Diagnostic and prognostic value of procalcitonin for early intracranial infection after craniotomy

A prospective study of nanopore-targeted sequencing in the diagnosis of central nervous system infections

Central nervous system (CNS) infections are a leading cause of death in patients. Nanopore-targeted sequencing (NTS) has begun to be used for pathogenic microbial detection. This study aims to evaluate the ability of NTS in the detection of pathogens in cerebrospinal fluid (CSF) through a prospective study. Fifty CSF specimens collected from 50 patients with suspected CNS infections went through three methods including NTS, metagenomic next-generation sequencing (mNGS), and microbial culture in parallel. When there was an inconsistency between NTS results and the results of the mNGS, the 16S rDNA gene was amplified followed by Sanger sequencing to further verify pathogens detected by NTS. Among 50 CSF specimens, 76% were NTS-positive, which is lower than mNGS (94.0%), yet higher than microbial culture (16.0%). The overall validation rate, diagnostic accordance rate (DAR), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of NTS were 86.7%, 50.0%, 71.0%, 15.8%, 57.9%, and 25.0%, respectively. In the CSF total nucleated cell (TNC) number ≤10 cells/µL, DAR, specificity, and PPV were 20%, 11.1%, and 11.1%, whereas in that with CSF TNC number >10 cells/µL, DAR, sensitivity, specificity, PPV, and NPV were 57.5%, 70.0%, 20.0%, 72.4%, and 18.2%, respectively. Although NTS has a higher microbial detection rate than microbial culture, it should combine CSF TNC result to evaluate the value of NTS for the diagnosis of CNS infections.

IMPORTANCE

This study aims to prospectively evaluate the ability of nanopore-targeted sequencing (NTS) in the detection of pathogens in cerebrospinal fluid (CSF). It was the first time combining mNGS and microbial culture to verify the NTS-positive results also using 16S rDNA amplification with Sanger sequencing. Although microbial culture was thought to be the gold standard for pathogens detection and diagnosis of infectious diseases, this study suggested that microbial culture of CSF is not the most appropriate way for diagnosing central nervous system (CNS) infection. NTS should be recommended to be used in CSF for diagnosing CNS infection. When evaluating the value of NTS for diagnosis of CNS infections, the results of CSF TNC should be combined, and NTS-positive result is observed to be more reliable in patients with CSF TNC level >10 cells/μL.

Diagnostic Accuracy of Procalcitonin in Bacterial Infections of the CNS: An Updated Systematic Review, Meta-Analysis, and Meta-Regression

OBJECTIVES

To evaluate diagnostic accuracy of serum and cerebrospinal fluid (CSF) procalcitonin for diagnosing CNS bacterial infections.

DATA SOURCES

We searched MEDLINE, Cochrane Central Register of Controlled Trials, and International Web of Science databases from January 1, 2016, to September 30, 2022.

STUDY SELECTION

Randomized controlled trials and observational studies, either prospective or retrospective, focusing on procalcitonin as a biomarker for CNS infections.

DATA EXTRACTION

We screened and extracted studies independently and in duplicate. We assessed risk of bias using the revised Quality Assessment for Studies of Diagnostic Accuracy tool. Data for diagnostic sensitivity and specificity were pooled using the bivariate or hierarchical model, as appropriate.

DATA SYNTHESIS

Of 5,347 citations identified, 23 studies were included. Overall, CSF procalcitonin showed slightly higher pooled sensitivity, specificity, and positive likelihood ratio compared with serum procalcitonin. In adults, pooled sensitivity of CSF procalcitonin was 0.89 (95% CI, 0.71-0.96), specificity 0.81 (95% CI, 0.66-0.91); pooled sensitivity of serum procalcitonin was 0.82 (95% CI, 0.58-0.94), specificity 0.77 (95% CI, 0.60-0.89). In children, pooled sensitivity of CSF procalcitonin was 0.96 (95% CI, 0.88-0.99), specificity 0.91 (95% CI, 0.72-0.97); pooled sensitivity of serum procalcitonin was 0.90 (95% CI, 0.75-0.97), specificity 0.83 (95% CI, 0.67-0.92). In post-neurosurgical patients, pooled sensitivity of CSF procalcitonin was 0.82 (95% CI, 0.53-0.95), specificity 0.81 (95% CI, 0.63-0.91); pooled sensitivity of serum procalcitonin was 0.65 (95% CI, 0.33-0.88), specificity 0.61 (95% CI, 0.41-0.78). Logistic regression revealed between-study heterogeneity higher for serum than CSF procalcitonin. For the latter, threshold variability was found as source of heterogeneity.

