Delayed neurocognitive recovery (dNCR) is a major complication after anesthesia and surgery in older adults. Alpha‐synuclein (α‐syn; encoded by the gene, SNCA) has recently been shown to play an important role in hippocampus‐dependent working memory. Aggregated forms of α‐syn are associated with multiple neurotoxic mechanisms, such as mitochondrial dysfunction and cell death. In this study, we found that blocking α‐syn improved both mitochondrial function and mitochondria‐dependent neuronal apoptosis in a mouse model of dNCR. Various forms of α‐syn (including total α‐syn, phosphorylated‐Ser129‐α‐syn, and oligomers) were upregulated in hippocampal tissue and extracted mitochondria after surgical challenge. Clenbuterol is a novel transcription modulator of Scna. Clenbuterol significantly attenuated surgery‐induced progressive accumulation of various toxic α‐syn forms in the hippocampus, as well as mitochondrial damage and memory deficits in aged mice following surgery. We also observed excessive mitochondrial α‐syn accumulation and increased mitochondria‐mediated apoptosis in vitro using nerve growth factor‐differentiated PC12 cells and primary hippocampal neurons exposed to lipopolysaccharide. To further validate the neuroprotective effect of α‐syn inhibition, we used a lentiviral Snca‐shRNA (Lv‐shSnca) to knockdown Snca. Of note, Lv‐shSnca transfection significantly inhibited neuronal apoptosis mediated by the mitochondrial apoptosis pathway in neurons exposed to lipopolysaccharide. This α‐syn inhibition improved the disruption to mitochondrial morphology and function, as well as decreased levels of apoptosis. Our results suggest that targeting pathological α‐syn may achieve neuroprotection through regulation of mitochondrial homeostasis and suppression of apoptosis in the aged hippocampus, further strengthening the therapeutic potential of targeting α‐syn for dNCR.

Objective: This study aimed to explore possible biomarkers of postoperative delirium (POD) of Parkinson’s disease (PD) patients received deep brain stimulation (DBS) of the subthalamic nuclei. Materials and methods: This nested case control study analyzed perioperative plasma and cerebral spinal fluid (CSF) of patients (n = 40) who developed POD undergone DBS surgery (n = 10) and those who did not (n = 30). Blood sample was collected before surgery and on the first day postoperative, CSF sample was collected at the beginning of the operation. POD was assessed by the Confusion Assessment Method (CAM) twice a day between 7:00 am and 7:00 pm after the surgery until discharge. Plasma and CSF sample from the two groups were analyzed to investigate possible biomarkers for POD in PD patients. Results: There was no difference between POD and Non-POD groups on the concentration of Interleukin 6 and Tumor Necrosis Factor-α in CSF, preoperative plasma and postoperative plasma. There was no difference between POD and Non-POD groups on the concentration of S100 calcium-binding protein β protein (S100β) and Neurofilament light chain (NFL) in preoperative plasma and postoperative plasma. The concentration of C-reactive protein (CRP), NFL and S100β were significant higher in POD group than non-POD group in CSF. The concentration of CRP was significantly higher in POD group than non-POD group in preoperative plasma and postoperative plasma. CSF concentration of S100β might be a potential biomarker for POD via the receiver operating characteristic curve analysis and the area under the curve value of 0.973. Conclusion: For PD patients received DBS surgery, CSF S100β might be a marker for aiding detection of high-risk patients with delirium. This requires further confirmation in clinical trials.

Background. Deep brain stimulation of the subthalamic nuclei (STN-DBS) is a standard treatment option for advanced Parkinsons disease (PD) patients. Delirium following DBS electrode implantation is common, by several studies, and cognitive impairment is a risk factor for developing postoperative delirium (POD). This prospective observational study was conducted to identify whether preoperative baseline cognitive status has an association with POD in PD patients undergoing DBS surgery. Methods. Preoperatively, neuropsychiatric and neuropsychological assessments of the patients were performed including clinical dementia rating (CDR) score, instrumental activities of daily living (IADL) score, mini-mental state exam (MMSE) score, Montreal cognitive assessment (MoCA) score, Hamilton anxiety (HAMA) and Hamilton depression (HAMD) scores, and numerical cancellation test. POD was identified by the confusion assessment method (CAM) twice per day on postoperative day 1 until discharge. Results. Twenty-seven (21.6) of 125 patients developed POD. Among the variables screened, age, CDR score, MMSE score, and HAMA score were indicated to be independent influence factors of POD. The cutoff score, AUC, sensitivity, and specificity of age, CDR score, MMSE score, and HAMA score associated with POD was 58.5, 0.751, 92.6, 52.0; 0.5, 0.848, 77.8, 91.8; 27.5, 0.827, 88.9, 62.2; and 12.5, 0.706, 85.2, 54.1, respectively. Conclusions. We observed age, CDR score, MMSE score, and HAMA score were independent influence factors of POD in PD patients who received DBS. It is necessary to assess the cognitive status of PD patients before surgery to identify high-risk patients.

