Prevalence and correlates of cognitive asymmetry in a large sample of Alzheimer’s disease patients

ABSTRACT

Previous research has suggested that a significant minority of patients with Alzheimer’s disease (AD) exhibit asymmetric cognitive profiles (greater verbal than visuospatial impairment or vice versa) and that these patient subgroups may differ in demographic and other characteristics. Prior studies have been relatively small, and this investigation sought to examine correlates of asymmetry in a large patient sample (N = 438). Patients were classified into the following cognitive profile groups: low verbal, symmetric, and low visuospatial. Consistent with past research, 28.3% of participants were classified as having asymmetric cognitive profiles, with more participants in the low visuospatial subgroup. Low visuospatial participants were younger than members of the other subgroups, and low verbal participants performed worse on a measure estimating premorbid verbal intelligence. Findings regarding apolipoprotein E (ApoE) ε4 genotype were equivocal, although results provided some evidence for an effect of the ɛ4 allele on cognitive asymmetry. These results suggest systematic differences between neuropsychological asymmetry profiles that support the possibility of distinct subgroups of the disease.

KEYWORDS:

• Alzheimer’s
• neuropsychology
• asymmetry
• cognition
• heterogeneity
• dementia

Acknowledgements

This paper is based on the Master’s thesis of the first author at the University of Houston. Portions of the paper were also presented at the 43rd annual meeting of the International Neuropsychological Society, 2015, in Denver, CO. The authors have no conflicts of interest or funding sources to disclose. Special thanks to the individuals involved in the database and to Julia Hannay of the University of Houston and Mario Dulay of The Methodist Hospital for their comments on the original thesis manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).