Home › Research › Down syndrome and Alzheimer's
Relationship between plaques, tangles, and dementia in Down syndrome
Ropper AH, Williams RS.. Neurology, 1980-06-01
Topic: Brain proteins, microglia and lab models
In patients with Down syndrome, senile plaques and neurofibrillary tangles accumulate in the cortex at an earlier age than in persons of normal karyotype. We studied 20 Down syndrome patients dying after age 30 (average age, 49); all had neocortical plaques and tangles, but only 3 of 20 had been demented. In 12 cases (average age, 53), tissue was available for quantitative study of plaque and tangle densities and estimation of cell loss in the hippocampus. Although at least 8 of these 12 cases had plaque and tangle densities comparable to those previously reported in demented old people, only 1 had dementia. The regional distribution of plaques and tangles in the hippocampus of these Down cases differed from the pattern in senile dementia. Although Alzheimer-like dementia occurs in Down disease, it is less prevalent than the plethoric plaques and tangles in the cortex.
Key findings
- We studied 20 Down syndrome patients dying after age 30 (average age, 49); all had neocortical plaques and tangles, but only 3 of 20 had been demented.
- In 12 cases (average age, 53), tissue was available for quantitative study of plaque and tangle densities and estimation of cell loss in the hippocampus.
- Although at least 8 of these 12 cases had plaque and tangle densities comparable to those previously reported in demented old people, only 1 had dementia.
- The regional distribution of plaques and tangles in the hippocampus of these Down cases differed from the pattern in senile dementia.
- Although Alzheimer-like dementia occurs in Down disease, it is less prevalent than the plethoric plaques and tangles in the cortex.
Why it matters
Among 20 people with Down syndrome dying after age 30, all had neocortical plaques and tangles but only 3 had been demented, and among 12 studied quantitatively at least 8 had plaque and tangle densities comparable to demented older people while only 1 had dementia. This shows that Alzheimer-like brain changes and dementia can be dissociated in Down syndrome, and it reports no treatment or cure.
Study details
- Participants20
- Evidence strengthLow
How this study scored 51/100
Published in a leading specialty journal. Scored zero for study design, effect reported and randomised / blinded because the record does not state it. We have no data on senior author's track record, so that was left out: it earned 49 of the 96 points we could judge it on, which is 51 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Neurology) |
| Journal's citation record | 4 / 4 | Neurology: journal h-index 525 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 1980 — older than 20 years, still counted |
| Sample size | 1 / 4 | 20 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 193 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 4.0 citations a year over 48 year(s) since 1980 |
| Impact for its field and year | 5 / 6 | Cited 21.4× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 16 other studies in this library |
| Still being cited | 1 / 4 | Cited 4 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | 2 / 3 | Massachusetts General Hospital: institution h-index 2,057 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 6446047) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 49 / 96 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 49 of the 96 points we could judge it on is 51 out of 100. |
| Total | 51 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
May need a subscription OpenAlex found no free copy of the full text (checked 6 Feb 1020), so the publisher may charge for it. The PubMed abstract is free.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Ropper, A. H., & Williams, R. S. (1980). Relationship between plaques, tangles, and dementia in Down syndrome. Neurology. https://doi.org/10.1212/wnl.30.6.639
Vancouver
Ropper AH, Williams RS. Relationship between plaques, tangles, and dementia in Down syndrome. Neurology. 1980. doi:10.1212/wnl.30.6.639. PMID: 6446047.
BibTeX
@article{ropper1980-6446047,
author = {Ropper, A. H. and Williams, R. S.},
title = {{Relationship between plaques, tangles, and dementia in Down syndrome}},
journal = {Neurology},
year = {1980},
doi = {10.1212/wnl.30.6.639},
pmid = {6446047},
url = {https://doi.org/10.1212/wnl.30.6.639}
}
Later studies that cite this one
16 studies in the alzhub library list this one in their references. Showing the 8 highest-scoring.