Preserved XXXX in vegetative and minimal conscious states: systematic review and meta-analysis.

@entity1 @entity1545 @entity29365 @entity47 @entity1662 @entity15131
Active, passive and resting state paradigms using functional MRI (fMRI) or EEG may reveal @entity1662 in the vegetative (VS) and the @entity47 ( @entity47 ). A meta-analysis was performed to assess the prevalence of preserved @entity1662 in VS and @entity47 as revealed by fMRI and EEG, including command following (active paradigms), cortical functional connectivity elicited by external stimuli (passive paradigms) and @entity15131 (resting state). Studies were selected from multiple indexing databases until February 2015 and evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2. 37 studies were identified, including 1041 @entity1 (mean age 43   years, range 16-89; male/female 2.1:1; 39.5% traumatic @entity1545 ). @entity47 @entity1 were more likely than VS @entity1 to follow commands during active paradigms (32% vs 14%; OR 2.85 (95% CI 1.90 to 4.27; p<0.0001)) and to show preserved functional cortical connectivity during passive paradigms (55% vs 26%; OR 3.53 (95% CI 2.49 to 4.99; p<0.0001)). Passive paradigms suggested preserved @entity1662 more often than active paradigms (38% vs 24%; @entity29365 (95% CI 1.54 to 2.54; p<0.0001)). Data on resting state paradigms were insufficient for statistical evaluation. In conclusion, active paradigms may underestimate the degree of @entity1662 as compared to passive paradigms. While @entity47 @entity1 show signs of preserved @entity1662 more frequently in both paradigms, roughly 15% of @entity1 with a clinical diagnosis of VS are able to follow commands by modifying their brain activity. However, there remain important limitations at the single-subject level; for example, @entity1 from both categories may show command following despite negative passive paradigms.
