Brain MRI findings in relation to clinical characteristics and outcome of tuberculous meningitis

Convolutional neural network using magnetic resonance brain imaging to predict outcome from tuberculosis meningitis

INTRODUCTION

Tuberculous meningitis (TBM) leads to high mortality, especially amongst individuals with HIV. Predicting the incidence of disease-related complications is challenging, for which purpose the value of brain magnetic resonance imaging (MRI) has not been well investigated. We used a convolutional neural network (CNN) to explore the complementary contribution of brain MRI to the conventional prognostic determinants.

METHODS

We pooled data from two randomised control trials of HIV-positive and HIV-negative adults with clinical TBM in Vietnam to predict the occurrence of death or new neurological complications in the first two months after the subject's first MRI session. We developed and compared three models: a logistic regression with clinical, demographic and laboratory data as reference, a CNN that utilised only T1-weighted MRI volumes, and a model that fused all available information. All models were fine-tuned using two repetitions of 5-fold cross-validation. The final evaluation was based on a random 70/30 training/test split, stratified by the outcome and HIV status. Based on the selected model, we explored the interpretability maps derived from the models.

RESULTS

215 patients were included, with an event prevalence of 22.3%. On the test set our non-imaging model had higher AUC (71.2% [Formula: see text] 1.1%) than the imaging-only model (67.3% [Formula: see text] 2.6%). The fused model was superior to both, with an average AUC = 77.3% [Formula: see text] 4.0% in the test set. The non-imaging variables were more informative in the HIV-positive group, while the imaging features were more predictive in the HIV-negative group. All three models performed better in the HIV-negative cohort. The interpretability maps show the model's focus on the lateral fissures, the corpus callosum, the midbrain, and peri-ventricular tissues.

CONCLUSION

Imaging information can provide added value to predict unwanted outcomes of TBM. However, to confirm this finding, a larger dataset is needed.

Distinct features of ANCA-associated hypertrophic pachymeningitis compared with other etiologies: findings from a study of 74 patients

OBJECTIVES

We aimed to characterize the clinical and radiological features, and outcomes, of a large cohort of hypertrophic pachymeningitis (HP) patients from a single centre.

METHODS

We conducted a retrospective study at a tertiary referral centre, encompassing patients diagnosed with HP between 2003 and 2022. The diagnosis of HP relied on the identification of thickening of the dura mater via MRI of the brain or spine.

RESULTS

We included 74 patients, with a mean age of 43.6 ± 14.2 years, of whom 37 (50%) were male. Among the 74, 32 (43.2%) had an immune-mediated origin, including 21 with granulomatosis with polyangiitis (GPA) (predominantly PR3-ANCA positive), four with SLE, three with IgG4-related disease, three with idiopathic HP, and one with RA. Non-immune-mediated HP accounted for 45 cases (56.8%). Within this category, 21 (28.4%) were infectious cases, with 14 having Mycobacterium tuberculosis infection (TB-HP), and 21 (28.4%) having malignancy-associated HP. The clinical and MRI characteristics exhibited variations among the four etiological groups. Hypoglycorrhachia was primarily observed in infectious HP and malignancy-associated HP. Immune-mediated HP was associated with a peripheral pattern of contrast enhancement and the Eiffel-by-night sign. MRI features strongly indicative of TB-HP included leptomeningeal involvement, brain parenchymal lesions, and arterial stroke. MPO-ANCA GPA was associated with a higher prevalence of spinal HP.

CONCLUSIOS

Within our cohort, GPA and Mycobacterium tuberculosis emerged as the predominant causes of HP. We identified significant disparities in clinical and radiological features among the various etiologies, which could have implications for diagnosis.

