Cerebral amyloid angiopathy and visuospatial functioning: Analysis of the clock drawing test
Bibliographic record
Abstract
Abstract Background Cerebral amyloid angiopathy (CAA) contributes to cognitive impairment as well as dementia in the elderly. In clinical cohorts, symptomatic CAA is associated with impairments in executive function and processing speed. Because CAA severity tends to be highest in the occipital and posterior temporal and parietal lobes, it may also affect visuospatial function. We hypothesized that participants with a clinical diagnosis of CAA will have impaired performance on tests of visuospatial function when compared to control, mild cognitive impairment (MCI) and Alzheimer’s disease (AD) participants. Method Participants with CAA presented with lobar intracerebral hemorrhage, transient focal neurological episodes, or mild cognitive impairment; met Boston criteria for probable CAA; and did not have dementia. Clocks were scored based on a published 20‐point system (Mendez, JAGS 1992). Clock items were subcategorized by general contours, number items, and hand items (Mendez, JAGS 1992); and by a subset of 9 items correlated in prior literature with visuospatial function and temporal‐parietal hypoperfusion (visuospatial items). Result Data from 53 CAA without dementia, 43 MCI, 30 AD with mild dementia (MMSE ≥20), and 40 control participants were analyzed (mean age 71.6 [SD 7.5]; 47% women). Compared to controls, CAA participants performed significantly worse on total score, hand items, and visuospatial items (Table 1). AD participants performed worse than controls on all components except general contour, and MCI participants did not differ from controls. Among CAA participants, total and visuospatial scores did not correlate with history of stroke, number of microbleeds, or white matter hyperintensity volume (p>0.10). Conclusion Mean performance on the clock drawing test is lower in CAA patients without dementia than controls, suggesting visuospatial impairment. This impairment may be related to vascular amyloid deposition in posterior brain regions; however, it was not correlated with typical markers of CAA severity suggesting it may be an early but not necessarily progressive feature. Future research should investigate the mechanisms of visuospatial impairment in CAA—including whether it is related to posterior white matter damage or parieto‐occipital atrophy—and its association with daily function and risk for cognitive decline.
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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| 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".