Long noncoding RNAs (lncRNAs) play important roles in brain function modulation and neurodegenerative diseases. However, whether lncRNA regulations are involved in the mechanisms of perioperative neurocognitive disorders, especially in anesthesia‐related brain dysfunction, remain unknown. Therefore, we explored the expression and regulation pattern profiles of lncRNAs in the hippocampus of aged rats after sevoflurane anesthesia. Three lncRNAs and 772 protein‐coding genes were identified by microarray analysis and evidenced by in vitro and in vivo experiments as differentially expressed. Functional annotation and differentially expressed‐ (DE‐) lncRNA‐mRNA coexpression networks reveal that DE‐lncRNAs are associated with mitochondrial dysfunction and oxidative stress, aging‐related metabolism alterations, DNA damage, and apoptosis, as well as neurodegenerative features during sevoflurane anesthesia. These results suggest that lncRNAs play roles in general anesthesia‐related brain function modulation during the perioperative context and provide insights into the lncRNA‐related modulation mechanisms and targets.

Background: The selection of the maintenance of general anesthesia may affect the development of postoperative delirium (POD), notably for Parkinson’s disease (PD) patients, due to their lower cognitive reserve. The present study was designed to compare the potential impact of propofol vs. sevoflurane based general anesthesia maintenance methods on the development of POD in PD patients following deep brain stimulation (DBS) surgery. Methods: A total of 125 PD patients who were scheduled to undergo DBS surgery were randomly divided into the propofol (n = 63) and the sevoflurane groups (n = 62). The patients in the two groups randomly received propofol- or sevoflurane-based general anesthesia. The Confusion Assessment Method (CAM) was employed by an investigator who was blinded to the anesthesia regimen and was administered twice per day from postoperative day 1 until discharge. Results: The incidence of POD was 22.22% (14/63) with propofol anesthesia and 20.97% (13/62) with sevoflurane anesthesia (p = 0.865). In addition, no difference was noted in the duration and severity of delirium between the propofol and sevoflurane groups. Conclusions: In the present study, propofol- and sevoflurane-based general anesthesia exhibited comparable results with regard to the POD incidence in PD patients undergoing deep brain stimulation surgery.

Background: A simple, rapid, and effective cognitive screening test appropriate for fast-paced settings with limited resources and staff is essential, especially preoperatively. This study aimed to develop and validate the short versions of Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) for predicting postoperative delirium (POD) in patients with Parkinson’s disease (PD) who were scheduled for surgery. Methods: The current study was a secondary analysis of data collected from 128 inpatients scheduled for deep brain stimulation of the subthalamic nuclei (STN-DBS) lasting > 60 min, at Tsinghua University Yuquan Hospital, China. Preoperative cognitive screening was performed during the preoperative visit using the MMSE and MoCA. The optimal MMSE and MoCA cut-off scores for detecting PD-MCI was 27 and 23 respectively. The POD was assessed twice a day on the first postoperative day until discharge by the confusion assessment method. The backward conditional logistic regression analysis was used to organize the reduced versions of the MMSE or MoCA. Also, the areas under the receiver operating characteristic curves (AUCs) were examined using the DeLong test. Results: 125/128 PD patients were included in the analysis, and 27 (21.6%) developed POD. The MMSE reduced version (orientation to time, attention and calculation, and comprehension) demonstrated performance similar to the original MMSE in predicting POD (z=0.820, p=0.412). The AUC of the original MoCA and the short MoCA (visuospatial and executive attention and orientation) were 0.808 and 0.826, respectively. There was no significantly difference in the AUC values between the tests (z=0.561, p=0.575). Conclusion: Our simplified MMSE and MoCA could be efficiently used to identify patients at risk for POD. Also, short cognitive tests could be considered while predicting POD in fast-paced preoperative settings with limited resources and staff. Plain Language Summary: Routine preoperative cognitive screening is very important in predicting postoperative delirium.MMSE and MoCA are the most commonly used cognitive testing method which normally takes a long time.The short variant of MMSE and MoCA show a predictive performance similar to the original tests.