Do blood levels of neuron-specific enolase and S-100 protein reflect cognitive dysfunction after coronary artery bypass?

'Evaluation of beta-2-microglobulin and neuron-specific enolase as prognostic factors in patients over 65 years of age with frailty syndrome hospitalized for acute coronary syndrome'

BACKGROUND

The aim of the study is to assess the value of beta-2-microglobulin (B2M) and neuron-specific enolase (NSE) as prognostic factors in the population of patients over 65 years of age with frailty hospitalized due to acute coronary syndrome (ACS).

METHODS

Patients aged ≥65 years with ACS were included. Assessment of frailty was carried out using the FRAIL scale. The measurement of NSE and B2M was carried out three times during hospitalization: (1) at the time of admission, (2) on the second day of hospitalization, (3) on the seventh day of hospitalization, or the day of discharge if it was before the seventh day. The primary endpoint was all-cause mortality, and the secondary endpoint was unscheduled rehospitalization.

RESULTS

Of the 127 patients, frailty was identified in 39.3%. Multivariate analysis of variance showed significantly higher levels of NSE (P = 0.012) and B2M (P < 0.001) in patients with frailty compared to the nonfrail group and significant changes in marker levels during hospitalization - decreased NSE (P < 0.001) and increased B2M levels (P < 0.001). Elevated B2M-1 level was an independent marker of the occurrence of frailty [odds ratio (OR), 1.98 (1.09-4.00); P = 0.044], and the optimal cutoff point for the diagnosis of frailty was 2.85 mg/l [area under the curve (AUC), 0.718 (0.632-0.795)] with sensitivity 52% and specificity 84.4% (P < 0.001). Elevated NSE-3 level was associated with all-cause mortality, and each 1 ng/ml increase in NSE-3 increased the risk of death by 1.07-fold [OR, 1.07 (1.03-1.10]). Meanwhile, elevated B2M-3 level was associated with unscheduled rehospitalization, and each 1 mg/l increase in B2M-3 increased the risk of unscheduled rehospitalization by 1.21-fold [OR, 1.21 (1.03-1.42)]. The Harrell's C-index for all-cause mortality was higher for NSE-3 [0.820 (95% confidence interval {CI}, 0.706-0.934)] compared to frailty assessed by the FRAIL scale [0.715 (95% CI, 0.580-0.850)], which means that additional NSE-3 assessment may improve the prediction of all-cause mortality. However, Uno's C-Statistic analysis showed that the difference was not statistically significant (Pr>chi-square 0.556). Harrell's C-index for unscheduled rehospitalization was higher for frailty assessed by the FRAIL scale compared to B2M-3.

CONCLUSION

Monitoring NSE and B2M marker levels in patients over 65 years of age with frailty and ACS does not provide additional benefits in terms of prognostic ability compared to tests assessing frailty. B2M, assessed upon hospital admission and monitoring NSE and B2M levels during hospitalization may be considered in the diagnosis of frailty and risk stratification in a group of patients for whom currently available frailty diagnostic tools cannot be used.

Evaluation of the brain cellular damage during liver transplantations

Background

Neuroinflammation in patients undergoing major surgery can lead to neuronal damage, and neuronal damage can be detected through the measurement of biochemical markers of brain damage. S100 beta (S100 β), neuron-specific enolase (NSE), and glial fibrillary acidic protein (GFAP) levels are considered good biomarkers to detect brain damage that emerged with neurotoxicity.

Aim

To evaluate neuronal damage during liver transplantations.

Materials and Methods

After approval of the ethics committee and patient consents, preoperative and postoperative cognitive functions of 33 patients undergoing liver transplantation were measured using the Mini Mental State Examination (MMSE), whereas simultaneous neuronal damage was evaluated through the measurement of S100β, NSE, and GFAP levels.

Results

There was no statistically significant difference between preoperative and postoperative MMSE. There was a statistically significant decrease in postoperative GFAP (P < 0.05) and a statistically significant increase in NSE (P < 0.05) compared to preoperative values. The decrease in S100β (P > 0.05) level was statistically insignificant.

Conclusions

Neuroprotective approaches in anesthesia protocol protect patients from brain damage during liver transplantation and prevent the development of postoperative cognitive dysfunction. Since the significant increase in NSE levels during liver transplantations was deemed to have been associated with causes other than neuronal damage, NSE should not be evaluated as a marker of brain damage in these operations.

Potential Markers of Neurocognitive Disorders After Cardiac Surgery: A Bibliometric and Visual Analysis

Background

Identifying useful markers is essential for diagnosis and prevention of perioperative neurocognitive disorders (PNDs). Here, we attempt to understand the research basis and status, potential hotspots and trends of predictive markers associated with PNDs after cardiac surgery via bibliometric analysis.

Methods

A total of 4,609 original research articles and reviews that cited 290 articles between 2001 and 2021 were obtained from the Web of Science Core Collection (WoSCC) as the data source. We used the software CiteSpace to generate and analyze visual networks of bibliographic information, including published years and journals, collaborating institutions, co-cited references, and co-occurring keywords.

Results

The number of annual and cumulative publications from 2001 to 2021 has been increasing on the whole. The Harvard Medical School was a very prolific and important institution in this field. The journal of Ann Thorac Surg (IF 4.33) had the most publications, while New Engl J Med was the most cited journal. Neuron-specific enolase (NSE), S100b and kynurenic acid (KYNA) were frequently discussed as possible markers of PNDs in many references. Cardiopulmonary bypass (CPB) was a keyword with high frequency (430) and sigma (6.26), and inflammation was the most recent burst keyword.

Conclusion

Potential markers of PNDs has received growing attention across various disciplines for many years. The research basis mainly focuses on three classic biomarkers of S100b, NSE, and KYNA. The most active frontiers are the inflammation-related biomarkers (e.g., inflammatory cells, cytokines, or mediators) and surgery-related monitoring parameters (e.g., perfusion, oxygen saturation, and the depth of anesthesia).

Reduced Concentrations of NSE, S100β, Aβ, and Proinflammatory Cytokines in Elderly Patients Receiving Ultrasound-Guided Combined Lumbar Plexus-Sciatic Nerve Block during Hip Replacement

Objective

The increase of hip fractures is related to the aging of the population, which has caused a huge medical burden in many countries. Hip replacement has been approved as a highly successful surgical intervention for the patients with hip fractures. Different anesthesia choices in the surgical intervention are associated with the prognosis of patients. This study focused on investigating the application of ultrasound-guided combined lumbar plexus-sciatic nerve block in elderly patients with hip fractures.

Methods

In this retrospective study, 62 elderly patients received combined spinal-epidural anesthesia and 58 elderly patients underwent ultrasound-guided combined lumbar plexus-sciatic nerve block during the surgery. Hemodynamic monitoring including pulse oxygen saturation (SpO₂), heart rate and blood pressure, the assessment of pain intensity using Visual Analogue Scale (VAS), cognitive function assessment through Montreal Cognitive Assessment (MoCA) and biomarkers consisting of serum levels of neuron specific-enolase (NSE), S100 beta protein (S100-β), and amyloid beta protein (Aβ), as well as immune function by interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and high sensitivity C-reactive protein (hs-CRP) were detected in this study. Furthermore, length of hospital stay (LOS) and adverse reactions including hematoma, hypotension, nausea, and vomit were analyzed.

