Abstract P069: 1H-Magnetic Resonance Spectroscopy Reveals Elevation of MyoInositol and Other Markers of Inflammation in the Dorsal Medulla of Children with Orthostatic Intolerance
Bibliographic record
Abstract
Children with orthostatic intolerance (OI) have exaggerated decreases in heart rate variability (HRV) and suppression of baroreflex sensitivity (BRS) with standing. Inflammation is proposed as a possible factor contributing to impaired HRV in cardiometabolic disorders; whether systemic or brain inflammation better predicts impaired HRV is arguable. We used 1H magnetic resonance spectroscopy (MRS) to quantify markers of neuronal and glial integrity in children with OI compared with asymptomatic controls. Fifteen subjects ages 10-18 years were evaluated for blood pressure, HR, and autonomic function in supine and upright positions and 7 tested positive for OI. An average of 2 weeks following OI testing all subjects underwent 1H-MRS scans of dorsal medulla on a clinical 3T magnet while supine. OI subjects had higher myoinositol (mIns) as a marker of glial inflammation than asymptomatic controls (7.8 ± 0.4 vs 5.6 ± 0.9 mmol/L, p = 0.03). Trends were observed for higher glycerophosphocholine (higher GPC, reduced myelination and axonal integrity) (2.3 ± 0.2 vs 1.8 ± 0.2 mmol/L, p = 0.08) and lower N-acetyl aspartate (lower NAA, reduced neuronal integrity) (2.8 ± 0.3 vs. 3.7 ± 0.4 mmol/L, p = 0.1) in OI subjects vs controls (mean ± SEM). mIns concentrations did not correlate with indices of autonomic function measured in the supine position. However, supine measures of mIns correlated with autonomic measures taken in the upright position: negatively correlated with spontaneous BRS (R = -0.64, p = 0.01), parasympathetic tone measured by high frequency alpha index (HFα, R= -0.547, p=0.04) and HRV measured by root of mean square of successive differences (rMSSD, R = -0.45, p = 0.09); there was a positive correlation with HR (R = 0.53, p < 0.05). In summary, children with OI have higher mIns in dorsal medulla while supine that is predictive of impairment in BRS, HRV and parasympathetic tone upon upright posture. This first report that OI in children is associated with elevated mIns, a marker of glial inflammation in a variety of neuropathies, raises the intriguing possibility that brain inflammation plays a role in the autonomic dysfunction observed while standing in these subjects. Support: Centers for Integrative Medicine and Hypertension & Vascular Research; AHA12CRP9420029
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 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 | 0.000 |
| 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".