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Evolution of cognitive dysfunction in an incident Parkinson's disease cohort
Williams-Gray CH, Foltynie T, Brayne CE, Robbins TW, Barker RA.. Brain : a journal of neurology, 2007-05-29
Topic: Risk, prevention and care in population studies
We have previously performed detailed clinical and neuropsychological assessments in a community-based cohort of patients with newly diagnosed parkinsonism, and through analysis of a subcohort with idiopathic Parkinson's disease (PD), we have demonstrated that cognitive dysfunction occurs even at the time of PD diagnosis and is heterogeneous. Longitudinal follow-up of the cohort has now been performed to examine the evolution of cognitive dysfunction within the early years of the disease. One hundred and eighty (79%) eligible patients from the original cohort with parkinsonism were available for re-assessment at between 3 and 5 years from their initial baseline assessments. PD diagnoses were re-validated with repeated application of the UKPDS Brain Bank criteria in order to maximize sensitivity and specificity, following which a diagnosis of idiopathic PD was confirmed in 126 patients. Thirteen out of 126 (10%) had developed dementia at a mean (SD) of 3.5 (0.7) years from diagnosis, corresponding to an annual dementia incidence of 30.0 (16.4-52.9) per 1000 person-years. A further 57% of PD patients showed evidence of cognitive impairment, with frontostriatal deficits being most common amongst the non-demented group. However, the most important clinical predictors of global cognitive decline following correction for age were neuropsychological tasks with a more posterior cortical basis, including semantic fluency and ability to copy an intersecting pentagons figure, as well as a non-tremor dominant motor phenotype at the baseline assessment. This work clarifies the profile of cognitive dysfunction in early PD and demonstrates that the dementing process in this illness is heralded by both postural and gait dysfunction and cognitive deficits with a posterior cortical basis, reflecting probable non-dopaminergic cortical Lewy body pathology. Furthermore, given that these predictors of dementia are readily measurable within just a few minutes in a clinical setting, our work may ultimately have practical implications in terms of guiding prognosis in individual patients.
Key findings
- We have previously performed detailed clinical and neuropsychological assessments in a community-based cohort of patients with newly diagnosed parkinsonism, and through analysis of a subcohort with idiopathic Parkinson's disease (PD), we have demonstrated that cognitive dysfunction occurs even at the time of PD diagnosis and is heterogeneous.
Why it matters
In this community-based Parkinson's disease cohort, 10% developed dementia within about 3.5 years of diagnosis and a further 57% showed cognitive impairment. This concerns cognitive decline in Parkinson's disease, not Alzheimer's disease treatment, cure or prevention.
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Study details
- Study designlongitudinal study
- Participants126
- Evidence strengthModerate
How this study scored 68/100
Published in a leading specialty journal, and it is a longitudinal study following the same people over time. Scored zero for effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (Brain : a journal of neurology) |
| Journal's citation record | 4 / 4 | Brain: journal h-index 503 (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 | 1 / 5 | 2007 — within 20 year(s) of the newest study here |
| Sample size | 2 / 4 | 126 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 | 6 / 7 | Cited 936 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 44.6 citations a year over 21 year(s) since 2007 |
| Impact for its field and year | 5 / 6 | Cited 23.8× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 28 other studies in this library |
| Still being cited | 3 / 4 | Cited 77 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Roger A. Barker: h-index 124 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of Cambridge: institution h-index 1,973 (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 17535834) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 68 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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
Williams-Gray, C. H., Foltynie, T., Brayne, C. E., Robbins, T. W., & Barker, R. A. (2007). Evolution of cognitive dysfunction in an incident Parkinson's disease cohort. Brain : a journal of neurology. https://doi.org/10.1093/brain/awm111
Vancouver
Williams-Gray CH, Foltynie T, Brayne CE, Robbins TW, Barker RA. Evolution of cognitive dysfunction in an incident Parkinson's disease cohort. Brain : a journal of neurology. 2007. doi:10.1093/brain/awm111. PMID: 17535834.
BibTeX
@article{williamsgray2007-17535834,
author = {Williams-Gray, C. H. and Foltynie, T. and Brayne, C. E. and Robbins, T. W. and Barker, R. A.},
title = {{Evolution of cognitive dysfunction in an incident Parkinson's disease cohort}},
journal = {Brain : a journal of neurology},
year = {2007},
doi = {10.1093/brain/awm111},
pmid = {17535834},
url = {https://doi.org/10.1093/brain/awm111}
}
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