Subregional analysis of the amygdala, thalamus, and hypothalamus at the pre-decline stage in Parkinson’s disease groups with later cognitive impairment
Bibliographic record
Abstract
Abstract While cognitive decline in Parkinson’s disease (PD) significantly impacts patients’ quality of life, early detection remains challenging. Recent advances in magnetic resonance imaging analysis have enabled detailed examination of subcortical structures. This study aimed to investigate subtle changes in specific subregions of the amygdala, thalamus, and hypothalamus in PD patients before they developed cognitive decline. Magnetic resonance imaging data of 163 participants (97 healthy controls [HC], 45 PD patients with normal cognition [PDNC], and 21 PD patients who show cognitive impairment [PDCI]) from the Parkinson’s Progression Markers Initiative database were analyzed. Detailed subregional analyses of brain structures were performed. Cognitive function was assessed using the Montreal Cognitive Assessment and domain-specific tests. The PDCI group exhibited significantly lower intracranial occupancy rates in specific subregions of the amygdala, thalamus, and hypothalamus than the HC group; however, these changes did not correlate significantly with cognitive test scores. Conversely, significant structural changes were observed in extensive cortical regions, subcortical gray matter areas, and white matter areas, which correlated with various cognitive functions including memory, attention, executive function, and visuospatial abilities. Nevertheless, no significant associations were found between changes in individual brain regions and the risk of mild cognitive impairment progression. This study elucidates early brain structural changes associated with cognitive decline in PD. While structural alterations were observed in the amygdala, thalamus, and hypothalamus, widespread cortical changes demonstrated stronger associations with cognitive decline. These findings suggest that cognitive impairment in PD results from extensive cortical network alterations rather than changes in specific subcortical regions. This insight emphasizes the need for a comprehensive approach, considering multiple brain regions and their interactions, in early diagnosis and intervention strategies for PD-related cognitive impairment.
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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 | 0.000 |
| 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".