Postoperative Cognitive Dysfunction Patients Research Articles

Ratio of β-amyloid protein (Aβ) and Tau predicts the postoperative cognitive dysfunction on patients undergoing total hip/knee replacement surgery.

β-amyloid (Aβ) and Tau proteins are biomarkers of Alzheimer's disease neuropathogenesis. We hypothesized that they are also potential biomarkers for postoperative cognitive dysfunction (POCD). The present study was designed to evaluate the use of the Aβ-42/Tau ratio for the diagnosis of POCD in patients undergoing hip/knee replacement surgery. A total of 80 patients who underwent total hip/knee replacement surgery were grouped into POCD or non-POCD patients at 7 days, 1 and 3 months after surgery, according to a z-score recommended by the international study of POCD. Cerebrospinal fluid samples were collected prior to surgery and the concentration of Aβ-42 and Tau protein were detected. The ratio of Aβ-42/Tau was compared between the two groups at different time points. The patients completed the whole battery of neuropsychological tests following surgery. The POCD occurrence rates at 7 days, 1 and 3 months were 40, 25 and 15%, respectively. The Aβ-42/Tau ratios were much lower in the POCD group than those in the non-POCD group at 7 days (1.7±0.4 vs. 2.6±0.3), 1 month (1.6±0.5 vs. 2.4±0.4), and 3 months (1.6±0.4 vs. 2.5±0.4). The sensitivity and specificity for diagnosis of POCD as indicated by the ratios, at the three time points, were 91.7 vs. 81.2%, 86.7 vs. 70%, and 88 vs. 75.5%, respectively. The results show the incidence of POCD of patients aged at least 65 years who have undergone hip or knee fracture surgery gradually decrease as more patients recover. However, the Aβ-42/Tau ratio can be used in forecasting the occurrence of POCD elderly patients.

Relationships between adiponectin and matrix metalloproteinase-9 (MMP-9) serum levels and postoperative cognitive dysfunction in elderly patients after general anesthesia.

ObjectiveThe aim of this study was to evaluate the relationships between the serum levels of adiponectin (ADP) and matrix metalloproteinase-9 (MMP-9) and postoperative cognitive dysfunction (POCD) in elderly patients after general anesthesia.MethodsThe cognitive functions of 98 elderly patients who were scheduled to undergo selective hip replacement surgery under general anesthesia were assessed using the Montreal Cognitive Assessment (MoCA) 3 days before surgery and on postoperative Days 1, 2, 3, and 7. The serum levels of ADP and MMP-9 were determined at the same time points, and the presence of POCD on postoperative Day 3 was recorded. The patients were divided into a POCD group and non-POCD group.ResultsPostoperative cognitive dysfunction was observed in 28 patients (28.5 %). Serum MMP-9 levels significantly increased and serum ADP levels significantly decreased in the POCD group at each postoperative time point and in the non-POCD group on postoperative Days 1 and 2 compared to the presurgical levels. Serum MMP-9 levels were significantly higher and serum ADP levels were significantly lower in the POCD group compared with those in the non-POCD group at each time point. In the POCD patients, serum MMP-9 levels were significantly and negatively correlated and serum ADP levels were significantly and positively correlated with the MoCA scores.ConclusionsThe increased serum MMP-9 levels and decreased serum ADP levels in elderly patients after general anesthesia might be involved in the POCD pathophysiological process.

MicroRNA-572 improves early post-operative cognitive dysfunction by down-regulating neural cell adhesion molecule 1.

Post-operative cognitive dysfunction (POCD) is a commonly-seen postoperative complication in elderly patients. However, the underlying mechanisms of POCD remain unclear. miRNAs, which are reported to be involved in the pathogenesis of the nervous system diseases, may also affect POCD. In this study, miRNA microarray technology was used to analyze the circulating miRNA expression profile of POCD patients. Among the altered miRNAs, miR-572 had the greatest decrease, which was also verified in vivo in rat POCD model. Further analysis found that miR-572 could regulate the expression of NCAM1 in the hippocampal neurons and interfering miR-572 expression could facilitate the restoration of cognitive function in vivo. Moreover, clinical correlation analysis found that the miR-572 expression was associated with the incidence of POCD. Collectively, miR-572 is involved in the development and restoration of POCD and it may serve as a biological marker for early diagnosis of POCD.

