Medical and surgical management of spinal epidural abscess: a systematic review

OBJECT

Spinal epidural abscess (SEA) is a rare condition that has previously been treated with urgent surgical decompression and antibiotics. Recent availability of MRI makes early diagnosis possible and allows for the nonoperative treatment of SEA in select patients. The first retrospective review of medically and surgically managed SEA was published in 1999, and since that time several other retrospective institutional reports have been published. This study reviews these published reports and compares pooled data with historical treatment data.

METHODS

A PubMed keyword and Boolean search using ("spinal epidural abscess" OR "spinal epidural abscesses" AND [management OR treatment]) returned 429 results. Filters for the English language and publications after 1999 were applied, as the first study comparing operative and nonoperative management was published that year. Articles comparing operative to nonoperative treatment strategies for SEA were identified, and the references were further reviewed for additional articles. Studies involving at least 10 adult patients (older than 18 years) were included. Case reports, studies reporting either medical or surgical management only, studies not reporting indications for conservative management, or studies examining SEA as a result of a specific pathogen were excluded.

RESULTS

Twelve articles directly comparing surgical to nonsurgical management of SEA were obtained. These articles reported on a total of 1099 patients. The average age of treated patients was 57.24 years, and 62.5% of treated patients were male. The most common pathogens found in blood and wound cultures were Staphylococcus aureus (63.6%) and Streptococcus species (6.8%). The initial treatment was surgery in 59.7% of cases and medical therapy in 40.3%. This represented a significant increase in the proportion of medically managed patients in comparison with the historical control prior to 1999 (p < 0.05). Patients with no neurological deficits were significantly more likely to be treated medically than surgically (p < 0.05). There was no statistically significant difference overall between surgical and nonsurgical management, although several risk factors may predict failure of medical management.

CONCLUSIONS

Since the first reports of nonoperative treatment of SEA, there has been a substantial trend toward treating neurologically intact patients with medical management. Nevertheless, medical therapy fails in a fair number of cases involving patients with specific risk factors, and patients with these risk factors should be closely observed in consideration for surgery. Further research may help identify patients at greater risk for failure of medical therapy.

The primary prevention of epilepsy: A report of the Prevention Task Force of the International League Against Epilepsy

Among the causes of epilepsy are several that are currently preventable. In this review, we summarize the public health burden of epilepsy arising from such causes and suggest priorities for primary epilepsy prevention. We conducted a systematic review of published epidemiologic studies of epilepsy of 4 preventable etiologic categories-perinatal insults, traumatic brain injury (TBI), central nervous system (CNS) infection, and stroke. Applying consistent criteria, we assessed the quality of each study and extracted data on measures of risk from those with adequate quality ratings, summarizing findings across studies as medians and interquartile ranges. Among higher-quality population-based studies, the median prevalence of active epilepsy across all ages was 11.1 per 1000 population in lower- and middle-income countries (LMIC) and 7.0 per 1000 in high-income countries (HIC). Perinatal brain insults were the largest attributable fraction of preventable etiologies in children, with median estimated fractions of 17% in LMIC and 15% in HIC. Stroke was the most common preventable etiology among older adults with epilepsy, both in LMIC and in HIC, accounting for half or more of all new onset cases. TBI was the attributed cause in nearly 5% of epilepsy cases in HIC and LMIC. CNS infections were a more common attributed cause in LMIC, accounting for about 5% of all epilepsy cases. Among some rural LMIC communities, the median proportion of epilepsy cases attributable to endemic neurocysticercosis was 34%. A large proportion of the overall public health burden of epilepsy is attributable to preventable causes. The attributable fraction for perinatal causes, infections, TBI, and stroke in sum reaches nearly 25% in both LMIC and HIC. Public health interventions addressing maternal and child health care, immunizations, public sanitation, brain injury prevention, and stroke prevention have the potential to significantly reduce the burden of epilepsy.

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

West Nile Virus Infection in the Central Nervous System

West Nile virus (WNV), a neurotropic single-stranded flavivirus has been the leading cause of arboviral encephalitis worldwide.  Up to 50% of WNV convalescent patients in the United States were reported to have long-term neurological sequelae.  Neither antiviral drugs nor vaccines are available for humans.  Animal models have been used to investigate WNV pathogenesis and host immune response in humans.  In this review, we will discuss recent findings from studies in animal models of WNV infection, and provide new insights on WNV pathogenesis and WNV-induced host immunity in the central nervous system.

