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

NCT07527754 | Not Yet Recruiting

• 1 other identifier: APHP251504
• Study Type: observational
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Epilepsy; Cryptogenic Epilepsy

Keywords

Biomarker-guided diagnosis; Diagnostic differentiation between epilepsy and other causes of transient loss of consciousness; Early diagnostic orientation in the Emergency Department; Diagnostic performance of S100B measurement in transient loss of consciousness

Outcome Measures

Primary Outcomes (1)

• Area under the ROC curve (AUROC) of S100B measurement, assessing its ability to discriminate epilepsy from other causes of transient loss of consciousness

  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 Outcomes (7)

• Determination of the optimal S100B threshold for the diagnosis of epilepsy using Youden's index

  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).

  15 months

• Subgroup analyses based on adjudicated etiological diagnoses

  15 Months

• Analysis of S100B levels according to patient comorbidities

  15 months

• Analysis of results based on the time between symptom onset and sample collection (in hours).

  15 months

Study Arms (1)

S100B Evaluation Cohort for Transient Loss of Consciousness

Eligibility Criteria

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

You may qualify if:

• 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

You may not qualify if:

• 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)

Sponsors & Collaborators

• Assistance Publique - Hôpitaux de Paris: lead

Study Sites (1)

Hôpital Henri Mondor

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

Location

MeSH Terms

Conditions

Epilepsy

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Central Study Contacts

Christian KASSASSEYA, Dr

CONTACT

01.49.81.21.11; christian.kassasseya@aphp.fr

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 7, 2026
• First Posted: April 14, 2026
• Study Start: April 30, 2026
• Primary Completion (Estimated): July 30, 2027
• Study Completion (Estimated): July 30, 2027
• Last Updated: April 14, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

FR (1)