Immunopathogenesis of Craniotomy Infection and Niche-Specific Immune Responses to Biofilm.

Bacterial infections in the central nervous system (CNS) can be life threatening and often impair neurological function. Biofilm infection is a complication following craniotomy, a neurosurgical procedure that involves the removal and replacement of a skull fragment (bone flap) to access the brain for surgical intervention. The incidence of infection following craniotomy ranges from 1% to 3% with approximately half caused by Staphylococcus aureus (S. aureus). These infections present a significant therapeutic challenge due to the antibiotic tolerance of biofilm and unique immune properties of the CNS. Previous studies have revealed a critical role for innate immune responses during S. aureus craniotomy infection. Experiments using knockout mouse models have highlighted the importance of the pattern recognition receptor Toll-like receptor 2 (TLR2) and its adaptor protein MyD88 for preventing S. aureus outgrowth during craniotomy biofilm infection. However, neither molecule affected bacterial burden in a mouse model of S. aureus brain abscess highlighting the distinctions between immune regulation of biofilm vs. planktonic infection in the CNS. Furthermore, the immune responses elicited during S. aureus craniotomy infection are distinct from biofilm infection in the periphery, emphasizing the critical role for niche-specific factors in dictating S. aureus biofilm-leukocyte crosstalk. In this review, we discuss the current knowledge concerning innate immunity to S. aureus craniotomy biofilm infection, compare this to S. aureus biofilm infection in the periphery, and discuss the importance of anatomical location in dictating how biofilm influences inflammatory responses and its impact on bacterial clearance.

Brain Abscess in a Patient with Osteopetrosis: A Rare Complication

Brain abscess formation is extremely rare in patients with osteopetrosis. Herein, we report a case of viridans streptococci brain abscess in an immunocompromised child diagnosed with osteopetrosis. The patient presented with a sudden change in mental status and convulsions. Radiological evaluation revealed a temporal lobe brain abscess, and intravenous antibiotherapy was started immediately. The patient underwent abscess drainage, and laboratory investigation of pus material revealed viridans streptococci.

Central Nervous System Infections in the Immunocompromised Adult Presenting to the Emergency Department.

Over the past 2 decades, the population of immunocompromised patients has increased dramatically in the United States. These patients are at elevated risk for both community-acquired and opportunistic central nervous system infections. We review the most common and serious central nervous system pathogens affecting these patients and outline a diagnostic and therapeutic approach to their management in the emergency department. We recommend a broad diagnostic evaluation, including neuroimaging and cerebrospinal fluid studies where appropriate, empiric antimicrobial therapy, and early involvement of subspecialists to provide comprehensive care for these complex patients.

A Case of Brain Abscess Caused by Actinomyces Cardiffensis and Parvimonas Micra.

Brain abscesses occur in 0.3-1.3 per 100,000 worldwide each year with 0.4-0.9 in Japan alone. Most of the causes are direct infection from a nearby infectious lesion and are rarely caused by an odontogenic infection. Here, we reported a case of brain abscess suspected to be associated with odontogenic infection. The patient was a 55-year-old woman. Blurred eyes and pain in the left eye noted, for which she consulted an ophthalmologist, but her eyes were normal. She was conscious and was able to converse clearly, but she could not read the letters and had difficulty in writing at the time of admission. A brain abscess was diagnosed based on the head magnetic resonance imaging (MRI) and clinical course, and a small craniotomy abscess drainage was performed. A. cardiffensis and P. micra were detected in the abscess, suggesting the involvement of periodontal disease bacteria. After the surgery, antimicrobial treatment was performed for about 2 months. At the same time, perioperative treatment was performed. On the 70th day after the surgery, tooth extraction, which was considered as the source of infection, was performed. The patient was discharged 74 days after surgery. A good turning point was obtained without relapse of symptoms.

Risk Factors and Outcomes of Cutibacterium acnes Postoperative Central Nervous System Infection: A Case-Control Study.