Limited Correlation of Shotgun Metagenomics Following Host Depletion and Routine Diagnostics for Viruses and Bacteria in Low Concentrated Surrogate and Clinical Samples

The etiologic cause of encephalitis, meningitis or meningo-encephalitis is unknown in up to 70% of cases. Clinical shotgun metagenomics combined with host depletion is a promising technique to identify infectious etiologies of central nervous system (CNS) infections. We developed a straightforward eukaryotic host nucleic acid depletion method that preserves intact viruses and bacteria for subsequent shotgun metagenomics screening of clinical samples, focusing on cerebrospinal fluid (CSF). A surrogate CSF sample for a CNS infection paradigm was used to evaluate the proposed depletion method consisting of selective host cell lysis, followed by enzymatic degradation of the liberated genomic DNA for final depletion with paramagnetic beads. Extractives were subjected to reverse transcription, followed by whole genome amplification and next generation sequencing. The effectiveness of the host depletion method was demonstrated in surrogate CSF samples spiked with three 1:100 dilutions of Influenza A H3N2 virus (qPCR Ct-values 20.7, 28.8, >42/negative). Compared to the native samples, host depletion increased the amount of the virus subtype reads by factor 7127 and 132, respectively, while in the qPCR negative sample zero vs. 31 (1.4E-4 %) virus subtype reads were detected (native vs. depleted). The workflow was applied to thirteen CSF samples of patients with meningo-/encephalitis (two bacterial, eleven viral etiologies), a serum of an Andes virus infection and a nose swab of a common cold patient. Unlike surrogate samples, host depletion of the thirteen human CSF samples and the nose swab did not result in more reads indicating presence of damaged pathogens due to, e.g., host immune response. Nevertheless, previously diagnosed pathogens in the human CSF samples (six viruses, two bacteria), the serum, and the nose swab (Human rhinovirus A31) were detected in the depleted and/or the native samples. Unbiased evaluation of the taxonomic profiles supported the diagnosed pathogen in two native CSF samples and the native and depleted serum and nose swab, while detecting various contaminations that interfered with pathogen identification at low concentration levels. In summary, damaged pathogens and contaminations complicated analysis and interpretation of clinical shotgun metagenomics data. Still, proper consideration of these issues may enable future application of metagenomics for clinical diagnostics.

Management of suspected herpes simplex virus encephalitis in adults in a U.K. teaching hospital

The outcome of herpes simplex virus (HSV) encephalitis is improved with prompt initiation of aciclovir treatment. Delays are common, but there is little understanding of why they occur. The case notes of 21 adults admitted with suspected HSV encephalitis over one year were reviewed. The median (range) duration of illness was 2.5 (1-99) days. Seventeen (81%) patients had a lumbar puncture (LP) performed, at a median (range) time of 24 (2-114) hours after encephalitis was suspected. Lumbar puncture was delayed for a computed tomography (CT) scan in 15 patients, but only one of these had contraindications to an immediate LP. The median (range) time from presentation to starting aciclovir was 48 (2-432) hours. HSV-PCR (polymerase chain reaction) was requested on cerebrospinal fluid from 12 patients, one of whom was positive. Five (24%) patients were given the wrong dose of aciclovir. Overall the management of suspected HSV encephalitis was often sub-optimal, with delays in LP occurring due to unnecessary CT scans, and the wrong aciclovir dose administered. Guidelines for the management of suspected encephalitis are needed.

Myeloid-related protein 14 promotes inflammation and injury in meningitis

BACKGROUND

Neutrophilic inflammation often persists for days despite effective antibiotic treatment and contributes to brain damage in bacterial meningitis. We propose here that myeloid-related protein 14 (MRP14), an abundant cytosolic protein in myeloid cells, acts as an endogenous danger signal, driving inflammation and aggravating tissue injury.

METHODS

The release pattern of MRP14 was analyzed in human and murine cerebrospinal fluid (CSF), as well as in isolated neutrophils. Its functional role was assessed in a mouse meningitis model, using MRP14-deficient mice.