CONCLUSIONS

In children and critical post-neurosurgical patients, CSF procalcitonin gains superior sensitivity and specificity compared with serum procalcitonin. Overall, CSF procalcitonin appears to have a higher pooled positive likelihood ratio compared with serum procalcitonin.

The Value of CD64 in the Early Diagnosis for Intracranial Infection After Craniocerebral Surgery

PURPOSE

To investigate the value of CD64 in the early diagnosis of intracranial infection after craniocerebral surgery.

METHODS

A total of 93 patients who met the inclusion and exclusion criteria after neurosurgery in Lianyungang First People's Hospital and Lianyungang Second People's Hospital were admitted and divided into experimental group with intracranial infection (n = 32) and uninfected control group (n = 61) according to the results of cerebrospinal fluid culture. We performed relevant statistical analysis, drew the receiver operating characteristic curve and calculated area under the curve (AUC).

RESULTS

The sensitivity and specificity of the CD64, c-reactive protein (CRP), and white blood cell (WBC) counts were 84.38% and 86.89%, 78.13% and 75.41%, and 75.00% and 67.21%, respectively; the AUCs were 0.912, 0.858, and 0.851, respectively. Accuracy was the highest when the 3 diagnosis were combined, reaching 93.75%; the AUC could reach 0.948.

CONCLUSIONS

Serum CD64, CRP, and WBC count in the diagnosis of intracranial infection after craniocerebral surgery were significant. CD64 was more valuable than the others. The diagnostic efficiency could be improved when CD64, CRP, and WBC count were combined.

Detecting Diabetic Ketoacidosis with Infection: Combating a Life-Threatening Emergency with Practical Diagnostic Tools

BACKGROUND

Diabetic ketoacidosis (DKA) is a life-threatening acute complication of diabetes mellitus and can lead to patient demise if not immediately treated. From the recent literature, the diabetic ketoacidosis mortality rate, depending on age, is 2-5%. Insulin discontinuation and infection remain the two most common triggers for diabetic ketoacidosis. About 50% of cases of ketoacidosis result from bacterial infections like urinary tract infections and pneumonia. It is also important to diagnose the presence of infection in diabetic ketoacidosis patients to prevent the excessive use of antibiotics, which may lead to antibiotic resistance. Although performing bacterial culture is confirmatory for the presence or absence of bacterial infection, the time required to obtain the result is long. At the same time, emergency treatment needs to be started as early as possible.

METHODS

This narrative review examines various septic markers to identify the appropriate tools for diagnosis and to distinguish between diabetic ketoacidosis with and without infection. Electronic databases were searched using the Google engine with the keywords "Diabetes Mellitus", "Diabetic Ketoacidosis", "Infection with Diabetic Ketoacidosis", "biomarkers for infection in Diabetic Ketoacidosis", "Procalcitonin", "Inflammatory cytokines in DKA", "Lactic acidosis in DKA", and "White blood cell in infection in DKA".

RESULTS

This narrative review article presents the options for diagnosis and also aims to create awareness regarding the gravity of diabetic ketoacidosis with infection and emphasizes the importance of early diagnosis for appropriate management. Diabetes mellitus is a clinical condition that may lead to several acute and chronic complications. Acute diabetic ketoacidosis is a life-threatening condition in which an excess production of ketone bodies results in acidosis and hypovolemia. Infection is one of the most common triggers of diabetic ketoacidosis. When bacterial infection is present along with diabetic ketoacidosis, the mortality rate is even higher than for patients with diabetic ketoacidosis without infection. The symptoms and biomarkers of diabetic ketoacidosis are similar to that of infection, like fever, C reactive protein, and white blood cell count, since both create an environment of systemic inflammation. It is also essential to distinguish between the presence and absence of bacterial infection to ensure the appropriate use of antibiotics and prevent antimicrobial resistance. A bacterial culture report is confirmatory for the existence of bacterial infection, but this may take up to 24 h. Diagnosis needs to be performed approximately in the emergency room upon admission since there is a need for immediate management. Therefore, researching the possible diagnostic tools for the presence of infection in diabetic ketoacidosis patients is of great importance. Several of such biomarkers have been discussed in this research work.

