S100B Protein: a Diagnostic Aid in Episodes of Transient Loss of Consciousness? (EPILEPSY)

April 7, 2026 updated by: Assistance Publique - Hôpitaux de Paris

Diagnostic Performance of S100B Protein Measurement in Episodes of Transient Loss of Consciousness: a Prospective Cohort Study

S100B protein is a biomarker produced mainly by astrocytes and released into the bloodstream in the event of brain injury, with levels rising rapidly and markedly in acute conditions such as traumatic brain injury, stroke, or epileptic seizures, before declining quickly. Increased S100B levels following a convulsive seizure have been reported, suggesting potential value in distinguishing epilepsy from other causes; however, its use in the etiological assessment of transient loss of consciousness has not yet been studied. Loss of consciousness represents a common reason for Emergency Department visits and involves a wide range of causes, making diagnosis challenging due to often limited clinical history and resulting in numerous investigations. A biomarker such as S100B could help guide diagnosis more rapidly, particularly in distinguishing epilepsy from other causes, thereby reducing the need for additional tests and shortening hospital stay. To date, no study has evaluated the performance of S100B measurement in the etiological workup of transient loss of consciousness. The hypothesis underlying this study is that measurement of S100B levels in the Emergency Department could help differentiate epileptic seizures from other etiologies, particularly cardiac causes, and thus reduce additional investigations and hospital stay. This prospective observational study primarily aims to assess the diagnostic performance of S100B measurement for identifying epilepsy compared with other causes of transient loss of consciousness in adult patients presenting to the Emergency Department for this reason. The study will begin on April 30 and will last 15 months. In practice, eligible patients who do not oppose participation will undergo an additional blood sample at the time of initial sampling required for clinical management, with this sample used to measure plasma S100B levels; patient management will otherwise remain identical to standard care. Three months after the Emergency Department visit, an adjudication committee composed of a neurologist, a cardiologist, and an emergency physician will determine the final diagnosis based on all available data, including any additional investigations performed after the initial visit. The primary endpoint is the area under the ROC curve (AUROC) of S100B measurement, evaluating its ability to discriminate epilepsy from other causes of transient loss of consciousness.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • France
    • Île-de-France Region
      • Créteil, Île-de-France Region, France, 94000

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of adult patients presenting to the Emergency Department of Henri Mondor University Hospital during the inclusion period for an episode of transient loss of consciousness. Eligible patients will be screened consecutively and included if they meet all predefined inclusion criteria and none of the exclusion criteria.

Description

Inclusion Criteria:

  • • Adult ≥ 18 years old

    • Presentation to the Emergency Department of Henri Mondor University Hospital
    • History of loss of consciousness
    • Undergoing a blood test as part of Emergency Department care
    • Covered by social security
    • Has agreed to participate in the study

Exclusion Criteria:

  • Symptoms occurring more than 12 hours ago

    • History of head trauma without brain imaging performed
    • History of head trauma with intracranial bleeding confirmed on brain imaging
    • Refusal to participate in the study
    • Pregnant and/or breastfeeding women
    • Individuals unable to provide consent, particularly due to cognitive impairment
    • Individuals under legal protection:
    • Placed under guardianship
    • Deprived of liberty (incarcerated or hospitalized without consent)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
S100B Evaluation Cohort for Transient Loss of Consciousness

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Area under the ROC curve (AUROC) of S100B measurement, assessing its ability to discriminate epilepsy from other causes of transient loss of consciousness
Time Frame: 15 Months
The primary outcome measure is the area under the ROC curve (AUROC) of S100B measurement, assessing its ability to discriminate epilepsy from other causes of transient loss of consciousness. The reference standard is the final diagnosis established by an adjudication committee at 3 months, blinded to the S100B result. The AUROC will be estimated with its 95% confidence interval (95% CI). Statistical significance will be assessed using a test comparing the AUROC to 0.5. The test will be considered of diagnostic interest if the AUROC is ≥ 0.75 and/or if the lower bound of the 95% CI is > 0.65, and if the p-value of the test versus 0.50 is < 0.05.
15 Months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Determination of the optimal S100B threshold for the diagnosis of epilepsy using Youden's index
Time Frame: 15 months
15 months
Assessment of the diagnostic performance associated with the optimal S100B threshold for epilepsy diagnosis (sensitivity, specificity, positive predictive value, and negative predictive value).
Time Frame: 15 months
15 months
Subgroup analyses based on adjudicated etiological diagnoses
Time Frame: 15 Months
Diagnostic performance of S100B will be evaluated separately within each etiological subgroup defined by the adjudication committee (epilepsy, cardiac syncope, hypoglycemia, vasovagal syncope)
15 Months
Analysis of S100B levels according to patient comorbidities
Time Frame: 15 months
Plasma S100B concentrations will be measured using standard immunoassay techniques.
15 months
Analysis of results based on the time between symptom onset and sample collection (in hours).
Time Frame: 15 months
15 months
Analysis of results according to patient age (<65 years, 65-79 years, and ≥80 years).
Time Frame: 15 months
15 months
Analysis of results based on the occurrence of head trauma during the episode and, if applicable, the time between the trauma and the measurement of S100B (in hours).
Time Frame: 15 months
15 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Assistance Publique - Hôpitaux de Paris

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 30, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 7, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 7, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 14, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 14, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 7, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • APHP251504

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

DATAS ARE OWN BY ASSISTANCE PUBLIQUE - HOPITAUX DE PARIS, PLEASE CONTACT SPONSOR FOR FURTHER INFORMATION

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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