Model System:

TBI

Reference Type:

Journal article

Accession No.:

J81321

Journal:

Cortex

Year, Volume, Issue, Page(s):

, , ,

Publication Website:

Abstract:

Study investigated whether default mode network (DMN) properties in patients with covert consciousness are more similar to those in patients with overt consciousness than to patients with coma, vegetative state (VS), or minimally conscious state without language function (MCS-). Sixteen patients with acute severe traumatic brain injury (TBI) admitted to the intensive care unit (ICU) and 16 age- and sex-matched healthy subjects participated in task-based and resting-state functional magnetic resonance imaging (fMRI). Overt consciousness was defined by Coma Recovery Scale-Revised (CRS-R) diagnoses of MCS with language function (MCS+) and post-traumatic confusional state (PTCS). Covert consciousness was defined by fMRI activation in supplementary motor or premotor cortices during a hand-squeezing imagery task, in the absence of language function on the CRS-R. Thus, in addition to coma and VS patients, MCS- patients who performed the fMRI task were also considered to be covertly conscious. Three DMN properties were analyzed: (1) resting blood-oxygen-level-dependent correlations within the DMN; (2) resting anticorrelations between DMN nodes and the whole brain; and (3) task-based DMN deactivations. DMN preservation differed between patients with covert and overt consciousness in the ICU. Whereas all overtly conscious patients had at least one intact DMN property (range 1to 3), covertly conscious patients had 0 to 2 intact DMN properties. Compared to healthy subjects, patients diagnosed with coma, VS, MCS-, and covert consciousness had fewer intact DMN properties than did patients diagnosed with MCS+ or PTCS. Furthermore, like DMN correlations, DMN deactivations were present more frequently than anticorrelations, supporting prior evidence that anticorrelations are the last DMN property to reemerge

Author(s):

Bodien, Yelena G.|Threlkeld, Zachry D.|Edlow, Brian L.|

Participating Centers: