Neuropsychological Profiles of an Elderly Cohort Undergoing Elective Surgery and the Relationship Between Cognitive Performance and Delirium

Abstract

Background/Objectives To examine the baseline (preoperative) neuropsychological test performance in a cohort of elderly individuals undergoing elective surgery and the association between specific neuropsychological domains and post-operative delirium. Design/Setting/Participants An ongoing prospective cohort study of elderly patients (n=300) scheduled for elective (non-cardiac) surgery. Measurements Neuropsychological testing, including standardized assessments of memory, divided and sustained attention, speed of mental processing, verbal fluency, working memory, language, and an overall measure of premorbid cognitive functioning, was obtained 2-4 weeks prior to surgery. The relationship of the individual neuropsychological tests and delirium status was examined using linear regression, adjusting for age, gender and education. Results After adjustment, patients who developed post-operative delirium performed significantly lower pre-operatively on measures of speed of mental processing and divided attention (Trails Making Test B, mean difference=17.55, p=0.02), category fluency (animal naming, -1.94, p=0.01), sustained visual attention (Visual Search and ATtention, -3.19, p <0.001) and working memory with new learning and recall, (HVLT-R Total, -0.53 to -0.79, p <0.01). Conclusion Lower performance scores on tests evaluating the areas of complex attention, executive functioning, and rapid access to verbal knowledge or semantic networks are seen at baseline in patients who later develop delirium. Future studies to better understand how the identified cognitive profiles may predispose individuals towards developing delirium may help pave the way to greater understanding of the mechanisms of delirium.

Factors Influencing Clinical Correlates of Chronic Traumatic Encephalopathy (CTE): a Review

“…Fong et al examined preoperative differences on neuropsychological testing between patients who did and did not develop postoperative delirium and found patients in the postoperative delirium group performed worse preoperatively, on average, in cognitive flexibility (Trails B), category fluency (animal naming), new learning and recall (HVLT-R), and visual and sustained attention. However, predicting postoperative delirium based on preoperative performance is likely difficult because, at the individual level, a minority of postoperative delirium patients showed impaired performance preoperatively, ranging from 15% impaired on cognitive flexibility to 27% impaired on visual and sustained attention (Fong et al 2015). …”

Predicting postoperative delirium severity in older adults: The role of surgical risk and executive function

“…[32][33][34] However, as identified by our recent systematic review of delirium prediction models in older adults, an executive function measure has not been applied previously. The preoperative NSQIP-SC score is a composite variable, combining data on both predisposing risk factors for delirium and surgical severity, (ie, the precipitating event for delirium) and is well positioned to contribute information on the risk of delirium severity.…”

“…[22][23][24] Built using data from 1 414 006 patients including 1557 distinct surgical procedures, the NSQIP risk score has been widely validated and applied to predict outcomes in various surgical populations but has not been applied in delirium severity risk assessment. [32][33][34] The purpose of this study is twofold. 30 As delirium is a cognitive disorder, we further hypothesized that cognitive data (that are not included in the NSQIP calculation) could enhance the prediction of the surgical risk scores.…”

“…31 Significant associations between preoperative executive function and postoperative delirium incidence have been reported and are plausible given the extensive impairment of executive functions in delirium. [32][33][34] The purpose of this study is twofold. First is to examine the potential of the NSQIP risk scores and a measure of executive function to predict postoperative delirium severity among other potential candidate predictors.…”

Effect of Cognitively Stimulating Activities on Symptom Management of Delirium Superimposed on Dementia: A Randomized Controlled Trial

“…36, 37 In clinical studies, fronto-executive dysfunction independently predicted postoperative delirium even in the absence of cognitive impairment. 38 Patients who recover from delirium have short 5 and long-term 4 impairments in executive function. Jackson and colleagues 18 reported greater benefits for executive function using cognition-focused and physical therapy verses physical therapy only in ICU survivors.…”