Tuberculosis of the central nervous system in immunocompromised patients: HIV infection and solid organ transplant recipients

A retrospective study on intracranial mixed infection with tuberculous meningitis in Shenzhen, China

Tuberculous meningitis (TBM) is a prevalent global intracranial infection and the most lethal and disabling form of tuberculosis. TBM with mixed intracranial infections is clinically rare but has a higher mortality rate. To investigate the clinical characteristics of TBM with mixed intracranial infections, demographic and clinical data of TBM and pulmonary tuberculosis (PTB) patients admitted to Shenzhen Third People's Hospital between January 2015 and October 2022 were collected anonymously. A total of 207 cases of TBM were diagnosed, of which 16 cases (7.73%) were TBM with mixed intracranial infections. The overall mortality rate of TBM cases was 16.4%, while the mortality rate of TBM cases with mixed intracranial infections was as high as 35.7%. Compared to simple TBM cases, TBM cases with mixed intracranial infections had severer clinical symptoms. The percentage of human immune deficiency virus (HIV)-positive TBM cases with mixed intracranial infections reached up to 68.8%. HIV co-infection, CD4+/CD8+ T-cell counts less than 1, cranial nerve impairment, paralysis, cerebral infarction, PRO less than 450 mg/L, WBC less than 10 × 106 /L, and CL more than 120 mmol/L were risk factors for TBM cases with mixed intracranial infections. Compared to PTB, HIV co-infection, CD4+ T cell less than 550 /uL, and age less than 45 years were risk factors for TBM, and TBM was associated with higher mortality rates. Our study provides additional data to better understand single TBM and TBM with mixed intracranial infections. More than two-thirds of TBM cases with mixed intracranial infections were HIV-positive. Clinicians should consider the possibility of multiple infections in people with TBM/HIV co-infection.

IMPORTANCE

TBM can cause severe neurological damage and death, and TBM with mixed intracranial infections can exacerbate the damage and poor prognosis of the disease. TBM with mixed intracranial infections is a rare disease, which has led to an incomplete understanding of its clinical features. This study investigated the clinical features of TBM and its associated factors by comparing the characteristics of TBM with mixed intracranial infections, single TBM and pulmonary tuberculosis. This information will help to improve the understanding of TBM, diagnostic accuracy and treatment outcomes.

Magnetic resonance imaging findings in central nervous system tuberculosis: A pictorial review

Central nervous system (CNS) tuberculosis is a post-primary form of tuberculosis. It has high mortality and morbidity rates despite early diagnosis and treatment. CNS tuberculosis can manifest as subacute/chronic meningitis, parenchymal tuberculous lesions, and spinal tuberculosis. Hematogenous spread of tuberculous bacilli to the brain results in the development of so called "rich foci" on the pial surface, ependyma, and grey-white matter junction. Rupture of these "rich foci" into the subarachnoid space triggers an intense granulomatous inflammatory reaction. Tuberculous meningitis can manifest as leptomeningitis or pachymeningitis. Intracranial parenchymal tuberculous lesions may present as tuberculoma, tuberculous abscess, cerebritis, rhombencephalitis, and encephalopathy, with atypical presentations not uncommon. Complications of CNS tuberculosis encompass hydrocephalus, syrinx formation, vasculitis, infarcts, neuritis, and enduring neurological deficits. Post-contrast 3D fluid-attenuated inversion recovery (FLAIR) and post-contrast T1 spin-echo sequences excel in detecting tuberculous meningitis compared to other conventional magnetic resonance imaging (MRI) sequences. In proton magnetic resonance spectroscopy (PMRS), the presence of a lipid peak at 1.3 ppm is indicative of tuberculous lesions. Magnetization transfer (MT) imaging enhances the detection of tuberculous lesions, as the magnetization transfer ratio (MTR) of tuberculous pathologies, owing to their high lipid content, is lower than that in bacterial or fungal pathologies and higher than that in viral pathologies. This review article delves into the various typical and atypical imaging presentations of CNS tuberculosis in MRI, along with recent advances in imaging techniques.

Brain Abscesses in the Tropics

Purpose of Review

This review aims to elucidate the etiologies of brain abscesses in the tropics. Despite the similarities in causes of brain abscesses across global regions, tropical settings manifest distinguishing characteristics, prominently observed on computed tomography or magnetic resonance imaging.

Recent Findings

In tropical climates, the leading conditions predisposing individuals to brain abscesses are polymicrobial bacterial infections originating from paranasal sinuses, dental sources, and otitis media. However, the tropics present unique etiologies to be aware of, including Trypanosoma cruzi (Chagas disease), free-living amoebas like Balamuthia mandrillaris, infections from Burkholderia pseudomallei (melioidosis), fungi such as Talaromyces marneffei, and Mycobacterium tuberculosis. Given the differential diagnoses, which include neoplastic, inflammatory, and demyelinating diseases, a stereotactic biopsy coupled with a microbiological assessment remains valuable for accurate diagnosis.

Summary

In tropical regions, brain abscesses are a concern when confronted with mass-occupying or other types of brain lesions. Successful clinical management of brain abscesses typically combines surgical intervention and extended anti-microbial treatment. However, specific parasitic invasions like Chagas disease, free-living amoebas, and Entamoeba histolytica necessitate targeted anti-parasitic therapies. Furthermore, international policy efforts should focus on prevention measures in resource limited regions with heightened risks and disease burden.

Bacterial and Viral Infection and Sepsis in Kidney Transplanted Patients

Kidney transplanted patients are a unique population with intrinsic susceptibility to viral and bacterial infections, mainly (but not exclusively) due to continuous immunosuppression. In this setting, infectious episodes remain among the most important causes of death, with different risks according to the degree of immunosuppression, time after transplantation, type of infection, and patient conditions. Prevention, early diagnosis, and appropriate therapy are the goals of infective management, taking into account that some specific characteristics of transplanted patients may cause a delay (the absence of fever or inflammatory symptoms, the negativity of serological tests commonly adopted for the general population, or the atypical anatomical presentation depending on the surgical site and graft implantation). This review considers the recent available findings of the most common viral and bacterial infection in kidney transplanted patients and explores risk factors and outcomes in septic evolution.

