The impact of S100b and persistent high levels of neuron-specific enolase on cognitive performance in elderly patients after cardiopulmonary bypass

A scoping review of incidence and assessment tools for post-intensive care syndrome following cardiac surgery

BACKGROUND

Post-intensive care syndrome is a new or worsening persistent deterioration in cognitive, mental, and/or physical health following a prolonged admission to an intensive care unit. Post-intensive care syndrome remains underexplored following cardiac surgery, with a lack of understanding of the incidence and tools used to measure the symptoms. A scoping review was conducted to determine the incidence and to identify the tools commonly used to measure symptoms of post-intensive care syndrome following cardiac surgery.

METHODS

The electronic databases Medline (Ovid), EMBASE (Ovid), PsycINFO (Ovid), Scopus, and CINAHL (EBSCOhost) and Google Scholar were searched with keywords and controlled vocabulary to describe both cardiac surgery and post-intensive care syndrome (cardiac surgical procedures, heart surgery, and post-intensive care symptoms) and symptoms (delirium, depression, mobility and quality of life). Included were articles written in English and published after 2005 that described cognitive, mental, and physical symptoms of post-intensive care syndrome following cardiac surgery. 3,131 articles were found, with 565 duplicates, leaving 2,566 articles to be screened. Of these, seven unique studies were included.

RESULTS

Five studies explored cognitive health, three mental health, one cognitive and mental health, and none physical health. No identified studies reported the overall incidence of post-intensive care syndrome following cardiac surgery. The incidence of cognitive health issues ranged from 21% to 38%, and mental health issues ranged from 16% to 99%. In total, 17 different tools were identified - 14 for cognitive health and three for mental health. No identified studies used the same tools to measure symptoms. No single tool was found to measure all three domains.

CONCLUSION

This scoping review identified a literature gap specific to the incidence and inconsistency of assessment tools for post-intensive care syndrome in cardiac surgery patients.

CLINICAL IMPLICATIONS

This work impacts clinical practice for the bedside nurse by raising awareness of an emerging health issue.

Research progress of neuron-specific enolase in cognitive disorder: a mini review

Numerous studies have demonstrated that neuron-specific enolase (NSE) serves as a distinctive indicator of neuronal injury, with its concentration in blood reflecting the extent and magnitude of nervous system damage, and the expression of serum NSE is correlated with cognitive dysfunction. The assessment of NSE holds significant importance in diagnosing cognitive dysfunction, assessing disease severity, predicting prognosis, and guiding treatment. In this review, the research progress of NSE in cognitive dysfunction was reviewed, and the value of serum NSE level in predicting disease severity and prognosis of patients with cognitive dysfunction was discussed.

Serum Proteomics of Older Patients Undergoing Major Cardiac Surgery: Identification of Biomarkers Associated With Postoperative Delirium

Background

Postoperative delirium (POD) is an acute altered mental state commonly encountered after cardiac surgery. The pathophysiological mechanisms underlying POD remain unclear. We aimed to identify circulating proteins significantly altered after major cardiac surgery with cardiopulmonary bypass (CPB). We also aimed to enable inferences on associations with POD.

Methods

Serum and whole blood samples were collected before CPB (n = 16 patients; n = 8 with POD) and again from the same patients on postoperative day 1. All patients were clinically evaluated for POD on postoperative days 1–3. An aptamer-based proteomics platform (SOMAscan) was used to quantify serum protein abundance in patients with POD compared with non-POD controls. We also performed a lipopolysaccharide (LPS)-based in vitro functional analysis (TruCulture) on whole blood samples from patients with POD and non-POD controls to approximate surgical stress. Cytokine levels were determined using a Luminex immunoassay.

