Central Nervous System Antimicrobial Exposure and Proposed Dosing for Anthrax Meningitis

BACKGROUND

The high mortality of systemic anthrax is likely a consequence of the severe central nervous system (CNS) inflammation that occurs in anthrax meningitis. Effective treatment of such infections requires, at a minimum, adequate cerebrospinal fluid (CSF) antimicrobial concentrations.

METHODS

We reviewed English medical literature and regulatory documents to extract information on serum and CSF exposures for antimicrobials with in vitro activity against Bacillus anthracis. Using CSF pharmacokinetic exposures and in vitro B. anthracis susceptibility data, we employed population pharmacokinetic modeling and Monte Carlo simulations to predict whether a specific antimicrobial dosage would likely achieve effective CSF antimicrobial activity in patients with normal to inflamed meninges (i.e., an intact to markedly disrupted blood brain barrier).

RESULTS

Probability of microbiologic success at achievable antimicrobial dosages was high (≥95%) for ciprofloxacin, levofloxacin (500 mg q12 h), meropenem, imipenem/cilastatin, penicillin G, ampicillin, ampicillin/sulbactam, doxycycline, and minocycline; acceptable (90-95%) for piperacillin/tazobactam and levofloxacin (750 mg q24 h); and low (<90%) for vancomycin, amikacin, clindamycin, and linezolid.

CONCLUSION

Prompt empiric antimicrobial therapy of patients with suspected or confirmed anthrax meningitis may reduce the high morbidity and mortality. Our data support using several β-lactam-, fluoroquinolone-, and tetracycline-class antimicrobials as first-line and alternative agents for treatment of patients with anthrax meningitis; all should achieve effective microbiologic exposures. Our data also suggest antimicrobials that should not be relied upon to treat suspected or documented anthrax meningitis. Furthermore, the protein synthesis inhibitors clindamycin and linezolid can decrease toxin production and may be useful components of combination therapy.

Necrotizing Primary Angiitis of the Central Nervous System Mimicking Brain Abscess: A Case Report and Literature Review

Primary angiitis of the central nervous system (PACNS) is a rare vasculitis in the central nervous system. Herein, we report a case of diagnosis and treatment of necrotic pattern PACNS, which was difficult to differentiate from a brain abscess. A 19-year-old male presented with blurred vision and a headache. Brain MRI revealed irregular rim-enhancing necrotic masses with central diffusion-high signal intensity in the corpus callosum and peripheral diffusion-high signal intensity in the left parietotemporal periventricular area. Susceptibility-weighted imaging revealed multiple punctate hemorrhages in the lesions. The patient was diagnosed with unusual abscess or tumefactive PACNS. Therefore, we initially treated the patient with antibiotics to rule out brain abscess. However, the brain lesions did not improve on follow-up MRI after the antibiotic treatment. Surgical biopsy was performed, and the histopathological diagnosis was PACNS with a necrotic pattern. The necrotic lesions became smaller on follow-up MRI after high-dose corticosteroid treatment.

Into the Unknown: Diagnosing Mysterious Brain Lesions

The case discussed involves a 49-year-old male with simultaneous pancreas-kidney transplant who presented with fever, headache and was found to have multifocal brain lesion on brain imaging. This article is protected by copyright. All rights reserved.

Brain abscess caused by dental peri-implantitis

We report the case of a patient presenting with severe headache and progressive aphasia due to a large brain abscess. End-stage peri-implantitis on a dental implant in the upper jaw with contact to the maxillary sinus floor causing maxillary and frontal sinusitis could be identified as the source of infection. Multidisciplinary treatment included broad-spectrum antibiotics, craniotomy for abscess drainage, sinus surgery, and the removal of the implant. Despite all the care taken, the patient died, underlining the importance of oral hygiene and a frequent recall in patients with dental implants. To the best of our knowledge, this is the first report of a brain abscess caused by peri-implantitis in the literature.