Increase of beta-amyloid and C-reactive protein in liver transplant recipients with postoperative cognitive dysfunction

Postoperative cognitive dysfunction (POCD) is an adverse condition characterized by declined cognitive functions following surgeries and anesthesia. POCD has been associated with increased hospital stay and mortality. There are histological similarities to Alzheimer's disease. Most early studies were conducted in patients receiving cardiac surgery. Since there is no information about POCD in liver transplant recipients, we measured the incidence of POCD in patients after liver transplantation and examined the correlation between neurological dysfunction and biological markers of dementia-based diseases. We studied 25 patients who had a liver transplan-tation between July 2008 and February 2009. Patients with prior encephalopathy or risk factors associated with the development of POCD were excluded from the study. Five validated neuropsychiatric tests were used for diagnosis. The diagnosis was based on one standard deviation decline in two of the five neuropsychiatric tests. The correlation between patient variables and the development of POCD was examined. Serum levels of beta-amyloid and C-reactive protein were measured by standard ELISA and compared between patients with and without POCD. POCD was present in 11 (44%) of the 25 patients. Patients with POCD had significantly higher MELD scores, were more often Child-Pugh class C and received more blood transfusion during surgery. The serum beta-amyloid protein and C-reactive protein concentrations were significantly increased at 24 hours after surgery in the POCD group. The incidence of POCD in our group of liver transplant patients was greater than that reported in other surgical patients. The increase in the serum biomarkers of dementia in the POCD patients supports the hypothesis that chronic cognitive defects are due to a process similar to that seen in Alzheimer's disease.

Early postoperative cognitive dysfunction is associated with higher cortisol levels in aged patients following hip fracture surgery

This study aimed to evaluate the relationship between plasma cortisol levels and the occurrence of postoperative cognitive dysfunction (POCD) in aged patients following hip fracture surgery. A total of 175 patients, aged 65 years or older, who were scheduled for hip fracture surgery with spinal anesthesia were enrolled. Perioperative plasma levels of cortisol and neurocognitive tests were determined at 1 day preoperatively and 7 days postoperatively. Seventy-seven patients completed both blood sample collections and neurocognitive tests. POCD occurred in 29.9 % of patients at 7 days postoperatively. POCD patients presented significantly higher cortisol levels compared with non-POCD patients (P < 0.05). Furthermore, plasma cortisol levels were negatively correlated with mini-mental state examination (MMSE) scores at 7 days postoperatively (P < 0.0001). A specificity of 93 % and a sensitivity of 35 % were identified for the plasma cortisol measurement to discriminate POCD patients from non-POCD patients. The results suggest higher plasma cortisol levels are associated with POCD in aged patients following hip fracture surgery with spinal anesthesia.

Can urinary excretion rate of 8-isoprostrane and malonaldehyde predict postoperative cognitive dysfunction in aging?

Oxidative stress has been associated with mild cognitive impairment (MCI) and Alzheimer's disease (AD). However, little is known about oxidative stress in postoperative cognitive dysfunction (POCD) in aging. The aim of this study was to investigate urinary excretion rate of 8-isoprostane:creatinine (U8-isoPG:Cr) and malonaldehyde:creatinine (UMDA:Cr) to predict short-term POCD in elderly patients undergoing general and orthopedic surgery. 72 patients aged above 65 years were enrolled in this prospective observational study. Each patient underwent cognitive testing to determine POCD performed by an investigator before surgery and 1 week after surgery. Morning urine was collected at baseline, 1, 2, and 7 days postoperatively. U8-isoPG was performed using enzymelinked immunosorbent assay (ELISA), and UMDA levels were measured by chemiluminescence detection. Creatinine levels were also analyzed if differences in the oxidative biomarkers were observed in the urine creatinine concentration. (1). Of 72 patients who completed cognitive testing, postoperative cognitive dysfunction was detected in 29.2 % (n = 21) of patients in 7 days. (2) U8-isoPG:Cr levels in 7 days postoperatively were significantly higher in POCD patients compared with the non-POCD group (p = 0.01). When measuring change from baseline, U8-isoPG:Cr levels were higher than that of control groups (p = 0.01). (3) UMDA:Cr levels were significantly elevated in 1 and 2 days postoperatively in both groups (p < 0.05). U8-isoPG:Cr level seems to be a valuable marker to detect lipid peroxidation early in POCD patients. However, it will also be important to take into account or reduce potential confounders to improve the identification of changes in the status of oxidative stress as a marker for POCD.

