Increased Risk of Dementia after Anesthesia and Surgery

Background: The potential relationship between anesthesia, surgery, and onset of dementia remains elusive. Aims: To determine whether the risk of dementia increases after surgery with anesthesia, and to evaluate possible associations among age, mode of anesthesia, type of surgery, and risk of dementia. Method: The study cohort included an anesthetized group of patients aged 50 years and older who were anesthetized between January 1, 2004 and December 31, 2007, and a control group of randomly selected ageand sex-matched patients. Patients were followed until December 31, 2010 to identify signs of early dementia. Results: Relative to control patients who were not anesthetized, patients who underwent anesthesia and surgery exhibited an increased risk of dementia (HR = 1.99) and a reduced mean interval to dementia diagnosis. The risk of dementia increased in patients who received intravenous (IV) or intramuscular (IM) anesthesia, regional anesthesia (RA), and general anesthesia (GA). Conclusions: The results of our nationwide population-based study suggest that patients who undergo anesthesia and surgery are at increased risk for dementia.