Abstract
Objectives Recently, it has been demonstrated that patients with subtle preexisting cognitive impairment were susceptible to delayed neurocognitive recovery (DNR). This present study investigated whether preoperative alterations in gray matter volume, spontaneous activity, or functional connectivity (FC) were associated with DNR. Methods This was a nested case-control study of older adults (≥60 years) undergoing noncardiac surgery. All patients received MRI scan at least 1 day prior to surgery. Cognitive function was assessed prior to surgery and at 7-14 days postsurgery. Preoperative gray matter volume, amplitude of low-frequency fluctuation (ALFF), and FC were compared between the DNR patients and non-DNR patients. The independent risk factors associated with DNR were identified using a multivariate logistic regression model. Results Of the 74 patients who completed assessments, 16/74 (21.6%) had DNR following surgery. There were no differences in gray matter volume between the two groups. However, the DNR patients exhibited higher preoperative ALFF in the bilateral middle cingulate cortex (MCC) and left fusiform gyrus and lower preoperative FC between the bilateral MCC and left calcarine than the non-DNR patients. The multivariate logistic regression analysis showed that higher preoperative spontaneous activity in the bilateral MCC was independently associated with a higher risk of DNR (OR = 3.11, 95% CI, 1.30-7.45; P = 0.011). A longer education duration (OR = 0.57, 95% CI, 0.41-0.81; P = 0.001) and higher preoperative FC between the bilateral MCC and left calcarine (OR = 0.40, 95% CI, 0.18-0.92; P = 0.031) were independently correlated with a lower risk of DNR. Conclusions Preoperative higher ALFF in the bilateral MCC and lower FC between the bilateral MCC and left calcarine were independently associated with the occurrence of DNR. The present fMRI study identified possible preoperative neuroimaging risk factors for DNR. This trial is registered with Chinese Clinical Trial Registry ChiCTR-DCD-15006096.
Highlights
Delayed neurocognitive recovery (DNR) is a common and well-known neurological complication following a procedure, especially in older adults [1, 2]
We investigated the differences in preoperative gray matter volume, amplitude of low-frequency fluctuation (ALFF), and functional connectivity (FC) between the patients with and without DNR
There were no differences in age, sex, height, weight, body mass index (BMI), smoking status, surgery history, comorbidities, surgical duration, nature of surgery, and dose of intraoperative anesthetics between the DNR group and non-DNR group (Table 1)
Summary
Delayed neurocognitive recovery (DNR) is a common and well-known neurological complication following a procedure, especially in older adults [1, 2]. It was suggested that patients with subtle preexisting cognitive impairment were more susceptible to postoperative cognitive impairment [5, 6]. These findings implied that preoperative cognitive function decline is an important risk factor for neurocognitive disorders following surgery and anesthesia [7]. Numerous studies have demonstrated that cognitive function was closely related to individual brain structure and function [8]. In our pilot study with small sample size, we found that there were differences of regional homogeneity in the right hippocampus/parahippocampus between the DNR patients and non-DNR patients (Gaussian random field corrected) [10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
