Tuberculous meningitis-related optic neuritis: recovery of vision with thalidomide in 4 consecutive cases

The leptomeninges as a critical organ for normal CNS development and function: First patient and public involved systematic review of arachnoiditis (chronic meningitis)

BACKGROUND & IMPORTANCE

This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward.

METHODS

The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions.

RESULTS

Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic.

DISCUSSION & CONCLUSION

DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed.

Neuro-ophthalmic manifestations of tuberculosis

Neuro-ophthalmic features are a known association in tuberculosis, especially common in central nervous system tuberculosis (CNS-TB). They are mostly the result of the visual pathway and/or ocular motor and other cranial nerve involvement. Furthermore, toxic optic neuropathy and paradoxical response to anti-tubercular drugs (ATT) are also not uncommon. The etiopathogenesis is by the complex interplay of various factors like exudates, vasculitis, arachnoiditis, presence of tuberculomas, hydrocephalus, brain infarcts and/or immune-mediated reaction. The entity often poses a diagnostic dilemma for the ophthalmologists/neuro-ophthalmologists and may lead to irreversible vision loss. The presence of neuro-ophthalmic features not only affect the visual outcome but are also predictors of systemic morbidity of the disease. Therefore, understanding and knowledge about this entity are necessary for the comprehensive management of the disease. While various forms of TB including CNS-TB have been well-dealt with in literature, little is discussed specifically about the neuro-ophthalmic manifestations of tuberculosis. Therefore, the purpose of this review is to highlight current understanding of the types of neuro-ophthalmic involvement in tuberculosis, its etiopathogenesis, diagnosis and management.

Treatment and outcome in children with tuberculous meningitis - a multi-centre Paediatric Tuberculosis Network European Trials Group study

INTRODUCTION

Currently, data on treatment, outcome, and prognostic factors in children with tuberculous meningitis (TBM) in Europe are limited. To date, most existing data on TBM originate from adult studies, or studies conducted in low-resource settings.

METHODS

Multicentre, retrospective study involving 27 paediatric healthcare institutions in nine European countries via an established paediatric TB research network, before and after the 2014 revision of WHO dosing recommendations.

RESULTS

Of 118 children, 39 (33.1%) had TBM grade 1, 68 (57.6%) grade 2 and 11 (9.3%) grade 3. Fifty-eight (49.1%) children received a standard four-drug treatment regimen; other commonly used drugs included streptomycin, prothionamide, and amikacin. Almost half of the patients (48.3%; 56/116) were admitted to intensive care unit, with a median stay of 10 (IQR 4.5-21.0) days. Of 104 children with complete outcome data, 9.6% (10/104) died, and only 47.1% (49/104) recovered fully. Main long-term sequelae included spasticity of one or more limbs and developmental delay both in 19.2% (20/104), and seizure disorder in 17.3% (18/104). Multivariate regression analyses identified microbiological confirmation of TBM, the need for neurosurgical intervention and mechanical ventilation as risk factors for unfavourable outcome.

DISCUSSION

There was considerable heterogeneity in the use of TB drugs in this cohort. Despite few children presenting with advanced disease and the study being conducted in a high-resource setting, morbidity and mortality were high. Several risk factors for poor outcome were identified, which may aid prognostic predictions in children with TBM in the future.

The use of thalidomide to treat children with tuberculosis meningitis: A review

Much of the morbidity and mortality caused by tuberculous meningitis (TBM) is mediated by a dysregulated immune response. Effective host-directed therapy is therefore critical to improve survival and clinical outcomes. Currently only one host-directed therapy (HDT), corticosteroids, is proven to improve mortality. However, there is no evidence that corticosteroids reduce morbidity and the mechanism of action for mortality reduction is uncertain. Further, it has no proven benefit in HIV co-infected individuals. One promising host-directed therapy approach is to restrict the immunopathology arising from tumour necrosis factor (TNF)-α excess is via TNF-α inhibitors. There are accumulating data on the role of thalidomide, anti-TNF-α monoclonal antibodies (infliximab, adalimumab) and the soluble TNF-α receptor (etanercept) in TBM treatment. Thalidomide was developed nearly seventy years ago and has been a highly controversial drug. Birth defects and toxic adverse effects have limited its use but an improved understanding of its immunological mechanism of action suggest that it may have a crucial role in regulating the destructive host response seen in inflammatory conditions such as TBM. Observational studies at our institution found low dosage adjunctive thalidomide safe in treating tuberculous mass lesions and blindness related to optochiasmatic arachnoiditis, with good clinical and radiological response. In this review, we discuss possible mechanisms of action for thalidomide, based on our clinico-radiologic experience and post-mortem histopathological work. We also propose a rationale for its use in the treatment of certain TBM-related complications.

Host Directed Therapies for Tuberculous Meningitis

A dysregulated host immune response significantly contributes to morbidity and mortality in tuberculous meningitis (TBM). Effective host directed therapies (HDTs) are critical to improve survival and clinical outcomes. Currently only one HDT, dexamethasone, is proven to improve mortality. However, there is no evidence dexamethasone reduces morbidity, how it reduces mortality is uncertain, and it has no proven benefit in HIV co-infected individuals. Further research on these aspects of its use, as well as alternative HDTs such as aspirin, thalidomide and other immunomodulatory drugs is needed. Based on new knowledge from pathogenesis studies, repurposed therapeutics which act upon small molecule drug targets may also have a role in TBM. Here we review existing literature investigating HDTs in TBM, and propose new rationale for the use of novel and repurposed drugs. We also discuss host variable responses and evidence to support a personalised approach to HDTs in TBM.