RESULTS

We detected large quantities of MRP14 in CSF specimens from patients and mice with pneumococcal meningitis. Immunohistochemical analyses and a cell-depletion approach indicated neutrophils as the major source of MRP14. In a meningitis model, MRP14-deficient mice showed a better resolution of inflammation during antibiotic therapy, which was accompanied by reduced disease severity. Intrathecal administration of MRP14 before infection reverted the phenotype of MRP14-deficient mice back to wild type. Moreover, intrathecal injection of MRP14 alone was sufficient to induce meningitis in a Toll-like receptor 4 (TLR4)-CXCL2-dependent manner. Finally, treatment with the MRP14 antagonist paquinimod reduced inflammation and disease severity significantly, reaching levels comparable to those achieved after genetic depletion of MRP14.

CONCLUSIONS

The present study implicates MRP14 as an essential propagator of inflammation and potential therapeutic target in pneumococcal meningitis.

Transcranial Doppler Ultrasonography Provides Insights into Neurovascular Changes in Children with Cerebral Malaria

OBJECTIVE

To evaluate neurovascular changes in pediatric patients with cerebral malaria.

STUDY DESIGN

African children with cerebral malaria were enrolled and underwent daily transcranial Doppler ultrasound (TCD) examinations through hospital day 8, discharge, or death. Neurologic outcomes were assessed 2 weeks after enrollment.

RESULTS

In total, 160 children with cerebral malaria and 155 comparison patients were included. In patients with cerebral malaria, TCD flow changes characterized as hyperemia were seen in 42 (26%), low flow in 46 (28%), microvascular obstruction in 35 (22%), cerebral vasospasm in 21 (13%), and isolated posterior hyperemia in 7 (4%). Most had a single neurovascular phenotype observed throughout participation. Among comparison patients, 76% had normal TCD findings (P < .001). Impaired autoregulation was present in 80% of cases (transient hyperemic response ratio 1.01 ± 0.03) but improved through day 4 (1.1 ± 0.02, P = .014). Overall mortality was 24% (n = 39). Neurologic deficits were evident in 21% of survivors. Children meeting criteria for vasospasm were most likely to survive with sequelae, and children meeting criteria for low flow were most likely to die. Autoregulation was better in children with a normal neurologic outcome (1.09, 95% CI 1.06-1.12) than in others (0.98, 95% CI 0.95-1) (P ≤ .001).

CONCLUSIONS

Several distinct changes in TCD measurements were identified in children with cerebral malaria that permitted phenotypic grouping. Groups had distinct associations with neurologic outcomes. Validation of pathogenic mechanisms associated with each phenotype may aid in developing TCD as a portable, easy-to-use tool to help guide targeted adjunctive therapy in cerebral malaria aimed at causative mechanisms of injury on an individual level.

Nocardia Infections in Hematopoietic Cell Transplant Recipients: A Multicenter International Retrospective Study of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation

BACKGROUND

Nocardiosis is rare after hematopoietic cell transplantation (HCT). Little is known regarding its presentation, management, and outcome in this population.

METHODS

This retrospective international study reviewed nocardiosis episodes in HCT recipients (1/1/2000-31/12/2018; 135 transplant centers; 33 countries) and described their clinical, microbiological, radiological, and outcome characteristics.

RESULTS

We identified 81 nocardiosis episodes in 74 allo- and 7 auto-HCT recipients. Nocardiosis occurred a median of 8 (IQR: 4-18) months post-HCT. The most frequently involved organs were lungs (70/81; 86%) and brain (30/81; 37%); 29 (36%) patients were afebrile; 46/81 (57%) had disseminated infections. The most common lung imaging findings were consolidations (33/68; 49%) or nodules (32/68; 47%); brain imaging findings were multiple brain abscesses (19/30; 63%). Ten of 30 (33%) patients with brain involvement lacked neurological symptoms. Fourteen of 48 (29%) patients were bacteremic. Nocardia farcinica was the most common among molecularly identified species (27%; 12/44). Highest susceptibility rates were reported to linezolid (45/45; 100%), amikacin (56/57; 98%), trimethoprim-sulfamethoxazole (57/63; 90%), and imipenem (49/57; 86%). One-year and last follow-up (IQR: 4-42.5 months) all-cause mortality were 40% (32/81) and 52% (42/81), respectively. In the multivariable analysis, underlying disease not in complete remission (HR: 2.81; 95% CI: 1.32-5.95) and prior bacterial infection (HR: 3.42; 95% CI: 1.62-7.22) were associated with higher 1-year all-cause mortality.

