The use of repetitive anesthesia with isoflurane (one of the most common anesthetics by inhalation) increases the risk of developing changes similar to those observed in Alzheimer’s disease brains in mice with mutations of the amyloid precursor protein (APP).
The findings suggest a possible mechanism of developing Alzheimer’s disease. Some epidemiological studies have shown an increased prevalence of Alzheimer’s disease in patients undergoing anesthesia and surgery. The researchers state that “before surgery requiring anesthesia, it may be ideal to know the genetic background of the patients so that the drugs used and the pattern of anesthesia may be personalized accordingly.”
The linkage between the repetitive use of isoflurane anesthesia and the development of Alzheimer’s disease changes in mice with mutations indicates the advisability of testing for genetic risk factors for Alzheimer’s disease in patients prior to surgery. Until recently, the most important genetic risk factor for Alzheimer’s disease was the presence of the allele E4 of the apolipoprotein E, but recently other genetic polymorphisms of risks have been identified. Once these polymorphisms of risks are identified and their relative impact on the pathogenesis of Alzheimer’s disease are known, a simple, automatic test for risk of Alzheimer’s disease should be performed in patients, namely the elderly, undergoing surgery under general anesthesia and the anesthetic procedure should be modified accordingly. A personalized clinical model that would enable the reduction of the patient’s potential risk for Alzheimer’s disease would reduce the risk of anesthesia.
The research has been based on the application of anesthesia twice a week during three months in normal mice and in mice with mutations (7-10 months old) that produce Alzheimer’s disease (known as APPswe ). The results show alterations produced in the brain of mice with mutations very similar to those observed in patients that have already developed Alzheimer’s disease.
The study confirms that anesthesia is safe for normal mice but risky for asymptomatic carriers of mutations which produce Alzheimer’s disease.
References:
1. Perucho J, et al. Anesthesia with Isoflurane Increases Amyloid Pathology in Mice Models of Alzheimer’S Disease. J Alzheimers Dis. PMID: 2000921
