Cognitive decline in Parkinson disease
Aarsland D, Creese B, Politis M, Chaudhuri KR, Ffytche DH, Weintraub D, Ballard C.. Nature reviews. Neurology, 2017-03-03
Topic: Risk, prevention and care in population studies
Dementia is a frequent problem encountered in advanced stages of Parkinson disease (PD). In recent years, research has focused on the pre-dementia stages of cognitive impairment in PD, including mild cognitive impairment (MCI). Several longitudinal studies have shown that MCI is a harbinger of dementia in PD, although the course is variable, and stabilization of cognition - or even reversal to normal cognition - is not uncommon. In addition to limbic and cortical spread of Lewy pathology, several other mechanisms are likely to contribute to cognitive decline in PD, and a variety of biomarker studies, some using novel structural and functional imaging techniques, have documented in vivo brain changes associated with cognitive impairment. The evidence consistently suggests that low cerebrospinal fluid levels of amyloid-β 42 , a marker of comorbid Alzheimer disease (AD), predict future cognitive decline and dementia in PD. Emerging genetic evidence indicates that in addition to the APOE*ε4 allele (an established risk factor for AD), GBA mutations and SCNA mutations and triplications are associated with cognitive decline in PD, whereas the findings are mixed for MAPT polymorphisms. Cognitive enhancing medications have some effect in PD dementia, but no convincing evidence that progression from MCI to dementia can be delayed or prevented is available, although cognitive training has shown promising results.
Key findings
- Several longitudinal studies have shown that MCI is a harbinger of dementia in PD, although the course is variable, and stabilization of cognition - or even reversal to normal cognition - is not uncommon.
- In addition to limbic and cortical spread of Lewy pathology, several other mechanisms are likely to contribute to cognitive decline in PD, and a variety of biomarker studies, some using novel structural and functional imaging techniques, have documented in vivo brain changes associated with cognitive impairment.
- The evidence consistently suggests that low cerebrospinal fluid levels of amyloid-β 42 , a marker of comorbid Alzheimer disease (AD), predict future cognitive decline and dementia in PD.
- Emerging genetic evidence indicates that in addition to the APOE*ε4 allele (an established risk factor for AD), GBA mutations and SCNA mutations and triplications are associated with cognitive decline in PD, whereas the findings are mixed for MAPT polymorphisms.
- Cognitive enhancing medications have some effect in PD dementia, but no convincing evidence that progression from MCI to dementia can be delayed or prevented is available, although cognitive training has shown promising results.
Why it matters
This review describes cognitive decline in Parkinson's disease, noting that low cerebrospinal fluid amyloid-beta 42 predicts future cognitive decline and dementia, and that APOE epsilon4, GBA and SCNA mutations are linked to this decline. It states there is no convincing evidence that progression from mild cognitive impairment to dementia can be delayed or prevented, though some cognitive-enhancing medications have some effect in Parkinson's disease dementia.
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Study details
- Study designlongitudinal study
- Evidence strengthModerate
How this study scored 65/100
Published in a peer-reviewed journal, and it is a longitudinal study following the same people over time. Scored zero for sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Nature reviews. Neurology) |
| Journal's citation record | 3 / 4 | Nature Reviews Neurology: journal h-index 269 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A longitudinal study following the same people over time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2017 — within 10 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 7 / 7 | Cited 1,025 times (OpenAlex, 2026-10-10) |
| Citations per year | 5 / 5 | 93.2 citations a year over 11 year(s) since 2017 |
| Impact for its field and year | 4 / 6 | Cited 11.5× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 13 other studies in this library |
| Still being cited | 4 / 4 | Cited 335 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Clive G. Ballard: h-index 141 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of Pennsylvania: institution h-index 1,859 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 6 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 28257128) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 65 / 100 | — |
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Read the original
Full text: free to read — PubMed Central lists this copy as free to read: the link above (checked 10 Oct 2026).
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. The record names 7 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.
APA 7th
Aarsland, D., Creese, B., Politis, M., Chaudhuri, K. R., Ffytche, D. H., Weintraub, D., et al. (2017). Cognitive decline in Parkinson disease. Nature reviews. Neurology. https://doi.org/10.1038/nrneurol.2017.27
Vancouver
Aarsland D, Creese B, Politis M, Chaudhuri KR, Ffytche DH, Weintraub D, et al. Cognitive decline in Parkinson disease. Nature reviews. Neurology. 2017. doi:10.1038/nrneurol.2017.27. PMID: 28257128.
BibTeX
@article{aarsland2017-28257128,
author = {Aarsland, D. and Creese, B. and Politis, M. and Chaudhuri, K. R. and Ffytche, D. H. and Weintraub, D. and Ballard, C.},
title = {{Cognitive decline in Parkinson disease}},
journal = {Nature reviews. Neurology},
year = {2017},
doi = {10.1038/nrneurol.2017.27},
pmid = {28257128},
url = {https://doi.org/10.1038/nrneurol.2017.27}
}
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