Results

Cardiac surgery with CPB resulted in a significant (p_adj < 0.01) change in 48.8% (637 out of 1,305) of proteins detected by SOMAscan. Gene set enrichment showed that the most impacted biological processes involved myeloid cell activation. Specifically, activation and degranulation of neutrophils were the top five highest-scoring processes. Pathway analyses with the Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that metabolic enzymes, particularly those of glycolysis, were elevated in serum concentration after surgery. Several proteins were significantly increased postoperatively in patients diagnosed with POD relative to the non-POD controls, with interleukin-6 (IL-6) showing the greatest fold-change. LPS stimulation of whole blood samples confirmed these findings. Linear regression analysis showed a highly significant correlation between Confusion Assessment Method (CAM) scores and CPB-mediated changes in cGMP-inhibited 3′,5′-cyclic phosphodiesterase A (PDE3A).

Conclusions

Cardiac surgery with CPB resulted in inflammasome changes accompanied by unexpected increases in metabolic pathways. In exploratory analyses, we found that POD was associated with changes in the expression level of various proteins, most notably IL-6 and PDE3A. This study and ongoing protein biomarker studies will likely help quantify risk or confirm the diagnosis for POD and increase understanding of its pathophysiological mechanisms.

Serum Proteomics of Older Patients Undergoing Major Cardiac Surgery: Identification of Biomarkers Associated With Postoperative Delirium

BACKGROUND

Postoperative delirium (POD) is an acute altered mental state commonly encountered after cardiac surgery. The pathophysiological mechanisms underlying POD remain unclear. We aimed to identify circulating proteins significantly altered after major cardiac surgery with cardiopulmonary bypass (CPB). We also aimed to enable inferences on associations with POD.

METHODS

Serum and whole blood samples were collected before CPB (n = 16 patients; n = 8 with POD) and again from the same patients on postoperative day 1. All patients were clinically evaluated for POD on postoperative days 1-3. An aptamer-based proteomics platform (SOMAscan) was used to quantify serum protein abundance in patients with POD compared with non-POD controls. We also performed a lipopolysaccharide (LPS)-based in vitro functional analysis (TruCulture) on whole blood samples from patients with POD and non-POD controls to approximate surgical stress. Cytokine levels were determined using a Luminex immunoassay.

RESULTS

Cardiac surgery with CPB resulted in a significant (p_adj < 0.01) change in 48.8% (637 out of 1,305) of proteins detected by SOMAscan. Gene set enrichment showed that the most impacted biological processes involved myeloid cell activation. Specifically, activation and degranulation of neutrophils were the top five highest-scoring processes. Pathway analyses with the Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that metabolic enzymes, particularly those of glycolysis, were elevated in serum concentration after surgery. Several proteins were significantly increased postoperatively in patients diagnosed with POD relative to the non-POD controls, with interleukin-6 (IL-6) showing the greatest fold-change. LPS stimulation of whole blood samples confirmed these findings. Linear regression analysis showed a highly significant correlation between Confusion Assessment Method (CAM) scores and CPB-mediated changes in cGMP-inhibited 3',5'-cyclic phosphodiesterase A (PDE3A).

CONCLUSIONS

Cardiac surgery with CPB resulted in inflammasome changes accompanied by unexpected increases in metabolic pathways. In exploratory analyses, we found that POD was associated with changes in the expression level of various proteins, most notably IL-6 and PDE3A. This study and ongoing protein biomarker studies will likely help quantify risk or confirm the diagnosis for POD and increase understanding of its pathophysiological mechanisms.

Significance of serum neuron-specific enolase in transient global amnesia

Neuron-specific enolase (NSE) is a glycolytic enzyme, which is associated with neuronal cell dysfunction in the brain. This study evaluated the role of serum NSE levels of patients with transient global amnesia (TGA). In addition, the relationship between serum NSE levels and the clinical features of TGA was explored. Forty-eight patients with TGA were prospectively included, and their serum NSE levels were measured. We investigated serum NSE levels in patients with TGA. In addition, we analyzed the differences in clinical characteristics between patients with elevated and normal serum NSE levels. Of the 48 patients with TGA, 16 patients (33.3%) had elevated serum NSE levels (25.0 ± 11.5 ng/mL), whereas 32 patients (66.7%) showed normal serum NSE levels (12.8 ± 2.1 ng/mL). The patients with elevated serum NSE levels exhibited higher levels of cognitive impairment than those with normal serum NSE levels (4/16 vs. 1/32, p = 0.036). The serum NSE levels showed a relatively high discrimination (AUC 0.684) between patients with and without cognitive impairment, with 80.0% sensitivity and 74.4% specificity at a cut-off value 17.3 ng/mL. A third of all patients with TGA carry elevated serum NSE levels, which suggests that the neuronal cell dysfunction could be associated with TGA pathogenesis. In addition, it might be correlated with cognitive impairment.

