Stimulating the human midbrain to reveal the link between pain and blood pressure
Bibliographic record
Abstract
The periaqueductal grey area (PAG) in the midbrain is an important area for both cardiovascular control and modulation of pain. However, the precise relationship between pain and blood pressure is unknown. We prospectively studied 16 patients undergoing deep brain stimulation of the rostral PAG for chronic pain. Pre-operatively, post-operatively, and at 1 year, pain scores were assessed using both visual analogue scores and the McGill Pain Questionnaire. Patients were tested post-operatively to determine whether electrical stimulation of the PAG would modulate blood pressure. We found that the degree of analgesia induced by deep brain stimulation of the rostral PAG in man is related to the magnitude of reduction in arterial blood pressure. We found that this relationship is linear and is related to reduced activity of the sympathetic nervous system. Thus stimulation of the PAG may partly control pain by reducing sympathetic activity as predicted by William James over a century ago.
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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 | 0.005 | 0.001 |
| 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".