Central nervous system infection during immunosuppression

A Blast From the Past: Toxoplasmic Encephalitis As the Initial Presentation of HIV/AIDS

Many opportunistic infections (OIs) seen early in the human immunodeficiency virus (HIV) epidemic receded in prevalence with the advent of antiretroviral therapy (ART). Despite the availability of early detection and treatment of HIV as well as guidelines for near-universal screening, there remains a sizable population of individuals living with HIV who are not yet aware of their HIV status. These individuals are at risk for OIs such as toxoplasmosis, which would otherwise be preventable with ART and appropriate prophylaxis. Toxoplasmic encephalitis (TE) usually occurs in the late stages of HIV with acquired immunodeficiency syndrome (AIDS), but we present a case of a 38-year-old female with TE as the initial presentation of HIV/AIDS. Testing for the presence of an immunocompromising condition such as HIV is important in patients presenting with focal brain lesions as the differential diagnosis will change, and proper workup may spare invasive procedures such as a brain biopsy.

The role of optic nerve sheath diameter ultrasound in brain infection

Brain infections cause significant morbidity and mortality worldwide, especially in resource-limited settings with high HIV co-infection rates. Raised intracranial pressure [ICP] may complicate brain infection and worsen neurological injury, yet invasive ICP monitoring is often unavailable. Optic nerve sheath diameter [ONSD] ultrasound may allow detection of raised ICP at the bedside; however, pathology in brain infection is different to traumatic brain injury, in which most studies have been performed. The use of ONSD ultrasound has been described in tuberculous meningitis, cryptococcal meningitis and cerebral malaria; however correlation with invasive ICP measurement has not been performed. Normal optic nerve sheath values are not yet established for most populations, and thresholds for clinical intervention cannot be assumed to match those used in non-infective brain pathology. ONSD ultrasound may be suitable for use in resource-limited settings by clinicians with limited ultrasound training. Standardisation of scanning technique, consensus on normal ONSD values, and action on abnormal results, are areas for future research. This scoping review examines the role of ONSD ultrasound in brain infection. We discuss pathophysiology, and describe the rationale, practicalities, and challenges of utilising ONSD ultrasound for brain infection monitoring and management. We discuss the existing evidence base for this technique, and identify knowledge gaps and future research priorities.

Non-congenital viral infections of the central nervous system: from the immunocompetent to the immunocompromised child

Non-congenital viral infections of the central nervous system in children can represent a severe clinical condition that needs a prompt diagnosis and management. However, the aetiological diagnosis can be challenging because symptoms are often nonspecific and cerebrospinal fluid analysis is not always diagnostic. In this context, neuroimaging represents a helpful tool, even though radiologic patterns sometimes overlap. The purpose of this pictorial essay is to suggest a schematic representation of different radiologic patterns of non-congenital viral encephalomyelitis based on the predominant viral tropism and vulnerability of specific regions: cortical grey matter, deep grey matter, white matter, brainstem, cerebellum and spine.

An Approach to Neurological Disorders in a Kidney Transplant Recipient

Kidney transplantation is the preferred treatment modality in patients with ESKD. However, there are associated complications that arise from immunosuppressive medications, infections, and associated comorbidities. Neurologic disorders frequently develop in patients who have received a kidney transplant, which in turn increases the associated morbidity and mortality. This review discusses the common neurologic disorders after kidney transplantation, including infections, cognitive decline, drug-related conditions, malignancy, seizure, and other neurologic complications.

Neurologic complications of kidney transplantation

Renal transplant is the most common organ transplant in the United States, and the frequency of kidney transplants continues to rise as transplant offers improved survival and quality of life compared to dialysis. However, complications are not uncommon and patients frequently encounter issues requiring hospitalization, especially in the first year postoperatively. Complications that arise are typically related to surgical complications, immunosuppressive medications, or infection due to immunosuppression. Neurological complications are fairly common post-operatively, and are associated with increased morbidity and mortality in this population. This review discusses the most common etiologies of neurological complications after kidney transplant, including infection, malignancy, medication related, acute neuropathy, and other neurological pathology.