Magic Dr.T? Tuberculous brain lesions in an immunocompetent patient-A case report

Tuberculomas in the form of multiple ring-enhancing brain lesions is an uncommon occurrence in immunocompetent patient. Central nervous system tuberculosis may manifest as meningitis, tuberculoma, or abscess and can even occur in patients with or without active respiratory tract infection. In the case of active infection, specific antibiotic combinations and dosing duration are required, and respiratory isolation/precautionary measures must be taken by the health care workers and members of the family. Most literature has reported Central nervous system tuberculosis in patients with immunosuppression such as from HIV infection or solid organ transplantation; however, in endemic areas, CNS tuberculoma should be a differential consideration even for immunocompetent patients presenting with ring enhancing lesion (s). Our case highlights the importance of maintaining this clinical suspicion. Early diagnosis and management of our patient helped prevent potentially serious neurological sequelae.

Central Nervous System Tuberculoma in the Corpus Callosum Mimicking a Butterfly Glioma: Literature Review of Radiological Findings and Our Experience

Context:

Central nervous system (CNS) tuberculoma is the most common form of intracranial parenchymal tuberculosis (TB) which accounts for approximately 40% of misdiagnosed brain lesions mimicking intracranial tumors. The most common sites are the cerebral hemispheres, basal ganglia, cerebellum, and brainstem.

Materials and Methods:

Radiological findings of corpus callosum tuberculomas have been described and set in relation with the available literature.

Results:

Corpus callosum tuberculomas are extremely rare, with only five cases reported in the current literature. Even though isolated CNS tuberculoma of the corpus callosum without systemic TB in immunocompetent patients occurs rarely, as in our case, it should be considered in the differential diagnosis of solitary corpus callosum lesions.

Conclusions:

Careful evaluation of the neuroradiological images with adequate clinicoradiological correlation allows for accurate diagnosis and ensures the proper and timely care.

Permeation Challenges of Drugs for Treatment of Neurological Tuberculosis and HIV and the Application of Magneto-Electric Nanoparticle Drug Delivery Systems

The anatomical structure of the brain at the blood-brain barrier (BBB) creates a limitation for the movement of drugs into the central nervous system (CNS). Drug delivery facilitated by magneto-electric nanoparticles (MENs) is a relatively new non-invasive approach for the delivery of drugs into the CNS. These nanoparticles (NPs) can create localized transient changes in the permeability of the cells of the BBB by inducing electroporation. MENs can be applied to deliver antiretrovirals and antibiotics towards the treatment of human immunodeficiency virus (HIV) and tuberculosis (TB) infections in the CNS. This review focuses on the drug permeation challenges and reviews the application of MENs for drug delivery for these diseases. We conclude that MENs are promising systems for effective CNS drug delivery and treatment for these diseases, however, further pre-clinical and clinical studies are required to achieve translation of this approach to the clinic.

Central nervous system infections after solid organ transplantation

PURPOSE OF REVIEW

Significant advances to our understanding of several neuroinfectious complications after a solid organ transplant (SOT) have occurred in the last few years. Here, we review the central nervous system (CNS) infections that are relevant to SOT via a syndromic approach with a particular emphasis on recent updates in the field.

RECENT FINDINGS

A few key studies have advanced our understanding of the epidemiology and clinical characteristics of several CNS infections in SOT recipients. Risk factors for poor prognosis and protective effects of standard posttransplant prophylactic strategies have been better elucidated. Newer diagnostic modalities which have broad clinical applications like metagenomic next-generation sequencing, as well as those that help us better understand esoteric concepts of disease pathogenesis have been studied. Finally, several studies have provided newer insights into the treatment of these diseases.

SUMMARY

Recent findings reflect the steady progress in our understanding of CNS infections post SOT. They provide several avenues for improvement in the prevention, early recognition, and therapeutic outcomes of these diseases.

Neurologic Infections in Patients on Immunomodulatory and Immunosuppressive Therapies

PURPOSE OF REVIEW

Both broadly immunosuppressive medications and selective immunomodulatory agents that act on particular components of the immune system are increasingly used in the treatment of neurologic and non-neurologic diseases. These therapies predispose patients to particular infections, some of which may affect the nervous system. Therefore, familiarity with the clinical and radiologic features of neurologic infections associated with specific immunomodulatory therapies is of importance for the practicing neurologist. This article reviews these neuroinfectious conditions, as well as other neurologic complications unique to transplant recipients and other patients who are immunocompromised.

RECENT FINDINGS

Diagnosis of infectious pathogens in patients who are immunocompromised may be particularly challenging because a decreased immune response can lead to atypical imaging or laboratory findings. Next-generation sequencing and other novel diagnostic modalities may improve the rate of early identification of neurologic infections in patients who are immunocompromised and ultimately ameliorate outcomes in this vulnerable population.

SUMMARY

A broad range of bacterial, viral, fungal, and parasitic infections of the nervous system can complicate solid organ and hematopoietic cell transplantation as well as other forms of immunocompromise. In addition to neurologic infections, such patients are at risk of neurotoxic and neuroinflammatory complications related to immunomodulatory and immunosuppressive therapies. Early recognition of infectious and noninfectious complications of immunocompromise is essential to guide appropriate treatment, which can include antimicrobial therapy and, in some cases, withdrawal of the predisposing medication with a transition to an alternative regimen.

Encephalitis and Brain Abscess

PURPOSE OF REVIEW

This article reviews infections of the brain parenchyma and includes an overview of the epidemiology, pathogenesis, diagnostic approach, and management of infectious encephalitis and brain abscess.