OBJECTIVE: Cutibacterium acnes has emerged as a significant cause of postoperative central nervous system infections (PCNSIs). We sought to determine risk factors and outcomes associated with C. acnes PCNSI. METHODS: This was a single-center 1:1 case-control study of patients with monobacterial C. acnes-associated PCNSI (cases) and unmatched controls with PCNSI caused by aerobic organisms. Patient and procedure-related characteristics were compared between groups. The main outcome was cure at 90 days after diagnosis. Mortality and neurologic disability were secondary outcomes. RESULTS: We identified 13 patients with C. acnes PCNSI and 13 controls. All patients had postoperative intracranial abscess. Onset of infection was significantly later for cases versus controls (median and range, 22 [19-116] days and 15 [1-27] days, respectively; P = 0.002). Prolonged anaerobic incubation was required for C. acnes isolation (median, 8 days vs. 2 days for aerobic pathogens; P < 0.0001). The use of sealant and implants, fever at presentation, and white blood cell and C-reactive protein levels were similar between the 2 groups. All patients underwent surgical drainage. Patients received a median of 4 antibiotic drugs and 85 antibiotic days of treatment, with no significant between-group differences. Cure at 90 days was achieved for 10 patients (76.9%) with C. acnes PCNSI and 11 (84.6%) controls (P = 1.0). CONCLUSIONS: C. acnes PCNSI presents later than infection with aerobic bacteria but is associated with similar risk factors and clinical outcomes. These results underscore the importance of prolonged anaerobic incubation to optimize the recovery of C. acnes in the laboratory.

[Brain abscess caused by Streptococcus intermedius: a case report]. / Abcès cérébral à Streptococcus intermedius : à propos d'un cas.

Streptococcus intermedius is considered as a commensal of the oropharynx, but can be a source of serious infections. We report a case of cerebral abscess in a young man of 18 years, who was admitted to the emergency room for consciousness disorder, and whose cerebral CT showed a frontal mass evoking the diagnosis of abscess. Diagnosis was confirmed by bacteriological examination of puncture fluid which was in favor of Streptococcus intermedius abscess.

Nocardial spinal epidural abscess with lumbar disc herniation: A case report and review of literature.

RATIONALE: Nocardial spinal epidural abscess is rare. The diagnosis is often difficult to make and, if delayed, poses a high risk of long-term disability. Nocardial spinal epidural abscess with severe lumbar disc herniation has not previously been reported. PATIENT CONCERNS: A 50-year-old man presented with progressive lumbago and leg pain for 6 weeks after receiving acupuncture therapy, and then the patient suddenly occurred urine retention after walking. DIAGNOSES: Clinical examination revealed sign of cauda equina syndrome. Magnetic resonance imaging (MRI) revealed a Lumbar(L)4 to L5 disc herniation, L3 to Sacrum(S)1 epidural abscess, and L2 to S1 paravertebral abscess. The causative organism was Nocardia farcinica. INTERVENTIONS: An urgent paravertebral abscess debridement and right L4 to L5 laminectomy were performed. Simultaneously, the disc tissue protruding into the spinal canal was removed, as well as irrigation and drainage. And antimicrobial treatment was continued for 12 months. OUTCOMES: Fortunately, the patient was able to walk with a cane and urinate autonomously without a catheter, although this remained difficult 7 days after surgery. After 1 year of treatment, the patient has recovered completely and returned to work. LESSONS: Nocardial spinal epidural abscess with severe lumbar disc herniation is extremely rare. Pain from spinal degenerative diseases often masks the early symptoms of spinal infection. It's worth noting that invasive treatment of spine is a way of causing spinal nocardial infection.

Neuroborreliosis and Neurosyphilis.

PURPOSE OF REVIEW: This article presents an overview of the current diagnosis and management of two spirochetal infections of the nervous system, neuroborreliosis (Lyme disease) and neurosyphilis, focusing on similarities and differences. Although neuroborreliosis was first identified almost a century ago, much confusion remains about how to accurately diagnose this quite treatable nervous system infection. Well-established diagnostic tools and therapeutic regimens exist for neurosyphilis, which has been well-known for centuries. RECENT FINDINGS: Serologic testing targeting the C6 antigen may simplify diagnostic testing in neuroborreliosis while improving accuracy. Historically, screening for syphilis has used a reaginic test followed by a treponeme-specific assay; alternative approaches, including use of well-defined recombinant antigens, may improve sensitivity without sacrificing specificity. In neuroborreliosis, measurement of the chemokine CXCL13 in CSF may provide a useful marker of disease activity in the central nervous system. SUMMARY: Lyme disease causes meningitis, cranial neuritis, radiculitis, and mononeuropathy multiplex. Cognitive symptoms, occurring either during (encephalopathy) or after infection (posttreatment Lyme disease syndrome) are rarely, if ever, due to central nervous system infection. Posttreatment Lyme disease syndrome is not antibiotic responsive. Syphilis causes meningitis, cranial neuritis, chronic meningovascular syphilis, tabes dorsalis, and parenchymal neurosyphilis. The organism remains highly sensitive to penicillin, but residua of chronic infection may be irreversible.

Brain abscess caused by Micrococcus luteus in a patient with systemic lupus erythematosus: case-based review.

