Preclinical amyloid‐PET SUVr in the precuneus and posterior cingulate associations with MoCA scores are driven by language domain subscores
Bibliographic record
Abstract
Abstract Background β‐amyloid (Aβ) deposition in the brain is the earliest pathological change supporting a diagnosis of preclinical Alzheimer’s disease (pAD). Such deposition can be quantified using amyloid‐PET scans, which also enable a quantitative evaluation of the distribution of the pathology in pAD. Cognitive screening instruments such as the Montreal Cognitive Assessment (MoCA) are widely used to detect cognitive decline as one transitions from pAD to mild cognitive impairment or dementia due to AD, but have little proven utility in tracking cognitive decline during the stage of pAD. The present study sought to identify potential relationships between regional Aβ deposition and domain specific subscales and items comprising the MoCA in pAD. Method Ninety‐nine clinically normal participants with a MoCA score ≥ 23 underwent F18‐florbetapir PET/CT scanning and regional standardized uptake value ratio (SUVr) was determined using the Siemens Syngo.via® Neurology software package. Relationships between regional SUVr and MoCA test performance as well as MoCA domain scores were analyzed using linear regression models adjusted for age and education. Result Subjects included 68 women and 31 men with a mean age of 74.2±6.3 years, education 16.7±2.6 years, and MoCA 26.6± 1.9. The adjusted linear regression analyses demonstrated that reduced global MoCA score was associated with increased regional SUVr in the precuneus and posterior cingulate regions only (p<0.05). This relationship appeared to be driven predominantly by the language domain index score rather than other subdomains of the MoCA (R2=0.122; p= 0.003). Conclusion These data demonstrate that increased Aβ deposition in the precuneus and posterior cingulate (the earliest brain regions affected with Aβ pathology) are associated with decreased global cognitive performance, driven by language domain subscores in individuals with pAD. Further research using more sensitive domain‐specific tests in cognitively normal individuals may help determine optimal low‐cost, non‐invasive, neuropsychological predictors of pAD.
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".