RECENT FINDINGS

The epidemiology of infectious encephalitis and brain abscess has changed in recent years. Vaccination has reduced the incidence of certain viruses associated with encephalitis, while a decrease in fulminant otogenic infections has led to fewer brain abscesses associated with otitis media. However, changes in climate and human population density and distribution have enabled the emergence of newer pathogens and expanded the geographic range of others, and greater adoption of intensive immunosuppressive regimens for autoimmune conditions has increased the risk of opportunistic infections of the brain. The widespread use of early neuroimaging, along with improved diagnostic methodologies for pathogen detection, newer antimicrobial therapies with better brain penetration, and less invasive neurosurgical techniques, has resulted in better outcomes for patients with infectious encephalitis and brain abscess. Novel technologies including metagenomic next-generation sequencing are increasingly being applied to these conditions in an effort to improve diagnosis. Nevertheless, both infectious encephalitis and brain abscess continue to be associated with substantial mortality.

SUMMARY

Infectious encephalitis and brain abscess can present as neurologic emergencies and require rapid assessment, thorough and appropriate diagnostic testing, and early initiation of empiric therapies directed against infectious agents. Close clinical follow-up, proper interpretation of diagnostic results, and appropriate tailoring of therapeutic agents are essential to optimizing outcomes. Diagnosis and management of parenchymal brain infections are complex and often best achieved with a multidisciplinary care team involving neurologists, neurosurgeons, neuroradiologists, infectious disease physicians, and pathologists.

Kidney Transplantation in HIV-positive Patients: Current Practice and Management Strategies

BACKGROUND

HIV-positive patients had been successfully transplanted for the last 15 y and the donor pool had successfully been expanded to also include HIV-positive donors.

METHODS

We aimed to evaluate the effectiveness of transplantation in HIV-positive patients and highlight some of the important issues reported in the literature. We pooled clinical data from different cohorts to show some of the common issues encountered in HIV-positive transplantation. Furthermore, we searched MEDLINE via PubMed, EMBASE, Cochrane CENTRAL to create a comprehensive table for current evidence for different issues currently encountered when transplanting HIV-positive patients.

RESULTS

We included data from 19 cohort studies and reported on outcomes of the current HIV-positive transplant programs. We made recommendations based on personal experience as well as the experience reported in the literature regarding rejection, opportunistic infection, and HIV-associated nephropathy. Opportunistic infections and malignancies are not a major problem for this population group.

CONCLUSIONS

HIV-positive patients encounter very specific issues after transplantation, specifically related to drug interactions and higher rejection rates. When utilizing HIV-positive donors, the recurrence of HIV-associated nephropathy in the graft kidney is an issue which can be important. Despite some issues with high rejection rates, HIV-positive patients have similar results to HIV-negative patients posttransplantation.

Strategies for the diagnosis and management of meningitis in HIV-infected adults in resource limited settings

INTRODUCTION

The incidence of human immunodeficiency virus-1 (HIV-1) associated meningitis has been declining in the post-combination antiretroviral treatment (ART) era, although survival rates remain low for the common causes like tuberculosis and cryptococcal disease. Diagnosis and treatment of meningitis in HIV-1 is complicated by atypical clinical presentations, limited accuracy of diagnostic tests, access to diagnostic tests, and therapeutic agents in low- and middle-income countries (LMIC) and immune reconstitution inflammatory syndrome (IRIS).

AREAS COVERED

We provide an overview of the common etiologies of meningitis in HIV-1-infected adults, suggest a diagnostic approach based on readily available tests, and review specific chemotherapeutic agents, host-directed therapies, supportive care, timing of ART initiation, and considerations in the management of IRIS with a focus on resource-limited settings. They identify key knowledge gaps and suggest areas for future research.

EXPERT OPINION

Evidence-based management of HIV-1-associated meningitis is sparse for common etiologies. More readily available and sensitive diagnostic tests as well as standardized investigation strategies are required in LMIC. There is a lack of availability of recommended drugs in areas of high HIV-1 prevalence and a limited pipeline of novel chemotherapeutic agents. Host-directed therapies have been inadequately studied.

Hemichorea-Hemiballismus as a Presentation of Cerebritis from Intracranial Toxoplasmosis and Tuberculosis

Background

There is limited literature documenting hemichorea-hemiballism (HCHB) resulting from co-infection of toxoplasmosis and tuberculosis (TB) in acquired immunodeficiency syndrome (AIDS). Toxoplasmic abscess is the most common cause while TB is a rare etiology.

Case Description

We describe a 24-year-old male with AIDS-related HCHB as the presentation of cerebritis on the right subthalamic nucleus and cerebral peduncle from intracranial toxoplasma and TB co-infection. Antimicrobials and symptomatic therapy were given. Marked improvement was seen on follow-up.

Discussion

HCHB may be the initial presentation of intracranial involvement of this co-infection in the setting of AIDS and is potentially reversible with timely management.

Highlights

Hemichorea-hemiballismus (HCHB) may be an initial presentation of intracranial involvement of concomitant toxoplasmosis and tuberculosis causing focal cerebritis in the contralateral subthalamic nucleus and cerebral peduncle, particularly in the setting of human immunodeficiency virus infection.Acquired immunodeficiency syndrome-related HCHB is potentially reversible with timely diagnosis and treatment.

Tuberculosis in Pediatric Solid Organ and Hematopoietic Stem Cell Recipients

Children undergoing solid organ and hematopoietic stem cell transplantation are at high risk of morbidity and mortality from tuberculosis (TB) disease in the post-transplant period. Treatment of TB infection and disease in the post-transplant setting is complicated by immunosuppression and drug interactions. There are limited data that address the unique challenges for the management of TB in the pediatric transplant population. This review presents the current understanding of the epidemiology, clinical presentation, diagnosis, management, and prevention for pediatric transplant recipients with TB infection and disease. Further studies are needed to improve diagnosis of TB and optimize treatment outcomes for these patients.

