Dopaminergic Disruption Induced by Traumatic Coma: Dopaminergic Pathways Abnormalities and Biomarkers of Recovery Using MRI and 18F-LBT-999 PET

Dopaminergic Disruption Induced by Traumatic Coma: Multimodal Neuroimaging Approaches to Characterize Dopaminergic Pathways Using 18F-LBT-999 PET

Dopaminergic Disruption Induced by Traumatic Coma: Dopaminergic Pathways Abnormalities and Biomarkers of Recovery Using MRI and 18F-LBT-999 PET (NCT06930261) is a Phase 2 interventional studying Coma, Traumatic, sponsored by Institut National de la Santé Et de la Recherche Médicale, France. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

The neural correlates of consciousness have been studied at the macroscopic level. However, the neurochemical basis of these processes remains poorly understood. The mesocircuit theory challenges the cortico-centric view of consciousness. It highlights the role of subcortical regulation by dopaminergic circuits, including the ventral tegmental area and striatal loops. Experimental data show the importance of dopamine in consciousness recovery. Animal TBI studies link dopamine deficits to loss of consciousness and recovery. In humans, imaging studies show disrupted dopaminergic networks in chronic consciousness disorders. Yet, early-phase dopaminergic disruptions in acute coma remain underexplored. Molecular imaging with PET or SPECT offers insights into dopamine system disturbances. The novel radiotracer 18F-LBT-999 enables detailed imaging of dopaminergic circuits, providing better spatial resolution and quantification than SPECT. This proof of concept study aims to explore acute subcortical dopaminergic loop disruptions. It will combine 18F-LBT-999 PET with structural and functional MRI in post-traumatic coma. Methods : Patients with severe traumatic brain injury (TBI) admitted to the intensive care unit state will be evaluated within 30 days post-injury. Participants will undergo clinical assessment after sedation clearance and will be categorized into three groups: (1) TBI-COMA (severe TBI with persistent coma), (2) TBI-REC (severe TBI with recovery of command-following), and (3) healthy controls. All participants will undergo clinical evaluations, anatomical and functional MRI, and molecular imaging: 18F-LBT-999-PET. Neurological outcome (CRS-r scale), Disability rating scale (DRS), Quality of life (QUOLIBRI) and axtrapyramidal symptoms (MDS-UPDRS) will be assessed at 3 month. Primary Hypothesis: Acute post-traumatic severe TBI patients with persistent coma (TBI-COMA) show reduced presynaptic dopamine receptor levels in the striatum, compared to healthy controls. Secondary Hypotheses: * Dopaminergic disruptions correlate with the severity of consciousness impairment, differentiating TBI-COMA and TBI-REC groups. * Structural damage in the striatum and nigrostriatal tract, identified via MRI, aligns with dopaminergic abnormalities. * Multimodal imaging findings during the acute phase can predict long-term neurological and quality-of-life outcomes. * Characterizing structural, functional, and metabolic variations in dopaminergic networks may guide personalized pharmacological treatments.

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against Coma, Traumatic and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 55 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Coma, Traumatic subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: For All Participants: - Aged 18-65 years. - Affiliated with or beneficiary of a social security system. - Signed willing to sign a consent form provided by the participant or a trusted representative (for patients). For all TBI Participant - Hospitalized for a non-penetrating traumatic brain injury (TBI) occurring within the last 30 days, with traumatic coma (Glasgow Coma Scale (GCS) \< 10 and motor score (M) \< 6) at hospital admission. - Sedative treatments discontinued for more than 48 hours. - Clinically stable (no hemodynamic, respiratory, or metabolic instability requiring specific interventions that contraindicate medical transfer to the imaging center). For the TBI-COMA Group: \- Severe TBI characterized by prolonged coma, defined as an initial GCS \< 10 with M \< 6, and no recovery of consciousness at inclusion (GCS \< 10 with M \< 6). For the TBI-REC Group: - Severe TBI characterized by prolonged coma, defined as an initial GCS \< 10 with M \< 6, with recovery of consciousness evidenced by simple command-following (GCS ≥ 10 with M = 6) at inclusion. - For Healthy Controls: Matched by age (± 2 years) and sex to patients in the TBI-COMA group. Who Should NOT Join This Trial: For All Participants: - Pregnant or breastfeeding women - Contraindications to MRI - Known allergy to the PET radiotracer or its excipients. - History of conditions affecting the dopaminergic system - Individuals under legal protection measures - Current treatment with dopaminergic agonists or antagonists. For Patients Only: - Coma due to causes other than TBI. - Decompressive craniectomy resulting in anatomical alterations incompatible with standardized image analysis (e.g., midline shift \> 2 cm). For Healthy Controls Only: - Women of childbearing potential without effective contraception. - Women unwilling to maintain effective contraception during the 30-day study period. Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: For All Participants: * Aged 18-65 years. * Affiliated with or beneficiary of a social security system. * Signed informed consent provided by the participant or a trusted representative (for patients). For all TBI Participant * Hospitalized for a non-penetrating traumatic brain injury (TBI) occurring within the last 30 days, with traumatic coma (Glasgow Coma Scale (GCS) \< 10 and motor score (M) \< 6) at hospital admission. * Sedative treatments discontinued for more than 48 hours. * Clinically stable (no hemodynamic, respiratory, or metabolic instability requiring specific interventions that contraindicate medical transfer to the imaging center). For the TBI-COMA Group: \- Severe TBI characterized by prolonged coma, defined as an initial GCS \< 10 with M \< 6, and no recovery of consciousness at inclusion (GCS \< 10 with M \< 6). For the TBI-REC Group: * Severe TBI characterized by prolonged coma, defined as an initial GCS \< 10 with M \< 6, with recovery of consciousness evidenced by simple command-following (GCS ≥ 10 with M = 6) at inclusion. * For Healthy Controls: Matched by age (± 2 years) and sex to patients in the TBI-COMA group. Exclusion Criteria: For All Participants: * Pregnant or breastfeeding women * Contraindications to MRI * Known allergy to the PET radiotracer or its excipients. * History of conditions affecting the dopaminergic system * Individuals under legal protection measures * Current treatment with dopaminergic agonists or antagonists. For Patients Only: * Coma due to causes other than TBI. * Decompressive craniectomy resulting in anatomical alterations incompatible with standardized image analysis (e.g., midline shift \> 2 cm). For Healthy Controls Only: * Women of childbearing potential without effective contraception. * Women unwilling to maintain effective contraception during the 30-day study period.

Treatments Being Tested

DRUG

LBT-999

LBT-999 administration for PET imaging

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

CHU de Toulouse

Toulouse, France

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT06930261), the sponsor (Institut National de la Santé Et de la Recherche Médicale, France), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT06930261 clinical trial studying?

Who can participate in NCT06930261?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT06930261?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT06930261. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT06930261. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.