Cognitive changes of older adults with an equivocal amyloid load

  • Kristell PothierEmail author
  • Laure Saint-Aubert
  • Claudie Hooper
  • Julien Delrieu
  • Pierre Payoux
  • Philipe de Souto Barreto
  • Bruno Vellas
  • MAPT/DSA Study Group
Original Communication



Observational and interventional studies addressing the link between amyloid (Aβ) burden and cognitive decline are increasing, but a clear definition of amyloid positivity is still lacking. This may represent a great stake for therapeutic studies enrolling Aβ + patients only. The main objective of this study was to define a population with “equivocal” amyloid status, and evaluate their cognitive changes.


Sixty-five participants over 75 years old, from the Control group of the interventional MAPT study, at risk to develop Alzheimer’s disease, were included. Participants were classified into three groups in terms of amyloid load: Aβ +, Aβ − and Equivocal participants (according to visual reading, global standardized uptake (SUVR) cut-offs, or a k-mean clustering method). The cognitive changes over time (memory, executive functions, attention and processing speed) of this Equivocal group were then compared to Aβ + and Aβ − participants.


When classified by visual read, Equivocal participants’ memory scores were comparable to the Aβ- participants, and greater than in Aβ + participants over time. Secondary analyses, using SUVR cut-offs classification, showed different trajectories with Equivocal participants being comparable to the Aβ + participants, and lower than Aβ-, on executive performance over time.


This original work pointed out a population that may be of great interest for interventional studies, raising the question of how amyloid status should be defined and integrated in such studies. These findings should be replicated in future studies on larger datasets, to confirm what methodological approach would be the most suitable to highlight this specific neuroimaging entity.


Amyloid imaging Memory Executive functions Equivocal cases 



This study was supported by grants from the French Ministry of Health (PHRC 2008), and the Institut de Recherche Pierre Fabre. The promotion of this study was supported by the University Hospital Center of Toulouse. Biological sample collection was supported by Exhonit Therapeutics. The AV45-MAPT study was supported by Avid radiopharmaceuticals/Eli Lilly and Company. Authors would like to thank all the members of the MAPT/DSA Study Group.


This work was funded by grants from the Gérontopôle of Toulouse, the French Ministry of Health (PHRC 2008, 2009), Pierre Fabre Research Institute, Exhonit Therapeutics SA, and Avid Radiopharmaceuticals Inc.

Compliance with ethical standards

Conflicts of interest

Prof. P. Payoux served on the scientific advisory board of Avid Radiopharmaceuticals and GEHC. Dr. J. Delrieu served on the scientific advisory board of Avid Radiopharmaceuticals. Prof. B. Vellas served on the scientific advisory board of Avid Radiopharmaceuticals. Other authors (Dr K. Pothier, Dr L. Saint-Aubert, Dr C. Hooper, Dr de Souto Baretto) declare that they have no conflict of interest.

Research involving human participants and/or animals

All procedures performed in studies involving human participants were in accordance with the ethical standards of the national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Supplementary material

415_2019_9203_MOESM1_ESM.docx (15 kb)
Supplementary material 1 (DOCX 14 KB)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Kristell Pothier
    • 1
    • 2
    Email author
  • Laure Saint-Aubert
    • 3
    • 4
  • Claudie Hooper
    • 1
  • Julien Delrieu
    • 1
    • 4
  • Pierre Payoux
    • 3
    • 4
  • Philipe de Souto Barreto
    • 1
    • 5
  • Bruno Vellas
    • 1
    • 5
  • MAPT/DSA Study Group
  1. 1.Gérontopôle de ToulouseCentre Hospitalo-Universitaire de Toulouse (CHU Toulouse)ToulouseFrance
  2. 2.EA 2114, Département de Psychologie-Psychologie des Ages de la Vie et AdaptationUniversity of ToursTours Cedex 1France
  3. 3.Department of Nuclear Medicine, Imaging PoleToulouse University HospitalToulouseFrance
  4. 4.Toulouse NeuroImaging CenterUniversité de Toulouse, Inserm, UPSToulouseFrance
  5. 5.UMR INSERM 1027, University of Toulouse IIIToulouseFrance

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