  This study aimed to identify white matter (WM) deficits underlying the loss
of consciousness in disorder of consciousness (DOC) patients using Diffusion
Tensor Imaging (DTI) and to demonstrate the potential value of DTI parameters
in predicting recovery outcomes of DOC patients. With 30 DOC patients (8
comatose, 8 unresponsive wakefulness syndrome/vegetative state, and 14 minimal
conscious state) and 25 patient controls, we performed group comparison of DTI
parameters across 48 core WM regions of interest (ROIs) using Analysis of
Covariance. Compared with controls, DOC patients had decreased Fractional
anisotropy (FA) and increased diffusivities in widespread WM area.The
corresponding DTI parameters of those WM deficits in DOC patients significantly
correlated with the consciousness level evaluated by Coma Recovery Scale
Revised (CRS-R) and Glasgow Coma Scale (GCS). As for predicting the recovery
outcomes (i.e., regaining consciousness or not, grouped by their Glasgow
Outcome Scale more than 2 or not) at 3 months post scan, radial diffusivity of
left superior cerebellar peduncle and FA of right sagittal stratum reached an
accuracy of 87.5% and 75% respectively. Our findings showed multiple WM
deficits underlying the loss of consciousness level, and demonstrated the
potential value of these WM areas in predicting the recovery outcomes of DOC
patients who have lost awareness of the environment and themselves.