Host Directed Therapies for Tuberculous Meningitis

A dysregulated host immune response significantly contributes to morbidity and mortality in tuberculous meningitis (TBM). Effective host directed therapies (HDTs) are critical to improve survival and clinical outcomes. Currently only one HDT, dexamethasone, is proven to improve mortality. However, there is no evidence dexamethasone reduces morbidity, how it reduces mortality is uncertain, and it has no proven benefit in HIV co-infected individuals. Further research on these aspects of its use, as well as alternative HDTs such as aspirin, thalidomide and other immunomodulatory drugs is needed. Based on new knowledge from pathogenesis studies, repurposed therapeutics which act upon small molecule drug targets may also have a role in TBM. Here we review existing literature investigating HDTs in TBM, and propose new rationale for the use of novel and repurposed drugs. We also discuss host variable responses and evidence to support a personalised approach to HDTs in TBM.

Thalidomide Use for Complicated Central Nervous System Tuberculosis in Children: Insights From an Observational Cohort

BACKGROUND

Much of the neurological sequelae of central nervous system (CNS) tuberculosis (TB) is due to an excessive cytokine-driven host-inflammatory response. Adjunctive corticosteroids, which reduce cytokine production and thus dampen the inflammation, improve overall survival but do not prevent morbidity. This has prompted investigation of more targeted immunomodulatory agents, including thalidomide.

METHODS

We describe a retrospective cohort of 38 children consecutively treated with adjunctive thalidomide for CNS TB-related complications over a 10-year period.

RESULTS

The most common presenting symptom was focal motor deficit (n = 16), followed by cranial nerve palsies and cerebellar dysfunction. Three of the 38 children presented with large dural-based lesions, manifesting as epilepsia partialis continua (EPC), 4 presented with blindness secondary to optochiasmatic arachnoiditis, and 2 children developed paraplegia due to spinal cord TB mass lesions. Duration of adjunctive thalidomide therapy (3-5 mg/kg/day) varied according to complication type. In children compromised by TB mass lesions, the median treatment duration was 3.9 months (interquartile range [IQR], 2.0-5.0 months), whereas in children with optic neuritis it was 2.0 months (IQR, 1.3-7.3 months) and in EPC it was 1.0 months (IQR, 1-2.5 months). Satisfactory clinical and radiological response was observed in 37 of the children. None of the children experienced rashes, hepatitis, or hematologic derangements or complained of leg cramps.

CONCLUSIONS

This study is the largest cohort of adult or pediatric patients treated with adjunctive thalidomide for CNS TB-related complications. The drug has proved to be safe and well tolerated and appears to be clinically efficacious. The potential role of thalidomide or analogues in the treatment of other tuberculous meningitis-related complications requires further exploration.

Neurotuberculosis: an update

Tuberculous (TB) meningitis (TBM), accounting for 70-80% of cases of neurotuberculosis, is one of the most severe forms of extrapulmonary tuberculosis. Two-thirds of new TB cases come from eight countries. Polymorphisms in toll-interleukin-1 receptor domain and in leukotriene A4 hydrolase (LTA4H) gene, affect the risk of inflammation in TBM. The common site of tuberculoma in children is cerebellum, and they may rarely develop tuberculous encephalopathy which has a high mortality. Young females with a high cerebrospinal fluid (CSF) protein have an increased predisposition to develop optochiasmatic arachnoiditis. Spinal TB meningitis may mimic transverse myelitis or Guillain-Barre syndrome. An extra-neural focus of TB should be sought clinically and radiologically as it may indicate safer and more accessible sites for diagnostic samplings. Cartridge-based nucleic acid amplification test (CBNAAT), also known as Genexpert test, is a polymerase chain reaction (PCR)-based method for detection of TB which also detects rifampicin resistance as it targets the rpob gene of mycobacteria. Line probe assays, based on PCR and reverse hybridization methods, identify mutations associated with drug resistance within a week. TBM being a paucibacillary disease, often evades a definite diagnosis and empirical treatment for a minimum of 9 months is warranted based on clinical judgement. All TBM patients should receive adjunctive corticosteroids, even those with HIV infection. Drug resistance is strongly associated with previous treatment and bedaquiline as well as delamanid have received approvals for multidrug resistant (MDR) TB. The key principle of managing MDR TB is never to add a single drug to a failing regimen. Correct combination and duration of most effective second line drugs in MDR TB require further modifications. Early shunting should be considered in those with hydrocephalus failing medical management. The single most important determinant of outcome is the stage of TBM at which treatment has been started.

Use of Infliximab to Treat Paradoxical Tuberculous Meningitis Reactions

We documented dramatic responses to infliximab in 4 tuberculous meningitis cases with severe paradoxical reactions after effective antibacterial treatment, despite high-dose steroids. In every instance, infliximab was used as a last resort after all other options were exhausted, resulting in delayed initiation that may have adversely affected patient outcomes.

Tumor necrosis factor antagonists for paradoxical inflammatory reactions in the central nervous system tuberculosis: Case report and review

RATIONALE

Paradoxical reaction/immune reconstitution inflammatory syndrome is common in patients with central nervous system tuberculosis. Management relies on high-dose corticosteroids and surgery when feasible.

