Prognostication after cardiac arrest: how EEG and evoked potentials may improve the challenge

Benghanem, Sarah; Pruvost-Robieux, Estelle; Bouchereau, Eléonore; Gavaret, Martine; Cariou, Alain

doi:10.1186/s13613-022-01083-9

Annals of Intensive Care

Table 1 Definitions and scales for disorders of consciousness assessment by the intensivist

From: Prognostication after cardiac arrest: how EEG and evoked potentials may improve the challenge

Behavioral criteria	Definitions and pragmatic criteria for diagnosis	Scales and/or scores
Coma [11]	No wakefulness/arousal (no spontaneous eye opening) No awareness of self or environment	Glasgow coma scale [17] Four score or RASS in mechanical ventilated patients [155, 156]
VS also known as UWS [9, 17, 157]	Wakefulness/arousal preserved (spontaneous eye opening) No awareness of self or environment No sustained, reproductible, purposeful behavioral responses to external stimuli No language comprehension or expression Could presented reflex behavioral signs as sound localization Relatively preserved hypothalamic/brainstem autonomic functions Variably preserved cranial-nerve and spinal reflexes	CRS-r [158]
MCS also called CMS [157, 159]	Wakefulness/arousal preserved (spontaneous eye opening) Fluctuating awareness with reproductible, purposeful behavioral responses to external stimuli as visual pursuit, reaching for objects, contingent behavior or orientation to noxious stimulation Does not necessary correspond to “residual consciousness” but at least demonstrates contribution of cortical networks in the behavioral responses (CMS)	CRS-r [158]
Emergence from MCS (E-MCS) [9, 17, 157]	Wakefulness/arousal preserved (spontaneous eye opening) Sign of awareness: following commands, intelligible verbalization or intentional communication	CRS-r [158]
Cognitive-motor dissociation [93]	Wakefulness/arousal preserved (spontaneous eye opening) No or very limited behavioral evidence of awareness but empirical evidence of command-following via fMRI, qEEG or similar indirect measurements of brain response to spoken language	Dissociation between behavioral motor dysfunction and the preserved higher cognitive functions only measurable by functional techniques [89, 92, 92, 160]
Delirium [161]	Acute and fluctuating disturbance of consciousness: attention and impairment of cognition associated with motor hyperactivity or hypoactivity	CAM–ICU and/or ICD-SC [161,162,163]

Pragmatic criteria of DoC assessment for the intensivist are shown in bold.
CAM-ICU Confusion Assessment Method in the ICU, CMS Cortically mediated state, CRS-r Coma Recovery Scale-revised, DoC disorders of consciousness, E-MCS emergence from minimally conscious state, fMRI functional magnetic resonance imaging, ICD-SC Intensive Care Delirium Screening Checklist, MCS minimally conscious state, qEEG quantitative EEG, RASS Richmond Agitation-Sedation Scale, UWS unresponsive wakefulness syndrome, VS vegetative state

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