Plasma S100β and neuron-specific enolase, but not neuroglobin, are associated with early cognitive dysfunction after total arch replacement surgery: A pilot study

To investigate whether plasma concentrations of S100β protein, neuron-specific enolase (NSE), and neuroglobin (NGB) correlate with early postoperative cognitive dysfunction (POCD) in patients undergoing total arch replacement.This prospective study analyzed 40 patients who underwent total arch replacement combined with stented elephant trunk implantation at our hospital between March 2017 and January 2019. Cognitive function was assessed using the Mini-mental State Examination (MMSE) preoperatively, on the day after extubation and on day 7 after surgery. Plasma levels of S100β, NSE, and NGB POCD were assayed preoperatively and at 1, 6, and 24 hours after cardiopulmonary bypass. POCD was defined as a decrease of at least 1 unit in the MMSE score from before surgery until day 7, and patients were stratified into those who experienced POCD or not. The 2 groups were compared in clinicodemographic characteristics and plasma levels of the 3 proteins.Plasma levels of all 3 biomarkers increased significantly during and after cardiopulmonary bypass. Levels of S100β and NSE, but not NGB, were significantly higher in the 15 patients who showed POCD than in the remainder who did not. For prediction of early POCD, S100β showed an area under the receiver operating characteristic curve (AUC) of 0.71 (95% confidence interval [CI] 0.55-0.87), sensitivity of 48%, and specificity of 87%. The corresponding values for NSE were 0.77 (95%CI 0.60-0.94), 92%, and 67%. Together, S100β and NSE showed an AUC of 0.81 (95%CI 0.66-0.96), sensitivity of 73%, and specificity of 80%. NGB did not significantly predict early POCD (AUC 0.62, 95%CI 0.43-0.80).Plasma S100β protein and NSE, but not NGB, may help predict early POCD after total arch replacement.

High Serum Neuron-Specific Enolase Level Is Associated with Mild Cognitive Impairment in Patients with Diabetic Retinopathy

PURPOSE

Diabetic retinopathy (DR) can increase the risk of mild cognitive impairment (MCI), which has been confirmed by previous researches. With the frequent occurrence of MCI in patients with DR, the early detection of MCI has become a research hot-spot. The aim of this study was to investigate the relationship between neuron-specific enolase (NSE) and MCI in patients with DR.

PATIENTS AND METHODS

A total of 124 patients with DR, including 56 MCI patients and 68 normal cognition patients, were recruited in this cross-sectional study. The demographic and clinical data of patients were collected through questionnaires. Serum NSE was measured using electrochemiluminescence immunoassay. The Minimum Mental State Examination (MMSE) scale was used to evaluate the cognitive function of the participants.

RESULTS

Compared with the normal cognition group, serum NSE levels and HbA1c levels in the MCI group were higher, while MMSE scores and educational level were lower (P<0.05). Serum NSE levels were significantly negatively correlated with MMSE total score, attention and calculation score, and language score (P<0.05). After adjusting for confounding factors, serum NSE still increased the MCI risk in DR patients (OR:1.606, 95CI%:1.264-2.041, P<0.001). The areas under the receiver operating characteristics (ROC) curves (AUC) of the crude model and the adjusted model were 0.75 and 0.73, respectively.

CONCLUSION

A high serum NSE level is an independent risk factor for MCI in DR patients. In addition, serum NSE is expected to be a potential biomarker in DR patients with MCI.