Sinus venosus atrial septal defect presenting with brain abscess in a 33-year-old man

This study aimed to present a case of 33-year old man who was admitted with a history of one week headache and acute diplopia. No important finding was reported in his past medical history. Brain CT-scan revealed a large mass lesion in left parieto-occipital area with prominent vasogenic edema and midline shift. Brain magnetic resonance imaging (MRI) showed a mass with size of 5*4*5 centimeter with ring enhancement. After cranial surgery and removing the mass, transthoracic and transesophageal echocardiography (TEE) were conducted to find the source of brain abscess. Right ventricular (RV) and right atrial (RA) enlargement, significant left to right shunt, normal left ventricular (LV) and RV function, bidirectional shunt in addition to moderate size superior sinus venosus type atrial septal defect (ASD) were detected. Considering that most of brain abscesses have hematogenous source, a complete cardiac evaluation including TEE with contrast study is suggested for evaluation of patients with brain abscess.

Multiple Brain Abscesses Caused by Citrobacter Koseri in a Preterm Neonate - Case Report

Background

Brain abscesses are very rarely diagnosed in neonates, but if present, they are associated with a high risk of severe complications and mortality. In neonates, brain abscesses can be detected on transfontanelle ultrasonography, in which they appear as hyperechogenic lesions surrounded by a hypoechogenic border.

Case Report

We present a female neonate, born in the 28^th week of gestation, with birth weight of 950 grams, who was born in an ambulance by spontaneous vaginal vertex delivery. No signs of infection were present until the 35^th day of hospitalization, when a sudden and serious deterioration in the patient’s condition was observed due to late-onset sepsis. Cranial US, performed on the 40^th day of life, revealed hyperechogenic lesions with a hypoechogenic halo in the right frontal lobe, which could correspond to brain abscesses. These lesions were caused by Citrobacter koseri septicaemia, identified by transfontanelle ultrasonography, and confirmed on magnetic resonance imaging. The patient recovered and was discharged on the 91th day of life (39 PCA) with a recommendation of permanent neurological surveillance.

Conclusions

Ultrasonography of the central nervous system can reveal inflammatory changes and developing brain abscesses. In neonates, magnetic resonance imaging should be performed as the method of choice for confirming brain abscesses.

The burden and epidemiology of community-acquired central nervous system infections: a multinational study

Risk assessment of central nervous system (CNS) infection patients is of key importance in predicting likely pathogens. However, data are lacking on the epidemiology globally. We performed a multicenter study to understand the burden of community-acquired CNS (CA-CNS) infections between 2012 and 2014. A total of 2583 patients with CA-CNS infections were included from 37 referral centers in 20 countries. Of these, 477 (18.5%) patients survived with sequelae and 227 (8.8%) died, and 1879 (72.7%) patients were discharged with complete cure. The most frequent infecting pathogens in this study were Streptococcus pneumoniae (n = 206, 8%) and Mycobacterium tuberculosis (n = 152, 5.9%). Varicella zoster virus and Listeria were other common pathogens in the elderly. Although staphylococci and Listeria resulted in frequent infections in immunocompromised patients, cryptococci were leading pathogens in human immunodeficiency virus (HIV)-positive individuals. Among the patients with any proven etiology, 96 (8.9%) patients presented with clinical features of a chronic CNS disease. Neurosyphilis, neurobrucellosis, neuroborreliosis, and CNS tuberculosis had a predilection to present chronic courses. Listeria monocytogenes, Staphylococcus aureus, M. tuberculosis, and S. pneumoniae were the most fatal forms, while sequelae were significantly higher for herpes simplex virus type 1 (p < 0.05 for all). Tackling the high burden of CNS infections globally can only be achieved with effective pneumococcal immunization and strategies to eliminate tuberculosis, and more must be done to improve diagnostic capacity.

Endogenous Nocardial Endophthalmitis in an Immunosuppressed Patient: A Serious Warning of an Underlying Life Threatening and Blinding Disorder

Purpose:

To report a case of bilateral endogenous nocardial endophthalmitis with central nervous system involvement in an immunocompromised individual with an extremely poor outcome.

