Investigation of Mnesic Capacities in Patients With a Disorder of Consciousness

NCT06959212 | Recruiting

• 1 other identifier: APHP240232
• Study Type: interventional
• Target: 175
• Locations: 1 country
• Sites: 2

Brief Summary

Following severe brain damage, some individuals lose partial or total awareness of themselves and their environment, falling into a coma that can evolve towards a Disorder of Consciousness (DoC). Accurately diagnosing the depth of consciousness alteration, and thus characterizing the patient's residual state of consciousness, is a real medical challenge, yet crucial for establishing a neurological prognosis, predicting cognitive outcome, and guiding medical decisions. Clinicians attempt to classify DoC patients into different global states (e.g. coma, Unresponsive Wakefulness Syndrome (UWS), Minimally Conscious State (MCS)) depending on their residual level of arousal and awareness. In recent years, the improvement of diagnostic tools and the use of a multimodal approach combining clinical, neurophysiological and neuroimaging examinations, have greatly refined this assessment and revealed the existence of possible discrepancies between clinical observation (e.g. poor consciousness state like UWS) and brain activity (richer, MCS+ type, or even conscious) so-called Cognitive-Motor Dissociation, making it essential to search for any 'hidden cognition' not revealed by the clinical behavioral examination. It is therefore essential to have tools that can not only probe consciousness level, but also provide a detailed profile of patients' residual cognitive abilities - such as language, attention or memory - which are essential dimmensions of conscious experience and shape waking cognitive life. This could crucially improve the neurological diagnostic and prognostic' accuracy of these disorders, as well as allowing to infer the eventual subjective experience of these patients. Indeed, The investigator still know very little about the possible conscious 'contents' involved in these states. What does the possible 'mental life' of DoC patients look like? A multidimensional exploration of their cognition is needed, requiring the development of innovative methods capable of probing cognitive functions in the absence of any communication with the patient. Thus, the general aim of this study lies in the development of tools for the cognitive exploration of DoC patients and their application at patients' bedside in the Intensive Care Unit (ICU). We're particularly interested in assessing memory capacities in these patients, as exploration of memory has immediate clinical implications, since memory encoding during DoC could impact patients' quality of life and be implicated in the occurrence of post-traumatic stress disorder (PTSD) in case of consciousness recovery. More specifically, the investigator want to tackle the following questions: Are patients suffering from a DoC able to form, consolidate and retrieve new memories (anterograde memory)? Are they able to recall memories from their 'past life' (retrograde memory)? Previous research suggests that some DoC patients retain the ability to reactivate old autobiographical memory traces, and to present automatic short-term sensory memory processes, or residual working memory. Nevertheless, DoC patients' memory abilities have been little studied to date, despite their clinical relevance. The investigator postulate that memory could be differentially preserved between different clinical states of DoC such as UWS and MCS. At the group level, we expect MCS patients to have better learning and memory retrieval abilities than UWS patients. The investigator therefore expect memory functions to be affected by brain lesions and, consequently, by consciousness alteration, although the invenvisage the preservation of unconscious memory processes (e.g. in non-declarative memory subtypes such as perceptual memory) in UWS patients. We hypothesize that the presence of robust markers of memory processes will vary, at the single-patient level, according to the types and stages of memory tested, informing the cognitive profile of the patient suffering from a DoC. By providing information on the potential presence of memory capacities that cannot be revealed by clinical examination, the physiological tools we are developing in this study will open a crucial window onto non-communicating patients' cognition. Defining DoC patients' memory profile could not only improve their care during and after the disorder (reflection on the quality of life in ICU; better understanding of cognitive and psychological symptoms occurring after a DoC (e.g. amnesia, PTSD); orientation of rehabilitation strategies), but also improve the diagnostic accuracy of these troubles if memory proves to be differentially preserved between different DoC states such as UWS and MCS. Ultimately, we aim to refine the neurological prognosis of these non-responsive patients, by predicting their cognitive outcome thanks to these innovative physiological tools. On a more fundamental level, this project questions the interplay of memory and consciousness, exploring which forms of memory do and do not require a conscious state.