Multi-spectral Pattern of Clinical Presentation and the Resultant Outcome in Central Nervous System Tuberculosis: A Single Center Study on the Ubiquitous Pathogen

Central nervous system (CNS) tuberculosis (TB) is a great medical masquerader having a multi-spectral pattern of clinical presentation, thereby complicating early diagnosis and appropriate management. This review article describes clinical presentation of CNS TB in a group of 47 patients, who were managed in the Nobel Medical College and Teaching Hospital in Biratnagar, Nepal during the last 2 years. We evaluated demographic profile, mode of management, and clinical outcome in these patients. The findings were that intracranial TB was present in 27 (57.5%) patients and the spinal involvement was in 20 (42.5%) patients. The most frequent presentation of the former was TB meningitis with hydrocephalus (55.5%) and that of the latter was Pott's spine with abscess in 50% of cases. TB meningitis with hydrocephalus was the commonest cause of mortality (83.3%) among the patients. CNS TB should be considered in the differential diagnosis in patients presenting with equivocal neurological signs and symptoms, especially in TB endemic regions. It seems prudent to commence early antitubercular therapy for safeguarding such patients from poor neurological outcome as well as mortality it harbingers.

Central nervous system tuberculosis

The purpose of this article is to review the many facets of central nervous system tuberculosis (CNS-TB). The entities described are tuberculous meningitis (TBM) and its complications, spinal cord disorders, tuberculomas and co-infection with the human immune-deficiency virus (HIV). The latter has become a common problem worldwide becoming a more fulminant disease. The accuracy of the conventional and the modern molecular techniques for the diagnosis of TBM have a high specificity but a low to moderate sensitivity. Computerised tomographic scans and magnetic resonance imaging have many characteristic features which have vastly improved the diagnostic accuracy of CNS-TB. The recommended therapeutic regimens are an extrapolation of the regimen used for pulmonary TB, hence the optimal composition, dosage and duration of the therapy are not yet established. Multidrug resistant TB is emerging as a global threat and the delay in recognition of drug resistance combined with the lack of data on appropriate drug regimen adds to its high mortality.

Immunosuppressive Agents and Infectious Risk in Transplantation: Managing the "Net State of Immunosuppression"

Successful solid organ transplantation reflects meticulous attention to the details of immunosuppression, balancing risks for graft rejection against risks for infection. The 'net state of immune suppression' is a conceptual framework of all factors contributing to infectious risk. Assays which measure immune function in the immunosuppressed transplant recipient relative to infectious risk and allograft function are lacking. The best measures of integrated immune function may be quantitative viral loads to assess the individual's ability to control latent viral infections. Few studies address adjustment of immunosuppression during active infections. Thus, confronted with infection in solid organ recipients, the management of immunosuppression is based largely on clinical experience. This review examines known measures of immune function and the immunologic effects of common immunosuppressive drugs and available studies reporting modification of drug regimens for specific infections. These data provide a conceptual framework for the management of immunosuppression during infection in organ recipients.

A Rare Form of Pott's Disease With Multifaceted Pathological Complications

While tuberculosis is globally very prevalent, especially in the developing world, tuberculosis of the central nervous system (CNS) (including Pott's `disease) is an extremely rare occurrence for neurology/neurosurgery departments in the modern era. It is normally treated via rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE) therapy with the need for surgical intervention deemed by the presence of neurological deficiency or abscess, spinal instability, or significant kyphosis. Here we describe a case of an elderly woman with Pott's disease and a history of HIV presenting with neurologic deficiencies in both legs and an infected mass causing mid-thoracic compression and kyphotic deformity. The presence of a compromised immune system greatly complicates treatment and worsens outcomes. The patient underwent trans-thoracic corpectomy for decompression and mass removal. Spinal realignment was accomplished with an anterior graft, using the patient's rib, preceding posterior stabilization with instrumentation. Postoperatively, the patient received RIPE therapy. Despite a compromised immune system, the full neurologic function of both legs was restored in four months.

Outcome of management of brain abscess in children

Objective

To find out the outcome of management of brain abscess in children.

Methods

This is prospective observational study conducted in the Department of Paediatric Neurosurgery at Children's Hospital and Institute of Child Health, Multan from July 2014 to June 2017. Children up to the age of 14 years suffering from brain abscess were admitted. After taking clinical history, general and systemic physical examination and necessary investigations, abscess was evacuated and abscess wall excised after performing craniotomy. Data was collected on a predesigned performa. Results were analyzed and compared with national and international literature through statistical package for social sciences (SPSS-20).

Results

Twenty five patients up to 14 years of age were included. Seventeen (68%) were male and eight (32%) female. Fever and vomiting were present in all 25 (100%) patients. Paranasal sinusitis was predisposing causative factor in 9(36%) followed by otitis media in 7 (28%). Abscess was present in frontal lobe in 9 (36%), temporoparietal region in 8 (32%), posterior fossa in 5 (20%) and multiple abscesses in 3 (12%). Craniotomy was performed, pus evacuated and abscess wall excised in all 25 (100%) patients. Three (12%) patients expired.

Conclusion

Incidence of brain abscess can be decreased by treatment of its predisposing causes as sinusitis and otitis media. Small abscess less than 2cm can be treated with antibiotics. Complete evacuation of pus and excision of abscess wall after performing craniotomy along with appropriate antibiotics is gold standard management of brain abscess in children.

Symptomatic central nervous system tuberculoma, a case report in the United States and literature review

Intracranial tuberculoma is one of the rare central nervous system manifestations of Mycobacterium tuberculosis (MTB), seen in only 1% of tuberculosis patients. It can manifest as single or multiple lesions, most commonly located in the frontal and parietal lobes. Clinical features are similar to any space-occupying lesion in the brain and can present in the absence of MTB symptoms in other parts of the body. In this article, a 69-year-old immunocompetent man, with history of treated latent tuberculosis infection (LTBI) was reported. He presented with multiple joint arthralgias, weight loss, odd behavior, forgetfulness, intermittent fevers and syncope. Brain imaging revealed numerous enhancing intra-parenchymal lesions in cerebral and cerebellar hemispheres. Patient was successfully treated with anti-tuberculosis medications and corticosteroids, with clinical improvement on future follow ups. High clinical suspicion for tuberculoma as a differential diagnosis of any brain lesion, even in immunocompetent patients in low MTB prevalence countries, can result in early diagnosis and successful clinical outcomes.

