PT  - JOURNAL ARTICLE
AU  - Haibo Di
AU  - Melanie Boly
AU  - Xuchu Weng
AU  - Didier Ledoux
AU  - Steven Laureys
TI  - Neuroimaging activation studies in the vegetative state: predictors of recovery?
AID  - 10.7861/clinmedicine.8-5-502
DP  - 2008 Oct 01
TA  - Clinical Medicine
PG  - 502--507
VI  - 8
IP  - 5
4099  - http://www.rcpjournals.org/content/8/5/502.short
4100  - http://www.rcpjournals.org/content/8/5/502.full
SO  - Clin Med2008 Oct 01; 8
AB  - The vegetative state (VS) is a devastating clinical condition characterised by wakefulness without awareness. Functional neuroimaging permits to objectively measure brain responsiveness to external stimuli in VS. The literature on functional magnetic resonance imaging and positron emission tomography studies in these patients has been reviewed. Results from 15 studies were classified in: absent cortical activation or ‘typical’ activation of ‘low level’ primary sensory cortices and ‘atypical’ activation spreading to ‘higher level’ associative cortices. This descriptive review on 48 published cases suggests that ‘atypical’ activation patterns seem to herald recovery from VS with a 93% specificity and 69% sensitivity. Passive stimulation paradigms, however, do not permit to make strong claims about the absence or presence of consciousness. Recently proposed mental imagery paradigms permit to identify signs of consciousness in non-communicative brain damaged patients. The clinical application of these functional neuroimaging techniques awaits validation from ongoing multi-centric cohort studies in these challenging patients with chronic disorders of consciousness.