Serum neuron-specific enolase, a marker of neuronal injury, increases after catheter ablation of atrial fibrillation

Objective

Catheter ablation of atrial fibrillation (AF) can lead to thromboembolic complications, especially stroke. We measured the periprocedural serum neuron-specific enolase (NSE) level, which is a biomarker of neuronal injury, after ablation of AF.

Methods

Forty-three patients with paroxysmal AF were prospectively enrolled before radiofrequency ablation. A neurological examination was performed before and after the procedure. The serum NSE level was determined before and at the end of the procedure and at 2, 24, and 48 h after the procedure.

Results

No patients developed new neurological deficits. However, the median (interquartile range) NSE level increased after ablation from 6.7 (3.87) ng/mL at baseline to 11.48 (5.3) ng/mL at 24 h postoperatively. The NSE level exceed the upper reference limit of normal (17 ng/mL) in 14 patients (33%), and these patients were found to have a larger left atrium.

Conclusions

Serum NSE increased in most of the patients undergoing ablation for AF, and it exceeded the normal limit in one-third of the patients. Although NSE is a biomarker of neuronal injury, the clinical importance of this increase after AF ablation and its relationship with the left atrial diameter should be evaluated in a longitudinal study.

Incidence, risk factors, and clinical implications of post-operative delirium in lung transplant recipients

BACKGROUND

Delirium significantly affects post-operative outcomes, but the incidence, risk factors, and long-term impact of delirium in lung transplant recipients have not been well studied.

METHODS

We analyzed 155 lung transplant recipients enrolled in the Lung Transplant Outcomes Group (LTOG) cohort at a single center. We determined delirium incidence by structured chart review, identified risk factors for delirium, determined whether plasma concentrations of 2 cerebral injury markers (neuron-specific enolase [NSE] and glial fibrillary acidic protein [GFAP]) were associated with delirium, and determined the association of post-operative delirium with 1-year survival.

RESULTS

Fifty-seven (36.8%) patients developed post-operative delirium. Independent risk factors for delirium included pre-transplant benzodiazepine prescription (relative risk [RR] 1.82; 95% confidence interval [CI] 1.08 to 3.07; p = 0.025), total ischemic time (RR 1.10 per 30-minute increase; 95% CI 1.01 to 1.21; p = 0.027), duration of time with intra-operative mean arterial pressure <60 mm Hg (RR 1.07 per 15-minute increase; 95% CI 1.00 to 1.14; p = 0.041), and Grade 3 primary graft dysfunction (RR 2.13; 95% CI 1.27 to 3.58; p = 0.004). Ninety-one (58.7%) patients had plasma available at 24 hours. Plasma GFAP was inconsistently detected, whereas NSE was universally detectable, with higher NSE concentrations associated with delirium (risk difference 15.1% comparing 75th and 25th percentiles; 95% CI 2.5 to 27.7; p = 0.026). One-year mortality appeared higher among delirious patients, 12.3% compared with 7.1%, but the difference was not significant (p = 0.28).

CONCLUSIONS

Post-operative delirium is common in lung transplant recipients, and several potentially modifiable risk factors deserve further study to determine their associated mechanisms and predictive values.

Effect of the type of cardiopulmonary bypass pump flow on postoperative cognitive function in patients undergoing isolated coronary artery surgery

OBJECTIVE

Pulsatile flow, generated by a pump during cardiopulmonary bypass, has been accepted as more physiological in coronary artery bypass grafting surgery (CABG). Therefore, we aimed to investigate the effects of pulsatile and nonpulsatile flow on postoperative cognitive function and to review relationship with the biomarkers S100ß and neuron-specific enolase (NSE).

METHODS

Patients who underwent isolated CABG were included this prospective, randomized, double-blind study, which was performed between March 2010 and December 2010. Patients were divided into two groups: pulsatile (Group I, n=20) and nonpulsatile (Group II, n=20) flow. Blood samples were collected 1 day before surgery and in the sixth postoperative hour for the analysis of S100ß and NSE. In addition, Mini-Mental State Examination (MMSE) was performed during preoperative period and on third postoperative day. Outcomes were determination of effects of pump flow type on cognitive function and relationships with concentrations of S100ß and NSE.

