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Homogeneity and heterogeneity in mild cognitive impairment and Alzheimer's disease: a cross-sectional and longitudinal study of 55 cases
Lambon Ralph MA, Patterson K, Graham N, Dawson K, Hodges JR.. Brain : a journal of neurology, 2003-07-22
Topic: Amyloid, tau and blood-test diagnosis
This study investigated cross-sectional and longitudinal neuropsychological data from 55 patients: 38 with Alzheimer's disease and 18 with mild cognitive impairment (MCI). The analyses were designed to investigate two issues: the relationship of MCI to Alzheimer's disease, and that of atypical to typical Alzheimer's disease. When longitudinal data were averaged across individual patients, a consistent staging of neuropsychological deficits emerged: the selective amnesia characteristic of the MCI phase was joined next by semantic and other linguistic impairments plus emerging difficulties with demanding visuospatial tasks. A two-stage statistical procedure was used to extract underlying factors that corresponded to the severity-governed decline in neuropsychological test scores and then to the consistent deviations away from this typical longitudinal profile; i.e. identifying patterns of atypical Alzheimer's disease. The severity-based factor accounted for nearly 60% of the variance in this MCI-Alzheimer's disease longitudinal and cross-sectional database. This suggests that there is a fairly high degree of homogeneity within this group of patients, and that most of their longitudinal progression can be predicted by dementia severity alone. There were also two main patterns of atypical variation corresponding to patients with exaggerated semantic or visuospatial deficits. Although such cases may mimic more focal lobar degenerative conditions, patients with atypical Alzheimer's disease have pronounced episodic memory impairments, suggesting amnesia as a critical diagnostic feature.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Lambon Ralph, M. A., Patterson, K., Graham, N., Dawson, K., & Hodges, JR. (2003). Homogeneity and heterogeneity in mild cognitive impairment and Alzheimer's disease: a cross-sectional and longitudinal study of 55 cases. Brain : a journal of neurology. https://doi.org/10.1093/brain/awg236
Vancouver
Lambon Ralph MA, Patterson K, Graham N, Dawson K, Hodges JR. Homogeneity and heterogeneity in mild cognitive impairment and Alzheimer's disease: a cross-sectional and longitudinal study of 55 cases. Brain : a journal of neurology. 2003. doi:10.1093/brain/awg236. PMID: 12876147.
BibTeX
@article{lambonralph2003-12876147,
author = {Lambon Ralph, M. A. and Patterson, K. and Graham, N. and Dawson, K. and Hodges, JR.},
title = {{Homogeneity and heterogeneity in mild cognitive impairment and Alzheimer's disease: a cross-sectional and longitudinal study of 55 cases}},
journal = {Brain : a journal of neurology},
year = {2003},
doi = {10.1093/brain/awg236},
pmid = {12876147},
url = {https://doi.org/10.1093/brain/awg236}
}
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Key findings
- This suggests that there is a fairly high degree of homogeneity within this group of patients, and that most of their longitudinal progression can be predicted by dementia severity alone.
Why it matters
In this study of 55 patients, a severity-based factor accounted for nearly 60% of the variance, suggesting a fairly high degree of homogeneity and that most longitudinal progression could be predicted by dementia severity alone. Two patterns of atypical variation were also found, but no treatment or prevention is tested.
Study details
- Study designcross-sectional
- Participants55
- Evidence strengthModerate
How this study scored 55/100
Published in a leading specialty journal, and it is a snapshot of people at one point in 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 | 4 / 12 | A snapshot of people at one point in 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 | 2003 — older than 20 years, still counted |
| Sample size | 1 / 4 | 55 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 228 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 9.1 citations a year over 25 year(s) since 2003 |
| Impact for its field and year | 3 / 6 | Cited 5.7× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 2 other studies in this library |
| Still being cited | 1 / 4 | Cited 14 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author John R. Hodges: h-index 99 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | Medical Research Council: institution h-index 1,249 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 3 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 12876147) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 55 / 100 | — |
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