Primary intracranial leiomyosarcoma among patients with AIDS in the era of new chemotherapeutic and biological agents

Primary intracranial leiomyosarcoma (PIL) is a rare non-infectious aetiology of focal mass lesions among HIV-infected individuals. With only 16 published cases worldwide, information on its pathophysiology, risk factors, clinical course and management options is limited. We report two cases of PIL in HIV-infected Filipino men who presented with 1-3 months history of persistent headache, progressing in severity. Both had cranial MRI revealing intracranial mass diagnosed as leiomyosarcoma by excision biopsy and immunohistochemical staining. Both patients underwent adjuvant cranial radiotherapy and chemotherapy. Biologics were initiated in one patient. Both patients were alive with evidence of the disease.

[Intracranial tuberculomas in Nouakchott, Mauritania]

Tuberculosis is a major public health problem in developing countries. Cerebral tuberculomas is a tuberculous granulation tissue mass restrained and limited by immune defenses of the host. This study aims to describe the characteristics and the evolutionary profile of intracranial tuberculomas in Mauritania. Data of 34 patients with intracranial tuberculoma were collected retrospectively in several hospitals in the city of Nouakchott between January 2005 and June 2017. Evolutionary features of patients under treatment were analyzed. Our retrospective study involved 20 men and 14 women (sex ratio 1.4). The average age of our patients was 28.7 years. Twelve patients were less than or equal to 16 years. Symptomatology was dominated by increased intracranial pressure and seizures in 27 cases (79.41%) and 20 cases (58.82%) respectively. Intradermo tuberculin reaction was positive in 14 (41.17%) cases. Supratentorial lesion was found in 24 patients (70.58%). In all patients, therapeutic approach was based on multidrug chemotherapy for a period greater than or equal to 12 months. Surgical procedure was performed in 12 patients (35.29%). Outcome was favorable with complete healing without sequelae in 23 cases, reflecting a rate of 67.64%. Given the non-specific role of imaging exams in the diagnosis of intracranial tuberculoma and the lack of the stereotactic biopsy in our Country where the disease is endemic, we recommend to perform a two-month therapeutic test in patients with suspicious lesions.

Alterations in natural killer and dendritic cell subsets in individuals with HIV-associated neurotuberculosis

One of the commonest HIV-associated opportunistic infections of the central nervous system is neurotuberculosis. Interaction between HIV, Mycobacterium tuberculosis and host immune system in co-infected individuals may result in altered frequencies of immune cells, thereby modulating dissemination and disease progression. We examined the frequencies of natural killer (NK) cell and dendritic cell (DC) subsets in HIV infected individuals with neurotuberculosis (HIVNTB) as compared to individuals with HIV associated systemic TB (HIVSTB), asymptomatic HIV, non-HIV NTB, non-HIV STB, and healthy controls. Peripheral blood mononuclear cells (PBMC) were stained with fluorochrome-conjugated monoclonal antibodies- Lineage cocktail (containing CD3, CD14, CD19, and CD20), HLA-DR, CD16, CD56, CD11c, and CD123, fixed with 2% paraformaldehyde and analyzed on the flow cytometer. The pDCs were significantly reduced in all HIV infected groups, with a marked reduction in HIVNTB cases as compared to healthy controls. While the CD56^- CD16^bt NK cell subset displayed a significant increase in frequency in all three HIV infected groups compared the three HIV negative groups, the CD56^dim CD16^bt subset was significantly lower in frequency in the HIVNTB compared to healthy controls. The decreased frequencies of plasmacytoid DCs and cytotoxic NK cells, which are crucial for innate immune defence against HIV, may result in ineffective virus control and lead to an exacerbated course of disease in HIVNTB individuals.

Matrix metalloproteinase-9 activity and a downregulated Hedgehog pathway impair blood-brain barrier function in an in vitro model of CNS tuberculosis

Central nervous system tuberculosis (CNS TB) has a high mortality and morbidity associated with severe inflammation. The blood-brain barrier (BBB) protects the brain from inflammation but the mechanisms causing BBB damage in CNS TB are uncharacterized. We demonstrate that Mycobacterium tuberculosis (Mtb) causes breakdown of type IV collagen and decreases tight junction protein (TJP) expression in a co-culture model of the BBB. This increases permeability, surface expression of endothelial adhesion molecules and leukocyte transmigration. TJP breakdown was driven by Mtb-dependent secretion of matrix metalloproteinase (MMP)-9. TJP expression is regulated by Sonic hedgehog (Shh) through transcription factor Gli-1. In our model, the hedgehog pathway was downregulated by Mtb-stimulation, but Shh levels in astrocytes were unchanged. However, Scube2, a glycoprotein regulating astrocyte Shh release was decreased, inhibiting Shh delivery to brain endothelial cells. Activation of the hedgehog pathway by addition of a Smoothened agonist or by addition of exogenous Shh, or neutralizing MMP-9 activity, decreased permeability and increased TJP expression in the Mtb-stimulated BBB co-cultures. In summary, the BBB is disrupted by downregulation of the Shh pathway and breakdown of TJPs, secondary to increased MMP-9 activity which suggests that these pathways are potential novel targets for host directed therapy in CNS TB.

Neurological complications of solid organ transplantation

ABSTRACT Solid organ transplantation is a significant development in the treatment of chronic kidney, liver, heart and lung diseases. This therapeutic approach has increased patient survival and improved quality of life. New surgical techniques and immunosuppressive drugs have been developed to achieve better outcomes. However, the variety of neurological complications following solid organ transplantation is broad and carries prognostic significance. Patients may have involvement of the central or peripheral nervous system due to multiple causes that can vary depending on time of onset after the surgical procedure, the transplanted organ, and the intensity and type of immunosuppressive therapy. Neurological manifestations following solid organ transplantation pose a diagnostic challenge to medical specialists despite extensive investigation. This review aimed to provide a practical approach to help neurologists and clinicians assess and manage solid organ transplant patients presenting with acute or chronic neurological manifestations.