CONCLUSIONS

Nocardiosis is a late post-HCT infection usually manifesting as a pulmonary disease with frequent dissemination, brain infection, and bacteremia. Brain imaging should be performed in HCT recipients with nocardiosis regardless of neurological symptoms. Overall mortality is high.

Suboptimal management of central nervous system infections in children: a multi-centre retrospective study

OBJECTIVE

We aimed to audit the regional management of central nervous system (CNS) infection in children.

METHODS

The study was undertaken in five district general hospitals and one tertiary paediatric hospital in the Mersey region of the UK. Children admitted to hospital with a suspected CNS infection over a three month period were identified. Children were aged between 4 weeks and 16 years old. Details were recorded from the case notes and electronic records. We measured the appropriateness of management pathways as outlined by national and local guidelines.

RESULTS

Sixty-five children were identified with a median age of 6 months (range 1 month to 15 years). Ten had a CNS infection: 4 aseptic meningitis, 3 purulent meningitis, 3 encephalitis [2 with herpes simplex virus (HSV) type 1]. A lumbar puncture (LP) was attempted in 50 (77%) cases but only 43 had cerebrospinal fluid (CSF) available for analysis. Of these 24 (57%) had a complete standard set of tests performed. Fifty eight (89%) received a third generation cephalosporin. Seventeen (26%) also received aciclovir with no obvious indication in 9 (53%). Only 11 (65%) of those receiving aciclovir had CSF herpes virus PCR. Seventeen had cranial imaging and it was the first management step in 14. Treatment lengths of both antibiotics and aciclovir were highly variable: one child with HSV encephalitis was only treated with aciclovir for 7 days.

CONCLUSIONS

The clinical management of children with suspected CNS infections across the Mersey region is heterogeneous and often sub-optimal, particularly for the investigation and treatment of viral encephalitis. National guidelines for the management of viral encephalitis are needed.

Molecular Features of the Measles Virus Viral Fusion Complex That Favor Infection and Spread in the Brain

Measles virus (MeV) bearing a single amino acid change in the fusion protein (F)—L454W—was isolated from two patients who died of MeV central nervous system (CNS) infection. This mutation in F confers an advantage over wild-type virus in the CNS, contributing to disease in these patients. Using murine ex vivo organotypic brain cultures and human induced pluripotent stem cell-derived brain organoids, we show that CNS adaptive mutations in F enhance the spread of virus ex vivo. The spread of virus in human brain organoids is blocked by an inhibitory peptide that targets F, confirming that dissemination in the brain tissue is attributable to F. A single mutation in MeV F thus alters the fusion complex to render MeV more neuropathogenic.

Neonatal cranial sonography: ultrasound findings in neonatal meningitis-a pictorial review

Neonatal bacterial meningitis is a common manifestation of late onset neonatal sepsis. Cranial sonography (CRS) has a crucial role in assessment of infants with clinical suspicion of bacterial meningitis as well as follows up of its complications. CRS is performed with high frequency transducer through anterior fontanelle in both coronal and sagittal planes. Various sonographic findings range from echogenic and widened sulci, ventriculomegaly, ventriculitis, hydrocephalus, extra-axial fluid collections, cerebritis and brain abscess. Sonography is extremely beneficial in evaluating intraventricular contents, especially debris and intraventricular septations. Linear high frequency probe along with color Doppler interrogation are of utmost importance in evaluating extra-axial fluid collection and helps differentiating it from benign subarachnoid space enlargement. Due to low cost, easy portability, speed of imaging, no need for sedation and above all lack of ionizing radiation make it superior to other cross sectional imaging, like CT and MRI, in evaluation of these sick neonates. Apart from textbooks, there is paucity of recently available literature on cranial sonographic findings in neonatal meningitis. This article is written with an educational intent to review the spectrum of findings in neonatal meningitis, with stress on findings that will be beneficial in the clinical practice.

The Upside of Bias: A Case of Chronic Meningitis Due to Sporothrix Schenckii in an Immunocompetent Host

Chronic meningitis of unknown etiology is a vexing illness for patients and clinicians. Identification of the correct pathogen can be challenging and time consuming, leading to delays in appropriate treatment. Although Sporothrix schenckii is a recognized and treatable cause of chronic meningitis, neurologists and infectious diseases physicians may not regularly evaluate for Sporothrix infection. We describe an immunocompetent patient with chronic meningitis who partially responded to empiric fluconazole. Prompted by a recent culture-confirmed case of meningeal sporotrichosis, we tested for S schenckii antibodies from the cerebrospinal fluid, which were positive. His clinical and functional status improved, and the S schenckii antibody titer decreased with itraconazole therapy. Clinicians should consider S schenckii in the differential diagnosis for chronic meningitis, even in immunocompetent patients, particularly when the clinical picture does not respond to standard empiric therapy.