Results

The findings indicated that comparing with the patients receiving combined spinal-epidural anesthesia, those undergoing ultrasound-guided combined lumbar plexus-sciatic nerve block showed significantly lower level of heart rate, higher level of SpO₂, and lower level of diastolic pressure and systolic pressure at 5 minutes and 30 minutes after anesthesia and after surgery (P < 0.05), indicated obviously lower VAS score at 12, 24, and 48 hours after surgery (P < 0.05), and revealed higher MoCA score at 12 days after surgery (P < 0.05). A significantly higher level of NSE, S100β, Aβ, IL-6, IL-1β, TNF-α, and hs-CRP was revealed in the two groups receiving different anesthesia methods at 10 days after surgery compared with that before surgery (P < 0.05). However, the patients receiving ultrasound-guided combined lumbar plexus-sciatic nerve block had obviously lower expression of NSE, S100β, Aβ, IL-6, IL-1β, TNF-α, and hs-CRP compared with the group accepting combined spinal-epidural anesthesia (P < 0.05). The two groups indicated no significant difference in incidence of hypotension and vomit, etc. (P < 0.05), but showed remarkable difference referring to total incidence of adverse reactions and LOS (P < 0.05).

Conclusion

The application of ultrasound-guided combined lumbar plexus-sciatic nerve block in hip replacement contributes to the stability of hemodynamics and alleviation of postoperative pain intensity. It can reduce cognitive and immune impairment of the elderly patients with hip fractures.

Targeted temperature management in cardiac surgery: a systematic review and meta-analysis on postoperative cognitive outcomes

BACKGROUND

Postoperative cognitive decline occurs commonly after cardiac surgery. The available literature is inconclusive on the role of intraoperative causal or protective factors.

METHODS

We systematically reviewed studies evaluating delayed neurocognitive recovery (DNR), postoperative neurocognitive disorder (NCD), stroke, and the mortality rates among patients undergoing hypothermic or normothermic cardiopulmonary bypass (CPB). We further performed a subgroup analysis for age, surgery type (coronary artery bypass grafting [CABG], valve surgery, or combined), and the mean arterial blood pressure (MAP) during CPB, and conducted a proportion meta-analysis after calculation of single proportions and confidence intervals (CIs).

RESULTS

We included a total of 58 studies with 9609 patients in our analysis. Among these, 1906 of 4010 patients (47.5%) had DNR, and 2071 of 7160 (28.9%) had postoperative NCD. Ninety of 4625 patients (2.0%) had a stroke, and 174 of 7589 (2.3%) died. There was no statistically significant relationship between the considered variables and DNR, NCD, stroke, and mortality. In the subgroup analysis comparing hypothermic with normothermic CPB, we found higher NCD rates after combined surgery; for normothermic CPB cases only, the rates of DNR and NCD were lower after combined surgery compared with CABG surgery. A MAP >70 mm Hg compared with MAP=50-70 mm Hg during CPB was associated with a lower rate of DNR.

CONCLUSIONS

Temperature, MAP during cardiopulmonary bypass age, and surgery type were not associated with neurocognitive disorders, stroke, and mortality in cardiac surgery. Normothermic cardiopulmonary bypass, particularly when performed with MAP >70 mm Hg, may reduce the risk of postoperative neurocognitive decline after cardiac surgery.

PROSPERO REGISTRATION NUMBER

CRD42019140844.

S100B protein and neuron-specific enolase as predictors of postoperative cognitive dysfunction in aged dogs: a case-control study

OBJECTIVE

Postoperative cognitive dysfunction (POCD) may be related to brain injury. S100B protein and neuron-specific enolase (NSE) have been investigated as potential biochemical markers of neural cell injury in animals and humans. This study aimed to investigate the association between POCD, brain injury and serum concentrations of S100B and NSE after periodontal surgery in aged dogs.

STUDY DESIGN

Prospective observational animal study.

ANIMALS

A total of 24 male and female dogs undergoing periodontal surgery.

METHODS

Dogs were separated into two groups based on age: control group, 10 dogs ≤ 8 years and aged group, 14 dogs > 8 years. Cognitive function was measured preoperatively and on the seventh postoperative day using the Canine Cognitive Dysfunction Rating scale and the Age-Related Cognitive and Affective Disorders scale. S100B protein and NSE serum concentrations were measured before and immediately after the surgery.

RESULTS

POCD was not observed after surgery in the present study. Serum concentrations of S100B and NSE were increased postoperatively in the control group but not in the aged group (p = 0.04 and 0.03, respectively). Preoperative S100B serum concentrations were significantly higher in the aged group (p = 0.01).

CONCLUSIONS

There was no association between POCD and high concentrations of S100B and NSE in dogs. However, increased postoperative serum concentrations of S100B and NSE were found in the control group after surgery, an effect that may indicate neural damage.

CLINICAL RELEVANCE

The results suggest that anesthesia and oral surgery are associated with higher postoperative serum concentrations of S100B and NSE in dogs ≤ 8 years old, which may indicate neural damage. Serum concentrations of S100B were elevated in aged dogs before anesthesia, a finding that might be related to chronic preoperative brain damage.

Effects of edaravone on postoperative cognitive function in elderly patients undergoing hip joint replacement surgery: A randomized controlled trial

BACKGROUND

Postoperative cognitive dysfunction (POCD) is a complication of central nervous system in patients after surgery. Edaravone as a brain-protective agent may have protective effect on postoperative cognitive function. The study was designed to explore the effects of edaravone on postoperative cognitive function in elderly patients undergoing hip joint replacement surgery and potential mechanism.

PATIENTS AND METHODS

Patients undergoing hip joint replacement surgery were randomly allocated into 2 groups: the edaravone group (group E) and the control group (group C). Group E received intravenous edaravone at a dose of 0.5 mg/kg after induction of anesthesia, while group C received normal saline. The cognitive function was evaluated with the Mini-Mental State Examination (MMSE) 1day before surgery,3 days and the 7 days after surgery. Patients' plasma samples were collected to detect the levels of S100β protein (S100β), interleukin-6 (IL-6), matrix metalloproteinase-9 (MMP-9), superoxide dismutase (SOD) and malondialdehyde (MDA) before the induction of anesthesia, at the end of surgery and on postoperative day 3.

RESULTS

The MMSE scores in group E were higher than those of group C 3 days after surgery (25.98 ± 1.99 vs 24.86 ± 1.86, p = 0.003). There were remarkable rises (p < 0.05) in plasma IL-6, S100βand MMP-9 levels at the end of surgery and on postoperative day 3 in the two groups, however, edaravone pretreatment could reduce these levels to a certain extent compared with group C (p < 0.05).In group E, the SOD concentration was higher at the end of surgery (16.03 ± 2.46U/ml vs. 13.65 ± 2.53U/ml, p = 0.0001), while the MDA level was lower on postoperative day 3 than those in group C (7.01 ± 2.37 nmol/ml vs. 11.34 ± 3.18 nmol/ml, p = 0.0001).

CONCLUSION

The results indicated that preoperative intervention with edaravone may improve the postoperative cognitive function in elderly patients undergoing hip joint replacement surgery.