Prediction model of central nervous system infections in patients with severe traumatic brain injury after craniotomy

OBJECTIVE

The aim of this study was to develop and evaluate a nomogram to predict CNS infections in patients with severe traumatic brain injury (sTBI) after craniotomy.

METHODS

This retrospective study was conducted in consecutive adult patients with sTBI who were admitted to the neurointensive care unit (NCU) between January 2014 and September 2020. We applied the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression analysis to construct the nomogram, and k-fold cross-validation (k=10) to validate it. The receiver operator characteristic area under the curve (AUC) and calibration curve were applied to evaluate the predictive effect of the nomogram. The clinical usefulness was investigated by decision curve analysis (DCA).

RESULTS

A total of 471 patients with sTBI who underwent surgical treatment were included, of whom 75 patients (15.7%) were diagnosed with CNS infections. The serum level of albumin, cerebrospinal fluid (CSF) otorrhoea at admission, CSF leakage, CSF sampling, and postoperative re-bleeding were associated with CNS infections and incorporated into the nomogram. The results showed that our model yielded satisfactory prediction performance with an AUC value of 0.962 in the training set and 0.942 in the internal validation. The calibration curve exhibited satisfactory concordance between the predicted and actual outcomes. The model had good clinical use since the DCA covered a large threshold probability.

CONCLUSION

We established a straightforward individualized nomogram for CNS infections in sTBI patients in the NCU, which could help physicians screen high-risk patients to perform early interventions to reduce the incidence of CNS infections in sTBI patients.

Analysis of Cerebrospinal Fluid Routine Biochemical Level, Pathogenic Bacteria Distribution, and Risk Factors in Patients with Secondary Intracranial Infection after Brain Tumor Surgery

Purpose. Analysis of routine biochemical levels of cerebrospinal fluid (CSF), distribution of pathogenic bacteria, and risk factors in patients with intracranial infections secondary to brain tumour surgery. Methods. A total of 208 patients admitted to our hospital for brain tumour surgery from January 2020 to May 2022 were selected. Fully automated biochemical analyzer was employed for CSF routine and for measuring biochemical parameters such as white blood cell (WBC), micrototal protein (M-TP), glucose (GLU), and chlorine (CI). Double antibody sandwich assay for CSF procalcitonin (PCT), heparin-binding protein (HBP), and matrix metalloproteinase-9 (MMP-9) was performed. Fully automated microbiological analyzer for pathogen identification was utilized. Based on the above results, we determined whether the patients had secondary intracranial infections after surgery and analyzed the risk factors for secondary intracranial infections after brain tumour surgery by univariate and multifactorial logistic regression. Results. Among 208 patients with brain tumour surgery, 65 cases (31.25%) had secondary intracranial infection and 143 cases (68.75%) had no secondary intracranial infection. The levels of WBC, M-TP, CI, PCT, HBP, and MMP-9 in the CSF of intracranially infected patients were significantly higher than those of uninfected patients ( $P<0.05$ ), and GLU was significantly lower than that of uninfected patients ( $P<0.05$ ), and the levels of PCT, HBP, and MMP-9 in infected patients were significantly lower than those before treatment after 3, 7, and 10 d and tended to decrease over time ( $P<0.05$ ). A total of 62 pathogenic strains were isolated from 65 intracranial infections, of which 41 (66.13%) were Gram-negative bacteria, mainly resistant to amikacin and ciprofloxacin and sensitive to meropenem and imipenem; 19 (30.65%) were Gram-positive bacteria, mainly highly resistant to penicillin and erythromycin and sensitive to vancomycin. Univariate analysis showed that age, gender, tumour type, history of glucocorticoid application, and prophylactic application of antibiotics were not associated with secondary intracranial infection after brain tumour surgery ( $P>0.05$ ); tumour site, operation time, postoperative indwelling drainage time, postoperative cerebrospinal fluid leakage, and history of diabetics were all associated with secondary intracranial infection after brain tumour surgery ( $P<0.05$ ). Multivariate logistic regression analysis showed that infratentorial tumour, operation time ≥4 h, postoperative indwelling drainage time ≥24 h, and postoperative cerebrospinal fluid leakage were independent risk factors for secondary intracranial infection after brain tumour surgery ( $P<0.05$ ). Conclusion. Patients with intracranial infections secondary to brain tumour surgery have abnormal levels of CSF routine and biochemical parameters, and the detection rate of Gram-negative bacteria is higher than that of Gram-positive bacteria in patients. Treatment should be based on the characteristics of pathogenic bacteria and risk factors with targeted interventions to reduce intracranial infections.

