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Comparing phenotypic features between Parkinson’s disease dementia and dementia with Lewy bodies
Chaminda Withanachchi Gunawardana, Peter G.R. Burke, Anna Ignatavicius, Elie Matar, Simon J. G. Lewis. Journal of Neurology, 2026-02-01
Topic: Risk, prevention and care in population studies
Patients with PDD showed a more severe phenotype than those with DLB, with higher scores in motor severity, hallucinations, delusions, somnolence, and urinary dysfunction (all p≤0.01). The correlations between neuropsychiatric symptoms differed between groups. In both PDD and DLB, depression correlated with anxiety (PDD ρ=0.54; DLB ρ=0.65; both p<0.001). In PDD, depression was additionally correlated with delusions (ρ=0.47; p<0.001), apathy (ρ=0.41; p<0.001), and sexual preoccupation (ρ=0.35; p<0.001), whereas in DLB depression correlated with hallucinations (ρ=0.38; p<0.001). PDD patients showed greater impairment in activities of daily living (ADLs) than DLB patients (p<0.001), correlating with motor severity (ρ=0.65; p<0.001) and fatigue (ρ=0.58; p<0.001). In DLB, impaired ADLs were linked to hallucinations (ρ=0.39; p<0.05), poorer cognition (ρ=0.47; p<0.01), urinary dysfunction (ρ=0.38; p<0.001), and fatigue (ρ=0.45; p<0.001). Despite being grouped under Lewy body dementias, these findings show PDD and DLB have distinct phenotypes reflecting their neurobiological underpinnings. This has implications for symptomatic and disease-modifying management. Future research should explore pathological mechanisms of these characteristics to improve diagnosis and treatment strategies.
Key findings
- Patients with PDD showed a more severe phenotype than those with DLB, with higher scores in motor severity, hallucinations, delusions, somnolence, and urinary dysfunction (all p≤0.01).
- The correlations between neuropsychiatric symptoms differed between groups.
- In both PDD and DLB, depression correlated with anxiety (PDD ρ=0.54; DLB ρ=0.65; both p<0.001).
- In PDD, depression was additionally correlated with delusions (ρ=0.47; p<0.001), apathy (ρ=0.41; p<0.001), and sexual preoccupation (ρ=0.35; p<0.001), whereas in DLB depression correlated with hallucinations (ρ=0.38; p<0.001).
- PDD patients showed greater impairment in activities of daily living (ADLs) than DLB patients (p<0.001), correlating with motor severity (ρ=0.65; p<0.001) and fatigue (ρ=0.58; p<0.001).
Why it matters
This study found that Parkinson's disease dementia and dementia with Lewy bodies have distinct clinical phenotypes, with Parkinson's disease dementia showing more severe motor and psychiatric symptoms. These differences may inform symptomatic and disease-modifying management, but the work is about describing phenotypes rather than testing any treatment.
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Study details
- Participants31
- Evidence strengthLow
How this study scored 39/100
Published in a peer-reviewed journal. Scored zero for study design, effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Journal of Neurology) |
| Journal's citation record | 2 / 4 | Journal of Neurology: journal h-index 208 (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 | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 1 / 4 | 31 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 | 1 / 7 | Cited 1 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.5 citations a year over 2 year(s) since 2026 |
| Impact for its field and year | 3 / 6 | Cited 4.3× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 1 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 0 / 4 | Last-listed author Simon J. G. Lewis: h-index 2 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | The University of Sydney: institution h-index 1,466 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 3 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 41665721) |
| Free to read | 2 / 2 | Free to read |
| Total | 39 / 100 | — |
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Read the original
- DOI: 10.1007/s00415-026-13649-9
- PubMed: 41665721
- Original source →
- Free full text: Journal of Neurology →
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
Gunawardana, C. W., Burke, P. G., Ignatavicius, A., Matar, E., & Lewis, S. J. G. (2026). Comparing phenotypic features between Parkinson’s disease dementia and dementia with Lewy bodies. Journal of Neurology. https://doi.org/10.1007/s00415-026-13649-9
Vancouver
Gunawardana CW, Burke PG, Ignatavicius A, Matar E, Lewis SJG. Comparing phenotypic features between Parkinson’s disease dementia and dementia with Lewy bodies. Journal of Neurology. 2026. doi:10.1007/s00415-026-13649-9. PMID: 41665721.
BibTeX
@article{gunawardana2026-41665721,
author = {Gunawardana, Chaminda Withanachchi and Burke, Peter G.R. and Ignatavicius, Anna and Matar, Elie and Lewis, Simon J. G.},
title = {{Comparing phenotypic features between Parkinson’s disease dementia and dementia with Lewy bodies}},
journal = {Journal of Neurology},
year = {2026},
doi = {10.1007/s00415-026-13649-9},
pmid = {41665721},
url = {https://doi.org/10.1007/s00415-026-13649-9}
}
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