Slope Extrusion Microchannel Integrating Terahertz Meta-Sensor Embedded in Cerebrospinal Fluid for Precise Diagnosis of PCNSIs.

Postoperative central nervous system infection (PCNSI) in patients undergoing neurosurgical procedures represents a serious problem that requires immediate attention. PCNSI most commonly manifests as meningitis, subdural empyema, and/or brain abscess. Recent studies (which have included a minimum of 1000 operations) have reported that the incidence of PCNSI after neurosurgical procedures is 5%-7%, and many physicians believe that the true incidence is even higher. To address this issue, we examined the incidence of PCNSI in a sizeable patient population. The medical records and postoperative courses for patients involved in 2111 neurosurgical procedures at our institution during 1991-2005 were reviewed retrospectively to determine the incidence of PCNSI, the identity of offending organisms, and the factors associated with infection. The median age of patients at the time of surgery was 45 years. Of the 1587 cranial operations, 14 (0.8%) were complicated by PCNSI, whereas none of the 32 peripheral nerve operations resulted in PCNSI. The remaining 492 operative cases involved spinal surgery, of which 2 (0.4%) were complicated by PCNSI. The overall incidence of PCNSI was 0.8% (occurring after 16 of 2111 operations); the incidence of bacterial meningitis was 0.3% (occurring after 4 of 1587 operations), and the incidence of brain abscess was 0.2% (occurring after 3 of 1587 operations). The most common offending organism was Staphylococcus aureus (8 cases; 50% of infections), followed by Propionibacterium acnes (4 cases; 25% of infections). Cerebrospinal fluid leakage, diabetes mellitus, and male sex were not associated with PCNSI (P>.05). In one of the largest neurosurgical studies to have investigated PCNSI, the incidence of infection after neurosurgical procedures was <1%--more than 6 times lower than that reported in recent series of comparable numerical size. Cerebrospinal fluid leak, diabetes mellitus, and male sex were not associated with an increased incidence of PCNSI. The results from this study indicate that the true incidence of PCNSI after neurosurgical procedures may be greatly overestimated in the literature and that, in surgical procedures associated with a high risk of infection, prophylaxis for S. aureus and/or P. acnes infection should be of primary concern.

Post-operative central nervous system infections (PCNSIs) are serious complications of craniotomy. Many factors, including patient-related, surgical, and postoperative factors, affect the survival of patients with PCNSIs. Timely and effective implementation of antibiotics targeting pathogenic bacteria is crucial to reduce mortality. Metagenomic next-generation sequencing (mNGS) has been used successfully to detect pathogens associated with infectious diseases. This study was designed to evaluate the factors influencing mortality and to explore the application value of mNGS in patients with PCNSIs. We conducted a retrospective study of patients with PCNSIs in our unit from 1/12/2019 to 28/2/2021. Clinical data, cerebrospinal fluid (CSF) parameters, surgical information, and mNGS results were collected. Follow-up telephone calls were made in June 2021 for 90 days survival after discharge. 99 patients were enrolled, and the overall mortality rate was 36.4% (36/99). Kaplan–Meier survival analysis suggested that the risk factors for poor prognosis included age ≥ 53 years, Glasgow Coma scale (GCS) score ≤ 8, CSF/blood glucose ratio (C/B-Glu) ≤ 0.23, 2 or more operations, mechanical ventilation (MV), and non-mNGS test. MV and poor wound healing were independent risk factors for 90 day mortality according to the multivariate Cox proportional hazards model (OR = 6.136, P = .017, OR = 2.260, P = .035, respectively). Among the enrolled patients, causative pathogens were identified in 37. Gram-negative pathogens were found in 22 (59.5%) patients, and the remaining 15 (40.5%) were Gram-positive pathogens. Univariate analysis showed that white cell count and protein and lactate levels in the CSF of the Gram-negative group were higher than those of the Gram-positive group (P < .05). mNGS and conventional microbiological culture were tested in 34 patients, and the positive detection rate of mNGS was 52.9%, which was significantly higher than that of microbiological culture (52.9% vs 26.5%, χ2 = 4.54, P = .033). The mortality rate of PCNSIs is high, and patients with MV and poor wound healing have a higher mortality risk. Gram-negative pathogens were the predominant pathogens in the patients with PCNSIs. mNGS testing has higher sensitivity and has the potential to reduce the risk of mortality in patients with PCNSIs.

