Auditory Processing in DOC Patients

N/ANot Yet RecruitingNCT07455682

BDH-Klinik Hessisch Oldendorf42 enrolled

Overview

This prospective observational study investigates whether electroencephalography (EEG) can improve the differentiation between unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS) in patients with severe acquired brain injury. The study further examines the association between EEG markers of auditory processing and long-term functional outcome at 12 months.

Accurate classification of disorders of consciousness remains challenging in neurological early rehabilitation. Behavioral assessment is the clinical standard, yet misclassification persists, particularly in patients with severe motor impairment or fluctuating arousal. Neurophysiological measures may provide complementary information beyond observable behavior. This study applies event-related potential (ERP) paradigms during bedside EEG recording to assess hierarchical levels of auditory processing in patients with disorders of consciousness in the subacute phase after brain injury. The paradigms are designed to detect neural responses reflecting basic auditory discrimination as well as higher-order cognitive processing. The primary objective is to determine the highest neurophysiologically detectable level of auditory processing and to examine whether it differs between clinically defined consciousness groups. Secondary objectives include evaluating the relationship between EEG-derived markers and standardized behavioral assessments, as well as assessing the prognostic value of EEG findings for functional outcome one year after admission. The study aims to clarify the diagnostic and prognostic relevance of EEG-based measures in routine neurorehabilitation settings.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Disorder of Consciousness Unresponsive Wakefulness Syndrome Minimally Conscious State

Interventions

Coma Recovery Scale-Revised (CRS-R)BEHAVIORAL

The Coma Recovery Scale-Revised (CRS-R) is a standardized behavioral assessment instrument used to determine the level of consciousness in patients with severe brain injury. It comprises six subscales evaluating auditory, visual, motor, oromotor/verbal, communication, and arousal functions, with hierarchically structured items to identify the highest level of behavioral responsiveness.

Electroencephalography (EEG)BEHAVIORAL

Electroencephalography (EEG) is a non-invasive neurophysiological method used to record spontaneous and stimulus-related electrical brain activity via scalp electrodes. In this study, bedside EEG recordings are performed using structured auditory stimulation paradigms designed to elicit event-related potentials (ERPs). These include hierarchical paradigms assessing different levels of auditory processing, ranging from basic sensory discrimination (e.g., mismatch negativity, MMN) to higher-order cognitive processing (e.g., N400 responses). EEG-derived ERP markers are analyzed to determine the highest detectable level of auditory processing and to evaluate their association with clinical diagnosis and long-term functional outcome.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 80 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Presence of a disorder of consciousness (Unresponsive Wakefulness Syndrome \[UWS\] or Minimally Conscious State \[MCS\]), classified using the Coma Recovery Scale-Revised (CRS-R) based on three assessments conducted on at least two separate days * Age between 18 and 80 years * Written informed consent provided by the patient's legal representative * Preserved brainstem auditory evoked potentials (BAEPs) on at least one side Exclusion Criteria: * Ongoing sedation at the time of EEG assessment * Current treatment with medications known to significantly affect cortical functional state, including barbiturates, neuroleptics (antipsychotics), antiepileptic drugs, benzodiazepines, or comparable agents * Colonization with multidrug-resistant organisms requiring isolation precautions (e.g., 4MRGN) * Pregnancy * Impaired language comprehension (e.g., insufficient German language proficiency or aphasia) * Temporal bone fractures or severe infratentorial brain injury associated with unilateral or bilateral absence of auditory evoked potentials (AEPs) * Bilateral hearing impairment or deafness, or presence of a cochlear implant * Scalp wounds or conditions preventing placement of an EEG electrode cap

Locations (1)

BDH-Klinik Hessisch Oldendorf

Hessisch Oldendorf, Lower Saxony, Germany

Outcomes

Primary Outcomes

Highest Detectable Hierarchical Level of Auditory Processing

The primary endpoint is the highest neurophysiologically detectable hierarchical level of auditory processing, operationalized by the presence of significant auditory event-related potential (ERP) effects. For each ERP paradigm, analyses are conducted at the individual patient level to determine whether a statistically significant ERP effect is present within predefined time windows and electrode regions. The highest hierarchy level showing a significant effect defines the individual outcome (ordinal scale: levels 1-4).

Time frame: week 2-3 after admission to neurological rehabilitation

Secondary Outcomes

Association Between Clinical Level of Consciousness and Neurophysiological Cognitive Processing

Relationship between clinically determined consciousness status (e.g., UWS vs. MCS) and the highest achieved hierarchical level of auditory processing as measured by ERP responses.

Time frame: week 2-3 after admission to neurological rehabilitation

Prognostic Validity of ERP-Based Hierarchical Processing Level

Predictive value of the highest achieved hierarchical level of auditory processing for functional outcome at 12 months after admission. Functional status will be assessed using a standardized outcome measure.

Time frame: 12 months after EEG measurement

Data from ClinicalTrials.gov

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