Biochemical Parameters in Cognitive Functions

Cognitive impairment is a common disease. Many studies attempt to explain the mechanisms of these dysfunctions formation, including correlations between cognitive functions and biochemical parameters. Scientists search for substances that would be indicators of cognitive functions and which could be determined in the cerebrospinal fluid or blood of the subjects. To date, they have isolated a few of such substances; however, research on their specificity, validity and the possibility of their use in diagnostics and prognostic assessment is still ongoing. However, there have been only few reports in the literature systematizing the existing knowledge on this subject, and they are mostly related to Alzheimer's disease, not cognition in general, or referring only to a specific group of substances. This article discusses the most important biochemical exponents of cognitive functions.

Effects of methylprednisolone on blood-brain barrier and cerebral inflammation in cardiac surgery-a randomized trial

BACKGROUND

Cognitive dysfunction is a frequent complication to open-heart surgery. Cerebral inflammation caused by blood-brain barrier (BBB) dysfunction due to a systemic inflammatory response is considered a possible etiology. The effects of the glucocorticoid, methylprednisolone, on cerebrospinal fluid (CSF) markers of BBB function, neuroinflammation, and brain injury in patients undergoing cardiac surgery with cardiopulmonary bypass were studied.

METHODS

In this prospective, randomized, blinded study, 30 patients scheduled for elective surgical aortic valve replacement were randomized to methylprednisolone 15 mg/kg (n = 15) or placebo (n = 15) as a bolus dose administered after induction of anesthesia. CSF and blood samples were obtained the day before and 24 h after surgery for assessment of systemic and brain inflammation (interleukin-6, interleukin-8, tumor necrosis factor-alpha), axonal injury (total-tau, neurofilament light chain protein), neuronal injury (neuron-specific enolase), astroglial injury (S-100B, glial fibrillary acidic protein), and the BBB integrity (CSF/serum albumin ratio).

RESULTS

In the control group, there was a 54-fold and 17-fold increase in serum interleukin-6 and interleukin-8, respectively. This systemic activation of the inflammatory cytokines was clearly attenuated by methylprednisolone (p < 0.001). The increase of the CSF levels of the astroglial markers was not affected. A postoperative BBB dysfunction was seen in both groups as the CSF/serum albumin ratio increased from 6.4 ± 8.0 to 8.0 in the placebo group (p < 0.01) and from 5.6 ± 2.3 to 7.2 in the methylprednisolone group (p < 0.01) with no difference between groups (p = 0.98). In the CSF, methylprednisolone attenuated the interleukin-6 release (p < 0.001), which could be explained by the fall in systemic interleukin-6, and the serum to CSF gradient of IL-6 seen both at baseline and after surgery. In the CSF, methylprednisolone enhanced the interleukin-8 release (p < 0.001) but did not affect postoperative changes in CSF levels of tumor necrosis factor alpha. Serum levels of S-100B and neuron-specific enolase increased in both groups with no difference between groups. CSF levels of total tau, neurofilament light chain protein, and neuron-specific enolase were not affected in any of the groups.

CONCLUSIONS

Preventive treatment with high-dose methylprednisolone attenuated the systemic inflammatory response to open-heart surgery with cardiopulmonary bypass, but did not prevent or attenuate the increase in BBB permeability or the neuroinflammatory response.

TRIAL REGISTRATION

Clinical Trials, Identifier: NCT01755338 , registered 24 December 2012.

Effect of bispectral index-guided anesthesia on consumption of anesthetics and early postoperative cognitive dysfunction after liver transplantation: An observational study

The objective of this study was to summarize the incidence of postoperative cognitive dysfunction (POCD) after 7days following liver transplantation (LT), and to evaluate the effectiveness of bispectral index (BIS) guided anesthetic intervention in reducing POCD. Additional serum concentrations of S100β and neuron-specific enolase (NSE) were detected during surgery to determine whether they were reliable predictors of POCD.Patients who underwent LT at Beijing YouAn Hospital Affiliated to Capital University of Medical Science from January 2014 to December 2015 were enrolled. BIS monitor was needed during surgery. Patients who underwent LT without BIS monitoring during August 2012 to December 2014 served as historical controls. A battery of 5 neuropsychological tests were performed and scored preoperatively and 7days after surgery. POCD was diagnosed by the method of one standard deviation (SD). The blood samples of BIS group were collected at 5 time points: just before induction of general anesthesia (T0), 60 minutes after skin incision (T1), 30 minutes after the start of the anhepatic phase (T2), 15 minutes after reperfusion of the new liver (T3), and at 24 hours after surgery (T4).A total of 33 patients were included in BIS group, and 27 in the control group. Mean arterial pressure was different between 2 groups at 30 minutes after the start of the anhepatic phase (P = .032). The dose of propofol using at anhepatic phase 30 min and new liver 15 min was lower in the BIS group than control group (0.042 ± 0.021 vs. 0.069 ± 0.030, P < .001; 0.053 ± 0.022 vs. 0.072 ± 0.020, P = .001). Five patients were diagnosed as having POCD after 7 days in the BIS group and the incidence of POCD was 15.15%. In the control group, 9 patients had POCD and the incidence of POCD was 33.33%. The incidence of POCD between 2 groups had no statistical difference (P = .089). S100β increased at stage of anhepatic 30 minutes (T2) and new liver 15 minutes (T3) compared with the stage of before anesthesia (T0) (1.49 ± 0.66 vs. 0.72 ± 0.53, P < .001; 1.92 ± 0.78 vs. 0.72 ± 0.53, P < .001). NSE increased at stage of anhepatic 30 minutes (T2) and new liver 15 minutes (T3) compared with the stage of before anesthesia (T0) (5.80 ± 3.03 vs. 3.58 ± 3.24, P = .001; 10.04 ± 5.65 vs. 3.58 ± 3.24, P < .001). At 24 hours after surgery, S100β had no difference compared to one before anesthesia (1.0 ± 0.62 vs. 0.72 ± 0.53, P = .075), but NSE still remained high (5.19 ± 3.64 vs. 3.58 ± 3.24, P = .043). There were no significant differences in the serum concentrations of S100β between patients with and without POCD at 5 time points of operation (P > .05). But at 24 hours after surgery, NSE concentrations were still high of patients with POCD (8.14 ± 3.25 vs. 4.81 ± 3.50, P = .035).BIS-guided anesthesia can reduce consumption of propofol during anhepatic and new liver phase. Patients in BIS group seem to have a mild lower incidence of POCD compared to controls, but no statistical significant. The influence of BIS-guided anesthesia on POCD needs to be further confirmed by large-scale clinical study. S100β protein and NSE are well correlative with neural injury, but NSE is more suitable for assessment of incidence of postoperative cognitive deficits after surgery.

Remote ischemic preconditioning improves the cognitive function of elderly patients following colon surgery: A randomized clinical trial

BACKGROUND

Cognitive function impairment is one of the most common complications in elderly patients after surgery, and an ideal nonpharmacological therapy has not yet been identified. Thus, we hypothesized that remote ischemic preconditioning could improve cognitive functions in elderly patients after surgery and investigated the mechanism underlying this effect.