Central Nervous System Infection with Histoplasma capsulatum

Histoplasmosis is an endemic fungal infection that may affect both immune compromised and non-immune compromised individuals. It is now recognized that the geographic range of this organism is larger than previously understood, placing more people at risk. Infection with Histoplasma capsulatum may occur after inhalation of conidia that are aerosolized from the filamentous form of the organism in the environment. Clinical syndromes typically associated with histoplasmosis include acute or chronic pneumonia, chronic cavitary pulmonary infection, or mediastinal fibrosis or lymphadenitis. Disseminated infection can also occur, in which multiple organ systems are affected. In up to 10% of cases, infection of the central nervous system (CNS) with histoplasmosis may occur with or without disseminated infection. In this review, we discuss challenges related to the diagnosis of CNS histoplasmosis and appropriate treatment strategies that can lead to successful outcomes.

Various brain-eating amoebae: the protozoa, the pathogenesis, and the disease

Among various genera of free-living amoebae prevalent in nature, some members are identified as causative agents of human encephalitis, in which Naegleria fowleri followed by Acanthamoeba spp. and Balamuthia mandrillaris have been successively discovered. As the three dominant genera responsible for infections, Acanthamoeba and Balamuthia work as opportunistic pathogens of granulomatous amoebic encephalitis in immunocompetent and immunocompromised individuals, whereas Naegleria induces primary amoebic meningoencephalitis mostly in healthy children and young adults as a more violent and deadly disease. Due to the lack of typical symptoms and laboratory findings, all these amoebic encephalitic diseases are difficult to diagnose. Considering that subsequent therapies are also affected, all these brain infections cause significant mortality worldwide, with more than 90% of the cases being fatal. Along with global warming and population explosion, expanding areas of human and amoebae activity in some regions lead to increased contact, resulting in more serious infections and drawing increased public attention. In this review, we summarize the present information of these pathogenic free-living amoebae, including their phylogeny, classification, biology, and ecology. The mechanisms of pathogenesis, immunology, pathophysiology, clinical manifestations, epidemiology, diagnosis, and therapies are also discussed.

Enterovirus D68-Associated Acute Flaccid Myelitis in Immunocompromised Woman, Italy

In Italy in 2016, acute flaccid myelitis developed in a woman who had received a hematopoietic stem cell transplant. Enterovirus D68 viral genome was detected in respiratory and cerebrospinal fluid samples, and the viral protein 1 sequence clustered with lineage B3. Immunocompromised adults may be at risk for enterovirus D68-associated neurologic complications.

Neurodevelopmental Outcomes of Infants Younger Than 90 Days Old Following Enterovirus and Parechovirus Infections of the Central Nervous System

Enteroviruses (EVs) and human parechoviruses (HPeVs) are a major cause of central nervous system (CNS) infection in young infants. They have been implicated in neurodevelopmental delay, however limited data are available. The aim of this study is to describe the clinical outcome of young infants and to assess and compare the medium-term neurodevelopment following CNS infections caused by EV and HPeV. A multicentre observational ambispective study was conducted between May 2013 and March 2018. Children under 3 months of age with EV or HPeV CNS infection excluding encephalitis were included. Infants were contacted 1 year after the acute infection and their neurological development was evaluated using the Ages and Stages Questionnaire-3 (ASQ-3). If any area assessed was abnormal during the first round of tests, a second round was completed 6 to 12 months later. Forty-eight young infants with EV and HPeV CNS infection were identified: 33 (68.8%) were positive for EV and 15 (31.3%) for HPeV. At first assessment 14 out of 29 EV (48.3%) and 3 out of 15 HPeV (20%) positive cases presented some developmental concern in the ASQ-3 test. EV-positive infants showed mild and moderate alteration in all domains analyzed and HPeV-positive infants showed mild alterations only in gross and fine motor domains. Significant alterations in communication were observed in EV-positive but not in HPeV-positive infants (31 vs. 0%, p = 0.016). At second assessment 4 out of 13 EV-positive patients (30.8%) showed mild to moderate concerns in communication and gross motor function domains and 3 out of 13 (23.1%) showed significant concern in fine motor function. Although CNS infections without associated encephalitis are generally assumed to be benign our study shows that at a median age of 18 months almost half of the EV-infected infants (48.3%) and 20% of HPeV-positive infants presented some developmental concern in the ASQ-3 test. We recommend monitor the neurological development of infants during the first years of life after HPeV CNS infection and especially after EV CNS infection, even in mild cases, for an early intervention and stimulation of psychomotor development if necessary.

