Persistent metabolic crisis as measured by elevated cerebral microdialysis lactate-pyruvate ratio predicts chronic frontal lobe brain atrophy after traumatic brain injury*
Bibliographic record
Abstract
OBJECTIVE: To determine whether persistent metabolic dysfunction in normal-appearing frontal lobe tissue is correlated with long-term tissue atrophy. DESIGN: Prospective monitoring with retrospective data analysis. SETTING: Single-center academic neurointensive care unit. PATIENTS: Fifteen patients with moderate to severe traumatic brain injury (Glasgow Coma Scale score 3-12). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Hourly cerebral microdialysis was performed for the initial 96 hrs after trauma to determine extracellular levels of glucose, glutamate, glycerol, lactate, and pyruvate in normal appearing frontal lobes. Six months after injury, the anatomical outcome was assessed by measures of global and regional cerebral atrophy using volumetric brain magnetic resonance imaging. The lactate/pyruvate ratio was elevated >40 after traumatic brain injury in most patients, with a mean percent time of 32 +/- 29% of hours monitored. At 6 months after traumatic brain injury, there was a mean frontal lobe atrophy of 12 +/- 11% and global brain atrophy of 8.5 +/- 4.5%. The percentage of time of elevated lactate/pyruvate ratio correlated with the extent of frontal lobe brain atrophy (r = -.56, p < 0.01), but not global brain atrophy (r = -.31, p = 0.20). The predictive effect of lactate/pyruvate ratio was independent of patient age, Glasgow Coma Scale score, and volume of frontal lobe contusion. CONCLUSION: Persistent metabolic crisis, as reflected by an elevated lactate/pyruvate ratio, in normal appearing posttraumatic frontal lobe, is predictive of the degree of tissue atrophy at 6 months.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".