METHODS

Ninety patients classified as American Society of Anaesthesiologists (ASA) physical status of 2 or 3 and aged 65 to 75 years who were scheduled for elective colon surgery under general anesthesia were randomly allocated to either a remote ischemic preconditioning group (Group R, n = 45) or a control group (Group C, n = 45). Remote ischemic preconditioning was performed by applying a static pressure of 200 mm Hg with a blood pressure cuff wrapped around the right upper limb for 3 ischemia cycles of 5 minutes each.

RESULTS

The Montreal Cognitive Assessment (MoCA) scores between the 2 groups were not significantly different on the day before surgery or the seventh day after surgery, but the scores on the first day after surgery (26.87 ± 0.84 vs 25.96 ± 0.85, P < .001) and third day after surgery (27.49 ± 0.66 vs 27.02 ± 0.92, P = .009) were significantly higher for Group R than those for Group C. Moreover, remote ischemic preconditioning markedly decreased the serum concentrations of the interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and S100B proteins compared with the control group (P < .001).

CONCLUSION

Remote ischemic preconditioning improves postoperative cognitive function in elderly patients following colon surgery. The cognitive protective effects of remote ischemic preconditioning are partially related to the inhibition of inflammation.

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.

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.

Effects of Heart Bypass Surgery on Plasma Aβ40 and Aβ42 Levels in Infants and Young Children

Accumulation of β-amyloid (Aβ) plaques is a pathological hallmark of Alzheimer disease. Aβ levels in animals and adults were reported to be associated with postoperative cognitive dysfunction (POCD). Our goal was to determine the plasma levels of Aβ in infants and young children after cardiac surgery with cardiopulmonary bypass (CPB).Forty-two infants and young children aged from 1 to 35 months undergoing cardiac surgery with general anesthetics were prospectively enrolled from January to June 2014 at a tertiary medical center. Perioperative plasma samples were obtained, and Aβ42 and Aβ40 levels were measured using ELISA. Other clinical characteristics of the patients were also recorded.Plasma levels of Aβ42 and Aβ40 decreased dramatically 2 hours after surgery and remained significantly lower 6 hours after operation. Baseline Aβ42 level correlated significantly with surgical intensive care unit (SICU) length of stay (LOS) and was an independent predictor for SICU LOS on multivariate analysis.Cardiac surgery with CPB decreases plasma Aβ levels. Plasma levels of Aβ42 and Aβ40 might be used as novel biomarkers for predicting outcomes in the patient population.

Serum protein S100 as marker of postoperative delirium after off-pump coronary artery bypass surgery: secondary analysis of two prospective randomized controlled trials

Background:

To investigate the predictive value of S100 (biochemical marker of neuroglial injury) for the occurrence of postoperative delirium (POD) in patients undergoing off-pump coronary artery bypass (OPCAB)-surgery.

Methods:

We enrolled 92 patients older than 18 years undergoing elective OPCAB-surgery. Serum-levels of S100 were determined at baseline (BL), end of surgery (EOS) and on the first postoperative day (PD1). Postoperatively, all-patients were evaluated daily until PD5 for the presence of POD using the confusion assessment method (CAM) or the confusion assessment method for the intensive care unit (CAM-ICU) for patients in the intensive care unit (ICU).

Results:

The overall incidence of POD was 21%. S100-values on PD1 significantly predicted the occurrence of POD during the later hospital stay [area under the curve (AUC)=0.724 (95% confidence interval (CI): 0.619–0.814); p=0.0001] with an optimal cut-off level of 123 pg mL

Conclusions:

S100-levels <123 pg mL

Risk Factors Associated with Cognitive Decline after Cardiac Surgery: A Systematic Review

Modern day cardiac surgery evolved upon the advent of cardiopulmonary bypass machines (CPB) in the 1950s. Following this development, cardiac surgery in recent years has improved significantly. Despite such advances and the introduction of new technologies, neurological sequelae after cardiac surgery still exist. Ischaemic stroke, delirium, and cognitive impairment cause significant morbidity and mortality and unfortunately remain common complications. Postoperative cognitive decline (POCD) is believed to be associated with the presence of new ischaemic lesions originating from emboli entering the cerebral circulation during surgery. Cardiopulmonary bypass was thought to be the reason of POCD, but randomised controlled trials comparing with off-pump surgery show contradictory results. Attention has now turned to the growing evidence that perioperative risk factors, as well as patient-related risk factors, play an important role in early and late POCD. Clearly, identifying the mechanism of POCD is challenging. The purpose of this systematic review is to discuss the literature that has investigated patient and perioperative risk factors to better understand the magnitude of the risk factors associated with POCD after cardiac surgery.

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.

Aspartic acid in the hippocampus: a biomarker for postoperative cognitive dysfunction

This study established an aged rat model of cognitive dysfunction using anesthesia with 2% isoflurane and 80% oxygen for 2 hours. Twenty-four hours later, Y-maze test results showed that isoflurane significantly impaired cognitive function in aged rats. Gas chromatography-mass spectrometry results showed that isoflurane also significantly increased the levels of N,N-diethylacetamide, n-ethylacetamide, aspartic acid, malic acid and arabinonic acid in the hippocampus of isoflurane-treated rats. Moreover, aspartic acid, N,N-diethylacetamide, n-ethylacetamide and malic acid concentration was positively correlated with the degree of cognitive dysfunction in the isoflurane-treated rats. It is evident that hippocampal metabolite changes are involved in the formation of cognitive dysfunction after isoflurane anesthesia. To further verify these results, this study cultured hippocampal neurons in vitro, which were then treated with aspartic acid (100 μmol/L). Results suggested that aspartic acid concentration in the hippocampus may be a biomarker for predicting the occurrence and disease progress of cognitive dysfunction.

The influence of preoperative serum anticholinergic activity and other risk factors for the development of postoperative cognitive dysfunction after cardiac surgery

OBJECTIVE

Patients undergoing cardiac surgery are at risk for postoperative cognitive dysfunction (POCD). Evaluating preoperative risk factors represents 1 possible way to minimize the postoperative risk of cognitive dysfunction. We investigated marked deterioration in cholinergic neurotransmission as 1 such potential risk factor for transient and long-lasting POCD. Serum anticholinergic activity (SAA) has already been described as a risk factor for developing delirium in an elderly study population. However, the role of SAA for long-lasting POCD is unknown.

METHODS

Following local ethics board approval and written informed consent, we recruited a cohort of patients aged ≥ 55 years undergoing cardiac surgery. Before surgery, levels of SAA were measured and a battery of neuropsychologic tests (NPTs) was applied. S100 calcium binding protein ß concentration was measured intraoperatively. Pre-, intra-, and postoperative patient-specific characteristics were recorded. The NPTs were repeated 3 months after hospital discharge to evaluate 3-month POCD. A group of nonsurgical patients (n = 34) was recruited as control subjects to adjust NPT scores, using reliable methods for the change index. Logistic multivariate regression was used to evaluate independent predictors of POCD.

RESULTS

One hundred fifty-four patients were screened before surgery, and 117 completed the second NPT. POCD was identified in 25.6% of patients. In contrast to intraoperatively increased S100 calcium binding protein ß, preoperative SAA was not associated with POCD following adjustment for covariates.

CONCLUSIONS

Preoperatively increased SAA did not predict POCD 3 months after cardiac surgery.

