Cerebrovascular Responses to Orthostatic Stress after Spinal Cord Injury
Bibliographic record
Abstract
Orthostatic hypotension (OH) is a debilitating condition affecting individuals with spinal cord injury (SCI) that may be associated with cerebral hypoperfusion. We studied orthostatic cerebral control in individuals with SCI with different levels and severities of injury to spinal cardiovascular autonomic pathways. We measured beat-to-beat cardiovascular and cerebrovascular responses to passive orthostatic stress in 16 controls and 26 subjects with chronic SCI. Cerebrovascular control was assessed from diastolic cerebral blood flow velocity (CBFV(D)), and indices of static and dynamic cerebral autoregulation. Severity of autonomic injury was inferred from spectral analyses of systolic arterial pressure, and supine plasma noradrenaline concentrations. Symptoms of OH were evaluated using questionnaires. CBFV(D) decreased during orthostasis only in individuals with autonomically complete injuries above T6. Orthostatic CBFV(D) was significantly correlated (p<0.05) with the severity of autonomic injury. Individuals with injuries above T6 had impaired dynamic autoregulation (p<0.05) compared to controls, and this was correlated (p<0.05) with the severity of autonomic injury. Individuals with autonomically complete SCI reported increased severity of symptoms relative to controls (p<0.05). Symptom severity was correlated with the efficacy of dynamic autoregulation. During orthostatic stress, SCI individuals have impaired cerebrovascular control that is related to the level and severity of autonomic injury.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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 | 0.001 |
| 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".