Reversal of Normal Pressure Hydrocephalus Symptoms by Subdural Collections
Bibliographic record
Abstract
BACKGROUND: The pathogenesis of symptoms in normal pressure hydrocephalus (NPH) is unclear. One theory is that in the presence of enlarged lateral ventricles, the ventricular fluid exerts increased force on the ventricular walls, the cerebrospinal fluid pressure remaining normal. This is in accordance with Pascal's principle of F = PxA. It has not been possible to obtain direct evidence for this view. METHOD: The opportunity to gain insight into the matter arose when it was observed that two patients with symptomatic NPH were relieved of their symptoms when they developed bilateral subdural collections, one after head trauma, the other after ventriculo-peritoneal shunting for NPH. RESULT: In each case, concomitant with the subdural collections and the reversal of symptoms, the ventricular system became smaller. In the first patient, symptoms returned when the subdural collections were resorbed. In the second patient, symptoms returned when the subdural collections became excessive. CONCLUSION: Although documentation was less thorough than desired, it was concluded that relief of symptoms was related to the decrease in the ventricular size rather than lowering of the intraventricular pressure, thus providing evidence for operation of the principle F = PxA as the mechanism of symptoms in NPH.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.002 |
| 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".