PATIENT CONCERN

We describe 2 cases of HIV-negative patients with corticosteroid-refractory paradoxical reactions of central nervous system tuberculosis.

DIAGNOSES

The 2 patients experienced clinical impairment shortly after starting therapy for TB, and magnetic resonance imaging showed the presence of tuberculomas, leading to the diagnosis of a paradoxical reaction.

INTERVENTIONS

We added infliximab, an anti-tumor necrosis factor (TNF)-alpha monoclonal antibody, to the dexamethasone.

OUTCOMES

Both patients had favorable outcomes, 1 achieving full recovery but 1 suffering neurologic sequelae.

LESSONS

Clinicians should be aware of the risk of paradoxical reactions/immune reconstitution inflammatory syndrome when treating patients with tuberculosis of the central nervous system and should consider the prompt anti-TNF-α agents in cases not responding to corticosteroids.

Successful Treatment of a Severe Vision-Threatening Paradoxical Tuberculous Reaction with Infliximab: First Pediatric Use

A 7-year-old girl with tuberculous (TB) meningitis developed optochiasmatic arachnoiditis, a vision-threatening paradoxical reaction, after starting TB treatment including adjunctive steroid therapy. She was treated with infliximab with complete recovery. This is the first report of the use of a tissue necrosis factor α inhibitor for the treatment of a severe paradoxical TB reaction in a child.

Intravitreal thalidomide ameliorates inflammation in a model of experimental uveitis induced by BCG

Uveitis encompasses a heterogeneous and complex group of conditions characterized by intraocular inflammation, frequently affecting young individuals and representing an important cause of irreversible blindness worldwide. Animal models have been critical to understand etiology and pathogenesis of uveitis, being also employed to assess new therapeutic strategies, preceding human studies. However, there is still a need of developing and studying different models, due to the difficulties in recapitulating all forms of human uveitis effectively. Although corticosteroids are usually the first-line therapy for non-infectious uveitis, their long-term use is limited by potentially serious side effects in all possible delivery routes. Thus, thalidomide, a drug with anti-inflammatory and antiangiogenic properties, was investigated in a novel experimental model of uveitis, induced by Mycobacterium bovis Calmette-Guérin Bacillus (BCG), in rabbits. The experimental protocol consisted of two subcutaneous injections of BCG, followed by two intravitreal injections of the same antigen, inducing panuveitis. Animals were treated with a single intravitreal injection of thalidomide suspension or PBS. Clinical manifestations of uveitis improved after intravitreal thalidomide, involving both anterior and posterior segments. Protein content, N-acetyl-b-glucosaminidase (NAG) and myeloperoxidase (MPO) activities were elevated in ocular tissues after disease induction, further decreasing post-treatment with intravitreal thalidomide. This therapeutic response was also confirmed on ocular electrophysiology, as well as histopathology. This experimental model induced panuveitis in rabbits using a low-cost mycobacterial antigen, with intraocular inflammation subsequently improving after treatment. Intravitreal thalidomide may be a potential alternative to treat intraocular inflammation in corticosteroid-sparing therapies.

Thalidomide and Phosphodiesterase 4 Inhibitors as Host Directed Therapeutics for Tuberculous Meningitis: Insights From the Rabbit Model

Tuberculous meningitis (TBM) is the most devastating form of extrapulmonary Mycobacterium tuberculosis infection in humans. Severe inflammation and extensive tissue damage drive the morbidity and mortality of this manifestation of tuberculosis (TB). Antibiotic treatment is ineffective at curing TBM due to variable and incomplete drug penetration across the blood-brain barrier (BBB) and blood-cerebrospinal fluid (CSF) barriers. Adjunctive corticosteroid therapy, used to dampen the inflammation, and the pathologic manifestation of TBM, improves overall survival but does not entirely prevent the morbidity of the disease and has significant toxicities, including immune-suppression. The rabbit has served as a fit for purpose experimental model of human TBM since the early 1900s due to the similarity in the developmental processes of the brain, including neuronal development, myelination, and microglial functions between humans and rabbits. Consistent with the observations made in humans, proinflammatory cytokines, including TNF-α, play a critical role in the pathogenesis of TBM in rabbits focusing the attention on the utility of TNF-α inhibitors in treating the disease. Thalidomide, an inhibitor of monocyte-derived TNF-α, was evaluated in the rabbit model of TBM and shown to improve survival and reduce inflammation of the brain and the meninges. Clinical studies in humans have also shown a beneficial response to thalidomide. However, the teratogenicity and T-cell activation function of the drug limit the use of thalidomide in the clinic. Thus, new drugs with more selective anti-inflammatory properties and a better safety profile are being developed. Some of these candidate drugs, such as phosphodiesterase-4 inhibitors, have been shown to reduce the morbidity and increase the survival of rabbits with TBM. Future studies are needed to assess the beneficial effects of these drugs for their potential to improve the current treatment strategy for TBM in humans.