Neurological biomarkers in the perioperative period

The rapid detection and evaluation of patients presenting with perioperative neurological dysfunction is of great clinical relevance. Biomarkers have been defined as biological molecules that can be used as an indicator of new onset or progression of a biological process or effect of treatment. Biomarkers have become increasingly important in this setting to supplement other modalities of diagnosis such as EEG, sensory- or motor-evoked potential, transcranial Doppler, near-infrared spectroscopy, or imaging methods. A number of neuro-proteins have been identified and are currently under investigation for potential to provide insights into injury severity, outcome, and the ability to monitor cellular damage and molecular events that occur during neurological injury. S100B is a protein released by glial cells and is considered a marker of blood-brain barrier dysfunction. Clinical studies in patients undergoing cardiac and non-cardiac surgery indicate that serum levels of S100B are increased intraoperatively and after operation. The neurone-specific enolase has also been extensively investigated as a potential marker of neuronal injury in the context of cardiac and non-cardiac surgery. A third biomarker of interest is the Tau protein, which has been linked to neurodegenerative disorders. Tau appears to be more specific than the previous two biomarkers since it is only found in the central nervous system. The metalloproteinase and ubiquitin C terminal hydroxylase-L1 (UCH-L1) are the most recently researched markers; however, their usefulness is still unclear. This review presents a comprehensive overview of S100B, neuronal-specific enolase, metalloproteinases, and UCH-L1 in the perioperative period.

Elevated postoperative inflammatory biomarkers are associated with short- and medium-term cognitive dysfunction after coronary artery surgery

PURPOSE

We tested the hypothesis that elevated postoperative interleukin-6 (IL-6) and C-reactive protein (CRP) concentrations are associated with short- and medium-term impairment of cognitive functions in patients after coronary artery surgery using cardiopulmonary bypass.

METHODS

Eighty-six age- and education-balanced patients ≥55 years of age undergoing elective coronary artery bypass surgery with cardiopulmonary bypass and 28 nonsurgical controls with coronary artery disease were enrolled. Recent verbal and nonverbal memory and executive functions were assessed before surgery and at 1 week and 3 months after surgery using a cognitive test battery. IL-6 concentrations were measured before surgery and 4 h after cardiopulmonary bypass, and CRP concentrations were measured before surgery and at 24 and 72 h after anesthetic induction. Overall cognitive function between high and low biomarker concentration groups was analyzed by the Wilcoxon rank-sum test.

RESULTS

Recent memory was at least 1 standard deviation (SD) impaired at 1 week and 3 months in the high-CRP compared with low-CRP and in the high-IL-6 compared with low-IL-6 concentration groups. Overall cognitive function was significantly (P = 0.04 and P = 0.01, respectively) different between the high- and low-CRP concentration groups (CRP assayed 24 h after anesthetic induction) at both 1 week and 3 months. Overall cognitive function was also significantly (P = 0.04) different between the high and low-IL-6 concentration groups at 1 week after surgery.

CONCLUSION

The results suggest that elevated postoperative IL-6 and CRP concentrations are associated with the subsequent development of short- and medium-term impairment of cognitive functions after coronary artery surgery.

Postoperative Delirium is Associated with Postoperative Cognitive Dysfunction at One Week after Cardiac Surgery with Cardiopulmonary Bypass

Postoperative delirium with cognitive impairment frequently occurs after cardiac surgery. It was hypothesized that delirium is associated with residual postoperative cognitive dysfunction in patients after surgery using cardiopulmonary bypass. Male cardiac surgical patients ( M age = 66 yr., SD = 8; M education = 13 yr., SD = 2) and nonsurgical controls ( M age = 62, SD = 7; M education = 12, SD = 2) 55 years of age or older were balanced on age and education. Delirium was assessed by the Intensive Care Delirium Screening Checklist preoperatively and for up to 5 days postoperatively. Recent verbal and nonverbal memory and executive functions were assessed (as scores on particular tests) before and 1 wk. after surgery. In 56 patients studied ( n = 28 Surgery; n=28 Nonsurgery), nine patients from the Surgery group developed delirium. In the Surgery group, the proportion of patients having postoperative cognitive dysfunction was significantly greater in those who experienced delirium (89%) compared with those who did not (37%). The odds of developing this dysfunction in patients with delirium were 14 times greater than those who did not. Postoperative delirium is associated with scores for residual postoperative cognitive dysfunction 1 wk. after cardiac surgery.

A history of alcohol dependence increases the incidence and severity of postoperative cognitive dysfunction in cardiac surgical patients

Postoperative cognitive dysfunction (POCD) commonly occurs after cardiac surgery. We tested the hypothesis that a history of alcohol dependence is associated with an increased incidence and severity of POCD in male patients undergoing cardiac surgery using cardiopulmonary bypass. Recent verbal and nonverbal memory and executive functions were assessed before and one week after surgery in patients with or without a history of alcohol dependence. Cognitive function was significantly reduced after cardiac surgery in patients with versus without a history of alcohol dependence. The results suggest that a history of alcohol dependence increases the incidence and severity of POCD after cardiac surgery.

Markers of cerebral damage during delirium in elderly patients with hip fracture

Background

S100B protein and Neuron Specific Enolase (NSE) can increase due to brain cell damage and/or increased permeability of the blood-brain-barrier. Elevation of these proteins has been shown after various neurological diseases with cognitive dysfunction. Delirium is characterized by temporal cognitive deficits and is an important risk factor for dementia. The aim of this study was to compare the level of S100B and NSE of patients before, during and after delirium with patients without delirium and investigate the possible associations with different subtypes of delirium.

Methods

The study population were patients aged 65 years or more acutely admitted after hip fracture. Delirium was diagnosed by the Confusion Assessment Method and the subtype by Delirium Symptom interview. In maximal four serum samples per patient S100B and NSE levels were determined by electrochemiluminescence immunoassay.

Results

Of 120 included patients with mean age 83.9 years, 62 experienced delirium. Delirious patients had more frequently pre-existing cognitive impairment (67% vs. 18%, p < 0.001). Comparing the first samples during delirium to samples of non-delirious patients, a difference was observed in S100B (median 0.16 versus 0.10 μg/L, p = < 0.001), but not in NSE (median 11.7 versus 11.7 ng/L, p = 0.97). Delirious state (before, during, after) (p < 0.001), day of blood withdrawal (p < 0.001), pre- or postoperative status (p = 0.001) and type of fracture (p = 0.036) were all associated with S100B level. The highest S100B levels were found 'during' delirium. S100B levels 'before' and 'after' delirium were still higher than those from 'non-delirious' patients. No significant difference in S100B (p = 0.43) or NSE levels (p = 0.41) was seen between the hyperactive, hypoactive and mixed subtype of delirium.

Conclusion

Delirium was associated with increased level of S100B which could indicate cerebral damage either due to delirium or leading to delirium. The possible association between higher levels of S100B during delirium and the higher risk of developing dementia after delirium is an interesting field for future research. More studies are needed to elucidate the role of S100B proteins in the pathophysiological pathway leading to delirium and to investigate its possibility as biomarker for delirium.

Dexmedetomidine during coronary artery bypass grafting surgery: is it neuroprotective?--A preliminary study

BACKGROUND

In the present study, we aimed to determine whether during coronary artery bypass grafting (CABG) surgery, dexmedetomidine has protective effects against cerebral ischemic injury.