A systemic review of tuberculosis with HIV coinfection in children

The epidemiology of tuberculosis is adversely impacted by the human immunodeficiency virus (HIV) coinfection. HIV-infected patients are more prone to opportunistic infections, most commonly tuberculosis, and the risk of death in coinfected patients is higher than in those without HIV. Due to the impaired cellular immunity and reduced immunological response in HIV-infected patients, the classic imaging features of tuberculosis usually seen in patients without HIV may present differently. The aim of this review article is to highlight the imaging features that may assist in the diagnosis of tuberculosis in patients with HIV coinfection.

The Importance of a Complete Differential: Case Report of a Tuberculoma in a Patient without Pulmonary Involvement

Patients with a tuberculoma typically present with pulmonary involvement of tuberculosis and have risk factors for tuberculosis (TB). The risk factors for tuberculosis include bacillary load, proximity to infectious case, immunosuppressive conditions, malnutrition, young age, diabetes mellitus, working in healthcare, recent incarceration, alcohol use, and tobacco use. Although rare, it is possible for a patient to present with a tuberculoma despite the absence of risk factors for tuberculosis other than diabetes and without pulmonary involvement.

Central Nervous System Infections

This chapter provides an overview of infectious syndromes, pathogens, and diagnostic testing modalities for central nervous system infections in the immunocompromised host.

A scoring system to effectively evaluate central nervous system tuberculosis in patients with military tuberculosis

There is currently no convenient way to effectively evaluate whether a miliary tuberculosis patient is complicated with central nervous system (CNS) tuberculosis. We aimed to find such a way by analyzing the clinical data of these patients. Fifty patients with confirmed miliary tuberculosis and 31 patients with confirmed miliary tuberculosis complicated with CNS tuberculosis from 2010 to 2014 were selected. Their general conditions, clinical features and laboratory tests were analyzed. Factors that were significantly different between them were chosen to performed multivariate and univariate logistic regression analyses, and factors with significant P values were used to establish a scoring system. Eight factors, i.e., age, cough, nausea, headache, hemoglobin (HGB), serum albumin (ALB), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), were significantly different (P < 0.05). Multivariate logistic regression analysis showed that ALB was the independent risk predictor (HR = 1.29, 95% CI 1.09–1.52, P < 0.01), whereas the others were non-independent predictors except age (P < 0.05). The scoring system was based on a summation of the scores of the assigned values of the seven predictors and had an area under the curve (AUC) of 0.86 to confirm CNS tuberculosis, with a sensitivity of 81.5% and a specificity of 81.4% at a score of 0.75 and with a specificity of 95.3% at a score of 2.75. In contrast, a score below -0.75 excluded CNS tuberculosis, with a sensitivity of 88.9% and a specificity of 62.7%. The scoring system should be useful to evaluate whether a miliary tuberculosis patient is complicated with CNS tuberculosis and could help doctors avoid excessive investigation.

Spinal Intramedullary Tuberculosis with Concurrent Supra- and Infratentorial Intracranial Disease in a 9-Month-Old Boy: Case Report and Comprehensive Review of the Literature

BACKGROUND

Tuberculous involvement of the spinal cord parenchyma is an exceedingly rare clinical entity; even more so is concurrent intracranial tuberculosis (TB). Spinal intramedullary TB presents with a characteristic subacute myelopathy, with slowly progressive paraplegia, sensory deficits, and/or bowel and bladder dysfunction. Diagnosis is strongly suspected with a clinical history of known TB in conjunction with characteristic findings on magnetic resonance imaging. Management involves multiagent antitubercular chemotherapy without or with operative intervention.

CASE DESCRIPTION

We present a case of a 9-month-old boy with a retrospectively recognized history of pulmonary TB presenting with fever and back tenderness found to have lower-extremity hypertonia and clonus. Imaging revealed concurrent intracranial and spinal intramedullary tuberculomas. The patient was treated for hydrocephalus with external ventricular drainage followed by T8-T10 laminectomy, drainage of abscess, and duraplasty. Parietal lobe biopsies proved the tuberculous etiology of intracranial lesions.

CONCLUSION

Etiopathogenesis, diagnosis, and management considerations of spinal intramedullary tuberculosis are reviewed and discussed.

Clinical features and outcomes of tuberculosis in transplant recipients as compared with the general population: a retrospective matched cohort study

There are no previous studies comparing tuberculosis in transplant recipients (TRs) with other hosts. We compared the characteristics and outcomes of tuberculosis in TRs and patients from the general population. Twenty-two TRs who developed tuberculosis from 1996 through 2010 at a tertiary hospital were included. Each TR was matched by age, gender and year of diagnosis with four controls selected from among non-TR non-human immunodeficiency virus patients with tuberculosis. TRs (21 patients, 96%) had more factors predisposing to tuberculosis than non-TRs (33, 38%) (p <0.001). Pulmonary tuberculosis was more common in non-TRs (77 (88%) vs. 12 TRs (55%); p 0.001); disseminated tuberculosis was more frequent in TRs (five (23%) vs. four non-TRs (5%); p 0.005). Time from clinical suspicion of tuberculosis to definitive diagnosis was longer in TRs (median of 14 days) than in non-TRs (median of 0 days) (p <0.001), and invasive procedures were more often required (12 (55%) TRs and 15 (17%) non-TRs, respectively; p 0.001). Tuberculosis was diagnosed post-mortem in three TRs (14%) and in no non-TRs (p <0.001). Rates of toxicity associated with antituberculous therapy were 38% in TRs (six patients) and 10% (seven patients) in non-TRs (p 0.014). Tuberculosis-related mortality rates in TRs and non-TRs were 18% and 6%, respectively (p 0.057). The adjusted Cox regression analysis showed that the only predictor of tuberculosis-related mortality was a higher number of organs with tuberculosis involvement (adjusted hazard ratio 8.6; 95% CI 1.2-63). In conclusion, manifestations of tuberculosis in TRs differ from those in normal hosts. Post-transplant tuberculosis resists timely diagnosis, and is associated with a higher risk of death before a diagnosis can be made.

