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Reduced hippocampal functional connectivity in Alzheimer disease
Allen G, Barnard H, McColl R, Hester AL, Fields JA, Weiner MF, Ringe WK, Lipton AM et al.. Archives of neurology, 2007-10-01
Topic: Amyloid, tau and blood-test diagnosis
Objective To determine if functional connectivity of the hippocampus is reduced in patients with Alzheimer disease. Design Functional connectivity magnetic resonance imaging was used to investigate coherence in the magnetic resonance signal between the hippocampus and all other regions of the brain. Participants Eight patients with probable Alzheimer disease and 8 healthy volunteers. Results Control subjects showed hippocampal functional connectivity with diffuse cortical, subcortical, and cerebellar sites, while patients demonstrated markedly reduced functional connectivity, including an absence of connectivity with the frontal lobes. Conclusion These findings suggest a functional disconnection between the hippocampus and other brain regions in patients with Alzheimer disease.
Key findings
- Results Control subjects showed hippocampal functional connectivity with diffuse cortical, subcortical, and cerebellar sites, while patients demonstrated markedly reduced functional connectivity, including an absence of connectivity with the frontal lobes.
- Conclusion These findings suggest a functional disconnection between the hippocampus and other brain regions in patients with Alzheimer disease.
Why it matters
In a very small study of 8 patients with probable Alzheimer's disease and 8 healthy volunteers, patients showed markedly reduced functional connectivity between the hippocampus and other brain regions, including an absence of connectivity with the frontal lobes. This describes a functional disconnection in the disease but does not show how to treat or cure it.
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Study details
- Evidence strengthLow
How this study scored 47/100
Published in a peer-reviewed journal. Scored zero for study design, 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 (Archives of neurology) |
| Journal's citation record | 3 / 4 | Archives of Neurology: journal h-index 353 (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 | 2007 — within 20 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 | 6 / 7 | Cited 356 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 17.0 citations a year over 21 year(s) since 2007 |
| Impact for its field and year | 3 / 6 | Cited 6.5× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 11 other studies in this library |
| Still being cited | 2 / 4 | Cited 49 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author C. Munro Cullum: h-index 72 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | The University of Texas Southwestern Medical Center: institution h-index 1,356 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 5 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 17923631) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 47 / 100 | — |
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Read the original
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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's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Allen, G., Barnard, H., McColl, R., Hester, A. L., Fields, J. A., Weiner, M. F., et al. (2007). Reduced hippocampal functional connectivity in Alzheimer disease. Archives of neurology. https://doi.org/10.1001/archneur.64.10.1482
Vancouver
Allen G, Barnard H, McColl R, Hester AL, Fields JA, Weiner MF, et al. Reduced hippocampal functional connectivity in Alzheimer disease. Archives of neurology. 2007. doi:10.1001/archneur.64.10.1482. PMID: 17923631.
BibTeX
@article{allen2007-17923631,
author = {Allen, G. and Barnard, H. and McColl, R. and Hester, A. L. and Fields, J. A. and Weiner, M. F. and Ringe, W. K. and Lipton, A. M. and others},
title = {{Reduced hippocampal functional connectivity in Alzheimer disease}},
journal = {Archives of neurology},
year = {2007},
doi = {10.1001/archneur.64.10.1482},
pmid = {17923631},
url = {https://doi.org/10.1001/archneur.64.10.1482}
}
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