Neuroinflammation as a Factor of Neurodegenerative Disease: Thalidomide Analogs as Treatments

Neuroinflammation is initiated when glial cells, mainly microglia, are activated by threats to the neural environment, such as pathogen infiltration or neuronal injury. Although neuroinflammation serves to combat these threats and reinstate brain homeostasis, chronic inflammation can result in excessive cytokine production and cell death if the cause of inflammation remains. Overexpression of tumor necrosis factor-α (TNF-α), a proinflammatory cytokine with a central role in microglial activation, has been associated with neuronal excitotoxicity, synapse loss, and propagation of the inflammatory state. Thalidomide and its derivatives, termed immunomodulatory imide drugs (IMiDs), are a class of drugs that target the 3'-untranslated region (3'-UTR) of TNF-α mRNA, inhibiting TNF-α production. Due to their multi-potent effects, several IMiDs, including thalidomide, lenalidomide, and pomalidomide, have been repurposed as drug treatments for diseases such as multiple myeloma and psoriatic arthritis. Preclinical studies of currently marketed IMiDs, as well as novel IMiDs such as 3,6'-dithiothalidomide and adamantyl thalidomide derivatives, support the development of IMiDs as therapeutics for neurological disease. IMiDs have a competitive edge compared to similar anti-inflammatory drugs due to their blood-brain barrier permeability and high bioavailability, with the potential to alleviate symptoms of neurodegenerative disease and slow disease progression. In this review, we evaluate the role of neuroinflammation in neurodegenerative diseases, focusing specifically on the role of TNF-α in neuroinflammation, as well as appraise current research on the potential of IMiDs as treatments for neurological disorders.

The current global situation for tuberculous meningitis: epidemiology, diagnostics, treatment and outcomes

Tuberculous meningitis (TBM) results from dissemination of M. tuberculosis to the cerebrospinal fluid (CSF) and meninges. Ischaemia, hydrocephalus and raised intracranial pressure frequently result, leading to extensive brain injury and neurodisability. The global burden of TBM is unclear and it is likely that many cases are undiagnosed, with many treated cases unreported. Untreated, TBM is uniformly fatal, and even if treated, mortality and morbidity are high. Young age and human immunodeficiency virus (HIV) infection are potent risk factors for TBM, while Bacillus Calmette-Guérin (BCG) vaccination is protective, particularly in young children. Diagnosis of TBM usually relies on characteristic clinical symptoms and signs, together with consistent neuroimaging and CSF parameters. The ability to confirm the TBM diagnosis via CSF isolation of M. tuberculosis depends on the type of diagnostic tests available. In most cases, the diagnosis remains unconfirmed. GeneXpert MTB/RIF and the next generation Xpert Ultra offer improved sensitivity and rapid turnaround times, and while roll-out has scaled up, availability remains limited. Many locations rely only on acid fast bacilli smear, which is insensitive. Treatment regimens for TBM are based on evidence for pulmonary tuberculosis treatment, with little consideration to CSF penetration or mode of drug action required. The World Health Organization recommends a 12-month treatment course, although data on which to base this duration is lacking. New treatment regimens and drug dosages are under evaluation, with much higher dosages of rifampicin and the inclusion of fluoroquinolones and linezolid identified as promising innovations. The inclusion of corticosteroids at the start of treatment has been demonstrated to reduce mortality in HIV-negative individuals but whether they are universally beneficial is unclear. Other host-directed therapies show promise but evidence for widespread use is lacking. Finally, the management of TBM within health systems is sub-optimal, with drop-offs at every stage in the care cascade.

Host-directed therapies to combat tuberculosis and associated non-communicable diseases

Mycobacterium tuberculosis (Mtb) has coevolved with a human host to evade and exploit the immune system in multiple ways. Mtb is an enormously successful human pathogen that can remain undetected in hosts for decades without causing clinical disease. While tuberculosis (TB) represents a perfect prototype of host-pathogen interaction, it remains a major challenge to develop new therapies to combat mycobacterial infections. Additionally, recent studies emphasize on comorbidity of TB with different non-communicable diseases (NCDs), highlighting the impact of demographic and lifestyle changes on the global burden of TB. In the recent past, host-directed therapies have emerged as a novel and promising approach to treating TB. Drugs modulating host responses are likely to avoid the development of bacterial resistance which is a major public health concern for TB treatment. Interestingly, many of these drugs also form treatment strategies for non-communicable diseases. In general, technological advances along with novel host-directed therapies may open an exciting and promising research area, which can eventually deliver effective TB treatment as well as curtail the emergent synergy with NCDs.

Late-onset paradoxical reactions 10 years after treatment for tuberculous meningitis in an HIV-negative patient: a case report

Background

Although paradoxical reactions (PRs) to anti-tuberculosis (anti-TB) therapy during treatment are well-established occurrences, PRs presenting as a new lesion after the completion of treatment are extremely rare, and little is known about the management of such cases, particularly of central nervous system (CNS) tuberculosis.

Case presentation

A 27-year-old female, with a past medical history of tuberculous meningitis 10 years ago and who completed the anti-TB treatment with asymptomatic remnant tuberculomas in the basal cistern, was admitted to our hospital because of a headache and the worsening of pre-existing visual disturbance. Contrast-enhanced T1-weighted brain magnetic resonance imaging (MRI) revealed new tuberculomas in the left sylvian fissure with a diffuse low signal around it. Because repeated polymerase chain reaction and Mycobacterium tuberculosis culture presented negative results and the patient had no laboratory data suggestive of a relapse of tuberculous meningitis, she was diagnosed with late-onset post-treatment PRs and treated with oral corticosteroids, tapered off over 1 year. Eventually, the symptoms were relieved, and the tuberculomas disappeared.