METHOD

Twenty-four patients, aged 50-70 years, undergoing CABG surgery were randomized into two groups of 12 patients each: those receiving dexmedetomidine (group D) and those not receiving it (group C). As basal blood samples from arterial and jugular bulb catheters were drawn, dexmedetomidine (1 microg/kg bolus and infusion at a rate of 0.7 microg/kg/h) was administered to patients in group D. Arterial and jugular venous blood gas analyses, serum S-100B protein (S-100B), neuron-specific enolase (NSE) and lactate measurements were performed after induction, 10 min after the initiation of cardiopulmonary bypass (CPB), 1 min after declamping, at the end of CPB, at the end of the operation and 24 h after surgery. Mann-Whitney U- and Wilcoxon's tests were used for statistical analyses.

RESULTS

No significant between-group differences were found regarding arterial and jugular venous pH, PO(2), PCO(2) and O(2) saturations. S-100B, NSE and lactate levels were also similar between groups D and C. During the post-operative period, there were no clinically overt neurological complications in any patient.

CONCLUSION

Cerebral ischemia marker (S-100B, NSE, lactate) patterns were as expected during CPB; however, there were no differences between the groups, which led us to believe that during CABG surgery dexmedetomidine has no neuroprotective effects. Future studies with larger populations are recommended to further establish the effects of this drug.

Cerebral dysfunction after cardiac surgery--are we moving forward?

This review focuses on the effects of cardiac surgery and cardiopulmonary bypass on the brain, with special emphasis on the results of recently conducted studies. The incidence of postoperative neurological and neuropsychological deficits and risk factors for cerebral injury are reviewed. The relationships between cerebral embolic load, release of biochemical markers of brain injury and cognitive dysfunction after cardiac surgery are also reviewed. Finally, recently gained information on the management of cardiopulmonary bypass is discussed, along with the results of recent pharmacological neuroprotective trials in patients undergoing cardiac surgery.

Predictive value of IL-18 and SC5b-9 for neurocognitive dysfunction after cardiopulmonary bypass

BACKGROUND

Neurological injury after cardiopulmonary bypass (CPB) continues to be a major problem after cardiac surgery. The aim of this study was to investigate the predictive value of Interleukin-18 (IL-18) and SC5b-9 as biochemical markers of neurocognitive dysfunction after cardiac surgery.

METHODS

A total of 30 patients undergoing elective cardiac surgery using CPB were recruited. Blood samples were obtained for IL-18 and SC5b-9 concentrations before induction, 24, 48, 72, 96 and 120 h post-CPB and 6 weeks after operation. In addition, patients underwent a standard battery of neuropsychometric tests before operation and at day 5 and 6 weeks after operation.

RESULTS

Serum concentration of IL-18, but not SC5b-9, was significantly different between patients with and without neurocognitive dysfunction; serum IL-18 concentration significantly increased in patients with neurocognitive dysfunction (P = 0.018). Neurological outcome was significantly dependent on peak difference in IL-18 concentration at day 5 (P = 0.033), but not on peak difference in SC5b-9 concentration (P = 0.16). Eight patients had neurocognitive dysfunction at day 5 and three had neurocognitive dysfunction at 6 weeks. In a very small number of patients, no significant association was demonstrated between IL-18 or SC5b-9 concentrations and neurocognitive dysfunction at 6 weeks.

CONCLUSIONS

IL-18 has the potential as a useful marker of neurological dysfunction, requiring further investigation.

Serologic markers of brain injury and cognitive function after cardiopulmonary bypass

OBJECTIVE

To examine the association between biochemical markers of brain injury (MBI) and the inflammatory response in relation to neurocognitive deficiency (NCD) after cardiopulmonary bypass (CPB).

SUMMARY BACKGROUND DATA

In cardiac surgery, NCD is a common but underdiagnosed complication with an unclear pathophysiology leading to significant morbidity. Despite extensive investigation, identification of a MBI for clinical use and clarifying the pathophysiology of NCD have not been achieved.

METHODS

Forty patients undergoing CABG and/or valve procedures using CPB were administered a validated neurocognitive battery preoperatively and postoperatively at day 4 and 3 months. S-100b, neuron specific enolase (NSE), and tau protein were assayed as MBIs preoperatively and postoperatively at 6 hours and day 4. C-reactive protein (CRP), interleukin (IL)-6, C3a, and total peroxide levels were also quantified from serum. Impact of cardiotomy suction and antifibrinolytics on markers of brain injury was assessed.

RESULTS

The incidence of early NCD was 40% (16 of 40). NSE and tau protein at the 6-hour time point were both significantly elevated in the presence of NCD (NCD group) compared with those without NCD (NORM group) (8.69 +/- 0.82 vs. 5.98 +/- 0.61; P = 0.018 and 68.8 vs. 29.2%; P = 0.015; respectively). S-100b increase was not different between the NCD and NORM groups. Cardiotomy suction significantly elevated S-100b levels, whereas NSE and tau were not significantly influenced. Aprotinin did not have an effect on NCD or levels of MBIs. Also, the NCD group had significantly elevated CRP and peroxide levels compared with the NORM group at postoperative day 4 while C3a was significantly elevated at 6 hours.

CONCLUSION

NSE and tau are better associated with NCD and less influenced by cardiotomy suction compared with S-100beta. Inflammatory and oxidative stress is associated with NCD post-CPB.

Randomized Controlled Trial of Pericardial Blood Processing With a Cell-Saving Device on Neurologic Markers in Elderly Patients Undergoing Coronary Artery Bypass Graft Surgery

BACKGROUND

Processing of pericardial shed blood with a cell-saving device was claimed to prevent lipid microembolization and to protect from neurocognitive dysfunction after cardiopulmonary bypass. The present study tested the hypothesis that processing of pericardial shed blood with a cell-saving device during cardiopulmonary bypass would significantly decrease serum levels of protein S100B, and improve brain oxygen saturation and neurologic outcome, all markers of brain injury in elderly patients.

METHODS

Forty patients, 65 years of age and older, undergoing coronary artery bypass graft with cardiopulmonary bypass, were prospectively randomly assigned to processing of pericardial shed blood with a cell-saving device or to conventional use of a standard closed venous reservoir where cardiotomy blood was collected and reinfused through the arterial circuit (control group). Serum in S100B was measured 30 minutes, 4 hours, 24 hours, and 48 hours after surgery. Near-infrared spectroscopy monitoring was performed during the procedure and the National Institutes of Health stroke scale was measured before surgery and at the time of discharge of the hospital.

RESULTS

Patients in the cell-saving device group averaged 72 +/- 3 years of age and underwent 3.1 +/- 0.7 coronary artery grafts with a mean of 62 +/- 20 minutes of cardiopulmonary bypass time. Patients in the control group averaged 75 +/- 4 years of age (p = 0.03) and underwent 3.3 +/- 0.6 coronary artery grafts (p = 0.49) with a mean of 75 +/- 25 minutes of cardiopulmonary bypass time (p = 0.12). The quantity of blood administered from the cell-saving device averaged 281 +/- 162 mL per patient. Serum protein S100B levels averaged 0.06 +/- 0.03 before surgery and 0.51 +/- 0.23 microg/L 30 minutes after surgery in the cell-saving device patients compared with 0.076 +/- 0.04 before surgery (p = 0.32) and 1.48 +/- 0.66 (p < 0.0001) in the control patients. The near-infrared spectroscopy baseline mean value of left and right cortical region was 58% +/- 12% and 55% +/- 7% in the cell-saving device group versus 59% +/- 7% and 53% +/- 6% in the control group (p = 0.67 and 0.36), and no difference occurred over time in each group. The National Institutes of Health stroke score before and after surgery was similar in the two groups. There was one cerebrovascular complication in the control group (1 of 20, 5%) after surgery.