Combining modified Graeb score and intracerebral hemorrhage score to predict poor outcome in patients with spontaneous intracerebral hemorrhage undergoing surgical treatment

Objective

Spontaneous intracerebral hemorrhage (sICH) is a frequently encountered neurosurgical disease. The purpose of this study was to evaluate the relationship between modified Graeb Score (mGS) at admission and clinical outcomes of sICH and to investigate whether the combination of ICH score could improve the accuracy of outcome prediction.

Methods

We retrospectively reviewed the medical records of 511 patients who underwent surgery for sICH between January 2017 and June 2021. Patient outcome was evaluated by the Glasgow Outcome Scale (GOS) score at 3 months following sICH, where a GOS score of 1–3 was defined as a poor prognosis. Univariate and multivariate logistic regression analyses were conducted to determine risk factors for unfavorable clinical outcomes. Receiver operating characteristic (ROC) curve analysis was performed to detect the optimal cutoff value of mGS for predicting clinical outcomes. An ICH score combining mGS was created, and the performance of the ICH score combining mGS was assessed for discriminative ability.

Results

Multivariate analysis demonstrated that a higher mGS score was an independent predictor for poor prognosis (odds ratio [OR] 1.207, 95% confidence interval [CI], 1.130–1.290, p < 0.001). In ROC analysis, an optimal cutoff value of mGS to predict the clinical outcome at 3 months after sICH was 11 (p < 0.001). An increasing ICH-mGS score was associated with increased poor functional outcome. Combining ICH score with mGS resulted in an area under the curve (AUC) of 0.790, p < 0.001.

Conclusion

mGS was an independent risk factor for poor outcome and it had an additive predictive value for outcome in patients with sICH. Compared with the ICH score and mGS alone, the ICH score combined with mGS revealed a significantly higher discriminative ability for predicting postoperative outcome.

High-resolution mass spectrometry assay for quantifying ceramides and dihydroceramides in the cerebrospinal fluid from patients who experienced intracranial infection after craniotomy

Ceramides (CERs) and dihydroceramides (dhCERs) are biologically active lipids involved in cell proliferation, differentiation, and apoptosis, as well as associated with infectious diseases. The concentration of CERs and dhCERs in the cerebrospinal fluid (CSF) could potentially allow the distinction of patients with intracranial infection (ICI) after craniotomy from controls, but the quantification is limited by their ultralow concentrations. Therefore, a novel high performance liquid chromatography-triple-quadrupole/time-of-flight mass spectrometry (HPLC-QTOF-MS) with Sequential Window Acquisition of All Theoretical Fragment Ion Spectra (SWATH) was applied to measure CERs and dhCERs in CSF, since it possesses a higher sensitivity (LLOQ = 0.1 pmol/mL) than the multiple reaction monitoring (MRM) acquisition carried on triple quadrupole (QqQ) MS. This method was validated and applied to CSF samples from patients who experienced postoperative ICI (63 patients) and controls who did not experience it after surgery (62 patients). This assay was linear over the measuring range 0.1-100 pmol/mL for these CER and dhCER species with good accuracy and precision. Elevated CERs and dhCERs were observed in CSF from patients who experienced postoperative ICI. CER 16:0 was found with a clinical sensitivity of 93.65 % and specificity of 87.1 % in distinguishing the 63 patients with ICI from the 62 controls. Therefore, this method could be applied in the detection of CERs and dhCERs in CSF, which were correlated with the presence of ICI.

Systemic Infection Predictive Value of Procalcitonin to Lactic Acid Ratio in Diabetes Ketoacidosis Patients

INTRODUCTION

Early detection of bacterial infections associated with adequate antibiotic treatment is key to improving diabetic ketoacidosis (DKA) outcomes. Our study aimed to investigate the different sepsis markers (including procalcitonin to lactic acid ratio, PLR) to diagnose bacterial infection in patients with DKA within one hour after admission.

METHODS

A total of 165 patients diagnosed with DKA were enrolled between July 2014 and July 2018 and divided into an infection group (N =62) and a non-infection group (N=103) based on the positive aetiological tests such as blood culture, sputum culture, urine culture, or definite focus of pulmonary, soft tissue, kidney, etc.