Pediatric Meningeal Diseases: What Radiologists Need to Know

Evaluating altered mental status and suspected meningeal disorders in children often begins with imaging, typically before a lumbar puncture. The challenge is that meningeal enhancement is a common finding across a range of pathologies, making diagnosis complex. This review proposes a categorization of meningeal diseases based on their predominant imaging characteristics. It includes a detailed description of the clinical and imaging features of various conditions that lead to leptomeningeal or pachymeningeal enhancement in children and adolescents. These conditions encompass infectious meningitis (viral, bacterial, tuberculous, algal, and fungal), autoimmune diseases (such as anti-MOG demyelination, neurosarcoidosis, Guillain-Barré syndrome, idiopathic hypertrophic pachymeningitis, and NMDA-related encephalitis), primary and secondary tumors (including diffuse glioneuronal tumor of childhood, primary CNS rhabdomyosarcoma, primary CNS tumoral metastasis, extracranial tumor metastasis, and lymphoma), tumor-like diseases (Langerhans cell histiocytosis and ALK-positive histiocytosis), vascular causes (such as pial angiomatosis, ANCA-related vasculitis, and Moyamoya disease), and other disorders like spontaneous intracranial hypotension and posterior reversible encephalopathy syndrome. Despite the nonspecific nature of imaging findings associated with meningeal lesions, narrowing down the differential diagnoses is crucial, as each condition requires a tailored and specific treatment approach.

Miliary meningeal tuberculosis - an unusual imaging presentation for an early definitive diagnosis

PURPOSE

Tuberculous meningitis (TBM) causes significant morbidity and mortality in young children. Early treatment can be initiated with magnetic resonance (MR) imaging diagnosis. We present MR-detectable miliary meningeal TB in two patients. CASE 1: A 9-year-old girl developed fevers, cough, lethargy, and seizures. Brain MRI demonstrated multiple, small, T2-dark, rim-enhancing lesions, associated with cranial nerve and leptomeningeal enhancement. CSF showed pleocytosis, low glucose, and high protein. Chest CT showed mediastinal lymphadenopathy, multiple small interstitial lung nodules, and a splenic hypo enhancing lesion. Serial bronchoalveolar lavage studies were Xpert MTB/RIF and acid-fast negative. Endobronchial US-guided biopsy of a subcarinal lymph node was positive for Xpert MTB PCR. She was started on a 4-drug treatment for TBM and dexamethasone. Contact tracing revealed a remote positive contact with pulmonary tuberculosis. CASE 2: A 17-year-old female with Crohn's disease on adalimumab developed refractory ear infections despite multiple courses of antibiotics. She underwent myringotomy, with negative aerobic ear fluid culture. Brain MRI, obtained due to persistent otorrhea, showed multiple, small, round, T2-dark lesions. CSF studies were normal. CT chest, abdomen, and pelvis to assess for disseminated disease showed left upper lobe tree-in-bud nodules, hypoattenuating splenic lesions and a left obturator internus abscess with adjacent osteomyelitis. She underwent CT-guided aspiration of the obturator muscle collection, bronchoscopy with bronchoalveolar lavage, biopsy of two preexisting chronic skin lesions, and ear fluid aspiration. QuantiFERON Gold was positive. Ear fluid was Xpert MTB/RIF assay and acid-fast stain positive. Cultures from the ear fluid, skin tissue, muscle tissue, and alveolar lavage showed growth of acid-fast bacilli. She was started on 4-drug therapy and prednisone.

CONCLUSION

Our cases highlight that TBM in many cases remains a diagnostic dilemma - both our patients presented in a prolonged atypical manner. The term miliary TB not only refers to a pattern of interstitial nodules on chest radiographs but also indicates the hematogenous spread of the disease and concurrent pulmonary and extrapulmonary involvement with high risk of TB meningitis. We promote the use of the term miliary meningeal TB - in both cases, the neuroimaging diagnosis of TB preceded both chest imaging and laboratory confirmation of the disease. Miliary meningeal nodules on MRI may have characteristic T2 low signal and may be more conspicuous in children and immunocompromised individuals where background basal meningeal enhancement is less prominent.

Computer-aided prognosis of tuberculous meningitis combining imaging and non-imaging data

