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A multimodal approach for diagnosis and prognosis of covert awareness in disorders of consciousness in the acute stage

English title A multimodal approach for diagnosis and prognosis of covert awareness in disorders of consciousness in the acute stage
Applicant Diserens Karin
Number 189129
Funding scheme Project funding
Research institution Service de Neurologie Département des Neurosciences Cliniques CHUV
Institution of higher education University of Lausanne - LA
Main discipline Neurology, Psychiatry
Start/End 01.05.2020 - 30.04.2023
Approved amount 525'000.00
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Keywords (9)

Disorders of consciousness; Electrophysiology; Prognosis; Cognitive motor dissociation; Behavioural neurology; Covert awareness; Behavioural scales; Neuroimaging; Diagnosis

Lay Summary (French)

Lead
Le développement d’une approche combinant la clinique aux technologies paracliniques est primordial afin d’identifier dès la phase aiguë et de prendre en charge adéquatement des patients présentant une perception consciente cachée. Actuellement, la combinaison de ces méthodes n'est pas encore disponible et le risque de mauvais diagnostic reste élevé.
Lay summary

Contenu et objectifs du travail de recherche

Les désordres de la conscience sont une conséquence fréquente de lésions cérébrales graves. Les spécialistes en médecine intensive et neuro-réadaptation sont quotidiennement mis au défi de fournir des diagnostics et des pronostics précis afin de déterminer les choix thérapeutiques les plus appropriés.

Actuellement, l’évaluation de la conscience repose sur un examen clinique, ce qui peut être entravé par plusieurs facteurs conduisant souvent à un mauvais diagnostic de patients conscients comme inconscients.

Récemment, l’utilisation de méthodes complémentaires comme la neuro-imagerie et l’électrophysiologie a permis de détecter une perception consciente chez des patients qui n’interagissent pas sur le plan comportemental, un phénomène qualifié de dissociation cognitive-motrice.

Dans ce contexte, notre proposition vise à mettre en place une approche multimodale coordonnée impliquant 1) une évaluation neurocomportementale identifiant cliniquement dès la phase aiguë des patients avec perception consciente, associée à un protocole d’évaluation longitudinale ; 2) une évaluation en neuro-imagerie afin de recueillir des informations sur l'emplacement et l'étendue des lésions ; 3) une évaluation électroencéphalographique estimant l’intentionnalité des mouvements en l’absence de comportement moteur observable.

Cette approche multimodale améliorera le diagnostic, le pronostic et la prise en charge des patients avec perception consciente cachée et fournira une meilleure compréhension des mécanismes neurophysiologiques sous-jacents.

Contexte scientifique et social du projet de recherche

D'un point de vue clinique, ce projet fournira des recommandations de pratique fondées sur des données probantes (evidence-based medecine) et aura ainsi une incidence sur la politique en matière de soins donnés à ces patients complexes.

Du point de vue de la recherche, le projet contribuera à une meilleure compréhension de l’état encore méconnu de la dissociation cognitivo-motrice au stade aigu et approfondira les connaissances scientifiques sur les corrélats neuraux de la conscience humaine.

Direct link to Lay Summary Last update: 30.09.2019

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Abstract

Disorders of Consciousness (DOC) result from focal to global brain injuries. They present a crucial challenge to neurologists and neuro-rehabilitation specialists in terms of accuracy of diagnosis, outcome prediction and appropriate treatment-plan development. In particular, it is difficult to properly detect conscious processing in non-communicating individuals and objectively recommend an optimal medical strategy, especially in the early phase. Currently, diagnosing consciousness relies on clinical examination at the bedside. Widely used neurobehavioral rating scales designed to detect behavioral signs of consciousness have been found to generally provide good reliability and validity. However, their interpretation depends on several subjective parameters and they can be critically constrained by patient-specific characteristics such as motor abilities, vigilance fluctuation or aphasia. Over the past decade, supplementary approaches using neuroimaging and electrophysiological techniques have been designed to detect conscious awareness when behavioral examination suggests absent or low-level consciousness - a phenomenon whose proposed name is cognitive-motor dissociation (CMD). Recent studies using these techniques have demonstrated that a significant number of acute and chronic patients misclassified as DOC may indeed present CMD; motor deficits mask the patients’ ability to express language or respond purposefully to examiners at the bedside. Developing a synergetic combination of the technologies and methods for use in an acute clinical setting would have great impact on patient care. It is primordial to integrate the differentiation of classification of patients into the therapeutic decision-making pathway. Indeed, it would help to pave the way for new integrative and innovative models of early assessment and care of CMD patients that would have important implications for the Swiss health care system, including medico-legal ethics and societal issues. However, presently such a combination of methods is not yet available.In this context, our proposal aims to develop a coordinated multimodal approach involving several experts, integrating information from complementary sources to increase detection accuracy of covert awareness among DOC in the acute stage, to inform better the decision-making process and prognosis and to improve early therapeutic interventions. We plan to set up an interdisciplinary assessment between the specialized context of the Acute Neuro-rehabilitation (NRA) unit at University Hospital of Lausanne (CHUV) in collaboration with the Sleep-Wake-Epilepsy-Center at the Bern University Hospital (Inselspital), using three highly interconnected workgroups. (1) A neurobehavioral module that carries out routine clinical identification of CMD using the new validated motor observational-tool (MBT-r) and implements a longitudinal multi-assessment protocol. (2) A neuroimaging module (FDG positron emission tomography) to indicate the diagnostic/prognostic value of brain metabolism and magnetic resonance imaging to gather information on the location and extent of the lesion(s). (3) An electroencephalographic (EEG) assessment, using a Peri-Personal Space (PPS) approach that assesses movement intentionality in potential CMD patients and a quantification of the intra- and interhemispheric synchronization level as marker for consciousness. Such an integrated combination of technologies will provide a multimodal scientific verification of the clinical MBT-r tool and a better understanding of the neurophysiological mechanisms underlying CMD, hence reducing the risk for misdiagnosis. From a clinical perspective, this project will provide evidence-based recommendations for clinical use. From a research perspective, the project will contribute to improved understanding of the complex condition of CMD in the acute stage and will further scientific knowledge regarding neural correlates of human consciousness.
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