FilmArray® meningitis/encephalitis (ME) panel, a rapid molecular platform for diagnosis of CNS infections in a tertiary care hospital in North India: one-and-half-year review

BACKGROUND

Acute meningitis and encephalitis (AME) is a syndrome of central nervous system (CNS) infections, which could lead to neurological damage and fatality. This study evaluates the multiplex FilmArray® ME Panel which is aimed to diagnose agents causing suspect CNS infections in north India.

METHODS

A total number of 969 cerebrospinal fluid (CSF) samples collected between August 2016 and January 2018 from patients who showed clinical symptoms of CNS infections were analyzed using the FilmArray® ME Panel. Also a comparison of molecular diagnosis and various laboratory and radiological findings for Streptococcus pneumoniae, Enterovirus and Cryptococcus neoformans positive cases was done.

RESULT

Out of the 969 CSF samples, 101 cases were found to be positive for viral (n = 55), bacterial (n = 38), fungal (n = 7), and poly-microbial (n = 1) agents. Out of the 55 viral positive cases, the most detected pathogen was Enterovirus (n = 23) with predominance in the age group of 2-17 years, followed by Varicella Zoster virus (n = 14) and HSV1(n = 9) cases. Streptococcus pneumoniae (n = 26) was found to be the predominant bacterial pathogen, of which 17 were detected in the age group above 35 years. Cryptococcus neoformans was found in 7 cases.

CONCLUSION

The FilmArray® ME Panel aids in rapid detection of 14 pathogens directly from CSF. When compared to gram stain, culture, antigen detection, and CSF biochemical analysis, the FilmArray® ME Panel has detected more cases, some of which are difficult to diagnose by conventional methods. This rapid technology will help the clinicians in case of early patient management, outcomes and provide aid in antimicrobial stewardship.

Prevalence, healthcare resource utilization and overall burden of fungal meningitis in the United States

PURPOSE

Previous epidemiological and cost studies of fungal meningitis have largely focused on single pathogens, leading to a poor understanding of the disease in general. We studied the largest and most diverse group of fungal meningitis patients to date, over the longest follow-up period, to examine the broad impact on resource utilization within the United States.

METHODOLOGY

The Truven Health Analytics MarketScan database was used to identify patients with a fungal meningitis diagnosis in the United States between 2000 and 2012. Patients with a primary diagnosis of cryptococcal, Coccidioides, Histoplasma, or Candida meningitis were included in the analysis. Data concerning healthcare resource utilization, prevalence and length of stay were collected for up to 5 years following the original diagnosis.

RESULTS

Cryptococcal meningitis was the most prevalent type of fungal meningitis (70.1 % of cases over the duration of the study), followed by coccidioidomycosis (16.4 %), histoplasmosis (6.0 %) and candidiasis (7.6 %). Cryptococcal meningitis and candidiasis patients accrued the largest average charges ($103 236 and $103 803, respectively) and spent the most time in the hospital on average (70.6 and 79 days). Coccidioidomycosis and histoplasmosis patients also accrued substantial charges and time in the hospital ($82 439, 48.1 days; $78 609, 49.8 days, respectively).

CONCLUSION

Our study characterizes the largest longitudinal cohort of fungal meningitis in the United States. Importantly, the health economic impact and long-term morbidity from these infections are quantified and reviewed. The healthcare resource utilization of fungal meningitis patients in the United States is substantial.

Neurological complications of renal dialysis and transplantation

Neurological complications from renal replacement therapy contribute significantly to morbidity and mortality in patients with renal failure. Such complications can affect either the central or peripheral nervous systems. Most neurological disturbances associated with the uraemic state do not respond fully to renal replacement therapy. There are also complications specifically associated with dialysis and transplantation. A multidisciplinary approach, involving both nephrologists and neurologists, is critical for the diagnosis and effective management of these disorders.