Varicella-Zoster Virus Meningitis and Encephalitis: An Understated Cause of Central Nervous System Infections

Background Varicella-zoster virus (VZV) and herpes zoster cause infections of the central nervous system (CNS) manifesting as meningitis or encephalitis. As compared to enterovirus (EV) and herpes simplex virus 1 (HSV-1) and 2 (HSV-2), it is not often tested in CNS infections due to VZV and herpes zoster. There is a certain tendency to think that the findings in the cerebrospinal fluid in infections of the CNS by viruses are comparable among themselves. The exact proportion of patients with VZV primary and reactivation infection who present with lesions prior to or concomitant to its involvement in the CNS is unknown. It is also not known about the risk factors that lead to the reactivation of VZV and CNS involvement. Objective To describe the clinical characteristics and laboratory results of patients with a positive VZV polymerase chain reaction (PCR) and neurological signs and symptoms. Methods A retrospective and descriptive study was performed at the Hospital Universitario de la Pontificia Universidad Católica de Chile (Hospital Clínico UC CHRISTUS) from September 2012 to July 2014. The following parameters were recorded: neurological signs and symptoms, PCR for VZV in cerebrospinal fluid (CSF), comorbidities, personal medical history, cutaneous lesions, CSF characteristics, CNS imaging, electroencephalography (EEG), treatment, mortality, and neurological sequelae. Adult patients with meningitis, encephalitis, or meningoencephalitis due to VZV diagnosed with PCR were included. Results Out of 70 CSF samples analyzed in the previously mentioned period, 21 cases were VZV positive, 16 cases that had clinical information available were included. The mean age with VZV CNS reactivation was 47 years (range 19-80 years). Five patients (31.25%) were immunocompromised: three had human immunodeficiency virus (HIV), one had kidney transplantation, and one had primary immunodeficiency. Clinical presentation was meningitis in 11 patients (68.75%) and encephalitis in five patients (31.25%). Pleocytosis in CSF was observed in all the samples. The five immunocompromised patients had cutaneous lesions. All patients received antiviral treatment. Therapy duration was from 10 up to 21 days. The clinical course was positive in most patients and the mean hospitalization time was 15 days (range 5-60 days). No mortality was observed. Conclusions VZV is a worldwide virus and a common cause of CNS infection. The rising incidence is probably due to a better diagnostic method and a frequent clinical suspicion even in the absence of cutaneous lesions, except in immunocompromised cases, as it was observed in the present study. CNS infection presented as a wide spectrum of clinical manifestations with possible neurological sequelae. There was a reduction in neurological morbidity with antiviral therapy. Nonetheless, both the incidence and the morbidity of CNS VZV infection are expected to be diminished by varicella and herpes zoster vaccination. Additionally, there was no increase in mortality in these patients.

Nervous System Injury and Neuroimaging of Zika Virus Infection

In 2016, World Health Organization announced Zika virus infection and its neurological sequalae are a public health emergency of global scope. Preliminary studies have confirmed a relationship between Zika virus infection and certain neurological disorders, including microcephaly and Guillain–Barre syndrome (GBS). The neuroimaging features of microcephaly secondary to Zika virus infection include calcifications at the junction of gray–white matter and subcortical white matter with associated cortical abnormalities, diminution of white matter, large ventricles with or without hydrocephalus, cortical malformations, hypoplasia of cerebellum and brainstem, and enlargement of cerebellomedullary cistern. Contrast enhancement of the cauda equine nerve roots is the typical neuroimaging finding of GBS associated with Zika virus. This review describes the nervous system disorders and associated imaging findings seen in Zika virus infection, with the aim to improve the understanding of this disease. Imaging plays a key role on accurate diagnosis and prognostic evaluation of this disease.

