BACKGROUND/AIMS: The purpose of the present article is a systematic review of 
the proposed medical or surgical treatments in patients in chronic vegetative 
state (VS) or minimally conscious state (MCS), as well as of their mechanisms of 
action and limitations.
METHODS: For this review, we have agreed to include patients in VS or MCS having 
persisted for over 6 months in posttraumatic cases, and over 3 months in 
nontraumatic cases, before the time of intervention. Searches were independently 
conducted by 2 investigators between May 2009 and September 2009 in the 
following databases: Medline, Web of Science and the Cochrane Library. The 
electronic search was complemented by cross-checking the references of all 
relevant articles. Overall, 16 papers were eligible for this systematic review.
RESULTS: According to the 16 eligible studies, medical management by 
dopaminergic agents (levodopa, amantadine), zolpidem and median nerve 
stimulation, or surgical management by deep brain stimulation, extradural 
cortical stimulation, spinal cord stimulation and intrathecal baclofen have 
shown to improve the level of consciousness in certain cases.
CONCLUSION: The treatments proposed for disorders of consciousness have not yet 
gained the level of 'evidence-based treatments'; moreover, the studies to date 
have led to inconclusiveness. The published therapeutic responses must be 
substantiated by further clinical studies of sound methodology.