Lifetime surgical exposure, episodic memory, and forniceal microstructure in older adults

ABSTRACT

Introduction: Aging is associated with heterogeneous cognitive trajectories. There is considerable interest in identifying risk factors for pathological aging, with recent studies demonstrating a link between surgical procedures and proximal cognitive decline; however, the role of lifetime exposure to surgical procedures and cognitive function has been relatively unexplored. This pilot study aimed to evaluate the association between total lifetime surgical procedures and memory function in older adults.

Methods: A cohort of 62 older adults underwent a neuropsychological evaluation and health history assessment. Self-reported lifetime surgical history was categorized as “cardiac” or “non-cardiac.” General linear models were fit with demographics as nuisance covariates, and the total number of non-cardiac surgeries as our predictor of interest. Total scores on measures of episodic memory, language, working memory, fluency, and visuospatial function were separate outcome variables. In a secondary analysis, vascular risk factors were included as covariates. Diffusion tensor imaging was obtained for exploratory analyses of selected regions of interest.

Results: The mean age of participants was 70, and 0–13 lifetime non-cardiac surgical procedures were reported. Higher numbers of lifetime non-cardiac surgical procedures were associated with worse verbal learning and memory (p = .04). The negative association between lifetime non-cardiac procedures and cognition was specific to memory. Exploratory analyses showed that higher number of lifetime non-cardiac procedures was related to lower FA in the fornix body (p = .02).

Conclusions: These results of this pilot study suggest that greater lifetime exposure to surgery may be associated with worse verbal learning and memory in healthy older adults. These findings add to a growing body of literature suggesting that cumulative medical events may be risk factors for negative cognitive outcomes.

KEYWORDS:

• Cognitive aging
• healthy volunteers
• neuroimaging
• memory
• Alzheimer disease

Authors' contributions

James R Bateman was involved in the analysis/interpretation of data and drafting/review of manuscript. Christopher M. Filley was involved in the interpretation of data and drafting/review of manuscript. Rini Kaplan was involved in the study implementation and provided a critical review of the manuscript. Kate Heffernan was involved in the study design and implementation, and provided a critical review of the manuscript. Brianne M. Bettcher was involved in the study design, study implementation, analysis/interpretation of data, and drafting/review of manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

Dr. Bateman is supported by the Department of Veterans Affairs Office of Academic Affiliations Advanced Fellowship Program in Mental Illness Research and Treatment, the Medical Research Service of the W.G. (Bill) Hefner Veterans Affairs Medical Center, and the Department of Veterans Affairs Mid-Atlantic Mental Illness Research, Education, and Clinical Center (MIRECC); This study was supported in part by NIH-NIA research grants K23AG042492 and R01AG058772 (PI: Bettcher), and by philanthropic funds raised by Huntington Potter for Rocky Mountain Alzheimer’s Disease Center research. Supported by NIH/NCATS Colorado CTSA Grant Number UL1 TR002535 and NIH High-End Instrumentation Grant S10OD018435. Contents are the authors’ sole responsibility and do not necessarily represent the views of the Department of Veterans Affairs, Department of Defense, the Federal Government, or the National Institutes of Health.