Journal of the International Neuropsychological Society

Research Articles

Are Empirically-Derived Subtypes of Mild Cognitive Impairment Consistent with Conventional Subtypes?

Lindsay R. Clarka1, Lisa Delano-Wooda2a3, David J. Libona4, Carrie R. McDonalda3, Daniel A. Nationa2, Katherine J. Bangena3, Amy J. Jaka2a3, Rhoda Aua5, David P. Salmona6 and Mark W. Bondia2a3 c1

a1 San Diego State University/University of California San Diego Joint Doctoral Program in Clinical Psychology, San Diego, California

a2 Department of Veterans Affairs San Diego Healthcare System, San Diego, California

a3 Department of Psychiatry, UC San Diego, School of Medicine, La Jolla, California

a4 Department of Neurology, Drexel University, College of Medicine, Philadelphia, Pennsylvania

a5 Department of Neurology, Boston University, School of Medicine, Boston, Massachusetts

a6 Department of Neurosciences, UC San Diego, School of Medicine, La Jolla, California

Abstract

Given the importance of identifying dementia prodromes for future treatment efforts, we examined two methods of diagnosing mild cognitive impairment (MCI) and determined whether empirically-derived MCI subtypes of these diagnostic methods were consistent with one another as well as with conventional MCI subtypes (i.e., amnestic, non-amnestic, single-domain, multi-domain). Participants were diagnosed with MCI using either conventional Petersen/Winblad criteria (n = 134; >1.5 SDs below normal on one test within a cognitive domain) or comprehensive neuropsychological criteria developed by Jak et al. (2009) (n = 80; >1 SD below normal on two tests within a domain), and the resulting samples were examined via hierarchical cluster and discriminant function analyses. Results showed that neuropsychological profiles varied depending on the criteria used to define MCI. Both criteria revealed an Amnestic subtype, consistent with prodromal Alzheimer's disease (AD), and a Mixed subtype that may capture individuals in advanced stages of MCI. The comprehensive criteria uniquely yielded Dysexecutive and Visuospatial subtypes, whereas the conventional criteria produced a subtype that performed within normal limits, suggesting its susceptibility to false positive diagnostic errors. Whether these empirically-derived MCI subtypes correspond to dissociable neuropathologic substrates and represent reliable prodromes of dementia will require additional follow-up. (JINS, 2013, 19, 1–11)

(Received August 31 2012)

(Revised February 28 2013)

(Accepted March 01 2013)

(Online publication April 03 2013)

Keywords

  • Mild cognitive impairment;
  • Amnestic MCI;
  • Non-amnestic MCI;
  • Dementia;
  • Cluster analysis;
  • Neuropsychology

Correspondence

c1 Correspondence and reprint requests to: Mark W. Bondi, VA San Diego Healthcare System (116B), 3350 La Jolla Village Drive, San Diego, CA 92161. E-mail: mbondi@ucsd.edu