Impaired cortical autonomic responses during sympathetic activation in neurogenic orthostatic hypotension characterized by postganglionic autonomic dysfunction
Bibliographic record
Abstract
Neurogenic orthostatic hypotension (NOH) is a cardinal feature of autonomic dysfunction. The cortical autonomic network (CAN) is a network of brain regions associated with autonomic function. Therefore, our objective was to investigate whether impairment of CAN structures is involved in the pathophysiology of NOH. Fifteen controls (63 ± 13 yr) and 15 NOH patients (67 ± 6 yr; P = 0.2) with peripheral autonomic dysfunction completed standard tests of parasympathetic [deep breathing (DB)] and sympathetic [Valsalva maneuver (VM)] activation during a functional MRI. Blood-oxygen-level dependent (BOLD) contrasts were obtained and contrasted. Compared with controls, patients had significantly smaller heart rate responses to DB (control: 15.23 ± 9.6 vs. NOH: 5.7 ± 2.1) and Valsalva ratios (control: 2.1 ± 0.47 vs. NOH: 1.2 ± 0.1; P < 0.001). NOH patients had absent adrenergic phases (late phase II and phase IV) during VM as per a qualitative analysis. During VM, controls had greater activation in the right hippocampus (T-value: 8.03), left posterior cingulate (T L : 7.6), and bilateral thalamus (T R : 7.41, T L : 8.45; P < 0.05). During phase IV, controls had greater activation in the right hippocampus (T R : 5.78l P < 0.05). Following subtraction analysis, no significant differences were evident during DB. In conclusion, NOH patients have significantly less CAN activation during sympathetic, but not parasympathetic, activation. Impaired CANs associated with sympathetic activation may be involved in the pathophysiology of NOH. NEW & NOTEWORTHY Neurogenic orthostatic hypotension (NOH) is a cardinal feature of autonomic dysfunction characterized by failure of reflexive sympathetic activation. Our result reveal that patients with autonomic dysfunction caused by postganglionic sympathetic impairment also have impaired activation of structures within the cortical autonomic network. Impaired activation is evident during a test of sympathetic, but not parasympathetic, activation. Impaired cortical autonomic networks associated with sympathetic activation may be involved in the pathophysiology of NOH.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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".