The hitchhiker's guide to parasite dissemination

Toxoplasma gondii (T. gondii) is a parasitic protist that can infect nearly all nucleated cell types and tissues of warm-blooded vertebrate hosts. T. gondii utilises a unique form of gliding motility to cross cellular barriers, enter tissues, and penetrate host cells, thus enhancing spread within an infected host. However, T. gondii also disseminates by hijacking the migratory abilities of infected leukocytes. Traditionally, this process has been viewed as a route to cross biological barriers such as the blood-brain barrier. Here, we review recent findings that challenge this view by showing that infection of monocytes downregulates the program of transendothelial migration. Instead, infection by T. gondii enhances Rho-dependent interstitial migration of monocytes and macrophages, which enhances dissemination within tissues. Collectively, the available evidence indicates that T. gondii parasites use multiple means to disseminate within the host, including enhanced motility in tissues and translocation across biological barriers.

Clinical features, outcomes, and cerebrospinal fluid findings in adult patients with central nervous system (CNS) infections caused by varicella-zoster virus: comparison with enterovirus CNS infections

Varicella-zoster virus (VZV) is known to be associated with central nervous system (CNS) infections in adults. However, the clinical characteristics of VZV CNS infections are not well characterized. The aim of this study was to compare the clinical manifestations, outcomes, and cerebrospinal fluid (CSF) findings in patients with VZV CNS infections with those in patients with enterovirus (EV) CNS infections. This retrospective cohort study was performed at a 2,700-bed tertiary care hospital. Using a clinical microbiology computerized database, all adults with CSF PCR results positive for VZV or EV that were treated between January 1999 and February 2013 were identified. Thirty-eight patients with VZV CNS infection and 68 patients with EV CNS infection were included in the study. Compared with the EV group, the median age in the VZV group was higher (VZV, 35 years vs. EV, 31 years; P = 0.02), and showed a bimodal age distribution with peaks in the third and seventh decade. Encephalitis was more commonly encountered in the VZV group (VZV, 23.7% vs. EV, 4.4%; P = 0.01). The median lymphocyte percentage in the CSF (VZV, 81% vs. EV, 36%; P < 0.001) and the CSF protein level (VZV, 100 mg/dl vs. EV, 46 mg/dl; P < 0.001) were higher in the VZV group. Compared with patients with EV CNS infection, patients with VZV CNS infection developed encephalitis more often and exhibited more intense inflammatory reaction. Nevertheless, both VZV and EV CNS infections were associated with excellent long-term prognosis.

Severe childhood Guillain-Barré syndrome associated with Mycoplasma pneumoniae infection: a case series

We report seven children with recent Mycoplasma pneumoniae infection and severe Guillain-Barré syndrome (GBS) that presented to two European medical centres from 1992 to 2012. Severe GBS was defined as the occurrence of respiratory failure, central nervous system (CNS) involvement, or death. Five children had GBS, one Bickerstaff brain stem encephalitis (BBE), and one acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP). The five patients with severe GBS were derived from an original cohort of 66 children with GBS. In this cohort, 17 children (26%) had a severe form of GBS and 47% of patients with M. pneumoniae infection presented with severe GBS. Of the seven patients in this case series, five were mechanically ventilated and four had CNS involvement (two were comatose). Most patients presented with non-specific clinical symptoms (nuchal rigidity and ataxia) and showed a rapidly progressive disease course (71%). Antibodies against M. pneumoniae were detected in all patients and were found to be intrathecally synthesised in two cases (GBS and BBE), which proves intrathecal infection. One patient died and only two patients recovered completely. These cases illustrate that M. pneumoniae infection in children can be followed by severe and complicated forms of GBS. Non-specific clinical features of GBS in such patients may predispose a potentially life-threatening delay in diagnosis.