BackgroundEndoscopic Endonasal Surgery (EES) is an innovative surgical technique to remove brain tumors and lesions. Post-operative central nervous system (CNS) infections following EES are poorly described. The objective of this study was to define the epidemiology and characteristics of post-EES CNS infections.MethodsAdult patients who underwent EES between 1/2010 and 7/2021 were evaluated and included if microbiologically confirmed CNS infection occurred within 30 days of EES. Suspected contaminants, ventricular drain colonization, and pre-EES CNS infections were excluded.ResultsOverall, 2005 patients underwent EES; 1.8% (37/2005) developed CNS infection. The median [IQR] age was 51 [42-60] years, 32.4% (12/37) were female, and 54% (20/37) had a prior EES. The most common indications for EES were tumor resection [67.6% (25/37)] and cerebrospinal fluid (CSF) leak repair [24.3% (9/37)]. Post-operative CSF leaks were documented in 70.3% (26/37) of patients and 24.3% (9/37) had an extra-ventricular drain or shunt in place for >48 hours at the time of infection. Ceftriaxone prophylaxis was prescribed in 64.9% (24/37) of cases and other regimens varied. The median [IQR] time from EES to diagnosis of CNS infection was 12 [6-19] days. The most common pathogens were S. aureus, Enterobacterales, and P. aeruginosa(Fig 1). Among 20 patients with prior EES, pathogens included S. aureus (5/20), Enterobacterales (3/20), Enterococcus spp. (3/20) and polymicrobic infections (3/20). Overall, 35.1% (13/37) of patients developed CNS infection due to a pathogen susceptible to pre-EES prophylaxis. Among those colonized with MRSA at time of EES, 75% (3/4) developed MRSA CNS infection compared to 6.1% (2/33) of non-colonized MRSA patients (P=0.005). The overall 30-day mortality rate was 2.7% (1/37).Figure:MicrobiologyA polymicrobic case was defined as >1 pathogen isolated from CSF (n=1) or from rhinocerebral tissue if CSF cultures were negative (n=11). Among polymicrobic cases (n=12), P. aeruginosa (n=5), Enterococcus spp. (n=4). and S. aureus (n=3) were predominant. Cases labeled as other consisted of Trichoderma spp, A. xylosoxidans, P. acnes, S. epidermidis, Peptostreptococcus spp.ConclusionCNS infection post-EES is rare and causative pathogens vary. Given the predominance of S. aureus, antimicrobial prophylaxis should ensure adequate coverage of this pathogen in addition to sinus flora, and programs may benefit from screening patients for MRSA colonization pre-EES. Our data also suggest that prophylaxis should target Gram-negative and other colonizing bacteria among patients with prior EES.DisclosuresRyan K. Shields, PharmD, MS, Infectious Disease Connect: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Roche: Grant/Research Support.

To explore the association and predictive value of cerebrospinal fluid (CSF) heparin-binding protein (HBP) and cluster of differentiation 64 (CD64) levels with postoperative central nervous system (CNS) infection following hypertensive intracerebral hemorrhage surgery. A retrospective analysis was conducted on 64 patients who developed postoperative CNS infections (infection group) and 70 patients without infections (non-infection group) after surgical treatment for hypertensive intracerebral hemorrhage at Shangyu People's Hospital of Shaoxing between February 2021 and February 2024. CSF HBP and CD64 levels were measured within 24-48 hours postoperatively. Univariate and multivariate logistic regression analyses were performed to identify risk factors for CNS infection. Receiver operating characteristic curve analysis was used to assess the predictive performance of the biomarkers. Patients in the infection group were significantly older than those in the non-infection group. CSF HBP and CD64 levels were significantly elevated in the infection group (all P<0.05). Additionally, peripheral blood levels of procalcitonin, lactate dehydrogenase, and C-reactive protein were higher, whereas albumin levels were lower in the infection group (all P<0.05). Multivariate analysis identified elevated CSF HBP and CD64 as independent risk factors for CNS infection. The area under the curve values for predicting CNS infections were 0.745 for CSF HBP alone, 0.709 for CSF CD64 alone, and 0.846 when both markers were combined. Elevated CSF HBP and CD64 levels are closely associated with postoperative CNS infection following hypertensive intracerebral hemorrhage surgery. While each marker alone offers moderate predictive value, their combined use significantly enhances diagnostic accuracy.

