Central Nervous System Device Infections

Infectious Diseases of the Brain and Spine: Fungal Diseases

Advances in treatments of autoimmune diseases, acquired immunodeficiency syndrome, organ transplantation, and the use of long-term devices have increased the rates of atypical infections due to prolonged immune suppression. There is a significant overlap in imaging findings of various fungal infections affecting the central nervous system (CNS), often mimicking those seen in neoplastic and noninfectious inflammatory conditions. Nonetheless, there are imaging characteristics that can aid in distinguishing certain atypical infections. Hence, familiarity with a wide range of infectious agents is an important part of diagnostic neuroradiology. In this article, an in-depth review of fungal diseases of the CNS is provided.

Characteristics and outcomes of cerebrospinal fluid shunt and drain-associated infections

INTRODUCTION

Data on infections associated with cerebrospinal fluid shunt (CSF-S) or device-associated infection (CSF-SDI) are limited in adults. We performed a retrospective study to describe characteristics, management, and outcome of CSF-SDI.

METHODS

All patients with CSF-SDI and admitted to our institution from January 2013 to December 2019 were included.

RESULTS

Among 50 patients, fifty-six episodes of CSF-SDI (41 external ventricular device-associated infections (CSF-D) and 15 other shunt infections (CSF-S) were included. The incidence of CSF-SDI was 11.9 %. Fever was the most common symptom (81 %). Enterobacterales were more prevalent in CSF-S than in CSF-D (20 % vs 53 %, p = 0.02). As regards CSF-D, deceased patients (11/41, 27 %) more frequently had a Glasgow coma scale score decreasing from baseline (p < 0.01), lower glycorrhachia (p < 0.01), a higher protein level in CSF (p = 0.001) and a positive control CSF culture (p = 0.031).

CONCLUSIONS

CSF-SDIs are rare but with a high mortality rate. Mortality was more closely related to the infection than to comorbidities or underlying neurosurgical disease. A second CSF analysis significantly helped to detect patients with CSF-D with a poor prognosis.

Current Perspectives on the Diagnosis and Management of Healthcare-Associated Ventriculitis and Meningitis

Ventriculitis or post-neurosurgical meningitis or healthcare-associated ventriculitis and meningitis (VM) is a severe infection that complicates central nervous system operations or is related to the use of neurosurgical devices or drainage catheters. It can further deteriorate patients who have already presented significant neurologic injury and is associated with high morbidity, mortality, and poor functional outcome. VM can be difficult to distinguish from aseptic meningitis, inflammation that follows hemorrhagic strokes and neurosurgical operations. The associated microorganisms can be either skin flora or nosocomial pathogens, most commonly, Gram-negative bacteria. Classical microbiology can fail to isolate the culprit pathogen. Novel cerebrospinal fluid (CSF) biomarkers and molecular microbiology can fill the diagnostic gap and expedite pathogen identification and treatment. The pathogens may demonstrate significant resistant patterns and their antibiotic treatment can be difficult, as many important drug classes, including the beta-lactams and the glycopeptides, hardly penetrate to the CSF, and do not achieve therapeutic levels at the site of the infection. Treatment modifications, such as higher daily dose and prolonged or continuous administration, might increase antibiotic levels in the site of infection and facilitate pathogens clearance. However, in the case of therapeutic failure or infection due to difficult-to-treat bacteria, the direct antibiotic instillation into the CSF, in addition to the intravenous antibiotic delivery, may help in the resolution of infection. However, intraventricular antibiotic therapy may result in aseptic meningitis and seizures, concerning the administration of aminoglycosides, polymyxins, and vancomycin. Meanwhile, bacteria form biofilms on the catheter or the device that should routinely be removed. Novel neurosurgical treatment modalities comprise endoscopic evacuation of debris and irrigation of the ventricles. VM prevention includes perioperative antibiotics, antimicrobial impregnated catheters, and the implementation of standardized protocols, regarding catheter insertion and manipulation.

Central nervous system infections associated with neurologic devices

PURPOSE OF REVIEW

To review recent data on the epidemiology, microbiology, diagnosis, and management of central nervous system (CNS) infections associated with neurologic devices.

RECENT FINDINGS

The increasing use of implanted neurologic devices has led to an increase in associated infections. Cerebrospinal fluid (CSF) inflammation may be present after a neurosurgical procedure, complicating the diagnosis of CNS infection. Newer biomarkers such as CSF lactate and procalcitonin show promise in differentiating infection from other causes of CSF inflammation. Molecular diagnostic tests including next-generation or metagenomic sequencing may be superior to culture in identifying pathogens causing healthcare-associated ventriculitis and meningitis.

SUMMARY

Neurologic device infections are serious, often life-threatening complications. Rapid recognition and initiation of antibiotics are critical in decreasing morbidity. Device removal is usually required for cure.

Healthcare-associated ventriculitis: current and emerging diagnostic and treatment strategies

Introduction: Healthcare-associated ventriculitis and meningitis occur after neurosurgical procedures, is associated with an adverse outcome in the majority of patients and represent a diagnostic challenge to clinicians. As the cerebrospinal fluid (CSF) culture is the cornerstone of diagnosis, obtaining CSF studies prior to starting antibiotic therapy is key.Areas covered: This review will evaluate the incidence, risk factors, clinical presentation, diagnosis, empirical intravenous antibiotic therapy, adjunctive intrathecal therapy, microbiology, prognosis, and prevention of HCAVM. We highlight the challenges and limitations of the currently available diagnostic methods and definitions and explore novel technologies. Our review included the search for published literature until June 2020.Expert opinion: Despite available preventive measures, HCAVM continues to occur and to be independently associated with significant neurological morbidity and mortality in the majority of patients. The cornerstone of the diagnosis of HCAVM is a positive CSF culture but the microbiological yield is reduced to ~50% with prior antimicrobial therapy. Although the CSF profile is not affected by antibiotic therapy it has a fair diagnostic accuracy. Future research efforts should concentrate in identifying novel diagnostic tools such as polymerase chain reaction (PCR) or metagenomic sequencing.

Impact of Antibiotic Therapy in the Microbiological Yield of Healthcare-Associated Ventriculitis and Meningitis

The impact of antibiotic therapy on the diagnosis of healthcare-associated ventriculitis and meningitis (HCAVM) is unknown. Antibiotics were administered before obtaining cerebrospinal fluid (CSF) in 217 out of 326 (66%) patients with HCAVM, and they impacted the sensitivity of the cerebrospinal fluid Gram stain and culture (P ≤ .004).