RESULTS

Forty patients were included. No differences were observed between the groups with respect to complications, mortality, S100ß (Group I: 1.9±0.2 µ/L; Group II: 2.0±0.2 µ/L), NSE (Group I: 12.5±0.8 µ/L; Group II: 12.4±0.7 µ/L), MMSE scores [Group I: 25 (23-27); Group II: 25 (23-27)], and postoperative cognitive dysfunction (POCD) (p>0.05). No correlation was observed between MMSE scores and concentrations of S100ß (r=-0.032) and NSE (r=-0.423) (p>0.05).

CONCLUSION

There was no difference between types of pump flow for POCD and no relationship between cognitive dysfunction and S100ß and NSE concentrations. Pump flow type does not affect NSE concentrations.

Effect of hypoxia on cerebrovascular and cognitive function during moderate intensity exercise

Exercise in hypoxia places added demands on the brain and cerebrovasculature that can impact cognitive function. The purpose of this study was to investigate the effect of acute hypoxia on cerebrovascular hemodynamics, markers of neuro-steroidal modulation and brain-blood barrier (BBB) integrity, and cognition during exercise. Thirty healthy participants (21±4yrs., BMI 24.0±2.6kg∙m(-2); 15 men) were randomized to both a≈2.5h normoxic (FiO2 20.0%) and hypoxic (FiO2 12.5%) condition on two separate days. After 1.25h, participants underwent 10min of exercise-alone (cycling at 55% HRmax) and 15min of exercise+cognitive testing. Prefrontal cortex (PFC) tissue oxygenation and middle cerebral artery (MCA) mean blood velocity (MnV) were measured using near-infrared spectroscopy and transcranial Doppler respectively at rest, during exercise-alone, and during exercise+cognitive testing. Salivary levels of dehydroepiandosterone [DHEA], DHEA-sulfate [DHEAS]) and neuron specific enolase (NSE) were measured pre and post exercise. Cognition was assessed using standard metrics of accuracy and reaction time (RT), and advanced metrics from drift-diffusion modeling across memory recognition, N-Back and Flanker tasks. MCA MnV increased from rest to exercise (p<0.01) and was unchanged with addition of cognitive testing during exercise in both normoxia and hypoxia. PFC oxygenation increased during exercise (p<0.05) and was further increased with addition of cognitive challenge in normoxia but decreased during exercise in hypoxia (p<0.05) with further reductions occurring with addition of cognitive tasks (p<0.05). DHEA and NSE increased and decreased post-exercise, respectively, in both normoxia and hypoxia (p<0.01). Accuracy on cognitive tasks was similar in normoxia compared to hypoxia, while RT was slower in hypoxia vs normoxia across memory recognition (p<0.01) and Flanker tasks (p=0.04). Drift-diffusion modeling suggested changes in memory RT were due to increases in caution (p<0.01). Overall cognitive performance is maintained during exercise in hypoxia concomitant with slower RT in select cognitive tasks and reduced oxygenation in the PFC. These changes were accompanied by slight increases in neuro-steroidal modulation but appear independent of changes in NSE, a biomarker of BBB integrity. Maintained accuracy and select increases in RT during hypoxic exercise may be related behavioral changes in caution.

Serum levels of neuron-specific enolase in patients with fibromyalgia syndrome: Correlation with cognitive functions, quality of life and psychological state

BACKGROUND

Fibromyalgia syndrome (FMS) is a non-articular rheumatic disorder of unclear etiology, characterized by widespread body pain, fatigue and, psychological complaintsOBJECTIVES: To investigate the serum levels of neuron-specific enolase (NSE) in patients with FMS and to evaluate the relationship between cognitive function, quality of life and psychological state.

