Clinical and neuroimaging characterization of posterior cortical atrophy
Bibliographic record
Abstract
Objective To investigate the clinical and image characteristics in patients with posterior cortical atrophy (PCA). Methods Totally 5 patients with PCA and 6 patients with typical Alzheimer's disease (tAD) were selected in this study. Cognitive function was measured by the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MCA) and Clinical Dementia Rating (CDR). Brain magnetic resonance imaging was conducted to evaluate the ventricular enlargement, and posterior atrophy and medial temporal lobe atrophy. 18F- Fluorodeoxyglucose (FDG) and 11C-Pittsburg Compound B (PiB) PET cerebral imaging were performed. The above indictors were compared between PCA and AD patients. Results The most common symptoms at onset were visual space impairment, visual agnosia, apraxia, disorientation, agrapha, and acalculia in PCA patients. PCA subjects had marked impairment in visuospatial tasks, writing and calculation on neuropsychological testing. Posterior cortical atrophy were greater in PCA patients than in tAD patients (P L) in PCA, but more diffused cortical decreased in typical AD. Occipical cortex(BA18, 19, 37) was the most obvious rCMRGlu decreasing place in PCA relative to tAD. The voxel-based automatic quantitative analysis showed that the mean PIB standardized uptake value ratio (SUVR) was higher in the inferior parietal lobe, lateral temporal cortex, middle frontal gyrus, medial prefrontal cortex, posterior cingulate cortex and precuneus, occipital lobe, supplementary motor area, and striatum in PCA and typical AD patients as compared with controls (1.6-2.6 vs. 1.1-1.2, P 0.05). Conclusions PCA has visual spatial impairment, apraxia, parietal cortex atrophy and hypometabolism in right temporo-parieto-occipital region as the main characteristics, and amyloid deposition in cortex in PCA patients is similar to that in typical AD patients. Key words: Atrophy; Cerebral cortex; Alzheimer disease; Positron-emission tomography; Pittsburgh compound B; Fluorodeoxyglucose F18
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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 | 0.000 | 0.001 |
| 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) | 0.000 | 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".