This page is alzhub.org's plain-English summary of a published study, not the paper itself. It is generated from the record we hold for this study, sourced and linked below — check the original for the full text and methods.

51/100

✓ Peer-reviewed alzhub usefulness score 51 out of 100. Brain scans and imaging

Topic: Amyloid, tau and blood-test diagnosis

Objective The objective of this study was to examine practice effects and longitudinal cognitive change in 190 clinically normal elderly classified according to a two-feature biomarker model for Alzheimer's disease. Methods All participants completed neuropsychological testing, MRI, FDG-PET, and PiB-PET at their baseline evaluation. We divided participants into four groups based on neuroimaging measures of amyloid (A+ or A-) and neurodegeneration (N+ or N-) and reexamined cognition at 15- and 30-month intervals. Results The A-N- group showed significant improvements in the memory and global scores. The A+N- group also showed significant improvements in the memory and global scores as well as attention. The A-N+ group showed a significant decline in attention at 30 months. The A+N+ group showed significant improvements in memory and the global score at 15 months followed by a significant decline in the global score at 30 months. Conclusion Amyloidosis in the absence of neurodegeneration did not have an adverse impact on practice effects or the 30-month cognitive trajectories. In contrast, participants with neurodegeneration (either A-N+ or A+N+) had worse performance at the 30-month follow-up. Our results show that neurodegeneration has a more deleterious effect on cognition than amyloidosis in clinically normal individuals.

Key findings

Results The A-N- group showed significant improvements in the memory and global scores.
The A+N- group also showed significant improvements in the memory and global scores as well as attention.
The A-N+ group showed a significant decline in attention at 30 months.
The A+N+ group showed significant improvements in memory and the global score at 15 months followed by a significant decline in the global score at 30 months.
Our results show that neurodegeneration has a more deleterious effect on cognition than amyloidosis in clinically normal individuals.

Why it matters

In cognitively normal older adults, having amyloid buildup alone did not harm thinking over 30 months, but having signs of neurodegeneration was linked to worse thinking later. This suggests that treatments aimed at nerve damage may matter more than targeting amyloid alone in people without symptoms.

New to this subject? Start with our plain-English guide: Brain scans & tests →

Study details

Study designlongitudinal study
Evidence strengthModerate

How this study scored 51/100

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 and randomised / blinded because the record does not state it.

Component	Points	Why
Journal tier	7 / 10	Tier 3 — peer-reviewed journal (The Clinical neuropsychologist)
Journal's citation record	1 / 4	The Clinical Neuropsychologist: journal h-index 128 (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	3 / 3	Studied in people (pubmed indexes it as a clinical or observational study)
Randomised / blinded	0 / 2	No randomisation or blinding stated — scores zero (not stated in the record — scored 0)
Times cited	4 / 7	Cited 59 times (OpenAlex, 2026-10-10)
Citations per year	2 / 5	5.4 citations a year over 11 year(s) since 2017
Impact for its field and year	3 / 6	Cited 3.6× 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	1 / 4	Cited 14 times in 2024–2026 (2026 still in progress; OpenAlex)
Senior author's track record	4 / 4	Last-listed author Ronald Carl Petersen: h-index 209 (OpenAlex, whole career)
Institution's track record	2 / 3	Mayo Clinic: institution h-index 1,606 (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 27724156)
Free to read	0 / 2	Behind a paywall — scores zero
Total	51 / 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. 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

Machulda, M. M., Hagen, C. E., Wiste, H. J., Mielke, M. M., Knopman, D. S., Roberts, R. O., et al. (2017). [Formula: see text]Practice effects and longitudinal cognitive change in clinically normal older adults differ by Alzheimer imaging biomarker status. The Clinical neuropsychologist. https://doi.org/10.1080/13854046.2016.1241303

Vancouver

Machulda MM, Hagen CE, Wiste HJ, Mielke MM, Knopman DS, Roberts RO, et al. [Formula: see text]Practice effects and longitudinal cognitive change in clinically normal older adults differ by Alzheimer imaging biomarker status. The Clinical neuropsychologist. 2017. doi:10.1080/13854046.2016.1241303. PMID: 27724156.

BibTeX

@article{machulda2017-27724156,
  author  = {Machulda, M. M. and Hagen, C. E. and Wiste, H. J. and Mielke, M. M. and Knopman, D. S. and Roberts, R. O. and Vemuri, P. and Lowe, V. J. and others},
  title   = {{[Formula: see text]Practice effects and longitudinal cognitive change in clinically normal older adults differ by Alzheimer imaging biomarker status}},
  journal = {The Clinical neuropsychologist},
  year    = {2017},
  doi     = {10.1080/13854046.2016.1241303},
  pmid    = {27724156},
  url     = {https://doi.org/10.1080/13854046.2016.1241303}
}

Studies this one cites

Referenced by this study and also in the alzhub library, so you can read them here. Showing 12 of 25.

Related studies in Brain scans and imaging

Similar studies

More on Brain scans and imaging

See all studies in Brain scans and imaging →