Year, Volume, Issue, Page(s):10, 75, 21, 1871-1878
Study used functional magnetic resonance imaging (fMRI) to evaluate the feasibility of using a silent picture-naming task as a command-following paradigm to assess cognitive capacity in patients with disorders of consciousness (DOC) when conventional methods are not sufficient. A total of 10 patients with and without conventional evidence of awareness participated in this study, including 5 in the minimally conscious state (MCS), 3 in vegetative state (VS), 1 who emerged from MCS (EMCS), and 1 with locked-in syndrome (LIS). The LIS and EMCS patients engaged a complete network of essential language-related regions during the object-naming task. The MCS and 2 of the VS patients demonstrated both complete and partial preservation of the object-naming system. Patients who engaged a complete network scored highest on the Coma Recovery Scale-Revised. This study supports the view that fMRI during object naming can elicit brain activations in patients with DOC similar to those observed in healthy subjects during command following, and patients can be stratified by completeness of the engaged neural system. Results suggest that activity of the language network may serve as an indicator of high-level cognition and possibly volitional processes that cannot be discerned through conventional behavioral assessment alone.