Carbon Dioxide Administration and Brain Waste Clearance Study
This study is looking at whether different levels of carbon dioxide (CO2) exposure can safely increase the movement of proteins from the brain into the blood. Researchers believe this could be a way for the brain to clear waste products more effectively, which is important for conditions like traumatic brain injury (TBI) and aging disorders. You may be able to join if you are between 18 and 82 years old and have a history of TBI. The study will measure how CO2 affects blood flow in the brain (Cerebrovascular Reactivity or CVR) and the amount of proteins that move from the brain to the blood (Protein Efflux). The current recruitment status is unclear.
- Study design
- This interventional study plans to enroll 200 participants, including those with and without a history of traumatic brain injury. Each participant will receive different doses of CO2 during two separate visits, with the order of doses being random and unknown to the participant.
- What's involved
- You will undergo an MRI scan while performing a hypercapnia task, which involves breathing different levels of CO2. Blood will be drawn at several time points: before CO2 exposure, immediately before hypercapnia, and then 45, 90, and 150 minutes after hypercapnia.
- Compensation
- Not stated in the trial record.
- Follow-up
- Measurements for Cerebrovascular Reactivity (CVR) and vascular-elicited bulk cerebral spinal fluid (VE-bCSF) are taken 2.5 hours after the intervention. Protein Efflux is measured up to 150 minutes after hypercapnia.
AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.
Carbon Dioxide Administration and Brain Waste Clearance
At a glance
Conditions
Where it's being run
1 sites across 1 statesStudy leadership
- Andrew R Mayer, Phd · PRINCIPAL_INVESTIGATOR · Mind Research Network
Who to contact
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What this trial measures
- Cerebrovascular Reactivity (CVR), vascular-elicited bulk cerebral spinal fluid (VE-bCSF)2.5 hours post-intervention. Data will be reported at the conclusion of the study for all participants.
Cerebrovascular reactivity (CVR) will be quantified using time-shifted end-tidal carbon dioxide (ETCO₂) regressors to model blood oxygen level-dependent (BOLD) changes using functional magnetic resonance imaging, capturing the temporally lagged positive relationship between ETCO₂ and the BOLD signal. Vascular enhanced changes in bulk CSF flow will be assessed by regressing band-pass filtered global grey matter signals and their derivatives on CSF bulk flow to capture the temporally lagged, negative relationship. Both of these measurements are in arbitrary units, and will be quantified by calculating percent signal change and statistical fit between regressors.
- Protein Efflux (Surrogate Measure of Brain Waste Clearance)Blood will be drawn at baseline, immediately prior to hypercapnia, 45 minutes post-hypercapnia, 90 minutes post-hypercapnia and 150 minutes post-hypercapnia. Data will be reported at the conclusion of the study for all participants.
Protein efflux from the brain to the blood will be measured using Quanterix platform, with primary proteins including neurofilament light chain, brain-derived tau and glial fibrillary acidic protein (units=picogram/milligram). For neurofilament light chain (NfL), the limit of detection (LOD) is 0.104 pg/mL, the range is 0.025-0.276 pg/mL, and the lower limit of quantification (LLOQ) is 0.241 pg/mL. For glial fibrillary acidic protein (GFAP), the LOD is 0.221 pg/mL, the range is 0.042-0.481 pg/mL, and the LLOQ is 0.467 pg/mL. For brain-derived tau (BD Tau), the LOD is 0.024 pg/mL, the range is 0.007-0.059 pg/mL, and the LLOQ is 0.053 pg/mL. All values are obtained from the Quanterix website datasheets.