In the News
Determining awareness in patients with brain damage. In patients diagnosed with unresponsive wakefulness syndrome (vegetative state) or as being in a minimally conscious state, fluorodeoxyglucose-assisted positron emission tomography (FDG-PET) identified patients who were likely to recover consciousness better than functional magnetic resonance imaging (fMRI). FDG-PET results correlated well with results of the Coma Recovery Scale–Revised (CRS-R); in 81 patients deemed on assessment to be in a minimally conscious state, the sensitivity of FDG-PET to find the same was 93%, compared with just 45% with fMRI. FDG-PET achieved 85% congruency with CRS-R, whereas fMRI showed only 63% agreement. FDG-PET was 74% accurate in predicting patients who recovered within a year, compared with 56% with fMRI. Repeated testing with the CRS-R complemented with FDG-PET “provides a simple and reliable diagnostic programme with high sensitivity towards unresponsive but aware patients,” wrote the authors in the Lancet (online April 15), although they note that imaging cannot stand alone in the diagnosis of either condition.