title: Can mental imagery functional magnetic resonance imaging predict recovery in patients with disorders of consciousness?
abstract: OBJECTIVE
  To determine the potential prognostic value of using functional magnetic resonance imaging (fMRI) to identify patients with disorders of consciousness, who show potential for recovery.
  
  
  METHODS
  Observational study.
  
  
  METHODS
  Unit for acute rehabilitation care.
  
  
  METHODS
  Patients (N=22) in a vegetative state (VS; n=10) and minimally conscious state (MCS; n=12) during the first 200 days after the initial incident.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Further course on the Coma Recovery Scale-Revised.
  
  
  RESULTS
  Participants performed a mental imagery fMRI paradigm. They were asked to alternately imagine playing tennis and navigating through their home. In 14 of the 22 examined patients (VS, n=5; MCS, n=9), a significant activation of the regions of interest (ROIs) of the mental imagery paradigm could be found. All 5 patients with activation of a significant blood oxygen level dependent signal, who were in a VS at the time of the fMRI examination, reached at least an MCS at the end of the observation period. In contrast, 5 participants in a VS who failed to show activation in ROIs, did not (sensitivity 100%, specificity 100%). Six of 9 patients in an MCS with activation in ROIs emerged from an MCS. Of 3 patients in an MCS who did not show activation, 2 patients stayed in an MCS and 1 patient emerged from the MCS (sensitivity 85%, specificity 40%).
  
  
  CONCLUSIONS
  The fMRI paradigm mental imagery displays a high concordance with the further clinical course of patients in a VS. All 5 patients in a VS who showed significant activation of ROIs had a favorable further course until the end of the observation period. We therefore propose the term "functional minimally conscious state" for these patients. They may benefit from rehabilitation treatment. In cases where no significant activation was seen, the method has no prognostic value. Prediction of the clinical course of patients in an MCS by fMRI was considerably less accurate than in patients in a VS.
authors.affiliation: Schön Klinik Bad Aibling, Bad Aibling, Germany; Institute of Medical Psychology and Behavioral Neurobiology, Eberhard-Karls-University Tübingen, Tübingen, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Vogel
authors.forename: Alexandra
authors.initials: A
authors.lastname: Markl
authors.forename: Tao
authors.initials: T
authors.lastname: Yu
authors.forename: Boris
authors.initials: B
authors.lastname: Kotchoubey
authors.forename: Simone
authors.initials: S
authors.lastname: Lang
authors.forename: Friedemann
authors.initials: F
authors.lastname: Müller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003243:Consciousness / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018458:Persistent Vegetative State / Q000503:physiopathology*; D011379:Prognosis; D020127:Recovery of Function; D012047:Rehabilitation Centers; D055815:Young Adult
keywords: BOLD; CRS-R; Coma Recovery Scale-Revised; DOC; EEG; MCS; Magnetic resonance imaging; PET; Persistent vegetative state; Prognosis; ROI; Rehabilitation; TE; TR; VS; blood oxygen level dependent; disorder of consciousness; echo delay time; electroencephalography; fMRI; functional magnetic resonance imaging; minimally conscious state; positron emission tomography; region of interest; repetition time; vegetative state