Summary: Researchers report there is no increased risk of being diagnosed with dementia in those who received general anesthesia compared to those who didn’t.
Source: Wiley
There are concerns that exposure to general anesthesia during surgery may contribute to an increased risk of Alzheimer’s disease.
To investigate, researchers compared exposure to general anesthesia versus regional anesthesia during elective surgery, looking for potential links to the development of dementia.
The Journal of the American Geriatrics Society study included 7,499 matched pairs of community-dwelling individuals aged 66 years or older who underwent surgery between 2007 and 2011 and were followed for up to 5 years.
The investigators found no difference in risk of being diagnosed with dementia for individuals who received general anesthesia when compared with those who received regional anesthesia.
“Many older adults experience changes in their cognition immediately following surgery and wonder what role the type of anesthetic might have played in these changes,” said senior author Dallas P. Seitz, MD, PhD, FRCPC, of the University of Calgary, in Canada.

“Our study provides evidence that anesthetic technique used during elective surgeries, general anesthesia or regional anesthesia is not associated with a long-term risk of developing dementia.”
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Source: AAAS
Contact: Press Office – AAAS
Image: The image is credited to B. Conlon et al., Science Translational Medicine (2020).
Original Research: Closed access.
“N-Acetylglucosamine drives myelination by triggering oligodendrocyte precursor cell differentiation” by Michael Demetriou et al. Journal of Biological Chemistry.
Abstract
Association Between Exposure to General Versus Regional Anesthesia and Risk of Dementia in Older Adults
BACKGROUND/OBJECTIVES
Cognitive changes are commonly observed in older adults following surgical procedures. There are concerns that exposure to general anesthesia (GA) may contribute to an increased risk of Alzheimer’s disease. Our study examined the associations between exposure to GA compared with regional anesthesia (RA) administered for elective surgical procedures and the development of dementia.
DESIGN
Population‐based propensity matched retrospective cohort study.
SETTING
Linked administrative databases were accessed from ICES (formerly called the Institute for Clinical Evaluative Services) in Ontario, Canada.
PARTICIPANTS
We included all community‐dwelling individuals aged 66 and older who underwent one of five elective surgical procedures in Ontario, Canada, between April 1, 2007, and March 31, 2011. Individuals with evidence of dementia preceding cohort entry were excluded. Individuals who received GA were matched within surgical procedures to those who received RA on age, sex, cohort entry year, and a propensity score to control for potential confounders.
MEASUREMENTS
The baseline characteristics of the study sample were compared before and after matching. Individuals were followed for up to 5 years following cohort entry for the occurrence of dementia using a validated algorithm. Cox proportional hazards analysis was used to determine the hazard ratio (HR) and 95% confidence interval (CI) for the association between anesthetic type and dementia. Subgroup and sensitivity analyses were undertaken.
RESULTS
A total of 7,499 matched pairs were included in the final analysis. Overall, no difference was observed in the risk of being diagnosed with dementia for individuals who received GA when compared with RA (HR = 1.0; 95% CI = .8–1.2). There was also no association between anesthesia and dementia in most subgroup and sensitivity analyses.
CONCLUSION
Elective surgery using GA was not associated with an overall elevated risk of dementia when compared with RA. Future studies are required to determine whether surgery is a risk factor for dementia irrespective of anesthetic technique.