Tuberculous meningitis (TBM) is the most lethal form of tuberculosis. Clinical features, such as coma, can predict death, but they are insufficient for the accurate prognosis of other outcomes, especially when impacted by co-morbidities such as HIV infection. Brain magnetic resonance imaging (MRI) characterises the extent and severity of disease and may enable more accurate prediction of complications and poor outcomes. We analysed clinical and brain MRI data from a prospective longitudinal study of 216 adults with TBM; 73 (34%) were HIV-positive, a factor highly correlated with mortality. We implemented an end-to-end framework to model clinical and imaging features to predict disease progression. Our model used state-of-the-art machine learning models for automatic imaging feature encoding, and time-series models for forecasting, to predict TBM progression. The proposed approach is designed to be robust to missing data via a novel tailored model optimisation framework. Our model achieved a 60% balanced accuracy in predicting the prognosis of TBM patients over the six different classes. HIV status did not alter the performance of the models. Furthermore, our approach identified brain morphological lesions caused by TBM in both HIV and non-HIV-infected, associating lesions to the disease staging with an overall accuracy of 96%. These results suggest that the lesions caused by TBM are analogous in both populations, regardless of the severity of the disease. Lastly, our models correctly identified changes in disease symptomatology and severity in 80% of the cases. Our approach is the first attempt at predicting the prognosis of TBM by combining imaging and clinical data, via a machine learning model. The approach has the potential to accurately predict disease progression and enable timely clinical intervention.

Occurrence and determinants of seizures and their impact on tuberculous meningitis: a prospective evaluation

OBJECTIVE

To assess the incidence of seizures and the factors contributing to poor outcomes in patients with tuberculous meningitis (TBM).

METHODS

In this prospective observational study, 129 patients with TBM were enrolled at the Department of Neurology, King George's Medical University, Uttar Pradesh, India, from April 2021 to April 2023. Detailed clinical history, neurological examinations, baseline laboratory tests, contrast-enhanced Magnetic resonance imaging (MRI) and electroencephalography (EEG) were obtained for all patients. Patients received anti-tuberculous therapy and, if necessary, anti-epileptic treatment. Patients were followed for 6 months, with outcomes evaluated using the Modified Rankin Scale (MRS).

RESULTS

Of the 129 patients, 48 (37.2%) reported seizures. Advanced TBM stage (p = 0.040, OR = 2.50 95% CI:1.02-6.07), cortical involvement (p = .0.013, OR = 2.58 95% CI:1.20-5.51) and spike-wave discharges in the EEG (p = 0.001) were significantly associated with seizure occurrence. After multivariate analysis, only cortical involvement (p = 0.031, OR = 2.34, 95% CI:1.08-5.08) emerged as independent predictor of for seizures. Focal to bilateral seizures (p = 0.008, OR = 9.41, 95% CI: 1.76-74.04), status epilepticus (p = 0.002, OR = 8.00, 95% CI: 1.86-34.32), and rifampicin resistance (p = 0.022, OR = 9.25, 95% CI: 1.43-59.50) were significantly associated with poor outcomes at the 6-month mark.

CONCLUSION

Seizures were significantly associated with advanced stage of the disease, cortical involvement on neuro-imaging and epileptiform pattern on EEG. Additionally, focal to bilateral seizures and status epilepticus adversely affected the outcome.

Predicting cerebral infarction in tuberculous meningitis and its prognostic significance

Aim: Tuberculous meningitis (TBM) often causes cerebral infarction, but its predictive factors are not well understood. Methods: Patients aged ≥13 years admitted with TBM were enrolled prospectively. Cerebral infarction was diagnosed using magnetic resonance imaging. Results: Of 186 patients, 80 (43%) had infarction. Most infarctions were multiple and located in the cortical areas, basal ganglia and subcortical regions. Independent predictors of infarction at admission included high blood pressure, short illness duration, low Glasgow coma scale and hydrocephalus. Neuroimaging inflammation signs, cerebrospinal fluid analysis abnormalities and pre-existing cardiovascular risks did not predict infarction. In-hospital mortality was higher in TBM with infarction, particularly in those with advanced TBM (stage 3). Conclusion: Baseline parameters of raised intracranial pressure predict cerebral infarction in TBM.

Pediatric and adult meningeal, parenchymal, and spinal tuberculosis: A neuroimaging review