Conclusions

Clinicians should consider the possibility of PRs long after the completion of tuberculous meningitis treatment. Hence, a precise MRI-based examination is imperative for the follow-up of CNS tuberculosis, and the unnecessary administration of anti-TB drugs should be avoided. The use of corticosteroids as a treatment option for post-treatment PRs is seemingly safe when the isolated M. tuberculosis is sensitive to the first-line anti-TB therapy.

Standardized Methods for Enhanced Quality and Comparability of Tuberculous Meningitis Studies

Tuberculous meningitis (TBM) remains a major cause of death and disability in tuberculosis-endemic areas, especially in young children and immunocompromised adults. Research aimed at improving outcomes is hampered by poor standardization, which limits study comparison and the generalizability of results. We propose standardized methods for the conduct of TBM clinical research that were drafted at an international tuberculous meningitis research meeting organized by the Oxford University Clinical Research Unit in Vietnam. We propose a core dataset including demographic and clinical information to be collected at study enrollment, important aspects related to patient management and monitoring, and standardized reporting of patient outcomes. The criteria proposed for the conduct of observational and intervention TBM studies should improve the quality of future research outputs, can facilitate multicenter studies and meta-analyses of pooled data, and could provide the foundation for a global TBM data repository.

Efficacy of thalidomide therapy in pediatric Crohn’s disease with evidence of tuberculosis

AIM

To evaluate the efficacy of thalidomide for treating troublesome cases of pediatric Crohn’s disease (CD) with tuberculosis infection.

METHODS

A retrospective study of clinical outcome among children treated with thalidomide was conducted. All patients had evidence of tuberculosis infection with a failure of anti-tuberculosis treatment for more than one year, and were subsequently diagnosed with CD. All the patients received thalidomide treatment with a starting dose of 1.2-2.5 mg/kg per day. Remission was defined as pediatric CD activity index less than or equal to 10.

RESULTS

Ten patients with CD were treated with thalidomide at an average age of 7.2 years and followed up for a median of 22.2 mo. Clinical remission rate was 60% after 9-12 mo of thalidomide treatment. One patient with no response had an interleukin-10 receptor alpha gene mutation. Erythrocyte sedimentation rate, C-reactive protein and platelet count showed a dramatic decrease; hemoglobin level and weight improved significantly after thalidomide treatment when compared with the baseline values.

CONCLUSION

Thalidomide is an effective and safe drug for remission of CD in pediatric patients who have been treated for tuberculosis.

Tuberculous meningitis

Tuberculosis remains a global health problem, with an estimated 10.4 million cases and 1.8 million deaths resulting from the disease in 2015. The most lethal and disabling form of tuberculosis is tuberculous meningitis (TBM), for which more than 100,000 new cases are estimated to occur per year. In patients who are co-infected with HIV-1, TBM has a mortality approaching 50%. Study of TBM pathogenesis is hampered by a lack of experimental models that recapitulate all the features of the human disease. Diagnosis of TBM is often delayed by the insensitive and lengthy culture technique required for disease confirmation. Antibiotic regimens for TBM are based on those used to treat pulmonary tuberculosis, which probably results in suboptimal drug levels in the cerebrospinal fluid, owing to poor blood-brain barrier penetrance. The role of adjunctive anti-inflammatory, host-directed therapies - including corticosteroids, aspirin and thalidomide - has not been extensively explored. To address this deficit, two expert meetings were held in 2009 and 2015 to share findings and define research priorities. This Review summarizes historical and current research into TBM and identifies important gaps in our knowledge. We will discuss advances in the understanding of inflammation in TBM and its potential modulation; vascular and hypoxia-mediated tissue injury; the role of intensified antibiotic treatment; and the importance of rapid and accurate diagnostics and supportive care in TBM.

Tuberculous tales: an East London experience

Tuberculous meningitis presents a diagnostic and therapeutic challenge, and considering its long history and increasing global incidence, the evidence base for its treatment is relatively scanty. Many UK neurologists will have little first-hand experience of this deadly condition, and if faced with a patient with possible tuberculous meningitis will find decision making less than straightforward. In parts of East London (UK) the rates of tuberculosis and tuberculous meningitis are among the highest in Western Europe, and so the neurologists and respiratory physicians at the Royal London Hospital have encountered many such patients over the years. We have found experience to be a valuable teacher and so would like to share five cases that illustrate the complexities of diagnosis and management of the disease, and complications of its treatment.

Drug-resistant tuberculosis and advances in the treatment of childhood tuberculosis

Over the last 10 years, interest in pediatric tuberculosis (TB) has increased dramatically, together with increased funding and research. We have a better understanding of the burden of childhood TB as well as a better idea of how to diagnose it. Our appreciation of pathophysiology is improved and with it investigators are beginning to consider pediatric TB as a heterogeneous entity, with different types and severity of disease being treated in different ways. There have been advances in how to treat both TB infection and TB disease caused by both drug-susceptible as well as drug-resistant organisms. Two completely novel drugs, bedaquiline and delamanid, have been developed, in addition to the use of older drugs that have been re-purposed. New regimens are being evaluated that have the potential to shorten treatment. Many of these drugs and regimens have first been investigated in adults with children an afterthought, but increasingly children are being considered at the outset and, in some instances studies are only conducted in children where pediatric-specific issues exist.

