Abstract TMP81: Cerebral Blood Flow and Blood Pressure Reduction Do Not Affect Perihematomal Edema Growth in Acute Intracerebral Hemorrhage
Bibliographic record
Abstract
Background: Both vasogenic and cytotoxic (ischemic) processes have been postulated to play a role in perihematoma edema formation. In the Intracerebral Hemorrhage Acutely Decreasing Arterial Pressure Trial (ICH ADAPT), cerebral blood flow (CBF) was measured in ICH patients assigned to systolic blood pressure (SBP) targets of <150 or <180 mmHg. In this secondary analysis, we tested the hypotheses that edema growth is associated with reduced CBF and lower SBP. Methods: Non-contrast CT scans were obtained at baseline, 2h and 24h post-randomization. Mean relative CBF (rCBF) in the perihematoma region was calculated from raw CT Perfusion data obtained at 2h. Edema volume was measured using planimetric techniques and a Hounsfield unit threshold of ≤24 at baseline and 24h. Results: ICH patients were randomized (n=33 per group) at a median (IQR) of 7.6 (12.8) h after symptom onset. Mean SBP was significantly lower in the <150 mmHg (139±21 mmHg) than the <180 mmHg (163±11, p=<0.0001) at the time of CTP. Mean perihematoma rCBF in the <150 mmHg group (0.85±0.12) was similar to that in the <180 mmHg group (0.88±0.09, p=0.34). Treatment groups were balanced with respect to baseline SBP (180±18 vs. 185±25 mmHg, p=0.39) and acute ICH volume (20.7±22.0 vs. 28.0±25.8 ml, p=0.22). In all patients, median edema volume increased significantly between the baseline 1.8(2.5) ml and 24 h scans (3.1 (5.1) ml, p<0.0001). Linear regression indicated that ICH expansion predicted edema growth (β =0.3 [0.0, 0.2]). Lower perihematoma rCBF did not predict edema growth independently of ICH expansion (β =-0.2 [-229.5, 0.4]). Mean edema growth in the <150 group (2.4±6.9) was similar to that in the <180 group (2.9±6.4, p=0.737). Edema growth was not predicted by SBP change (β=0.12 [-0.45, 1.22]). Neither low SBP load (fraction of time SBP<150 mmHg over 24 h; β=0.07 [-0.13, 0.24]) nor high SBP load (time SBP >180 mmHg; β=0.07 [-0.13, 0.24]) predicted edema growth. Conclusion: Perihematoma edema growth is explained by ICH volume expansion. Lower perihematoma CBF and BP treatment do not exacerbate edema growth. These data are not consistent with a cytotoxic mechanism of edema formation and support the safety of early BP treatment.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.006 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".