The emergence of cognitive discrepancies in preclinical Alzheimer's disease: A six-year case study

Abstract

We present neuropsychological data from an 81-year-old individual who was followed over a six-year period, initially as a healthy control participant. She performed above age-adjusted cutoff scores for impairment on most neuropsychological tests, including learning and memory measures, until the final assessment when she received a diagnosis of probable Alzheimer's disease (AD). Despite generally normal scores on individual cognitive tests, her cognitive profile revealed increasingly large cognitive discrepancies when contrasting verbal versus visuospatial tasks, and complex versus basic-level tasks. The present case provides intriguing evidence that cognitive-discrepancy measures could improve our ability to detect subtle changes in cognition at the earliest, preclinical stages of AD.

Keywords:

• Alzheimer's disease
• Neuropsychology
• Cognition
• Discrepancy
• Preclinical

The authors wish to thank Dr Terry Jernigan, Sarah Archibald M.S., and Dr Christine Fennema-Notestine for their assistance with MRI image collection and presentation. We also thank the participant, as well as Jodessa Braga and the staff of the UCSD Alzheimer's Disease Research Center for their contributions to this research. Finally, we would like to thank the anonymous reviewers for their helpful comments. Dr Delis is a co-author of the D-KEFS and CVLT-II and receives royalties from them. Preparation of this article was supported in by a Veterans Administration Career Development Award (M.W.J.), a Veterans Administration Merit Review Award (D.D.), NIMH award R01MH063782 (G.M.P.); Alzheimer's Association Award IIRG-07-59343 (M.W.B.), National Institute on Aging awards K24 AG026431 and R01 AG012674 (M.W.B.), and NIA Grant P50 AG 05131 (UCSD ADRC).