MATERIALS AND METHODS

Fifty-five female patients diagnosed with fibromyalgia according to the American College of Rheumatology (ACR) classification criteria, and 40 healthy female subjects were enrolled in the study. Life quality scale [(Fibromyalgia Impact Questionnaire (FIQ)], psychological state (Beck Depression Scale), and cognitive dysfunction (mini mental test, clock drawing test) scales were used for patients and control subjects. Serum NSE levels were studied using the ECLIA method.

RESULTS

No significant differences were found in the serum NSE levels between the FMS patients and the control subjects (p> 0.05). Life quality and psychological state scores were found to be higher in FMS patients relative to the control group (p< 0.001). However, no significant differences were detected in cognitive function (p> 0.05). Significant correlations were not found between the serum NSE levels and quality of life, psychological state and cognitive functions (p> 0.05).

CONCLUSION

No significant difference was determined between the groups in terms of NSE levels. Further studies, including larger series, should be carried out to clarify this relationship.

S100 and S100β: biomarkers of cerebral damage in cardiac surgery with or without the use of cardiopulmonary bypass

OBJECTIVE

The present study is to describe the clinical impact of S100 and S100β for the evaluation of cerebral damage in cardiac surgery with or without the use of cardiopulmonary bypass (CPB).

METHODS

Quantitative results of S100 and S100β reported in the literature of the year range 1990-2014 were collected, screened and analyzed.

RESULTS

Cerebrospinal fluid and serum S100 levels showed a same trend reaching a peak at the end of CPB. The cerebrospinal fluid/serum S100 ratio decreased during CPB, reached a nadir at 6 h after CPB and then increased and kept high untill 24 h after CPB. Serum S100 at the end of CPB was much higher in infant than in adults, and in on-pump than in off-pump coronary artery bypass patients. ∆S100 increased with age and CPB time but lack of statistical significances. Patients receiving an aorta replacement had a much higher ∆S100 than those receiving a congenital heart defect repair. Serum S100β reached a peak at the end of CPB, whereas cerebrospinal fluid S100 continued to increase and reached a peak at 6 h after CPB. The cerebrospinal fluid/serum S100β ratio decreased during CPB, increased at the end of CPB, peaked 1 h after CPB, and then decreased abruptly. The increase of serum S100β at the end of CPB was associated with type of operation, younger age, lower core temperature and cerebral damages. ∆S100β displayed a decreasing trend with age, type of operation, shortening of CPB duration, increasing core temperature, lessening severity of cerebral damage and the application of intervenes. Linear correlation analysis revealed that serum S100β concentration at the end of CPB correlated closely with CPB duration.

CONCLUSION

S100 and S100β in cerebrospinal fluid can be more accurate than in the serum for the evaluations of cerebral damage in cardiac surgery. However, cerebrospinal fluid biopsies are limited. But serum S100β and ∆S100β seem to be more sensitive than serum S100 and ∆S100. The cerebral damage in cardiac surgery might be associated with younger age, lower core temperature and longer CPB duration during the operation. Effective intervenes with modified CPB circuit filters or oxygenators and supplemented anesthetic agents or priming components may alleviate the cerebral damage.

Critical illness and long-term cognitive impairment

EVALUATION OF: 

Pandharipande PP, Girard TD, Jackson JC et al. Long-term cognitive impairment after critical illness. N. Engl. J. Med. 369(14), 1306–1316 (2013). This study reports the association between long-term cognitive impairment and survivors of critical illness in adult intensive care patients. As part of the BRAIN-ICU study, 821 patients with respiratory failure or shock were enrolled from the medical and surgical intensive care units. Their global cognition and executive function were assessed at 3 and 12 months following discharge using the Repeatable Battery for the Assessment of Neuropsychological status and the Trail Making Test, Part B. A significant number of both older and younger patients were found to have cognitive deficits below the population mean at 3 months (40%), and in 24% of them it persisted at 12 months. This association was stronger in patients with longer duration of delirium, which was independently associated with worse outcomes, for both global cognition and executive functioning. This study provides further evidence that patients with delirium are at a higher risk of developing long-term cognitive impairment and dementia, and their worse cognitive functioning is related to the length of their delirium episode.