Postoperative Central Nervous System Infection After Neurosurgery in a Modernized, Resource-Limited Tertiary Neurosurgical Center in South Asia

A post-operative central nervous system infection (PCNSI) is a dangerous complication after cranial surgery. Although a large number of neurosurgical procedures are performed in hospitals in China, PCNSI-related data from this country are rarely reported. To address this issue, we examined the incidence of PCNSI after cranial surgery, the potential risk factors, and the offending etiologic agents in a large Chinese population. The medical records and post-operative courses for patients >16 years of age who underwent elective or emergency cranial surgeries between May 2010 and May 2012 and who survived for >7 days were reviewed retrospectively. Pre-operative data, surgery-related records, and post-operative variables were evaluated as risk factors for PCNSI after cranial surgery. Among 1,470 surgeries, 1,340 were craniotomies and 130 involved the cerebrospinal fluid (CSF). There were 109 patients with PCNSIs, resulting in a total infection rate of 7.4 %. The dominant Gram-positive organism isolated (Staphylococcus aureus) was the most common pathogen isolated. Based on multivariate analysis, the risk of PCNSI was increased by a CSF leak [odds ratio (OR), 3.545; 95 % confidence interval (CI), 2.053-6.122; p < 0.001], CSF drainage of any kind (OR, 2.858; 95 % CI, 1.577-5.181; p = 0.001), subsequent short-term surgery (OR, 2.224; 95 % CI, 1.229-4.024; p = 0.008), and surgery duration (OR, 1.331; 95 % CI, 1.230-1.440; p < 0.001). PCNSI remains a critical problem for neurosurgeons in China. CSF leakage, CSF drainage of any kind, subsequent short-term surgery, and surgery duration were major risk factors, indicating that surgery-focused management might be the most effective way to minimize the risk for PCNSI after cranial surgery.

Identification of the location and size of delamination is important for structural health monitoring of composite laminated structures, since delamination degrades compression stiffness of the structures. In the present study, a two-step delamination identification method using resonant and anti-resonant frequency changes is proposed. It is well known that resonant frequencies are changed depending on the location and size of delamination. As for anti-resonant frequencies, they also change mainly depending on the location of delamination. Since the resonant and anti-resonant frequencies are specified easily in the frequency response function, the present method is low cost and applicable to any structures. The present method is applied to delamination identification of carbon/epoxy cantilever beams, and effectiveness of the present method is discussed. Introduction Recently, composite laminated structures have been applied to many structures of vehicles because of its high specific stiffness and strength. Since interlaminar strength of composite laminated structure is relatively low, internal damage, such as delamination, can be easily induced in service. Since delamination degrades compression strength of the structure, it is necessary to identify the size and location of delamination nondestructively for the assessment of structural integrity. However, conventional nondestructive inspection methods, such as X-ray or ultrasonic inspection, are high cost, and application to large structures is difficult owing to size restriction of the apparatuses. The present study proposes a two-step delamination identification method using resonant and anti-resonant frequency changes. In order to examine effectiveness of the present method, delamination identification of a carbon/epoxy cantilever beam is conducted. As a preparation for delamination identification, the beam is divided into two domains based on the mode shapes. The delaminated domain in which delamination is supposed to exist is first identified from the anti-resonant frequency changes, and the delamination location and size are identified from the resonant frequency changes to the next. In order to analyze frequency response changes caused by delamination, finite element method was applied. Effectiveness of the present identification method was investigated both in analysis and experiment. Symmetry of Resonant Frequency Changes Fig.1 shows schematic of a carbon/epoxy cantilever beam with delamination. The beam is 1.45mm thick, 19mm wide and 200 mm long. The laminate configuration of the beam is [02/902]S, and a through width delamination is existed at one 0/90 interlayer. In order to examine effect of delamination location and size on the resonant frequencies of the beam, modal analyses of the beam were conducted by using ANSYS, a commercially available general-purpose finite element code. Table 1 shows material properties of uni-directional carbon/epoxy lamina used for calculation, where Key Engineering Materials Vols. 270-273 (2004) pp. 1852-1858 online at http://www.scientific.net © 2004 Trans Tech Publications, Switzerland Title of Publication (to be inserted by the publisher) subscript 1 means the direction parallel to the fiber and subscripts 2 and 3 means the direction perpendicular to the fiber. In the present paper, normalized values l/L and a/L are employed to express the delamination location and size respectively, where L is beam length. Fig.2 shows resonant frequency changes of the beam as a function of delamination location obtained by FEM analysis, where delamination size is constant value 0.1. In fig.2, abscissa means delamination location and ordinate means frequency value normalized by the intact value of each mode. In general, reduction of resonant frequency is caused by stiffness reduction of structures. For a composite laminated beam with delamination, reduction of the bending stiffness is caused when shear force acts on the delamination, and shear force distribution of each mode depend on each modal shape. For this reason, the resonant frequency changes of the cantilever beam shows quasi-symmetry in the region defined by 0.3≤l/L≤0.7 except for the first mode, though the cantilever beam is not a symmetric structure. This causes failure in identification of delamination location based on resonant frequency changes [1]. In order to make it possible to identify delamination location in the cantilever beam, another parameters that have information about delamination location and no symmetry. In the present study, anti-resonant frequency is adopted. (L=200mm, b=19mm, h=1.45mm) L h Delamination

