A Mayo Clinic study centered in Rochester, MN, determined that there is no association following surgery between anesthesia use in patients over age 40 and later development of cognitive degeneration.
Utilizing comprehensive patient data regarding patients aged 70-89 who were cognitively functionally normal as its outset, the study evaluated its 1,731 patients every 15 months to determine cognitive state. Over the study period, 31% of patients studied developed at least mild cognitive impairment; however, the development was not found to be associated with anesthesia use. This study falls in line with a prior Mayo Clinic study determining that older patients receiving anesthesia were not at increased risk to develop dementia. While these studies support the idea that general anesthesia after age 40 is not associated with cognitive decline, the authors caution against applying this finding to general anesthesia applied after age 60. According to the authors, there still may be a link between anesthesia application in older (60+) patients and cognitive impairment.
Another area of anesthesia risk that researchers are concerned with is the effect of anesthesia on the cognitive functions and neurodevelopment of young children. In this research setting, studies have unfortunately shown that receipt of general anesthesia in young children can significantly affect memory and cognitive development later in life. The authors of these studies again warn against overreaction, claiming that further study into the pediatric effects of anesthesia is needed before significant alteration of surgical guidelines for children. Both the fields of geriatric anesthesia and pediatric anesthesia, then, require significantly more studies conducted before the true effects of anesthesia on younger and older people will ever be definitively gleaned.