Neurotuberculosis is defined as a tuberculous infection of the meninges, brain parenchyma, vessels, cranial and spinal nerves, spinal cord, skull, and spine that can occur either in a localized or in a diffuse form. It is a heterogeneous disease characterized by many imaging appearances and it has been defined as "the great mimicker" due to similarities with many other conditions. The diagnosis of central nervous system (CNS) tuberculosis (TB) is based on clinical presentation, neuroimaging findings, laboratory and microbiological findings, and comprehensive evaluation of the response to anti-TB drug treatment. However, the absence of specific symptoms, the wide spectrum of neurological manifestations, the myriad of imaging findings, possible inconclusive laboratory results, and the paradoxical reaction to treatment make the diagnosis often challenging and difficult, potentially delaying adequate treatment with possible devastating short-term and long-term neurologic sequelae. Familiarity with the imaging characteristics helps in accurate diagnosis and may prevent or limit significantly morbidity and mortality. The goal of this review is to provide a comprehensive up-to-date overview of the conventional and advanced imaging features of CNS TB for radiologists, neuroradiologists, and pediatric radiologists. We discuss the most typical neurotuberculosis imaging findings and their differential diagnosis in children and adults with the goal to provide a global overview of this entity.

A preclinical model of TB meningitis to determine drug penetration and activity at the sites of disease

Tuberculosis meningitis (TBM) is essentially treated with the first-line regimen used against pulmonary tuberculosis, with a prolonged continuation phase. However, clinical outcomes are poor in comparison, for reasons that are only partially understood, highlighting the need for improved preclinical tools to measure drug distribution and activity at the site of disease. A predictive animal model of TBM would also be of great value to prioritize promising drug regimens to be tested in clinical trials, given the healthy state of the development pipeline for the first time in decades. Here, we report the optimization of a rabbit model of TBM disease induced via inoculation of Mycobacterium tuberculosis into the cisterna magna, recapitulating features typical of clinical TBM: neurological deterioration within months post-infection, acid-fast bacilli in necrotic lesions in the brain and spinal cord, and elevated lactate levels in cerebrospinal fluid (CSF). None of the infected rabbits recovered or controlled the disease. We used young adult rabbits, the size of which allows for spatial drug quantitation in critical compartments of the central nervous system that cannot be collected in clinical studies. To illustrate the translational value of the model, we report the penetration of linezolid from plasma into the CSF, meninges, anatomically distinct brain areas, cervical spine, and lumbar spine. Across animals, we measured the bacterial burden concomitant with neurological deterioration, offering a useful readout for drug efficacy studies. The model thus forms the basis for building a preclinical platform to identify improved regimens and inform clinical trial design.

Current Insights into Diagnosing and Treating Neurotuberculosis in Adults

Neurotuberculosis has the highest morbidity and mortality risk of all forms of extrapulmonary tuberculosis (TB). Early treatment is paramount, but establishing diagnosis are challenging in all three forms of neurotuberculosis: tuberculous meningitis (TBM), spinal TB and tuberculomas. Despite advancements in diagnostic tools and ongoing research aimed at improving TB treatment regimens, the mortality rate for neurotuberculosis remains high. While antituberculosis drugs were discovered in the 1940s, TB treatment regimens were designed for and studied in pulmonary TB and remained largely unchanged for decades. However, new antibiotic regimens and host-directed therapies are now being studied to combat drug resistance and contribute to ending the TB epidemic. Clinical trials are necessary to assess the effectiveness and safety of these treatments, addressing paradoxical responses in neurotuberculosis cases and ultimately improving patient outcomes. Pharmacokinetic-pharmacodynamic analyses can inform evidence-based dose selection and exposure optimization. This review provides an update on the diagnosis and treatment of neurotuberculosis, encompassing both sensitive and resistant antituberculosis drug approaches, drawing on evidence from the literature published over the past decade.

The diagnosis of tuberculous meningitis: advancements in new technologies and machine learning algorithms

Tuberculous meningitis (TBM) poses a diagnostic challenge, particularly impacting vulnerable populations such as infants and those with untreated HIV. Given the diagnostic intricacies of TBM, there's a pressing need for rapid and reliable diagnostic tools. This review scrutinizes the efficacy of up-and-coming technologies like machine learning in transforming TBM diagnostics and management. Advanced diagnostic technologies like targeted gene sequencing, real-time polymerase chain reaction (RT-PCR), miRNA assays, and metagenomic next-generation sequencing (mNGS) offer promising avenues for early TBM detection. The capabilities of these technologies are further augmented when paired with mass spectrometry, metabolomics, and proteomics, enriching the pool of disease-specific biomarkers. Machine learning algorithms, adept at sifting through voluminous datasets like medical imaging, genomic profiles, and patient histories, are increasingly revealing nuanced disease pathways, thereby elevating diagnostic accuracy and guiding treatment strategies. While these burgeoning technologies offer hope for more precise TBM diagnosis, hurdles remain in terms of their clinical implementation. Future endeavors should zero in on the validation of these tools through prospective studies, critically evaluating their limitations, and outlining protocols for seamless incorporation into established healthcare frameworks. Through this review, we aim to present an exhaustive snapshot of emerging diagnostic modalities in TBM, the current standing of machine learning in meningitis diagnostics, and the challenges and future prospects of converging these domains.