Epidemiologic Investigation of a Cluster of Neuroinvasive Bacillus cereus Infections in 5 Patients With Acute Myelogenous Leukemia

Background.  Five neuroinvasive Bacillus cereus infections (4 fatal) occurred in hospitalized patients with acute myelogenous leukemia (AML) during a 9-month period, prompting an investigation by infection control and public health officials. Methods.  Medical records of case-patients were reviewed and a matched case-control study was performed. Infection control practices were observed. Multiple environmental, food, and medication samples common to AML patients were cultured. Multilocus sequence typing was performed for case and environmental B cereus isolates. Results.  All 5 case-patients received chemotherapy and had early-onset neutropenic fevers that resolved with empiric antibiotics. Fever recurred at a median of 17 days (range, 9-20) with headaches and abrupt neurological deterioration. Case-patients had B cereus identified in central nervous system (CNS) samples by (1) polymerase chain reaction or culture or (2) bacilli seen on CNS pathology stains with high-grade B cereus bacteremia. Two case-patients also had colonic ulcers with abundant bacilli on autopsy. No infection control breaches were observed. On case-control analysis, bananas were the only significant exposure shared by all 5 case-patients (odds ratio, 9.3; P = .04). Five environmental or food isolates tested positive for B cereus, including a homogenized banana peel isolate and the shelf of a kitchen cart where bananas were stored. Multilocus sequence typing confirmed that all case and environmental strains were genetically distinct. Multilocus sequence typing-based phylogenetic analysis revealed that the organisms clustered in 2 separate clades. Conclusions.  The investigation of this neuroinvasive B cereus cluster did not identify a single point source but was suggestive of a possible dietary exposure. Our experience underscores the potential virulence of B cereus in immunocompromised hosts.

Clinical and Financial Impact of a Diagnostic Stewardship Program for Children with Suspected Central Nervous System Infection

OBJECTIVE

To investigate the optimal implementation and clinical and financial impacts of the FilmArray Meningitis Encephalitis Panel (MEP) multiplex polymerase chain reaction testing of cerebrospinal fluid (CSF) in children with suspected central nervous system infection.

STUDY DESIGN

A pre-post quasiexperimental cohort study to investigate the impact of implementing MEP using a rapid CSF diagnostic stewardship program was conducted at Children's Hospital Colorado (CHCO). MEP was implemented with electronic medical record indication selection to guide testing to children meeting approved use criteria: infants <2 months, immunocompromised, encephalitis, and ≥5 white blood cells/μL of CSF. Positive results were communicated with antimicrobial stewardship real-time decision support. All cases with CSF obtained by lumbar puncture sent to the CHCO microbiology laboratory meeting any of the 4 aforementioned criteria were included with preimplementation controls (2015-2016) compared with postimplementation cases (2017-2018). Primary outcome was time-to-optimal antimicrobials compared using log-rank test with Kaplan-Meier analysis.

RESULTS

Time-to-optimal antimicrobials decreased from 28 hours among 1124 preimplementation controls to 18 hours (P < .0001) among 1127 postimplementation cases (72% with MEP testing conducted). Postimplementation, time-to-positive CSF results was faster (4.8 vs 9.6 hours, P < .0001), intravenous antimicrobial duration was shorter (24 vs 36 hours, P = .004), with infectious neurologic diagnoses more frequently identified (15% vs 10%, P = .03). There were no differences in time-to-effective antimicrobials, hospital admissions, antimicrobial starts, or length of stay. Costs of microbiologic testing increased, but total hospital costs were unchanged.

CONCLUSIONS

Implementation of MEP with a rapid central nervous system diagnostic stewardship program improved antimicrobial use with faster results shortening empiric therapy. Routine MEP testing for high-yield indications enables antimicrobial optimization with unchanged overall costs.

Immovable Object Meets Unstoppable Force? Dialogue Between Resident and Peripheral Myeloid Cells in the Inflamed Brain

Inflammation of the brain parenchyma is characteristic of neurodegenerative, autoimmune, and neuroinflammatory diseases. During this process, microglia, which populate the embryonic brain and become a permanent sentinel myeloid population, are inexorably joined by peripherally derived monocytes, recruited by the central nervous system. These cells can quickly adopt a morphology and immunophenotype similar to microglia. Both microglia and monocytes have been implicated in inducing, enhancing, and/or maintaining immune-mediated pathology and thus disease progression in a number of neuropathologies. For many years, experimental and analytical systems have failed to differentiate resident microglia from peripherally derived myeloid cells accurately. This has impeded our understanding of their precise functions in, and contributions to, these diseases, and hampered the development of novel treatments that could target specific cell subsets. Over the past decade, microglia have been investigated more intensively in the context of neuroimmunological research, fostering the development of more precise experimental systems. In light of our rapidly growing understanding of these cells, we discuss the differential origins of microglia and peripherally derived myeloid cells in the inflamed brain, with an analysis of the problems resolving these cell types phenotypically and morphologically, and highlight recent developments enabling more precise identification.