Recent Developments and Future Opportunities in the Treatment of Tuberculosis in Children

Tuberculosis in children accounts for a significant proportion of the overall burden of disease, and yet for many years research into pediatric treatment has been neglected. Recently, there have been major developments in our understanding of pediatric tuberculosis, and a large number of studies are under way or planned. New drugs and regimens are being evaluated, and older drugs are being repurposed. Shorter regimens with potentially fewer side effects are being assessed for the treatment and prevention of both drug-susceptible and drug-resistant tuberculosis. It may be possible to tailor treatment so that children with less severe disease are given shorter regimens, and weekly dosing is under investigation for preventive therapy and for the continuation phase of treatment. The interaction with human immunodeficiency virus and the management of tuberculosis meningitis are also likely to be better understood. Exciting times lie ahead for pediatric tuberculosis, but much work remains to be done.

Sharpening nature's tools for efficient tuberculosis control: A review of the potential role and development of host-directed therapies and strategies for targeted respiratory delivery

Centuries since it was first described, tuberculosis (TB) remains a significant global public health issue. Despite ongoing holistic measures implemented by health authorities and a number of new oral treatments reaching the market, there is still a need for an advanced, efficient TB treatment. An adjunctive, host-directed therapy designed to enhance endogenous pathways and hence compliment current regimens could be the answer. The integration of drug repurposing, including synthetic and naturally occurring compounds, with a targeted drug delivery platform is an attractive development option. In order for a new anti-tubercular treatment to be produced in a timely manner, a multidisciplinary approach should be taken from the outset including stakeholders from academia, the pharmaceutical industry, and regulatory bodies keeping the patient as the key focus. Pre-clinical considerations for the development of a targeted host-directed therapy are discussed here.

Corticosteroids for managing tuberculous meningitis

BACKGROUND

Tuberculous meningitis is a serious form of tuberculosis (TB) that affects the meninges that cover a person's brain and spinal cord. It is associated with high death rates and with disability in people who survive. Corticosteroids have been used as an adjunct to antituberculous drugs to treat people with tuberculous meningitis, but their role has been controversial.

OBJECTIVES

To evaluate the effects of corticosteroids as an adjunct to antituberculous treatment on death and severe disability in people with tuberculous meningitis.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register up to the 18 March 2016; CENTRAL; MEDLINE; EMBASE; LILACS; and Current Controlled Trials. We also contacted researchers and organizations working in the field, and checked reference lists.

SELECTION CRITERIA

Randomized controlled trials that compared corticosteroid plus antituberculous treatment with antituberculous treatment alone in people with clinically diagnosed tuberculous meningitis and included death or disability as outcome measures.

DATA COLLECTION AND ANALYSIS

We independently assessed search results and methodological quality, and extracted data from the included trials. We analysed the data using risk ratios (RR) with 95% confidence intervals (CIs) and used a fixed-effect model. We performed an intention-to-treat analysis, where we included all participants randomized to treatment in the denominator. This analysis assumes that all participants who were lost to follow-up have good outcomes. We carried out a sensitivity analysis to explore the impact of the missing data.

MAIN RESULTS

Nine trials that included 1337 participants (with 469 deaths) met the inclusion criteria.At follow-up from three to 18 months, steroids reduce deaths by almost one quarter (RR 0.75, 95% CI 0.65 to 0.87; nine trials, 1337 participants, high quality evidence). Disabling neurological deficit is not common in survivors, and steroids may have little or no effect on this outcome (RR 0.92, 95% CI 0.71 to 1.20; eight trials, 1314 participants, low quality evidence). There was no difference between groups in the incidence of adverse events, which included gastrointestinal bleeding, invasive bacterial infections, hyperglycaemia, and liver dysfunction.One trial followed up participants for five years. The effect on death was no longer apparent at this time-point (RR 0.93, 95% CI 0.78 to 1.12; one trial, 545 participants, moderate quality evidence); and there was no difference in disabling neurological deficit detected (RR 0.91, 95% CI 0.49 to 1.69; one trial, 545 participants, low quality evidence).One trial included human immunodeficiency virus (HIV)-positive people. The stratified analysis by HIV status in this trial showed no heterogeneity, with point estimates for death (RR 0.90, 95% CI 0.67 to 1.20; one trial, 98 participants) and disability (RR 1.23, 95% CI 0.08 to 19.07; one trial, 98 participants) similar to HIV-negative participants in the same trial.

AUTHORS' CONCLUSIONS

Corticosteroids reduce mortality from tuberculous meningitis, at least in the short term.Corticosteroids may have no effect on the number of people who survive tuberculous meningitis with disabling neurological deficit, but this outcome is less common than death, and the CI for the relative effect includes possible harm. However, this small possible harm is unlikely to be quantitatively important when compared to the reduction in mortality.The number of HIV-positive people included in the review is small, so we are not sure if the benefits in terms of reduced mortality are preserved in this group of patients.

Advancing host-directed therapy for tuberculosis

Improved treatments are needed for nearly all forms of Mycobacterium tuberculosis infection. Adjunctive host-directed therapies have the potential to shorten tuberculosis treatment duration, prevent resistance and reduce lung injury by promoting autophagy, antimicrobial peptide production and other macrophage effector mechanisms, as well as by modifying specific mechanisms that cause lung inflammation and matrix destruction. The range of candidates is broad, including several agents approved for other clinical indications that are ready for evaluation in Phase II clinical trials. The promise of new and existing host-directed therapies that could accelerate response and improve tuberculosis treatment outcomes is discussed in this Opinion article.