Diagnostic validity of MRI for central nervous system tuberculosis: protocol for a systematic review and meta-analysis

INTRODUCTION

Central nervous system tuberculosis (CNSTB) is a severe condition, sometimes associated with a poor prognosis. Early diagnosis of CNSTB remains challenging, considering that conventional methods lack sensitivity or might lead to certain side effects. Herein, we presented a protocol for a systematic review and meta-analysis to assess the diagnostic efficacy of MRI for CNSTB.

METHODS AND ANALYSIS

SinoMed, Wanfang database, China National Knowledge Infrastructure, Embase, the Cochrane Library and PubMed will be searched to identify studies reporting on the use of MRI in the diagnosis of CNSTB from database inception to December 2023. The following keywords will be applied: 'Intracranial tuberculosis', 'Cerebral tuberculosis', 'Central nervous system tuberculosis', 'Spinal tuberculous arachnoiditis' and 'Magnetic Resonance Imaging'. Studies that evaluate the diagnostic accuracy of MRI for the diagnosis of CNSTB and report clear reference criteria will be included. Studies from which full true positive, false positive, false negative and true negative values cannot be extracted, those published in languages other than English or Chinese, abstracts not reporting the full text, and case reports will be excluded. Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) will be used to evaluate the methodological quality of each included study. Stata V.15.0 and RevMan V.5.3 will be used to perform a meta-analysis and generate forest plots and summary receiver operating characteristic curves. In case of significant heterogeneity between studies, possible sources of heterogeneity will be explored through subgroup and meta-regression analyses.

ETHICS AND DISSEMINATION

This research is based on public databases and does not require ethical approval. Results will be submitted for publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42023415690.

Tumor or not a tumor: Pitfalls and differential diagnosis in neuro-oncology

The majority of intracranial expansive lesions are tumors. However, a wide range of lesions can mimic neoplastic pathology. Differentiating pseudotumoral lesions from brain tumors is crucial to patient management. This article describes the most common intracranial pseudotumors, with a focus on the imaging features that serve as clues to detect pseudotumors.

Post-TB health and wellbeing

TB affects around 10.6 million people each year and there are now around 155 million TB survivors. TB and its treatments can lead to permanently impaired health and wellbeing. In 2019, representatives of TB affected communities attending the '1st International Post-Tuberculosis Symposium´ called for the development of clinical guidance on these issues. This clinical statement on post-TB health and wellbeing responds to this call and builds on the work of the symposium, which brought together TB survivors, healthcare professionals and researchers. Our document offers expert opinion and, where possible, evidence-based guidance to aid clinicians in the diagnosis and management of post-TB conditions and research in this field. It covers all aspects of post-TB, including economic, social and psychological wellbeing, post TB lung disease (PTLD), cardiovascular and pericardial disease, neurological disability, effects in adolescents and children, and future research needs.

A case report about a child with drug-resistant tuberculous meningitis

BACKGROUND

Hematogenous disseminated tuberculosis predisposes to concurrent tuberculous meningitis (TBM), the most devastating and disabling form of tuberculosis. However, children often have atypical clinical symptoms, difficulty in specimen collection, low specimen content, and an increasing incidence of drug-resistant tuberculosis. Thus, the accurate diagnosis and timely treatment of childhood tuberculosis face monumental challenges.

