title: Serial measurement of Wessex Head Injury Matrix in the diagnosis of patients in vegetative and minimally conscious states: a cohort analysis.
abstract: OBJECTIVE
  To evaluate serial application of the Wessex Head Injury Matrix (WHIM) in diagnosis of prolonged disorders of consciousness (PDOC). Specifically, to determine whether the trajectory of change predicts outcome status, and whether the current hierarchical order of WHIM items is correct for this context.
  
  
  METHODS
  Analysis of prospectively gathered clinical cohort data.
  
  
  METHODS
  Consecutive admissions to a tertiary in-patient neurorehabilitation service for evaluation of PDOC in real-life clinical practice, over a 10-year period (2004-2014).
  
  
  METHODS
  Patients (n=65) presenting in sudden-onset vegetative (VS) or minimally conscious states (MCS). Mean age 38.4 (sd14.1) years; male:female ratio 66%:33%. Aetiology of brain injury: 40(62%) traumatic; 12(19%) vascular; 11(17%) hypoxic; 3(3%) other.
  
  
  METHODS
  WHIM alongside detailed clinical evaluation.
  
  
  METHODS
  The WHIM was administered serially by the multidisciplinary team throughout an in-patient evaluation programme (mean length 74 (sd42) days). Patients were divided into four groups, according to PDOC status on discharge (VS, MCS-Minus, MCS-Plus or Emerged).
  
  
  RESULTS
  WHIM hierarchical scores (Most Advanced Behaviour (MAB)) correlated with PDOC status at discharge (Pearson r=0.49, p<0.001). In the original order, the MAB distinguished the 'VS', 'MCS' and 'Emerged' categories (analysis of variance (ANOVA) post hoc p<0.001), but not the subgroups of MCS-Minus and MCS-Plus. In stepwise regression analysis, MAB-Ex (excluding two items) accounted for 68% of the variance in PDOC status at discharge. On multilevel statistical modelling, trajectory of change in MAB separated the four PDOC groups, both at individual and at group level (p<0.001). After reordering of items, the new-order MAB accounted for more (73%) of the variance in PDOC status, and also distinguished significantly between MCS-Minus and MCS-Plus groups at discharge (p<0.002).
  
  
  CONCLUSIONS
  The WHIM is a useful diagnostic tool in PDOC, and trajectory of change is an important predictor of outcome. The proposed new hierarchical order requires further evaluation in future multicentre analyses.
authors.affiliation: Department of Palliative Care Policy and Rehabilitation, King's College London, School of Medicine, London, UK Regional Rehabilitation Unit, Northwick Park Hospital, London, UK.
authors.forename: Lynne
authors.initials: L
authors.lastname: Turner-Stokes
authors.affiliation: Statsconsultancy Ltd, London, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Bassett
authors.affiliation: Regional Rehabilitation Unit, Northwick Park Hospital, London, UK.
authors.forename: Hilary
authors.initials: H
authors.lastname: Rose
authors.affiliation: Department of Palliative Care Policy and Rehabilitation, King's College London, School of Medicine, London, UK Regional Rehabilitation Unit, Northwick Park Hospital, London, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Ashford
authors.affiliation: Regional Rehabilitation Unit, Northwick Park Hospital, London, UK.
authors.forename: Aung
authors.initials: A
authors.lastname: Thu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001930:Brain Injuries / Q000175:diagnosis; D003244:Consciousness Disorders / Q000175:diagnosis*; D006259:Craniocerebral Trauma / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008131:London; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000379:methods*; D018458:Persistent Vegetative State / Q000175:diagnosis; D011446:Prospective Studies; D055815:Young Adult
keywords: Brain Injuries; Minimally Conscious State; Patient Outcome Assessment; Prolonged Disorders of consciousness; Vegetative State; Wessex Head Injury Matrix