ObjectiveThe purpose of this study was to verify that hypothalamus-pituitary dysfunction is one of the risk factors for postoperative central nervous system infections (PCNSIs).MethodWe performed a retrospective analysis of all patients with sellar region lesions who underwent surgery between January 2016 and November 2019 at Peking Union Medical College Hospital. In total, 44 age− and sex-matched controls were enrolled. Univariate and multivariate analyses were performed to identify risk factors for PCNSIs.ResultWe enrolled 88 patients, 44 of whom had PCNSIs. Surgical approach (TCS) (P<0.001), previous surgery on the same site (P=0.001), intraoperative cerebral spinal fluid (CSF) leakage (P<0.001), postoperative adrenal insufficiency (P=0.017), postoperative DI (P=0.004) and the maximum Na+ levels(<0.001) correlated significantly with PCNSIs. Multivariate analysis showed that Surgery approach (TCS)(OR: 77.588; 95%CI: 7.981-754.263; P<0.001), intraoperative CSF leakage (OR: 12.906; 95%CI: 3.499-47.602; P<0.001), postoperative DI (OR: 6.999; 95%CI:1.371-35.723; P=0.019) and postoperative adrenal insufficiency (OR: 6.115; 95%CI: 1.025-36.469; P=0.047) were independent influencing factors for PCNSIs.ConclusionTCS, intraoperative CSF leakage, postoperative DI and postoperative adrenal insufficiency are risk factors for PCNSIs in patients with sellar region tumors.

Background: Post-operative central nervous system infection (PCNSI) caused by multi-drug-resistant/extensively drug-resistant (MDR/XDR) Acinetobacter baumannii is a severe complication. This study aimed to analyze the clinical presentation and treatment of this disorder. Patients and Methods: A retrospective study that recruited patients having PCNSI caused by MDR/XDR Acinetobacter baumannii was performed at our institute. The patients' demographic information and clinical data were recorded and analyzed. To analyze treatment, we assigned patients to different groups according to whether they had intraventricular/intrathecal injection of antibiotic agents or cerebrospinal fluid (CSF) drainage therapy. Results: Twenty-four patients were included. The risk factors were classified into two categories: environmental factors (intensive care unit stay, tracheal intubation or tracheotomy, positive culture of MDR/XDR Acinetobacter baumannii from other samples) or infectious approaches (CSF drainage, incision CSF leakage). Cerebrospinal fluid sterilization was achieved in 13 patients (54.2%) and the 30-day mortality was 50%. In the seven patients having intraventricular/intrathecal injection of antibiotic agents, the CSF sterilization rate was 71.4% (5/7) and 30-day mortality was 28.6% (2/7), compared with 47.1% (8/17; p = 0.27) and 58.8% (10/17; p = 0.18) in patients having only intravenous antibiotic agents. In 19 patients having CSF drainage therapy for PCNSI, the CSF sterilization rate was 63.2% (12/19) and 30-day mortality was 42.1% (8/19) compared with 20% (1/5; p = 0.08) and 80% (4/5; p = 0.13) in the remaining patients. Conclusions: The risk factors for PCNSI caused by Acinetobacter baumannii can be classified in two categories: environmental factors or infectious approaches. Both intraventricular/intrathecal injection of antibiotic agents and CSF drainage are helpful for CSF sterilization.

Introduction:The purpose of this study was to investigate the prevalence of Postoperative central nervous system infections (PCNSIs) and antibiotic resistance profiles of causative organisms in trauma patients following neuroinvasive procedures.Materials and Methods:This was a retrospective study conducted over a period of 4 years (2013–2017). All in-patients admitted under a neurotrauma unit meeting the inclusion criteria of PCNSIs were included in the study. Surgical site infections (SSIs) were defined according to the Centers for Disease Control and Prevention 2018 (CDC) criteria. We retrospectively examined the demographic characteristics, type of neurosurgery performed, laboratory data, causative organisms, and antimicrobial susceptibility testing results of patients who had positive cerebrospinal fluid cultures following craniotomy between January 2013 and December 2017.Results:Of total 2500 patients operated during the study, 961 patients were screened for PCNSIs. The estimated prevalence (95% confidence interval) of PCNSIs which is a type of organ/space SSI was 7.2% (6.3–8.3). Males were predominantly affected (85.0%). The mean age (standard deviation) of patients was 31.9 (16.5) years. Of all the cultures sent for microbiological examination, 18.6% were positive. The proportion of Gram-negative bacteria causing PCNSIs was 91.6%. Multidrug-resistant (MDR) Acinetobacter baumannii (41%) was the most common organism isolated. Among Gram-positive bacteria, the most common organism was Staphylococcus aureus (5.5%). All the Gram-positive isolates were susceptible to vancomycin, teicoplanin, and linezolid.Conclusion:There is a high burden of PCNSI caused by MDR Acinetobacter baumannii can pose a major clinical challenge with only few antimicrobials left in the pipeline.

