1144 PRESENCE OF MELATONIN RHYTHM IN ACUTE MODERATE-SEVERE TRAUMATIC BRAIN INJURY DESPITE SEVERE SLEEP-WAKE DISTURBANCES
Bibliographic record
Abstract
Sleep-wake disturbances (SWD) are present in the acute phase of moderate-severe traumatic brain injury (TBI), and could be related to circadian disturbances caused by the brain injury. The goal of this study was to 1) compare the rest-activity and melatonin rhythms of moderate-severe TBI patients to that of patients with severe orthopedic and/or spinal cord injuries (OSCI); and 2) evaluate the association between melatonin and the sleep-wake cycle in TBI patients. Seventeen moderate-severe TBI patients (Glasgow Coma Scale score: 6.8 ± 3.3; 30.3 ± 13.3yo; 14 men) and sixteen OSCI patients (30.9 ± 13.2yo; 13 men) were recruited in intensive care. Urine was collected from their urinary catheter every hour for 25 hours starting 18.7 ± 12.3 days post-injury, and concentration of 6-sulfatoxymelatonin was calculated to obtain area under the curve (AUC)(ng). A cosinor analysis was also carried out to obtain amplitude (ng/ml) and acrophase (h). Patients wore wrist actigraphs for 9.4 ± 4.2 days, starting 19.3 ± 12.6 days post-injury. Average nighttime (22:00-6:59) sleep duration and fragmentation index were calculated. The daytime activity ratio was used to quantify rest-activity cycle consolidation. We compared groups on actigraphy and melatonin variables using Student’s t-tests. Among TBI patients, we investigated associations between melatonin and actigraphy variables using Pearson’s correlations. Statistical significance was set at p<0.01. TBI patients had shorter nighttime sleep duration (TBI: 345.8 ± 101.2mins; OSCI: 449.0 ± 54.4mins, t(30)=-3.52, p<0.01), higher fragmentation index (TBI: 80.5 ± 34.0; OSCI: 52.6 ± 23.3, t(30)=2.68, p=0.012), and poorer rest-activity cycle consolidation (TBI: 75.8 ± 9.3%; OSCI: 86.1 ± 4.8%, t(30)=-3.87, p<0.001). A melatonin rhythm was present in TBI patients, and no group differences were found for AUC (TBI: 249.5 ± 165.6ng; OSCI: 162.3 ± 88.9ng), amplitude (TBI: 12.0 ± 7.5ng/ml; OSCI: 7.7 ± 4.8ng/ml), and acrophase (TBI: 5:08 ± 2:14; OSCI: 5:59 ± 3:16)(p-values>0.05). No associations were found between melatonin and actigraphy variables in TBI patients (p-values>0.01). This study shows that despite having more severe SWD, moderate-severe TBI patients have a melatonin rhythm similar to other trauma patients without a brain injury. Moreover, SWD do not seem to be associated to melatonin rhythm. This suggests that neural mechanisms other than the circadian system may be responsible for post-TBI SWD. Canadian Institutes of Health Research and Fonds de la recherche du Québec, Santé.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 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".