Management of paradoxical response in pediatric tubercular meningitis with methylprednisolone

Paradoxical response to anti-tubercular drugs remains a diagnostic dilemma. In India where tuberculosis is quite prevalent, paradoxical response to anti-tubercular treatment (ATT) is either misdiagnosed or under-diagnosed. We report two cases of optochiasmatic arachnoiditis due to paradoxical response in children suffering from tuberculous meningitis. Visual acuity was recorded as no light perception in all eyes of both patients while they were taking 4-drug ATT (isoniazid, rifampicin, pyrazinamide and ethambutol). However their systemic conditions did not worsen. They were treated with intravenous methylprednisolone for five days followed by systemic corticosteroids on a tapering dose for four weeks along with ATT. This case report highlights the importance of early recognition of this sight-threatening complication and timely, effective treatment to prevent permanent blindness.

Update on the diagnosis and management of tuberculous meningitis in children

Tuberculous meningitis (TBM), the most devastating manifestation of tuberculosis, is often missed or overlooked because of nonspecific symptoms and difficulties in diagnosis. It continues to be an important cause of neurologic handicap in resource-poor countries. Owing to the suboptimal performance of diagnostic tests of TBM, diagnosis relies on thorough history, clinical examination, and relevant investigations. The development of affordable, accurate diagnostic tests for TBM in resource-poor settings remains a priority. Short intensified treatment is safe and effective in both human immunodeficiency virus (HIV)-infected and HIV-uninfected children. Treatment of tuberculous hydrocephalus depends on the level of the cerebrospinal fluid obstruction. Corticosteroids reduce risk of neurodisability and death in HIV-uninfected children. Thalidomide should be considered in children compromised by tuberculosis abscesses and tuberculous-related optochiasmic arachnoiditis. In resource-poor countries, home-based TBM treatment after initial in-hospital stabilization is feasible in carefully selected patients. Early diagnosis and treatment of TBM is the single most important factor determining outcome.

Tuberculous meningitis: more questions, still too few answers

Tuberculous meningitis is especially common in young children and people with untreated HIV infection, and it kills or disables roughly half of everyone affected. Childhood disease can be prevented by vaccination and by giving prophylactic isoniazid to children exposed to infectious adults, although improvements in worldwide tuberculosis control would lead to more effective prevention. Diagnosis is difficult because clinical features are non-specific and laboratory tests are insensitive, and treatment delay is the strongest risk factor for death. Large doses of rifampicin and fluoroquinolones might improve outcome, and the beneficial effect of adjunctive corticosteroids on survival might be augmented by aspirin and could be predicted by screening for a polymorphism in LTA4H, which encodes an enzyme involved in eicosanoid synthesis. However, these advances are insufficient in the face of drug-resistant tuberculosis and HIV co-infection. Many questions remain about the best approaches to prevent, diagnose, and treat tuberculous meningitis, and there are still too few answers.

A rare cause of blindness

BACKGROUND

Mycobacterium tuberculosis (TB) infection remains a serious problem in many underdeveloped countries. TB is largely perceived as a disease affecting the pulmonary system, yet despite declining cases of pulmonary TB in the United States (US), extrapulmonary infections are being reported at an increasing proportion of total TB cases. Moreover, due to the insidious nature of extrapulmonary TB (EPTB), it may not be readily recognized by emergency physicians, as it masquerades as more commonly encountered infectious or inflammatory processes.

OBJECTIVES

The incidence of ocular TB infection varies widely by geographic area, but has historically been low in the US. However, a resurgence of TB in developed European nations is cause for concern, as an increasing percentage of these infections have revealed ocular involvement.

CASE REPORT

We present a case report of blindness caused by Mycobacterium tuberculosis and highlight some of the challenges the emergency physician may encounter when diagnosing EPTB. The case includes the patient's treatment course and subsequent follow-up.

CONCLUSION

Loss of vision may be a presenting complaint for active tuberculosis infection.

Tuberculous meningitis

Tuberculous (TB) meningitis is common in resource-poor communities but also occurs in developed countries where the diagnosis is frequently delayed because of unfamiliarity with the disease. TB meningitis develops whenever a small intracranial tuberculoma (Rich focus) ruptures causing predominantly basal meningitis. This results in hydrocephalus, cranial nerve palsies, and ischemic brain injury secondary to tuberculous vasculitis. The primary source of TB is usually the lung. Early diagnosis is difficult because patients tend to present subacutely with nonspecific symptoms such as fever, cough, vomiting, listlessness, and failure to thrive. Lumbar puncture typically shows clear and colorless CSF with a low, predominantly lymphocytic, leukocytosis and raised protein and low glucose levels. Decision to treat is mostly clinical because of difficulty in demonstrating TB bacilli on routine smear and time needed for culture. A positive TB contact, Mantoux skin test, chest radiograph, CT/MRI brain scan, PCR for tuberculosis on CSF, and demonstration of TB bacilli from extraneural sources are invaluable in supporting a diagnosis of TB meningitis. Current World Health Organization guidelines recommend treatment with a four-drug regimen for 2 months, followed by a two-drug regimen for 10 months, the total duration of treatment being 12 months. Corticosteroids reduce mortality without changing neurological morbidity. Outcome relates closely to age and stage of disease.

Neurological manifestations of TB-IRIS: a report of 4 children

INTRODUCTION

Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is a potentially life-threatening complication in HIV infected children with tuberculosis (TB) of the central nervous system. HIV-associated TB-IRIS has not been previously described in children with neurotuberculosis.

