Single-Domain Amnestic Mild Cognitive Impairment Identified by Cluster Analysis Predicts Alzheimer's Disease in the European Prospective DESCRIPA Study

Marinella Damian, Lucrezia Hausner, Katrin Jekel, Melany Richter, Lutz Froelich, Ove Almkvist, Merce Boada, Roger Bullock, Peter Paul De Deyn, Giovanni B. Frisoni, Harald Hampel, Roy W. Jones, Patrick Kehoe, Hermine Lenoir, Lennart Minthon, Marcel G. M. Olde Rikkert, Guido Rodriguez, Philip Scheltens, Hilkka Soininen, Luiza SpiruJacques Touchon, Magda Tsolaki, Bruno Vellas, Frans R. J. Verhey, Bengt Winblad, Lars-Olof Wahlund, Gordon Wilcock, Pieter Jelle Visser

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Background/Aims: To identify prodromal Alzheimer's disease (AD) subjects using a data-driven approach to determine cognitive profiles in mild cognitive impairment (MCI). Methods: A total of 881 MCI subjects were recruited from 20 memory clinics and followed for up to 5 years. Outcome measures included cognitive variables, conversion to AD, and biomarkers (e.g. CSF, and MRI markers). Two hierarchical cluster analyses (HCA) were performed to identify clusters of subjects with distinct cognitive profiles. The first HCA included all subjects with complete cognitive data, whereas the second one selected subjects with very mild MCI (MMSE ≥28). ANOVAs and ANCOVAs were computed to examine whether the clusters differed with regard to conversion to AD, and to AD-specific biomarkers. Results: The HCAs identified 4-cluster solutions that best reflected the sample structure. One cluster (aMCIsingle) had a significantly higher conversion rate (19%), compared to subjective cognitive impairment (SCI, p < 0.0001), and non-amnestic MCI (naMCI, p = 0.012). This cluster was the only one showing a significantly different biomarker profile (Aβ42, t-tau, APOE ε4, and medial temporal atrophy), compared to SCI or naMCI. Conclusion: In subjects with mild MCI, the single-domain amnestic MCI profile was associated with the highest risk of conversion, even if memory impairment did not necessarily cross specific cut-off points. A cognitive profile characterized by isolated memory deficits may be sufficient to warrant applying prevention strategies in MCI, whether or not memory performance lies below specific z-scores. This is supported by our preliminary biomarker analyses. However, further analyses with bigger samples are needed to corroborate these findings.
Original languageEnglish
Pages (from-to)1-19
JournalDementia and Geriatric Cognitive Disorders
Volume36
Issue number1-2
DOIs
Publication statusPublished - 2013

Keywords

  • Mild cognitive impairment
  • Alzheimer's disease
  • Mild cognitive impairment subtypes
  • Conversion to Alzheimer's disease

Cite this

Damian, M., Hausner, L., Jekel, K., Richter, M., Froelich, L., Almkvist, O., Boada, M., Bullock, R., De Deyn, P. P., Frisoni, G. B., Hampel, H., Jones, R. W., Kehoe, P., Lenoir, H., Minthon, L., Rikkert, M. G. M. O., Rodriguez, G., Scheltens, P., Soininen, H., ... Visser, P. J. (2013). Single-Domain Amnestic Mild Cognitive Impairment Identified by Cluster Analysis Predicts Alzheimer's Disease in the European Prospective DESCRIPA Study. Dementia and Geriatric Cognitive Disorders, 36(1-2), 1-19. https://doi.org/10.1159/000348354