Cerebrospinal Fluid Pressure Response to Upper Cervical Vertebral Motion and Displacement in the Anesthetized Rat
Bibliographic record
Abstract
OBJECTIVE: This study examined whether aligned or off-axis (subluxated) static and dynamic vertebral displacement within normal physiological ranges modulated cerebrospinal fluid pressure (CSF) as is considered to occur by some chiropractic theories. METHODS: Cerebrospinal fluid pressure pressure was measured via a subarachnoid catheter implanted at the lumbar level in 12 anesthetized adult male Wistar rats. A computer-driven manipulator was used to impose 3 motion patterns on the C2 vertebra: (i) dynamic oscillatory displacement (24 degrees peak-to-peak 1.0 and 2.0 Hz), (ii) static rotary (ramp 20 degrees at 10 degrees per second and hold for 4 minutes) displacement about both the normal and an offset axis of rotation, and (iii) a spinal manipulative thrust displacement (200 degrees per second; 12 degrees peak-to-peak). RESULTS: The CSF pressure at rest for all rats ranged from 4.5 to 9.1 mm Hg, with a mean (+/- SD) of 6.3 +/- 1.4 mm Hg. Of the imposed movements, only an offset ramp and hold displacement resulted in a significant (P < .05) difference between the CSF pressure before (6.1 +/- 0.7 mm Hg) and during the imposed movement (6.6 +/- 0.7 mm Hg). None of the interventions were associated with significant changes in the powers of the principal peaks of the CSF pressure power spectrum. CONCLUSIONS: The results of this study suggest that static or dynamic displacement of an upper cervical vertebra within the limits of tissue integrity do not induce physiologically important changes in absolute CSF pressure or pressure dynamics in anesthetized rats.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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) | 0.002 | 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 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".