RESULTS

Our findings suggest the following: 1) leucocytes (threshold above 10×10⁹ /L) and PLR (threshold above 0.438) within one hour after admission can help to identify patients with infection in the context of DKA. 2) A subgroup analysis demonstrated that PLR also has a high diagnostic efficacy for infection in patients with DKA, regardless of the type of diabetes.

CONCLUSION

This study concludes that leucocyte count (threshold > 10×10⁹/L) and PLR (threshold above 0.438) show a diagnostic value to help distinguish DKA patients with infection. By combining these two markers, the reduction of antibiotic misuse may be possible.

Expression of the α7 nAChR Subunit Duplicate Form (CHRFAM7A) Was Down-Regulated in Patients with Intracranial Infection and Reduced Inflammation in in vitro Model by p38 MAPK

OBJECTIVE

In this study, we investigated that the effects and possible mechanisms of the α7 nAChR subunit duplicate form (CHRFAM7A) affected inflammation in the model of intracranial infection.

METHODS

Mice of the model group were injected (intracranial injection) with Staphylococcus aureus. Mouse microglial BV2 cell was exposed with 200 ng of LPS for 4 h.

RESULTS

CHRFAM7A mRNA expressions were reduced in patients with intracranial infection. CHRFAM7A mRNA and protein expressions were suppressed in mice with intracranial infection in a time-dependent manner. CHRFAM7A reduced inflammation in mice with intracranial infection. The inhibition of CHRFAM7A reduced inflammation in mice with intracranial infection. CHRFAM7A suppressed p38 MAPK in mice with intracranial infection. The inhibition of p38 MAPK shows the effects of CHRFAM7A in intracranial infection.

CONCLUSION

Our data demonstrate that the expression of the CHRFAM7A was down-regulated in patients with intracranial infection and reduced inflammation in in vitro model by p38 MAPK, which suggests the potential role of CHRFAM7A as a diagnostic biomarker for intracranial infection.

The risk factors of intracranial infection in patients with intracerebral hemorrhage undergone hematoma puncture: what should we care

BACKGROUND

Intracranial infection after puncture of cerebral hematoma in patients with intracerebral hemorrhage is very common in the department of neurosurgery, yet the relevant risks remain unknown. We attempted to analyze the risk factors of intracranial infection after puncture of cerebral hematoma, to provide insights into the management of patients with intracerebral hemorrhage after puncture of cerebral hematoma.

METHODS

Patients with intracerebral hemorrhage after puncture of cerebral hematoma treated in our hospital from January 2017 to January 2020 were selected, the related characteristics of intracranial infection and no infection patients were compared. Logistic regression analyses were conducted to analyze the risk factors for intracranial infection after puncture of cerebral hematoma.

RESULTS

A total of 925 patients with puncture of cerebral hematoma were included. The incidence of postoperative intracranial infection was 7.03%. There were significant statistical differences between the infected group and the no infection group in the American Association of Anesthesiologists (ASA) grade, length of hospital stay, consecutive operation, duration of surgery, extra-ventricular drainage (EVD) use (all p < 0.05). There was statistically significant difference in the duration of EVD between the infection and no infection groups (p = 0.002), and there was no significant difference in the frequency of EVD insertion between the two groups (p = 0.094). The length of hospital stay≥10 days (OR1.832, 1.062-3.158), consecutive operation (OR2.158, 1.358-3.430), duration of surgery≥4 h (OR1.581, 1.031-2.425), EVD use (OR1.694, 1.074-2.670), and duration of EVD ≥ 7 days (OR2.699, 1.689-4.311) were the risk factors of intracranial infection in patients with intracerebral hemorrhage after puncture of cerebral hematoma (all p < 0.05).

CONCLUSION

Clinical medical workers should take corresponding preventive measures against the different risk factors for prevention of intracranial infection in patient with puncture of cerebral hematoma.

Application value analysis of magnetic resonance imaging and computed tomography in the diagnosis of intracranial infection after craniocerebral surgery

BACKGROUND

Intracranial infection is a common clinical disease. Computed tomography (CT) and magnetic resonance imaging (MRI) have certain sensitivity and have good diagnostic efficacy.

AIM

To study the application value of MRI and CT in the diagnosis of intracranial infection after craniocerebral surgery.

METHODS

We selected 82 patients who underwent craniocerebral surgery (including 40 patients with intracranial infection and 42 patients without infection) during the period from April 2016 to June 2019 in our hospital. All 82 patients received CT and MRI examinations, and their clinical data were reviewed. A retrospective analysis was performed, and the coincidence rate of positive diagnosis and the overall diagnosis coincidence rate of different pathogenic infection types were measured with the two examination methods. The diagnostic sensitivity and specificity as well as the positive and negative predictive values of the two examination methods were compared.

