title: Prediction of cognitive outcome based on the progression of auditory discrimination during coma.
abstract: To date, no clinical test is able to predict cognitive and functional outcome of cardiac arrest survivors. Improvement of auditory discrimination in acute coma indicates survival with high specificity. Whether the degree of this improvement is indicative of recovery remains unknown. Here we investigated if progression of auditory discrimination can predict cognitive and functional outcome.
  
  
  
  We prospectively recorded electroencephalography responses to auditory stimuli of post-anoxic comatose patients on the first and second day after admission. For each recording, auditory discrimination was quantified and its evolution over the two recordings was used to classify survivors as "predicted" when it increased vs. "other" if not. Cognitive functions were tested on awakening and functional outcome was assessed at 3 months using the Cerebral Performance Categories (CPC) scale.
  
  
  
  Thirty-two patients were included, 14 "predicted survivors" and 18 "other survivors". "Predicted survivors" were more likely to recover basic cognitive functions shortly after awakening (ability to follow a standardized neuropsychological battery: 86% vs. 44%; p=0.03 (Fisher)) and to show a very good functional outcome at 3 months (CPC 1: 86% vs. 33%; p=0.004 (Fisher)). Moreover, progression of auditory discrimination during coma was strongly correlated with cognitive performance on awakening (phonemic verbal fluency: rs=0.48; p=0.009 (Spearman)).
  
  
  
  Progression of auditory discrimination during coma provides early indication of future recovery of cognitive functions. The degree of improvement is informative of the degree of functional impairment. If confirmed in a larger cohort, this test would be the first to predict detailed outcome at the single-patient level.
authors.affiliation: Laboratoire de Recherche en Neuroimagerie (LREN), Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland; Neurology Service, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland. Electronic address: elsa.juan@unil.ch.
authors.forename: Elsa
authors.initials: E
authors.lastname: Juan
authors.affiliation: Laboratoire de Recherche en Neuroimagerie (LREN), Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland.
authors.forename: Marzia
authors.initials: M
authors.lastname: De Lucia
authors.affiliation: Department of Psychiatry, Psychotherapy, and Psychosomatics, University of Zurich, 8032 Zurich, Switzerland.
authors.forename: Athina
authors.initials: A
authors.lastname: Tzovara
authors.affiliation: Neuropsychology and Neurorehabilitation Service, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland.
authors.forename: Valérie
authors.initials: V
authors.lastname: Beaud
authors.affiliation: Department of Intensive Care Medicine, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland.
authors.forename: Mauro
authors.initials: M
authors.lastname: Oddo
authors.affiliation: Neuropsychology and Neurorehabilitation Service, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Clarke
authors.affiliation: Neurology Service, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland.
authors.forename: Andrea O
authors.initials: AO
authors.lastname: Rossetti
mesh_terms: D000328:Adult; D000368:Aged; D003071:Cognition / Q000502:physiology*; D003128:Coma / Q000209:etiology / Q000503:physiopathology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006323:Heart Arrest / Q000150:complications* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity
keywords: Cognition; EEG; Functional outcome; Post-anoxic coma; Prediction