Multicenter Evaluation of BioFire FilmArray Meningitis/Encephalitis Panel for Detection of Bacteria, Viruses, and Yeast in Cerebrospinal Fluid Specimens

Rapid diagnosis and treatment of infectious meningitis and encephalitis are critical to minimize morbidity and mortality. Comprehensive testing of cerebrospinal fluid (CSF) often includes Gram stain, culture, antigen detection, and molecular methods, paired with chemical and cellular analyses. These methods may lack sensitivity or specificity, can take several days, and require significant volume for complete analysis. The FilmArray Meningitis/Encephalitis (ME) Panel is a multiplexed in vitro diagnostic test for the simultaneous, rapid (∼1-h) detection of 14 pathogens directly from CSF specimens: Escherichia coli K1, Haemophilus influenzae, Listeria monocytogenes, Neisseria meningitidis, Streptococcus pneumoniae, Streptococcus agalactiae, cytomegalovirus, enterovirus, herpes simplex virus 1 and 2, human herpesvirus 6, human parechovirus, varicella-zoster virus, and Cryptococcus neoformans/Cryptococcus gattii We describe a multicenter evaluation of 1,560 prospectively collected CSF specimens with performance compared to culture (bacterial analytes) and PCR (all other analytes). The FilmArray ME Panel demonstrated a sensitivity or positive percentage of agreement of 100% for 9 of 14 analytes. Enterovirus and human herpesvirus type 6 had agreements of 95.7% and 85.7%, and L. monocytogenes and N. meningitidis were not observed in the study. For S. agalactiae, there was a single false-positive and false-negative result each, for a sensitivity and specificity of 0 and 99.9%, respectively. The specificity or negative percentage of agreement was 99.2% or greater for all other analytes. The FilmArray ME Panel is a sensitive and specific test to aid in diagnosis of ME. With use of this comprehensive and rapid test, improved patient outcomes and antimicrobial stewardship are anticipated.

Diagnosis and Management of Childhood Headache

Headache is one of the most common chief complaints seen in the pediatrician's office. Oftentimes, identifying the etiology of headache and differentiating primary and secondary causes can present a diagnostic conundrum. Understanding the most common causes of primary and secondary headache is vital to making a correct diagnosis. Here we review the typical presentations of the most common primary headache disorders and the approach to evaluation of the pediatric patient presenting with headache. Diagnostic workup, including the key features to elicit on physical examination, when to order head imaging, and the use of other ancillary tests, is discussed. Current treatment modalities and their indications are reviewed. We will also describe some of the new, emerging therapies that may alter the way we manage headache in the pediatric population. Headache can, at times, be a frustrating symptom seen in the pediatrician's office, but here we hope to better elucidate the approach to evaluation, management, and treatment as well as provide some hope in regards to more effective upcoming therapies.

An integrated model of care for neurological infections: the first six years of referrals to a specialist service at a university teaching hospital in Northwest England

Background

A specialist neurological infectious disease service has been run jointly by the departments of infectious disease and neurology at the Royal Liverpool University Hospital since 2005. We sought to describe the referral case mix and outcomes of the first six years of referrals to the service.

Methods

Retrospective service review.

Results

Of 242 adults referred to the service, 231 (95 %) were inpatients. Neurological infections were confirmed in 155 (64 %), indicating a high degree of selection before referral. Viral meningitis (35 cases), bacterial meningitis (33) and encephalitis (22) accounted for 38 % of referrals and 61 % of confirmed neurological infections. Although an infrequent diagnosis (n = 19), neurological TB caused the longest admission (median 23, range 5 – 119 days). A proven or probable microbiological diagnosis was found in 100/155 cases (64.5 %). For the whole cohort, altered sensorium, older age and longer hospital stay were associated with poor outcome (death or neurological disability); viral meningitis was associated with good outcome. In multivariate analysis altered sensorium remained significantly associated with poor outcome, adjusted odds ratio 3.04 (95 % confidence interval 1.28 – 7.22, p = 0.01).

Conclusions

A service of this type provides important specialist care and a focus for training and clinical research on complex neurological infections.

Central nervous system infections in cancer patients and hematopoietic stem cell transplant recipients

Central nervous system (CNS) infections in cancer patients present a diagnostic and therapeutic challenge for clinicians. While CNS infections are not frequent complications of cancer, its therapies, or hematopoietic stem cell transplantation, the importance of CNS infections lies in their propensity to result in profound morbidity and substantial mortality in this vulnerable patient population. With an expanding population of patients with malignant disease undergoing more potent and aggressive therapies and with the advent of newer immunomodulatory agents, the incidence of CNS infectious complications is likely to rise. This chapter will summarize the clinical and diagnostic evaluation of potential infections of the CNS in these patients and will discuss particular pathogens of interest with regard to this at-risk patient population.