Diagnosing and treating postoperative central nervous system infections (PCNSIs) remains challenging due to the low detection rate and time-consuming nature of traditional methods for identifying microorganisms in cerebrospinal fluid. Metagenomic next-generation sequencing (mNGS) technology provides a rapid and comprehensive understanding of microbial composition in PCNSIs by swiftly sequencing and analyzing the microbial genome. The current study aimed to assess the economic impact of using mNGS versus traditional bacterial culture-directed PCNSIs diagnosis and therapy in post-neurosurgical patients from Beijing Tiantan Hospital. mNGS is a relatively expensive test item, and whether it has the corresponding health-economic significance in the clinical application of diagnosing intracranial infection has not been studied clearly. Therefore, the investigators hope to explore the clinical application value of mNGS detection in PCNSIs after neurosurgery.

Postoperative central nervous system infection (PCNSI) is a serious complication following neurosurgery. Effective clinical management of PCNSI requires prompt antibiotic administration based on the identification of the causative pathogens and antibiotic resistance. This study aimed to investigate the causative pathogens of PCNSI and their antibiotic resistance profiles, which could help clinicians initiate appropriate empirical antibiotic therapy. The distribution and antimicrobial resistance of pathogens in patients with PCNSI from January 2014 to December 2023 were analyzed retrospectively. Cerebrospinal fluid samples were aseptically collected and subjected to standard microbiological methods for bacterial isolation and identification. Antibiotic sensitivity testing was performed via the Kirby-Bauer disk diffusion agar method. A total of 396 patients were diagnosed with PCNSI, and 385 pathogens were identified from these patients. The percentages of Gram-positive bacteria, Gram-negative bacteria, and fungi were 56.10, 41.30, and 2.60%, respectively. The predominant pathogens among the Gram-positive bacteria were coagulase-negative staphylococci (29.09%), whereas Acinetobacter baumannii (14.29%) was the most common Gram-negative bacterium. Compared with those from 2014 to 2018, the proportions of Enterococcus and Acinetobacter baumannii increased markedly from 2019 to 2023. Antimicrobial susceptibility testing revealed that all Gram-positive bacteria had 100% sensitivity to vancomycin and linezolid, whereas imipenem, meropenem, and amikacin were most effective against Gram-negative bacteria. Gram-positive bacteria, especially coagulase-negative staphylococci, were the predominant pathogens causing PCNSI. Furthermore, several Gram-negative species, especially Klebsiella pneumoniae and Acinetobacter baumannii, showed concerning trends of increasing resistance to common antibiotics. Acinetobacter baumannii showed an increasing proportion of infections, posing a clinical challenge due to the limited number of effective antibiotics.

Postoperative central nervous system infections (PCNSIs), including meningitis, cerebral abscesses, and implant-associated infections, represent critical complications following neurosurgical procedures. These infections pose significant risks to patient outcomes due to delayed diagnosis, escalating antimicrobial resistance, and limited therapeutic efficacy. Conventional diagnostic approaches, such as cerebrospinal fluid (CSF) analysis, microbial cultures, and neuroimaging, exhibit notable limitations in sensitivity, specificity, and rapidity. This review highlights transformative technologies reshaping PCNSI diagnostics, including molecular assays (e.g., quantitative PCR, digital droplet PCR), metagenomic next-generation sequencing (mNGS), CRISPR-based pathogen detection platforms, metabolomics, and advanced molecular imaging modalities. Furthermore, we address translational challenges in clinical adoption, including cost barriers, standardization gaps, and the need for interdisciplinary collaboration. Emerging artificial intelligence (AI)-driven strategies are proposed to optimize pathogen identification, predict antimicrobial resistance profiles, and tailor personalized therapeutic regimens.

Pathogen Diagnostic Value of Nanopore Sequencing in Postoperative Central Nervous System Infections.

Impact of Operating Room Environment on Postoperative Central Nervous System Infection in a Resource-Limited Neurosurgical Center in South Asia.