Mise au point Diagnostic et évaluation des états de conscience altérée Diagnosis and investigation of altered states of consciousness

Progress in intensive care has increased the number of patients who survive severe acute brain injury. Nevertheless, whereas some patients recover quickly, others take more time and pass through different states of altered consciousness (coma, vegetative state, minimally conscious state) before recovering a normal state of conscious awareness. Still other patients will remain in a more permanent state of altered consciousness. The management of these patients is thus very important. However, no methods can measure awareness directly. The bedside behavioural assessment is the main way to detect signs of awareness. In this context, a large number of scales have been developed (for instance, the Glasgow Coma Scale, the Wessex Head Injury Matrix or the Coma Recovery Scale). These give useful information about the patient’s recovery and allow to adapt the patients’ daily management. Additionally, functional neuroimaging techniques (e.g., positron emission tomography—PET or functional magnetic resonance imaging—fMRI) can be used to objectively measure brain function in these patients. Combining extensive neuropsychological testing with functional neuroimaging techniques permits to better estimate the residual cognitive capacities and their evolution over time. © 2004 Société de réanimation de langue française. Publié par Elsevier SAS. Tous droits réservés. Mots clés : État de conscience altérée ; Diagnostic ; Évaluation comportementale ; Imagerie fonctionnelle