Case Report:

A 35-year-old man with a history of long-term, prescribed oral steroid use for membranoproliferative glomerulonephritis presented with profound bilateral vision loss. Patient's diagnosis of bilateral endogenous nocardial endophthalmitis was delayed. Nocardia was finally isolated from a brain biopsy after a repeat magnetic resonance imaging revealed a brain abscess. With anti-nocardia therapy, patient improved systemically, but the visual outcome was poor, with no light perception in both eyes.

Conclusion:

Ocular nocardiosis is a serious vision and life threatening disorder, particularly in patients on immunosuppressive therapy. A high index of suspicion is required for successful treatment.

Aspergillus flavus-Induced Brain Abscess in an Immunocompetent Child: Case report

Intracranial aspergillosis is an extremely rare manifestation of invasive aspergillosis in immunocompetent children and is associated with high morbidity and mortality. We report a 12-year-old immunocompetent male child who was referred to the King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia, in May 2010 after a sudden-onset headache and loss of consciousness. Brain imaging revealed a large right space-occupying occipital lesion and the patient underwent a craniotomy and resection. Histopathology of the lesion revealed necrotising granulomatous fungal encephalitis with many hyphae engulfed by multinucleated giant histiocytes. Two days later, a computed tomography scan showed debulking of the fungal mass and the patient was discharged on oral voriconazole. However, imaging at a six-week follow-up showed progression of the abnormality. A residual or persistent fungal brain lesion was suspected. Further neurosurgical resection of the lesion was performed and cultures showed growth of Aspergillus flavus. The patient was treated successfully with antifungal therapy over the following two years.

Clinical and morphological aspects of gray matter heterotopia type developmental malformations

Background

Gray matter heterotopia (GMH) is a malformation of the central nervous system characterized by interruption of normal neuroblasts migration between the 7^th and 16^th week of fetal development.

The aim of the study was the analysis of clinical symptoms, prevalence rate and the most common concurrent central nervous system (CNS) developmental disorders as well as assessment of characteristic morphological changes of gray matter heterotopia in children hospitalized in our institution between the year 2001 and 2012.

Material/Methods

We performed a retrospective analysis of patients’ data who were hospitalized in our institution between the year 2001 and 2012. We assessed clinical data and imaging exams in children diagnosed with gray matter heterotopia confirmed in MRI (magnetic resonance imaging).

Results

GMH occurred in 26 children hospitalized in our institution between the year 2001 and 2012. Among children with gray matter heterotopia most common clinical symptoms were: epilepsy, intellectual disability and hemiparesis.

The commonest location of heterotopic gray matter were fronto-parietal areas of brain parenchyma, mostly subependymal region.

Gray matter heterotopia occurred with other developmental disorders of the central nervous system rather than solely and in most cases it was bilateral.

Schizencephaly and abnormalities of the corpus callosum were the most often developmental disorders accompanying GMH.

Conclusions

1. Subependymal gray matter heterotopia was more common than subcortical GMH. Subependymal GMH showed tendency to localize in the region of the bodies of the lateral ventricles. The least common was laminar GMH. 2. Gray matter heterotopia occurred more often with other developmental disorders of the central nervous system rather than solely. The most frequent concurrent disorders of the central nervous system were: schizencephaly, developmental abnormalities of the corpus callosum, arachnoid cyst, abnormalities of the septum pellucidum and the fornix. 3. GMH foci were more often bilateral than unilateral. 4. In the diagnostics of cell migration abnormalities, gray matter heterotopia included, MR imaging remains the method of choice.

Cerebral abscess complicating embolization of an arteriovenous malformation: Case report and review of litera

Central nervous system infection is a rare complication of endovascular procedures. We report a 21-year-old woman presented with headache, nausea, vomiting, and right-sided hemiparesis 4 months after endovascular embolization of cerebral arteriovenous malformation. Investigations led to the diagnosis of multiple brain abscesses. This is the sixth case report of brain abscess following endovascular interventions.