OBJECTIVE

To describe the neurological and neuro-radiological features of 4 consecutive cases of TB-IRIS in children with neurotuberculosis and to discuss possible management strategies.

RESULTS

Three patients treated for tuberculosis of the central nervous system experienced paradoxical worsening of neurological symptoms when combination antiretroviral therapy (cART) was initiated. Intracranial tuberculomas were unmasked in the 4th patient. All patients developed new neurological signs within 10 days of cART initiation. Neurological symptoms and signs included headache, seizures, meningeal irritation, decreased level of consciousness, ataxia and focal motor deficit. Interventions included the temporary discontinuation of cART and the use of corticosteroids in all patients. Three patients received thalidomide and 1 chloroquine and mycophenolate mofetil. One patient died and the others experienced prolonged hospitalization.

CONCLUSION

TB-IRIS should be considered when new neurological signs develop shortly after initiation of cART in children. There is little data to guide the timing of initiation of cART and the management of complications in children.

A life-threatening central nervous system-tuberculosis inflammatory reaction nonresponsive to corticosteroids and successfully controlled by infliximab in a young patient with a variant of juvenile idiopathic arthritis

We report a young patient with a variant of juvenile idiopathic arthritis, who, after 4 years of infliximab treatment, developed miliary tuberculosis (TB) with central nervous system involvement (meningitis and multiple tuberculomas). After anti-TB treatment, clinical and radiologic responses were observed, but severe cerebrospinal fluid and brain inflammatory reaction, nonresponsive to corticosteroids, persisted. It was considered a life-threatening paradoxical reaction based on initial cerebrospinal fluid isolation of Mycobacterium tuberculosis fully sensitive to primary anti-TB drugs. After 4 months in the hospital, infliximab was administered considering that infliximab is a potent tumor necrosis factor α inhibiting agent that participates in the formation and preservation of granulomas and may help to modulate the exaggerated cell-mediated immune response against mycobacterial antigens. Clinical complications associated to brain inflammation resolved, and after 3 years of follow-up, the patient remains self-sufficient without neurologic sequels.

Optochiasmatic tuberculoma as the sole manifestation of late recurrent tuberculosis

Brain tuberculomas account for 10-20% of space occupying brain lesions in developing countries. Most lesions are observed at time of tuberculosis diagnosis or soon after starting treatment. We herein describe a 32 year-old patient with a 14-month history of headache and progressive visual loss. Her past medical history revealed pulmonary tuberculosis treated eight years before. A brain MRI showed a T1- and T2-weighted isointense contrast-enhancing lesion in the optic chiasm. A presumptive diagnosis of optochiasmatic tuberculoma was made and isoniazid, rifampin, pyrazinamide, and ethambutol were started. Despite treatment, the patient evolved to blindness. The prompt recognition of this condition is extremely important since the presence of optochiasmal enhancement is associated with blindness in patients with tuberculosis.

Tuberculous optochiasmatic arachnoiditis: a devastating form of tuberculous meningitis

Tuberculous meningitis is primarily a disease of the meninges of brain and spinal cord along with adjacent brain parenchyma. The characteristic pathological changes are meningeal inflammation, basal exudates, vasculitis and hydrocephalus. Tuberculous meningitis has a strong predilection for basal parts of the brain. Exudates, if dominantly present in the interpeduncular, suprasellar and Sylvian cisterns, result in optochiasmatic arachnoiditis and tuberculoma. Optochiasmatic arachnoiditis and tuberculoma are devastating forms of tuberculous meningitis and often associated with profound vision loss. This clinical entity more frequently affects young adults. In a recent study, on the multivariate logistic regression analysis, female sex, younger age and raised cerebrospinal fluid protein content were identified as predictors for developing optochiasmatic arachnoiditis. Frequently, optochiasmatic tuberculoma and optochiasmatic arachnoiditis develop paradoxically while a patient is being treated with anti-TB drugs. MRI reveals confluent enhancing lesions that are present in the interpeduncular fossa, pontine cistern, and the perimesencephalic and suprasellar cisterns. Management of tuberculous optochiasmatic arachnoiditis and optochiasmatic arachnoiditis tuberculoma has been variable. Treatment of optochiasmatic arachnoiditis continues to be a challenge and the response is generally unsatisfactory. In isolated case reports and in small series, corticosteroids, methyl prednisolone, thalidomide and hyaluronidase have been used with variable success. The benefit from neurosurgery is controversial and deterioration may follow the initial temporary improvement. Management of paradoxical optochiasmatic arachnoiditis is also controversial. Some patients regain vision following treatment with anti-TB drugs and continued usage of corticosteroids. Neurosurgery may be considered in the patients with either treatment failure or when diagnosis is in doubt. In conclusion, presence of optochiasmatic arachnoiditis or tuberculoma has important therapeutic and prognostic implications for patients of tuberculous meningitis.

Mycobacteria and biological response modifiers: two sides of the relationship

With increasing use of biological response modifiers (BRMs) for various systemic inflammatory diseases there is a need to be vigilant about complications with the use of these therapies. It is important to have appropriate screening for the infections in patients requiring BRMs. However, many studies have reported benefits of certain BRMs in the treatment of infections such as tuberculosis as adjuncts. Continued research and technical advances in immunogenetics helps understand complex mechanisms in the usage of the BRMs. This article summarizes the different aspects of the relationship between mycobacterial infections and the use of various BRMs for inflammatory conditions.