Changes in plasma and cerebrospinal fluid biomarkers in aged patients with early postoperative cognitive dysfunction following total hip-replacement surgery

We hypothesized that different patterns of biomarkers of brain injury and inflammation exist in aged patients with postoperative cognitive dysfunction (POCD) after total hip-replacement with spinal anesthesia. Eighty-three patients older than 65years undergoing elective total hip-replacement surgery were enrolled in this prospective observational study. The CSF levels of Tau, phosphorylated-tau (pTau), amyloidβ1-42 (Aβ1-42), Tau/Aβ1-42, pTau/Aβ1-42, BDNF, IL-6, and IL-1β were measured preoperatively. Perioperative plasma levels of IL-1β, IL-6, brain-derived neurotrophic factor (BDNF), C-reactive protein (CRP), and malonaldehyde (MDA) as well as neurocognitive tests were determined preoperatively and sevendays postoperatively. Sixty-one patients completed both the CSF and blood samples collection and the neurocognitive tests. POCD occurred in 24.6% of patients at sevendays after surgery. Patients with POCD had significantly higher IL-1β, Tau/Aβ1-42, pTau/Aβ1-42, and a lower level of Aβ1-42 in CSF when compared with the Non-POCD group (P<0.05). Furthermore, POCD patients displayed significantly higher plasma levels of MDA when compared with Non-POCD patients at sevendays after surgery (P<0.05). There was no difference in preoperative CSF levels of Tau, IL-6, and pTau as well as plasma levels of IL-1β, IL-6, BDNF and CRP between POCD and Non-POCD groups (P>0.05). The POCD patients were associated with higher postoperative plasma levels of MDA, and higher IL-1β and lower Aβ1-42 levels in preoperative CSF that might predispose the development of POCD in aged patients following total hip-replacement surgery with spinal anesthesia.

Relationship between intracranial excitatory aminoacid levels and postoperative cognitive dysfunction in elderly patients after general anesthesia

Objective To investigate the relationship between the changes in intracranial excitatory amino acid(EAA) levels and the incidence of postoperative cognitive dysfunction (POCD) in eldedy patients after general anesthesia. Methods Forty ASA Ⅰ-Ⅲ patients of both sexes aged 65-79 yr weighing 48-76 kg undergoing elective non-cardiac surgery under general anesthesia were studied.Anesthesia was induced with midazolam,fentanyl,etomidate and succinylcholine and maintained with continuous iv infusion of propofol,remifentanil,isoflurane inhalation and intermittent iv boluses of vecuronium.The right internal jugular vein was cannulated with a catheter which was advanced cephalad until jugular bulb.The jugular bulb venous blood samples were taken before (T0,baseline),at the end of (T1) and at 24,48 and 72h(T2-4) after operation for measurement of plasma concentrations of glutamate (Glu),aspartate (Asp) and glycine (Gly) by RP-HPLC.The cognitive function was evaluated by mini-mental state examination (MMSE) at T0 and T4.Results Eleven of the 40 patients developed POCD (28%).The plasma Gh,Asp and Gly concentrations were significantly increased after operation as compared with the baseline values in POCD patients and were significantly higher than in non-POCD patients.The plasma concentrations of Glu and Asp were negatively correlated with MMSE score(Glu:r=-0.86.P<0.01;Asp:r=-0.99,P<0.01).Conclusion Elderly patients may develop POCD after operation performed under general anesthesia through increase in intracranial EAA levels. Key words: Excitatory amino acids; Aged; Postoperative complications; Cognition disorder; Anesthesia,general