RESULTS

For all types of pathogenic infections (Staphylococcus aureus, Staphylococcus hemolyticus, Staphylococcus epidermidis, and others), MRI scans had higher positive diagnostic coincidence rates than CT scans; the overall diagnostic coincidence rate, sensitivity, specificity, positive predictive value, and negative predictive values were significantly higher with MRI examinations than with CT examinations, and the differences were statistically significant (P < 0.05).

CONCLUSION

MRI examination can accurately diagnose intracranial infection after clinical craniocerebral surgery. Compared with CT, MRI had higher diagnostic efficiency. The diagnostic sensitivity and specificity, the diagnostic coincidence rate, and the positive and negative predictive values were significantly higher with MRI than with conventional CT, which can be actively promoted.

Application of combined cerebrospinal fluid physicochemical parameters to detect intracranial infection in neurosurgery patients

Routine test of cerebrospinal fluid (CSF), such as glucose concentrations, chloride ion, protein and leukocyte, as well as color, turbidity and clot, were important indicators for intracranial infection. However, there were no models to predict the intracranial infection with these parameters. We collected data of 221 cases with CSF positive-culture and 50 cases with CSF negative culture from January 1, 2016 to December 31, 2018 in the First Affiliated Hospital of Nanchang University, China. SPSS17.0 software was used to establish the model by adopting seven described indicators, and P < 0.05 was considered as statistically significant. Meanwhile, 40 cases with positive-culture and 10 cases with negative-culture were selected to verify the sensitivity and specificity of the model. The results showed that each parameter was significant in the model establishment (P < 0.05). To extract the above seven parameters, the interpretation model C was established, and C = 0.952–0.183 × glucose value (mmol/L) - 0.024 × chloride ion value (mmol/L)- 0.000122 × protein value (mg/L) - 0.0000859 × number of leukocytes per microliter (× 10⁶/L) + 1.354 × color number code + 0.236 × turbidity number code + 0.691 × clot number code. In addition, the diagnostic sensitivity and specificity of the model were 85.0 and 100%, respectively. The combining application of seven physicochemical parameters of CSF might be of great value in the diagnosis of intracranial infection for adult patients.

Intracranial Infections in Neurological Surgery: The Changes of Circular RNA Expression and Their Possible Function Mechanism

Methods

circRNA expression was analysed in six cerebrospinal fluid (CSF) samples from three patients of the infectious and noninfectious phases using an Arraystar Human circRNA Array. Differentially altered circRNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR) in the 66 CSF samples of 33 patients of the infectious and noninfectious phases. t-test was used for statistical analysis. A bioinformatics analysis was employed to investigate the function mechanism of the circRNAs.

Results

Firstly, 142 circRNAs were found significantly different in 6 CSF samples of the infection and noninfection phases of 3 patients. Fourteen circRNAs with the top largest fold changes were chosen from the 142 circRNAs for PCR validation in the same 6 CSF samples of 3 patients. Three circRNAs were selected to be validated in 60 CSF samples of 30 patients using the PCR test. In infection CSF, an upregulated hsa_circRNA_402632 and downregulated hsa_circRNA_008636 and hsa_circRNA_405481 were confirmed by PCR test. A bioinformatics analysis was used to investigate the function mechanism of the 3 circRNAs. hsa_circRNA_402632 is enriched in the insulin resistance pathway, the FoxO and AMPK signaling pathways are the most important pathways for hsa_circRNA_008636 gene expression, and hsa_circRNA_405481 is enriched in the endometrial cancer signaling pathway, Fc epsilon RI signaling pathway, and TGF-beta signaling pathway.

Conclusions

hsa_circRNA_402632, hsa_circRNA_008636, and hsa_circRNA_405481 may be potential diagnostic markers for central nervous system infection after neurological surgery.