CONCLUSIONS

The difference between the two groups occurred 30 minutes after surgery, at which time serum levels of protein S100B were significantly higher in the control group compared with cell-saving device patients. Although use of the cell-saving device was not associated with higher brain oxygen saturation nor changes in the National Institutes of Health stroke score, it is associated with lesser release of nonspecific markers of brain injury in elderly patients.

Use of P300 Cognitive Evoked Potentials in the Diagnosis of Impairments of Higher Mental Functions after Cardiac Surgery in Conditions of Cardiopulmonary Bypass

A total of 40 patients with ischemic heart disease undergoing aortocoronary shunting surgery in conditions of cardiopulmonary bypass were studied. Parameters of the P300 cognitive evoked potentials were studied before surgery and 7-9 days after surgery. Neurological and neuropsychological assessments were also performed. The most significant parameters of the P300 potential were found to be the latencies of the P3 and N2 components, increases in which showed positive correlations with the extent of the developing cognitive deficit. Evidence supporting the neuroprotective effects of Trasylol given during surgery was obtained. Patients given Trasylol showed less marked cognitive deficit and smaller changes in P300 parameters. Analysis of the P300 cognitive evoked potential can be recommended for detecting early cognitive dysfunction and assessing the efficacy of neuroprotective therapy in patients undergoing surgery with cardiopulmonary bypass.

Influence of Cardiopulmonary Bypass on the State of Cognitive Functions in Patients with Ischemic Heart Disease

Forty patients with ischemic heart disease and undergoing aortocoronary shunting surgery with cardiopulmonary bypass were studied. All patients were subjected to neuropsychological assessment and immunochemical analysis of the production of chemokines (IL-8, IP-10, MCP-1, MCP-3, MIP-1 beta, SDF-1 alpha) and cytokines (TNF-alpha and IL-10). The aims of the study were to assess the presence and severity of cognitive deficit developing after surgery with cardiopulmonary bypass and to assess the effects of intraoperative Trasylol on its severity. Cognitive deficit on day 9 after coronary shunting with cardiopulmonary bypass was seen as impairments of attention, hearing-speech memory, visual memory, and dynamic praxis. Trasylol had a marked neuroprotective effect and suppressed the systemic inflammatory response. Patients given intraoperative Trasylol had no clinically significant cognitive deficit in the early post-operative period.

The sensitivity and specificity of three common statistical rules for the classification of post-operative cognitive dysfunction following coronary artery bypass graft surgery

BACKGROUND

The application of statistical rules to determine post-operative cognitive dysfunction (POCD) has varied, and partially explains the wide range of reported incidences of POCD in the literature. The current study assessed the sensitivity and specificity of three commonly used statistical rules in a sample of coronary artery bypass graft (CABG) patients and healthy non-surgical controls.

METHODS

Two hundred and four CABG patients [mean age, 68.8 years; standard deviation (SD), 7.0 years] completed neuropsychological assessment pre-operatively (baseline) and 1 week and 3 months post-operatively. Ninety age- and gender-matched non-surgical controls (mean age, 67.8 years; SD, 7.9 years) completed the same tasks at the same time points. POCD was determined in each group using three rules: the 1SD decline on two or more tasks; the 20% decline on 20% of tasks rule; and a modified reliable change index.

RESULTS

The modified reliable change index demonstrated the greatest combination of sensitivity and specificity. The 20% decline on 20% of tasks rule detected the largest incidence of impairment in the CABG group, but showed large incidences of false positive classifications in the control group. The 1SD rule detected the lowest incidence of POCD in the CABG group, but detected a larger incidence of impairment in the control group.

CONCLUSIONS

The use of the modified reliable change index is recommended, given the sensitivity to change it displayed and the low rates of false positive classification in the control sample. The use of control groups in future research is also recommended.

Elevation of serum cerebral injury markers correlates with serum choline decline after coronary artery bypass grafting surgery

The aims of this study were to determine circulating choline status and its relationship to circulating levels of S-100β protein and neuron-specific enolase, biochemical markers of cerebral injury and cognitive decline, after coronary artery bypass grafting (CABG) surgery. Preoperatively, patients scheduled for off-pump or on-pump CABG surgery had serum concentrations of 12.0±0.2 and 11.7±0.4μmol/L free choline and 2640±65 and 2675±115μmol/L phospholipid-bound choline, respectively. Serum free and bound choline levels decreased by 22–37% or 34–47% and 16–36% or 31–38% at 48h after off-pump or on-pump surgery, respectively. Serum S-100β and neuron-specific enolase increased from preoperative values of 0.083±0.009 and 6.3±0.2μg/L to 0.405±0.022 and 11.4±0.8μg/L, respectively, at 0h postoperatively and remained elevated for 48h after off-pump surgery. Serum free and bound choline concentrations were inversely correlated with the concentrations of S-100β (r=−0.798; p<0.001 and r=−0.734; p<0.001) and neuron-specific enolase (r=−0.840; p<0.001 and r=−0.728; p<0.001). In conclusion, CABG surgery induces a decline in serum free and phospholipid-bound choline concentrations. The decreased serum choline concentrations were inversely correlated with the elevated levels of circulating cerebral injury markers. Thus, a decline in circulating choline may be involved in postoperative cognitive decline.

Profound Hypothermia Protects Neurons and Astrocytes, and Preserves Cognitive Functions in a Swine Model of Lethal Hemorrhage1

BACKGROUND

Lethal injuries can be repaired under asanguineous hypothermic arrest (suspended animation) with excellent survival. This experiment was designed to test the impact of this strategy on neuronal and astroglial damage in a swine model of lethal hemorrhage. Furthermore, our goal was to correlate the histological changes in the brain with neurological outcome, and the levels of circulating brain specific markers.

MATERIALS AND METHODS

Uncontrolled hemorrhage was induced in 32 female swine (80-120 lbs) by creating an iliac artery and vein injury, followed 30 min later by laceration of the thoracic aorta. Through a thoracotomy approach, organ preservation fluid was infused into the aorta using a roller pump. Experimental groups included normothermic controls (no cooling, NC), and groups where hypothermia was induced at three different rates: 0.5 degrees C/min (slow, SC), 1 degrees C/min (medium, MC), or 2 degrees C/min (fast, FC). Profound hypothermia (core temperature of 10 degrees C) was maintained for 60 min for repair of vascular injuries, after which the animals were re-warmed (0.5 degrees C/min) and resuscitated on cardiopulmonary bypass (CPB). Circulating levels of neuron specific enolase (NSE) and S-100beta were serially measured as markers of damage to neurons and astrocytes, respectively. Light microscopy and quantitative immunohistochemical techniques were used to evaluate hippocampal CA1 area and caudate putamen for neuronal injury and astrogliosis (astrocyte hyperplasia/hypertrophy). Surviving animals were observed for 6 weeks and neurological status was documented on an objective scale, and cognitive functions were evaluated using a technique based upon the concept of operant conditioning.