Coexistence of Spinal Intramedullary Tuberculoma and Multiple Intracranial Tuberculomas

Spinal intramedullary tuberculoma remains a very rare entity of central nervous system tuberculosis. This is the same with the coexistence of spinal intramedullary and intracranial tuberculomas that remains extremely rare with less than 20 cases reported at present. Authors describe this uncommon case by analyzing a 65-year-old female patient who had past history of kidney transplantation due to stage 5 chronic kidney disease and pulmonary tuberculosis on medication. The patient experiences progressive paraplegia and numbness on both lower extremities. Magnetic resonance imaging demonstrated an intramedullary mass at T9-10 level and multiple intracranial enhancing nodules. Microsurgical resection of spinal intramedullary mass was performed and the lesion was histopathologically confirmed as Mycobacterium tuberculosis. Efficient diagnosis and management of this rare disease are reviewed along with previously reported cases.

Ex vivo host and parasite response to antileishmanial drugs and immunomodulators

Background

Therapeutic response in infectious disease involves host as well as microbial determinants. Because the immune and inflammatory response to Leishmania (Viannia) species defines the outcome of infection and efficacy of treatment, immunomodulation is considered a promising therapeutic strategy. However, since Leishmania infection and antileishmanial drugs can themselves modulate drug transport, metabolism and/or immune responses, immunotherapeutic approaches require integrated assessment of host and parasite responses.

Methodology

To achieve an integrated assessment of current and innovative therapeutic strategies, we determined host and parasite responses to miltefosine and meglumine antimoniate alone and in combination with pentoxifylline or CpG 2006 in peripheral blood mononuclear cells (PBMCs) of cutaneous leishmaniasis patients. Parasite survival and secretion of TNF-α, IFN-γ, IL-10 and IL-13 were evaluated concomitantly in PBMCs infected with Luc-L. (V.) panamensis exposed to meglumine antimoniate (4, 8, 16, 32 and 64 μg Sb^V/mL) or miltefosine (2, 4, 8, 16 and 32 μM HePC). Concentrations of 4 μM of miltefosine and 8 μg Sb^V/mL were selected for evaluation in combination with immunomodulators based on the high but partial reduction of parasite burden by these antileishmanial concentrations without affecting cytokine secretion of infected PBMCs. Intracellular parasite survival was determined by luminometry and cytokine secretion measured by ELISA and multiplex assays.

Principal Findings

Anti- and pro-inflammatory cytokines characteristic of L. (V.) panamensis infection were evaluable concomitantly with viability of Leishmania within monocyte-derived macrophages present in PBMC cultures. Both antileishmanial drugs reduced the parasite load of macrophages; miltefosine also suppressed IL-10 and IL-13 secretion in a dose dependent manner. Pentoxifylline did not affect parasite survival or alter antileishmanial effects of miltefosine or meglumine antimoniate. However, pentoxifylline diminished secretion of TNF-α, IFN-γ and IL-13, cytokines associated with the outcome of infection by species of the Viannia subgenus. Exposure to CpG diminished the leishmanicidal effect of meglumine antimoniate, but not miltefosine, and significantly reduced secretion of IL -10, alone and in combination with either antileishmanial drug. IL-13 increased in response to CpG plus miltefosine.

Conclusions and Significance

Human PBMCs allow integrated ex vivo assessment of antileishmanial treatments, providing information on host and parasite determinants of therapeutic response that may be used to tailor therapeutic strategies to optimize clinical resolution.

Host determinants of the response to infection have increasingly been recognized as therapeutically relevant targets. Despite the pathogenesis of dermal leishmaniasis being mediated by the immune and inflammatory response, in vitro anti-leishmanial drug screening has been based on antimicrobial effect without consideration of effects on the host response. The results of this study show that peripheral blood mononuclear cells from patients allow an integrated evaluation of both antimicrobial efficacy and host response to drugs, immunomodulatory agents, and their combinations. This integrated approach to defining treatment strategies based on host and parasite responses opens the way for the optimization and tailoring of treatment to different clinical circumstances.

Microglia are crucial regulators of neuro-immunity during central nervous system tuberculosis

Mycobacterium tuberculosis (M. tuberculosis) infection of the central nervous system (CNS) is the most devastating manifestation of tuberculosis (TB), with both high mortality and morbidity. Although research has been fueled by the potential therapeutic target microglia offer against neurodegenerative inflammation, their part in TB infection of the CNS has not been fully evaluated nor elucidated. Yet, as both the preferential targets of M. tuberculosis and the immune-effector cells of the CNS, microglia are likely to be key determinants of disease severity and clinical outcomes. Following pathogen recognition, bacilli are internalized and capable of replicating within microglia. Cellular activation ensues, utilizing signaling molecules that may be neurotoxic. Central to initiating, orchestrating and modulating the tuberculous immune response is microglial secretion of cytokines and chemokines. However, the neurological environment is unique in that inflammatory signals, which appear to be damaging in the periphery, could be beneficial by governing neuronal survival, regeneration and differentiation. Furthermore, microglia are important in the recruitment of peripheral immune cells and central to defining the pro-inflammatory milieu of which neurotoxicity may result from many of the participating local or recruited cell types. Microglia are capable of both presenting antigen to infiltrating CD4(+) T-lymphocytes and inducing their differentiation-a possible correlate of protection against M. tuberculosis infection. Clarifying the nature of the immune effector molecules secreted by microglia, and the means by which other CNS-specific cell types govern microglial activation or modulate their responses is critical if improved diagnostic and therapeutic strategies are to be attained. Therefore, this review evaluates the diverse roles microglia play in the neuro-immunity to M. tuberculosis infection of the CNS.

Multiple intracranial space-occupying lesions in a renal transplant recipient from an area endemic for tuberculosis (TB): TB vs. toxoplasmosis

Renal transplant recipients may present with intracranial space-occupying lesions (SOLs) due to infections as well as a post-transplant lymphoproliferative disorder (PTLD). Here, we discuss a renal transplant recipient who presented with neurologic symptoms and magnetic resonance imaging (MRI) of the brain showed multiple focal SOLs. Tuberculosis (TB), toxoplasmosis, nocardiosis, fungal infections, and PTLD were considered in the differential diagnosis. MRI spectroscopy was suggestive of an infectious cause, such as toxoplasmosis or TB. Serologic tests using Toxoplasma were negative. A brain biopsy followed by immunohistochemical staining using Toxoplasma antibody demonstrated multiple intravascular cysts of toxoplasma. This case highlights the diagnostic dilemma in an immunocompromised patient with multiple focal brain lesions, especially in areas where TB is endemic.

