title: Transcranial magnetic stimulation combined with high-density EEG in altered states of consciousness.
abstract: BACKGROUND
  This review discusses the advantages of transcranial magnetic stimulation combined with high-density electroencephalography (TMS-hdEEG) over other current techniques of brain imaging.
  
  
  RESULTS
  Its application was reviewed, focusing particularly on disorders of consciousness, in the perspective of recent theories of consciousness. Assessment of non-communicative patients with disorders of consciousness remains a clinical challenge and objective measures of the level of consciousness are still needed. Current theories suggest that a key requirement for consciousness is the brain's capacity to rapidly integrate information across different specialized cortical areas. TMS-EEG allows the stimulation of any given cortical area and the recording of the immediate electrical cortical response. This technique has recently been successfully employed to measure changes in brain complexity under physiological, pharmacological and pathological conditions.
  
  
  CONCLUSIONS
  This suggests that TMS-EEG is a reliable tool to discriminate between conscious and unconscious patients at the single subject level. Future works are needed to validate and implement this technique as a clinical tool.
authors.affiliation: Department of Biomedical and Clinical Sciences 'Luigi Sacco', University of Milan , Milan , Italy .
authors.forename: Martino
authors.initials: M
authors.lastname: Napolitani
authors.forename: Olivier
authors.initials: O
authors.lastname: Bodart
authors.forename: Paola
authors.initials: P
authors.lastname: Canali
authors.forename: Francesca
authors.initials: F
authors.lastname: Seregni
authors.forename: Adenauer
authors.initials: A
authors.lastname: Casali
authors.forename: Steven
authors.initials: S
authors.lastname: Laureys
authors.forename: Mario
authors.initials: M
authors.lastname: Rosanova
authors.forename: Marcello
authors.initials: M
authors.lastname: Massimini
authors.forename: Olivia
authors.initials: O
authors.lastname: Gosseries
mesh_terms: D001930:Brain Injuries / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D003244:Consciousness Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D004569:Electroencephalography; D006801:Humans; D020127:Recovery of Function; D015203:Reproducibility of Results; D050781:Transcranial Magnetic Stimulation; D016896:Treatment Outcome
keywords: Consciousness; effective connectivity; electroencephalography; minimally conscious state; transcranial magnetic stimulation; unresponsive wakefulness syndrome; vegetative state