Higher Procalcitonin Level in Cerebrospinal Fluid than in Serum Is a Feasible Indicator for Diagnosis of Intracranial Infection

Objective: To explore the value of the difference in procalcitonin (PCT) levels in serum and cerebrospinal fluid (CSF) for diagnosing intracranial infection in post-neurosurgical patients. Methods: Patients who were treated at our hospital after craniotomy from January 2015 to January 2019 were enrolled in this study. Twenty patients eventually diagnosed with intracranial infection were included in a study group and 22 patients with no intracranial infection were included in a control group. A t-test was used to compare the differences between serum and CSF PCT levels of PCT, and the diagnostic value of PCT was evaluated by receiver operating characteristic (ROC) curve analysis. Results: The serum PCT levels in the study and control groups were 0. 10 ± 0. 03 ng/mL and 0. 09 ± 0. 03 ng/mL, respectively, and they were not substantially different between the groups. The CSF PCT level in the study group was substantially higher than that in the control group, with values of 0. 13 ± 0. 03 ng/mL and 0. 07 ± 0. 02 ng/mL, respectively. The CSF/serum PCT ratio in the study group was substantially higher than that in the control group, with values of 1. 31 ± 0. 19 and 0. 79 ± 0. 23, respectively. The areas under the ROC curve for serum PCT, CSF PCT and the CSF/serum PCT ratio were 0. 56, 0. 92, and 0. 95, respectively, resulting in a substantial difference among the three groups. Conclusion: CSF PCT may be a valuable marker for diagnosing intracranial infection in patients after neurosurgery; in particular, the specificity of CSF PCT is higher if the CSF PCT level is higher than the serum PCT level.

How can biomarkers be used to differentiate between infection and non-infectious causes of inflammation?

Diagnosis of sepsis is based on recognition of systemic inflammation and organ failure in the context of an inciting infection. Since none of the diagnostic criteria are specific to sepsis, it is easy to confound sepsis with noninfectious causes of systemic inflammation, including pancreatitis, cardiac ischemia, bowel perforation, vasculitis, and pulmonary embolism amongst others. Two widely used biomarkers, C-reactive protein and procalcitonin, have proven promising in sepsis diagnosis. Each has found varying success in the clinical context, with some centers relying heavily on these markers and others eschewing their use almost entirely. In this chapter, we present the evidence for their use in the diagnosis of sepsis and management of antibiotic therapy in the intensive care unit context.

Diffusion-weighted magnetic resonance imaging for detection of postoperative intracranial pyogenic abscesses in neurosurgery

BACKGROUND

Diffusion-weighted magnetic resonance imaging (MRI-DWI) is the modality of choice for detecting intracranial abscesses; however, it is unclear whether prior brain surgery has an influence on its diagnostic value. Thus, we assessed the robustness of MRI-DWI and determination of an ADC cutoff value for detecting intracranial abscesses in patients who underwent brain surgery.

METHODS

We retrospectively evaluated 19 patients prior to surgery for postoperative supratentorial parenchymal abscesses by means of MRI-DWI. Forty randomly selected patients with routine postoperative MRI-DWI were used for comparative analyses. Clinical and serum biomarkers (C-reactive protein, interleukin-6, white blood cell count) as well as from results of early postoperative imaging findings (computed tomography and/or MRI scan) were recorded. Additionally, ADC values, T1±gadolinium, and T2/fluid-attenuated inversion recovery sequences were investigated.

RESULTS

After initial surgery, early postoperative control imaging showed evidence of hemorrhage and/or hemostatic agents within the resection cavity in 10/19 patients of the abscess group and in 16/40 patients of the control group. No postoperative ischemia was detected. Neither hemostatic agents nor blood affected the mean ADC values in both the reference group (blood 2.96 ± 0.22 × 10^-3 mm²/s vs. no blood 2.95 ± 0.26 × 10^-3 mm²/s, p = 0.076) and in the abscess group (blood 0.87 ± 0.07 × 10^-3 mm²/s vs. no blood 0.76 ± 0.06 × 10^-3 mm²/s, p = 0.128). The mean ADC value within the resection cavity was significantly lower in the abscess group (1.5 T 0.88 ± 0.41 vs. 2.88 ± 0.20 × 10^-3 mm²/s, p < .01; 3.0 T 0.75 ± 0.24 vs. 3.02 ± 0.26 × 10^-3 mm²/s, p < 0.01). The optimal ADC cut-off for the differentiation of an abscess from normal postoperative findings was found at 1.87 × 10^-3 mm²/s (area-under-the-curve 1.0, sensitivity = 100%, specificity = 100%). Moreover, no differences between the abscess patients and the control group were seen with respect to the analyzed serum biomarkers.

CONCLUSION

MRI-DWI provides a robust tool to discriminate postoperative abscess formation from normal postoperative changes.