Tuberculous meningitis: Diagnostic and therapeutic challenges

Neurologists are often the first medical providers to evaluate patients with possible infectious meningitis. Knowledge of the clinical presentations and cerebrospinal fluid, microbiologic, and neuroimaging findings for different etiologies is essential to make a prompt diagnosis and initiate appropriate treatment. Tuberculosis is a common cause of meningitis in developing countries with a high prevalence of pulmonary tuberculosis. However, tuberculosis affects populations in every country and all neurologists need to be vigilant for possible cases of tuberculous meningitis presenting to their medical facilities. This article discusses the challenges of diagnosing and treating tuberculous meningitis and highlights recent advances in diagnostic technology.

When smear and molecular diagnostics fail: identification of tuberculosis in advanced HIV infection using the newly developed urine lipoarabinomannan lateral-flow assay

In HIV infection, progression of immunodeficiency is associated with increased risk of paucibacillary and disseminated forms of tuberculosis (TB). As a result, the clinical presentation may be atypical and the conventional diagnostic assays often unreliable, resulting in significant treatment delays. Here, we report a case of HIV-associated immune reconstitution inflammatory syndrome and TB meningitis. Although the smear and molecular assays were negative, Mycobacterium tuberculosis was identified in our patient using the new Determine-lipoarabinomannan (LAM) lateral-flow urine 'dip-stick' assay. This case report illustrates the clinical value of this assay for the diagnosis of TB in a subgroup of HIV-infected patients with advanced immunodeficiency. Also, although two recent studies have evaluated the use of the Determine TB-LAM assay in clinical settings, to the best of our knowledge, this is the first case report of TB diagnosed using this novel assay.

Central nervous system infections in travelers

International travelers commonly contract infections while abroad, many of which are primary neurological diseases or have potential neurological sequelae. The implications of these neuroinfectious diseases extend beyond the individual, since returning travelers may contribute to the spread of infection in novel areas. In this review, we discuss signs, symptoms, treatments, and prophylaxes for these infections, as well as emerging trends with regard to neuroinfectious diseases of the returning traveler.

Central Nervous System Tuberculosis: Challenges and Advances in Diagnosis and Treatment

Mycobacterium tuberculosis is one of the most prevalent human infections. Although the largest share of the burden of disease is in Africa and Asia, tuberculosis has a global footprint due to travel and migration. Resource constraints in many low- and middle-income countries are hampering efforts to control new infections and to prevent drug resistance. Infection of the central nervous system by Mycobacterium tuberculosis includes meningitis, tuberculoma, and abscess and carries a high morbidity and mortality. High clinical suspicion, combined with cerebrospinal fluid analysis and brain imaging studies, can improve the diagnostic certainty. The recent scale-up of nucleic acid amplification technology may allow earlier diagnosis of tuberculous meningitis in many regions of the world. Treatment of tuberculous infection of the central nervous system is usually empirical and follows conventional regimens for pulmonary tuberculosis. The optimal treatment regimen is still being elucidated and has been the subject of recent clinical trials.

Conservative management of spinal tuberculosis: initial series from pakistan

Study Design

A prospective study on spinal tuberculosis (TB) at a tertiary care hospital in an endemic region.

Purpose

The aim of the study is to reiterate the importance of conservative management of spinal TB.

Overview of Literature

Spinal tuberculosis can present with wide spectrum of symptoms, with back pain being the most common symptom. It is the leading cause of non-traumatic paraplegia in developing countries. There is an emerging trend to operate on patients early with spinal TB.

Methods

Forty-seven (M=14, F=33) patients were enrolled in the study during the four year study period. Initially, all the patients were subjected to computed tomography guided percutaneous needle aspiration (PCNA) followed by antituberculous therapy (ATT) for 12 months. Indications for surgery included patients with moderate to severe symptoms in which PCNA either failed, was impossible to carry out, or produced minimal improvement within 48 hours.

Results

Presenting complaints included pain (95.7%), weakness (85.1%) and sphincter involvement (12.8%). On the magnetic resonance imaging, a paravertebral abscess was seen in 37 (78.7%), disc and body destruction in 29 (61.7%), and an epidural abscess in 12 (25.9%) patients. Of the 47 patients, 9 (19.1%) required surgery, 4 of whom had failed PCNA attempts and 5 demonstrated indications despite successful PCNA.

Conclusions

The results of conservative treatment consisting of PCNA and ATT for at least 12 months in compliant patients are excellent. A combined approach using clinical staging, PCNA, and ATT can minimize surgical intervention in most patients. However, ATT remains to be the cornerstone of management of spinal TB.

Drug induced increases in CNS dopamine alter monocyte, macrophage and T cell functions: implications for HAND

Central nervous system (CNS) complications resulting from HIV infection remain a major public health problem as individuals live longer due to the success of combined antiretroviral therapy (cART). As many as 70 % of HIV infected people have HIV associated neurocognitive disorders (HAND). Many HIV infected individuals abuse drugs, such as cocaine, heroin or methamphetamine, that may be important cofactors in the development of HIV CNS disease. Despite different mechanisms of action, all drugs of abuse increase extracellular dopamine in the CNS. The effects of dopamine on HIV neuropathogenesis are not well understood, and drug induced increases in CNS dopamine may be a common mechanism by which different types of drugs of abuse impact the development of HAND. Monocytes and macrophages are central to HIV infection of the CNS and to HAND. While T cells have not been shown to be a major factor in HIV-associated neuropathogenesis, studies indicate that T cells may play a larger role in the development of HAND in HIV infected drug abusers. Drug induced increases in CNS dopamine may dysregulate functions of, or increase HIV infection in, monocytes, macrophages and T cells in the brain. Thus, characterizing the effects of dopamine on these cells is important for understanding the mechanisms that mediate the development of HAND in drug abusers.