Central nervous system infections, which are rarely seen in systemic lupus erythematosus (SLE), have considerably high mortality but they are difficult to distinguish from neuropsychiatric manifestation of lupus. This article reports the case of a patient with SLE with brain abscess which developed during immunosuppressive therapy for lupus nephritis. The patient completely recovered without neurological sequelae by open surgical drainage and 12-week antibiotic therapy. It is recommended that CNS infections must be excluded in patients with SLE, particularly who are receiving immunosuppressive therapy.

Salmonella brain abscess in an infant.

Brain abscess is a potentially life-threatening condition requiring rapid diagnosis and prompt medical and surgical intervention. Various etiological agents associated with different epidemiological backgrounds are implicated, including Gram-positive and Gram- negative bacterial agents as well as anaerobes. Salmonella is rarely reported to be the cause of this medical condition despite being known to cause invasive infections at extremes of age and the fact that this organism is a common cause of other clinical infectious diseases encountered in immunocompromised and immunocompetent individuals. A case of Salmonella brain abscess involving the right posterior parietal region of the brain is described in a 6-month-old infant. The clinical, microbiological, and radiological features, as well as the clinical management and outcome, are presented. This case highlights the slow-progression nature of brain abscess caused by Salmonella species and the challenge in achieving optimal resolution despite initial surgical intervention.

Intracranial Complications of Pediatric Sinusitis.

"Headache and fever" is a common presentation to the urgent care and emergency department setting and can have many etiologies. We present a case of a 10-year-old girl who presented with headache and fever and was found to have intracranial extension of sinusitis despite lack of typical sinus or chronic upper respiratory tract infection symptoms. This case illustrates the need in the emergency department or urgent care to keep a broad differential diagnosis for pediatric headache, especially when initial interventions are unsuccessful. We also review the epidemiology of pediatric sinusitis, age at sinus development, and associated intracranial complications.

Pyogenic brain abscess in children: a Tunisian multi-center experience.

BACKGROUND: Brain abscess (BA) is an uncommon intracranial suppurative infectious disease, especially in children. Treatment involves surgery and prolonged courses of antibiotics. OBJECTIVES: Our study aimed to describe clinical characteristics of children with BA treated in middle Tunisian health centers. METHODS: A retrospective study lasting 19 years (1995-2014) was conducted in Tunisia middle region. Forty one children having radiologic abnormalities suggestive of BA and confirmed per operative lesions were included. Mycobacterial, parasitic or fungal abscesses were excluded. Medical records were analyzed for age, gender, presenting symptoms, predisposing factors, imaging, microbiology results, treatment and outcome. RESULTS: The mean age was 4.9 years. The most common clinical presentations were intracranial hypertension symptoms (87%). BA was diagnosed in 95.1% on the basis of cranial imaging. The majority of abscesses was supra-tentorial (92.6%). The most frequent etiology was loco-regional infections (63.4%). No predisposing factor was found in 17%. Intravenous antibiotics were given in all cases with surgical drainage in 63.4%,. Causative organisms were identified in 53.7%. The mortality rate was 24.3%. Age less than 2 years was the only statistically significant prognostic factor identified. CONCLUSION: Our study confirmed the severity of this pathology and underlined the importance of early diagnosis and management.

Management of bacterial central nervous system infections.

Bacterial infections of the central nervous system present as a medical emergency, thus requiring rapid diagnosis and immediate treatment. The most prevalent bacterial infections seen in the intensive care unit can be summarized as acute bacterial meningitis, subdural empyema, intracerebral abscess, and ventriculitis, which all commonly involve the brain parenchyma. The infections can either be community-acquired or hospital-acquired, e.g., after neurosurgical intervention, as a complication of severe neurotrauma or related to indwelling cerebrospinal fluid drains. Community-acquired bacterial meningitis is most commonly caused by the pneumococcus (Streptococcus pneumoniae) and meningococcus (Neisseria meningtidis), and is often complicated by hearing loss, cerebrovascular complications, and seizures. Brain abscesses are frequently associated with contiguous or metastatic foci of infection such as otitis, sinusitis, pneumonia, or endocarditis which need to be detected and treated early during disease course. Despite optimal treatment, many patients are at risk for both major systemic and neurologic complications, leading to a substantial mortality and risk of major disability in survivors. Empiric treatment depends on regional antibiotic resistance patterns of common pathogens. For subdural empyema and brain abscesses, neurosurgical drainage of the infection is required alongside prolonged antibiotic treatment.

Bacterial Infections of the Central Nervous System.