Conditions

Disorders of Consciousness

Keywords

DoC; hidden cognition; subjective experience; memory; neurophysiology

Outcome Measures

Primary Outcomes (1)

• EEG-Electrodermal activity

  Composite primary outcome measure: Presence of at least one of the following three predifined markers of memory processes: * EEG cognitive evoked potentials * Significant modulation of electrodermal activity * Evidence of recollection of an auditory memory probe delivered during the Disorder of Consciousness

  during hospitalization and at a distance during a post-resuscitation follow-up consultation for the second semi-structured interview assessing the recovery of the musical memory probe, generally between 3 and 12 months

Study Arms (2)

Patients suffering or who have suffered from a Disorder of Consciousness

EXPERIMENTAL

Other: Physiological recordings, Semi-structured interviews, Psychological scales

Conscious Patients treated in Intensive Care Unit

ACTIVE COMPARATOR

Other: Physiological recordings, Semi-structured interviews, Psychological scales

Interventions

Physiological recordings, Semi-structured interviews, Psychological scales OTHER

(Neuro)-physiological paradigms based on EEG, ECG, electrodermal activity, and respiratory activity recordings, and auditory and olfactive stimuli, to assess memory processes without the need to communicate ('no report' approach) in patients suffering from a Disorder of Consciousness and conscious controls. Semi-structured interviews and neuropsychological assessments (scales) in patients who have recovered from a Disorder of Consciousness and conscious controls to explore memories and subjective experience of the ICU

Conscious Patients treated in Intensive Care Unit; Patients suffering or who have suffered from a Disorder of Consciousness

Eligibility Criteria

• Age: 15 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients suffering from a Disorder of Consciousness:
• Patient not conscious according to the CRS-R scale (Kalmar \& Giacino, 2005)
• Age over 15 years and 3 months
• Free and informed consent signed by a third party (parental authority, trusted support person)
• Conscious patients (controls) :
• Age over 15 years and 3 months
• Cared for in an Intensive Care Unit
• Free and informed consent signature
• Patients who have regained consciousness after having suffered from a Disorder of Consciousness (if not included during their disorder):
• Age over 15 years and 3 months
• Free and informed consent signature if able, otherwise signature of relative (holders of parental authority for minors)

You may not qualify if:

• Previous severe neurodegenerative disease (e.g. Alzheimer's disease, Lewy body dementia)
• Deafness
• Patients under guardianship or trusteeship
• Pregnant and breast-feeding women

Sponsors & Collaborators

• Institut National de la Santé Et de la Recherche Médicale, France: collaborator
• Assistance Publique - Hôpitaux de Paris: lead
• Institut du Cerveau et de la Moelle (ICM Institute): collaborator
• Sorbonne University, Paris, France: collaborator

Study Sites (2)

APHP, Pitié-Salpêtrière Hospital, Department of Anesthesia and Intensive Care, NeuroSurgery ICU

Paris, 75013, France

RECRUITING

APHP, Pitié-Salpêtrière Hospital, Department of Neurology, Neuro-ICU

Paris, 75013, France

RECRUITING

MeSH Terms

Conditions

Consciousness Disorders

Condition Hierarchy (Ancestors)

Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Neurocognitive Disorders; Mental Disorders

Study Officials

• Benjamin Rohaut, MD PhD

  Assistance Publique - Hôpitaux de Paris

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Benjamin Rohaut, MD PhD

CONTACT

01 84 82 78 88; benjamin.rohaut@icm-institute.org

Thomas Andrillon, PhD

CONTACT

06 44 82 00 32; thomas.andrillon@icm-institute.org

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 28, 2025
• First Posted: May 6, 2025
• Study Start: September 30, 2025
• Primary Completion (Estimated): August 30, 2030
• Study Completion (Estimated): August 30, 2030
• Last Updated: April 13, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

FR (2)