE: To study the relationship between thalamic glucose metabolism and neurological outcome after severe traumatic brain injury (TBI). METHODS: Forty-nine patients with severe and closed TBI and 10 healthy control subjects with (18)F-FDG PET were studied. Patients were divided into three groups: MCS&VS group (n = 17), patients in a vegetative or a minimally conscious state; In-PTA group (n = 12), patients in a state of post-traumatic amnesia (PTA); and Out-PTA group (n = 20), patients who had emerged from PTA. SPM5 software implemented in MATLAB 7 was used to determine the quantitative differences between patients and controls. FDG-PET images were spatially normalized and an automated thalamic ROI mask was generated. Group differences were analysed with two sample voxel-wise t-tests. RESULTS: Thalamic hypometabolism was the most prominent in patients with low consciousness (MCS&VS group) and the thalamic hypometabolism in the In-PTA group was more prominent than that in the Out-PTA group. Healthy control subjects showed the greatest thalamic metabolism. These differences in metabolism were more pronounced in the internal regions of the thalamus. CONCLUSIONS: The results confirm the vulnerability of the thalamus to suffer the effect of the dynamic forces generated during a TBI. Patients with thalamic hypometabolism could represent a sub-set of subjects that are highly vulnerable to neurological disability after TBI.