PURPOSE OF REVIEW: Bacterial infections of the central nervous system are neurologic emergencies. Prompt recognition and treatment are essential not only to prevent mortality, but also to decrease neurologic sequelae. This article focuses on the two most common central nervous system bacterial infections, bacterial meningitis and spinal epidural abscess. RECENT FINDINGS: Two outbreaks of serogroup B meningococcal disease have occurred on US college campuses. The meningococcal vaccine given to young adults does not contain serogroup B. SUMMARY: In bacterial meningitis and in bacterial spinal epidural abscess, the identification of and eradication of the pathogen with antimicrobial therapy is the easy part. It is the recognition of the disorder, the understanding of which diagnostic studies to obtain and their limitations, and the management of the neurologic complications that require the expertise of a neurologist.

Listeria monocytogenes infection in ruminants: Is there a link to the environment, food and human health? A review.

Listeria (L.) monocytogenes is widely distributed in the environment, but also has the ability to cause serious invasive disease in ruminants and humans. This review provides an overview of listeriosis in ruminants and discusses our insufficient understanding of reservoirs and possible cycling ofL. monocytogenes between animal and human hosts, food and the environment. It indicates gaps in our knowledge of the role of genetic subtypes in L. monocytogenes ecology and virulence as well as risk factors, in vivo diagnostics and pathogenesis of listeriosis in ruminants. Filling these gaps will contribute to improving the control of L. monocytogenes and enhancing disease prevention. As the prevalence of listeriosis in ruminants in Switzerland is likely to be underestimated, propositions concerning improvement options for surveillance of listeriosis in ruminants are provided.

Excessive external drainage of CSF might aggravate bacterial ventriculitis.

Bacterial ventriculitis is one of the most difficult diseases of neurosurgery, if not controlled well in the early stage, it will cause empyema, adhesion and separated infectious ventricle locules inside the ventricle. Few studies focus on the relationship between external drainage volume and the occurrence of adhesion and separation of the ventricle. This paper reported a case of ventriculitis, and we propose that excessive external drainage might increase the occurrence rate of the internal separation and adhesion of ventricle in patients with ventriculitis. Choosing an appropriate drainage method and avoiding excessive drainage might be the key to the treatment of ventriculitis.

Encephalitis.

Encephalitis is an infectious or inflammatory disorder of the brain that presents with fever, headache, and an altered level of consciousness. There may also be focal or multifocal neurologic deficits, and focal or generalized seizure activity. Of the infectious etiologies, herpesviruses are the most common and some of the few treatable viral causative agents of encephalitis. The etiology, clinical presentation, diagnosis, and treatment of viral encephalitis is discussed in this chapter.

Rickettsiae, protozoa, and opisthokonta/metazoa.

Rhizobiales (formerly named Rickettsiales) cause in rare instances meningitis and meningovasculitis, respectively. In case of history of exposure, infection by Rhizobiales needs to be considered since both diagnosis and therapy may be extremely difficult and pathogen-specific. The same applies to protozoa; in this chapter, Babesia species, free-living amoebae and Entamoeba histolytica infection, including severe meningitis and brain abscess, infection by Trypanosoma species (South American and African trypanosomiasis) are discussed with respect to history, epidemiology, clinical signs, and symptoms as well as differential diagnosis and therapy. Parasitic flatworms and roundworms, potentially able to invade the central nervous system, trematodes (flukes), cestodes (in particular, Cysticercus cellulosae), but also nematodes (in particular, Strongyloides spp. in the immunocompromised) are of worldwide importance. In contrast, filarial worms, Toxocara spp., Trichinella spp., Gnathostoma and Angiostrongylus spp. are seen only in certain geographically confined areas. Even more regionally confined are infestations of the central nervous system by metazoa, in particular, tongue worms (=arthropods) or larvae of flies (=maggots). The aim of this chapter is (1) to alert the neurologist to these infections, and (2) to enable the attending emergency neurologist to take a knowledgeable history, with an emphasis on epidemiology, clinical signs, and symptoms as well as therapeutic management possibilities.

Head and neck emergencies: bacterial meningitis, encephalitis, brain abscess, upper airway obstruction, and jugular septic thrombophlebitis.

Head and neck infectious disease emergencies can be rapidly fatal without prompt recognition and treatment. Empiric intravenous (IV) antibiotics should be initiated immediately in any patient with suspected bacterial meningitis, and IV acyclovir in any patient with suspected encephalitis. Surgical intervention is often necessary for brain abscesses, epiglottitis, and Ludwig's angina. A high index of suspicion is often needed to diagnose epiglottitis, Ludwig's angina, and Lemierre's syndrome. Brain infections can have high morbidity among survivors. In this article, the causes, diagnostic tests, treatment, and prognosis are reviewed for some of the more common head and neck infectious disease emergencies.