RESULTS

Normothermic arrest resulted in clinical brain death in all of the animals. None of the surviving hypothermic animals displayed any neurological deficits or cognitive impairment. On histological examination, normothermic animals were found to have ischemic changes in the neurons and astrocytes (hypertrophy). In contrast, all of the hypothermic animals had histologically normal brains. The circulating levels of brain specific proteins did not correlate with the degree of brain damage. The changes in NSE levels were not statistically significant, whereas S-100beta increased in the circulation after CPB, largely independent of the temperature modulation.

CONCLUSIONS

Profound hypothermia can preserve viability of neurons and astrocytes during prolonged periods of cerebral hypoxia. This approach is associated with excellent cognitive and neurological outcome following severe shock. Circulating markers of central nervous system injury did not correlate with the actual degree of brain damage in this model.

S-100B Concentration Is Not Related to Neurocognitive Performance in the First Month after Mild Traumatic Brain Injury

The serum concentration of S-100B is reported to reflect the severity of brain damage. The purpose of this study was to determine whether elevated serum S-100B concentrations were related to neuropsychological test performance of patients in the subacute phase of recovery from mild traumatic brain injury (TBI). S-100B concentrations were measured in blood samples taken within 6 h after TBI. Serum S-100B was estimated using an immunoluminometric assay. Cognitive speed and memory were assessed with neuropsychological tests at a median of 13 days (range 7-21 days) after injury. The two groups, formed on a median split of initial serum S-100B concentrations (>or<0.22 microg/l) did not differ in age or education. The neuropsychological performance of the TBI patients was also compared with that of a healthy control group. Cognitive speed and memory performance of mild TBI patients were inferior compared to those of healthy subjects. There were no significant differences within the TBI group when serum S-100B concentration was taken into consideration. The findings suggest that serum S-100B levels after mild TBI are not predictive of neuropsychological performance in the subacute stage of recovery.

Statistical and conceptual issues in defining post-operative cognitive dysfunction

The occurrence of post-operative cognitive dysfunction is a distressing complication following surgery. In an effort to gain a more complete understanding of patients' cognitive recovery following surgical procedures common neuropsychological assessment tools have been adopted in a repeated measures design. It is widely regarded that this represents the most comprehensive method of determining cognitive status in this population but it has resulted in a number of statistical and conceptual difficulties in attempting to infer significant change. The current paper outlines these core difficulties and provides some potential methods to overcome these.

Cerebral and extracerebral release of protein S100B in cardiac surgical patients

Although several clinical studies have shown that increased serum concentrations of protein S100B predict ischaemic brain damage after cardiac surgery, S100B may also be released from the heart or other injured tissue. We therefore investigated the correlation between serum S100B levels and those of the specific cardiac marker troponin I in order to assess the cerebral vs. extracerebral origin of S100B. In 64 cardiac surgical patients, serial blood samples were drawn for the measurement of S100B and troponin I before surgery and for seven days after surgery. Neurological function was assessed before with the National Institutes of Health Stroke Scale and the Folstein Mini Mental Test. The data show that a sustained increase in serum S100B levels is associated with neurological dysfunction, as witnessed by a positive correlation between S100B values and the results of the neuropsychological tests. In contrast, the early postoperative increased levels of protein S100B derive from cardiac tissue, as shown by the positive correlation between S100B and cardiac troponin I levels.

Biochemical markers for brain damage after carbon monoxide poisoning

BACKGROUND

Carbon monoxide poisoning is associated with high mortality and a substantial risk for brain damage in survivors. Evidence for acute brain dysfunction may be obtained by measuring concentrations of suitable biochemical markers. We hypothesized that increased serum concentrations of Neuron-specific enolase (NSE) and S-100beta protein could be detected after carbon monoxide poisoning and that the concentration would correlate with the severity of intoxication.

METHODS

Prospective non-interventional study in the university hospital. We included 20 patients admitted for hyperbaric treatment due to carbon monoxide poisoning. Serum levels of NSE and S-100beta protein were measured in all patients on admission and after 12, 24, 36 and 48 h. As a control group, we included 20 patients who underwent elective hyperbaric treatment.

RESULTS

Serum concentrations of NSE and S-100beta protein were not significantly different from the controls, with median values at admission being 10.6 vs. 9.7 microg l(-1) and 0.15 vs. 0.13 microg l(-1), respectively (P = 0.82 and P = 0.38). The concentrations did not change significantly during the sampling period. We were unable to show any significant relation to level of consciousness.

CONCLUSION

Blood concentrations of NSE and S-100beta protein were not significantly increased after carbon monoxide poisoning and do not seem to be related to a history of unconsciousness.

S100B in brain damage and neurodegeneration

S100B is a calcium-binding peptide produced mainly by astrocytes that exert paracrine and autocrine effects on neurons and glia. Some knowledge has been acquired from in vitro and in vivo animal experiments to understand S100B's roles in cellular energy metabolism, cytoskeleton modification, cell proliferation, and differentiation. Also, insights have been gained regarding the interaction between S100B and the cerebral immune system, and the regulation of S100B activity through serotonergic transmission. Secreted glial S100B exerts trophic or toxic effects depending on its concentration. At nanomolar concentrations, S100B stimulates neurite outgrowth and enhances survival of neurons during development. In contrast, micromolar levels of extracellular S100B in vitro stimulate the expression of proinflammatory cytokines and induce apoptosis. In animal studies, changes in the cerebral concentration of S100B cause behavioral disturbances and cognitive deficits. In humans, increased S100B has been detected with various clinical conditions. Brain trauma and ischemia is associated with increased S100B concentrations, probably due to the destruction of astrocytes. In neurodegenerative, inflammatory and psychiatric diseases, increased S100B levels may be caused by secreted S100B or release from damaged astrocytes. This review summarizes published findings on S100B regarding human brain damage and neurodegeneration. Findings from in vitro and in vivo animal experiments relevant for human neurodegenerative diseases and brain damage are reviewed together with the results of studies on traumatic, ischemic, and inflammatory brain damage as well as neurodegenerative and psychiatric disorders. Methodological problems are discussed and perspectives for future research are outlined.

Neurocognitive sequelae following coronary artery bypass graft. A research agenda for behavioral scientists

Several studies have demonstrated that a sizeable proportion of patients undergoing coronary artery bypass graft (CABG) demonstrate persistent declines in cognitive functioning. However, several important questions remain regarding cognitive changes following CABG. First, can patients vulnerable to cognitive decline after CABG be identified, providing valuable information that can be factored into clinical decisions? Second, the specificity of CABG as a cause of cognitive decline, when compared to other coronary procedures such as percutaneous coronary interventions, has not been established. Third, what mechanisms account for the neurocognitive decline after CABG? Several mechanisms have been proposed to lead to post-CABG neurocognitive deficits, including pre-CABG neurocognitive deficits, physiological injury, psychosocial factors, and/or the patient's perceptual processes. Finally, no study has demonstrated that cognitive changes, as measured by neuropsychological tests, have ecological validity. Specifically, behavioral sciences research is needed to demonstrate that measured cognitive changes significantly impact health status independent of other risk factors.