Near‐Infrared Spectroscopy Reveals Brain Hypoxia and Cerebrovascular Dysregulation in Primary Biliary Cholangitis
Bibliographic record
Abstract
Background and Aims Primary biliary cholangitis (PBC) is an autoimmune cholestatic liver disease linked to symptoms including fatigue and altered mood/cognition, indicating that chronic liver inflammation associated with PBC can impact brain function. We employed near‐infrared spectroscopy (NIRS), a noninvasive neuroimaging technique, to determine whether patients with PBC exhibit reduced cerebral oxygen saturation (StO 2 ) and altered patterns of microvascular cerebral blood perfusion and whether these alterations were associated with clinical phenotype. This observational case–control study was conducted at a tertiary hospital clinic (University of Calgary Liver Unit). Approach and Results Thirteen female patients with noncirrhotic PBC, seven female patients with cirrhotic PBC, and 11 healthy female controls were recruited by physician referral and word of mouth, respectively. NIRS was used to measure cerebral hemoglobin and oxygen saturation. A wavelet phase coherence method was used to estimate the coherent frequency coupling of temporal changes in cerebral hemodynamics. The PBC group demonstrated significantly reduced cerebral StO 2 ( P = 0.01, d = 0.84), indicating cerebral hypoxia, significantly increased cerebral deoxygenated hemoglobin concentration ( P < 0.01, d = 0.86), and significantly reduced hemodynamic coherence in the low‐frequency band (0.08‐0.15 Hz) for oxygenated hemoglobin concentration ( P = 0.02, d = 0.99) and total hemoglobin (tHb) concentration ( P = 0.02, d = 0.50), indicating alterations in cerebrovascular activity. Complete biochemical response to ursodeoxycholic acid (UDCA) therapy in early patients with PBC was associated with increased cerebral tHb concentration and decreased hemodynamic coherence. Conclusions Using NIRS, patients with PBC were found to have hypoxia, increased cerebral hemoglobin concentration, and altered cerebrovascular activity, which were reversed in part in UDCA responders. In addition, symptoms and quality‐of‐life measures did not correlate with brain hypoxia or cerebrovascular dysregulation in patients with PBC.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".