CASE PRESENTATION

The 14-year-old female presented to the hospital with intermittent fever, headache, and blurred vision. Her cerebrospinal fluid (CSF) showed a lymphocytic pleocytosis, an elevated protein level, and a decreased chloride level. And her CSF tested positive for TB-RNA. Xpert MTB/RIF detected Mycobacterium tuberculosis in her CSF, but the rifampin resistance test was unknown. Subsequently, her CSF culture was positive for Mycobacterium tuberculosis. The drug sensitivity test (DST) revealed resistance to isoniazid, rifampin, and fluoroquinolones. A computed tomography (CT) of the chest showed diffuse miliary nodules in both lungs. Intracranial enhanced magnetic resonance imaging (MRI) showed "multiple intensified images of the brain parenchyma, cisterns, and part of the meninges." The final diagnosis is miliary pulmonary tuberculosis and pre-extensive drug-resistant TBM. After 19 months of an oral, individualized antituberculosis treatment, she recovered with no significant neurological sequelae.

CONCLUSION

For patients with miliary pulmonary tuberculosis, especially children, even if there are no typical clinical symptoms, it is necessary to know whether there is TBM and other conditions. Always look for the relevant aetiological basis to clarify whether it is drug-resistant tuberculosis. Only a rapid and accurate diagnosis and timely and effective treatment can improve the prognosis and reduce mortality and disability rates.

Pediatric Moyamoya Syndrome Secondary to Tuberculous Meningitis: A Case Report

Objectives

Tuberculosis is uncommon in the United States and a rare cause of meningitis in children with severe neurologic consequences. Tuberculous meningitis (TBM) is an even rarer cause of moyamoya syndrome with only a handful of cases previously reported.

Methods

We report the case of a female patient who initially presented at 6 years of age with TBM and developed moyamoya syndrome requiring revascularization surgery.

Results

She was found to have basilar meningeal enhancement and right basal ganglia infarcts. She was treated with 12 months of antituberculosis therapy and 12 months of enoxaparin and maintained on daily aspirin indefinitely. However, she developed recurrent headaches and transient ischemic attacks and was found to have progressive bilateral moyamoya arteriopathy. At age 11 years, she underwent bilateral pial synangiosis for the treatment of her moyamoya syndrome.

Discussion

Moyamoya syndrome is a rare but serious sequalae of TBM and may be more common in pediatric patients. The risk of stroke may be mitigated by pial synangiosis or other revascularization surgeries in carefully selected patients.

Tuberculous meningitis

Tuberculous meningitis is possibly complicated with multiple cerebral infarctions and basal meningitis, and the mortality and neurological prognosis is reportedly poor. This case suggested that clinicians should consider tuberculous meningitis as a differential diagnosis of patients with disturbed consciousness in an aging country Japan.

Analysis of Cases with Cerebrospinal Fluid Characteristics Similar to Tuberculous Meningitis

Purpose

The diagnosis of tuberculous meningitis (TBM) is difficult and relies on the patient's clinical presentation and initial cerebrospinal fluid testing. Treatment outcomes for some patients with early consideration of TBM meningitis are often poor. Patients and Methods. In this study, we retrospectively analyzed 24 non-TBM patients whose early changes of cerebrospinal fluid were similar to those of TBM through the second-generation cerebrospinal fluid sequencing technology.

Results

All patients included in this study had an acute onset, including 5 patients with a history of upper respiratory tract infection, 9 patients with fever, 6 patients with headache, 5 patients with psychiatric symptoms, 6 patients with cognitive impairment, 9 patients with signs of meningeal irritation, and 6 patients with seizures. Sixteen patients presented with altered content and level of consciousness during their admission. The leukocyte counts (median, 124.0 × 10⁶/L) and total protein concentrations (median, 1300 mg/L) were higher than normal reference values in all patients, whereas glucose (median, 1.345 mmol/L) and chloride concentration values (average, 111.7 ± 5.2 mmol/L) were lower than normal reference values. The patients included 2 cases of Liszt's meningitis, 2 cases of Brucella infection in the CNS, 4 cases of Varicella zoster virus encephalitis, 2 cases of human herpes simplex virus type 1, 2 cases of lupus encephalopathy, 2 cases of anti-NMDAR receptor encephalitis, 2 cases of meningeal carcinomatosis, 5 cases of cryptococcal meningitis, 2 cases of CNS sarcoidosis, and a case of invasive Rhizopus oryzae infection. All patients were tested for NGS in cerebrospinal fluid. Eight patients were diagnosed with anti-NMDAR encephalitis, meningeal carcinomatosis, lupus encephalopathy, and CNS sarcoidosis. Nine patients experienced death; 15 patients had a good prognosis and left no significant sequelae.

Conclusion

The analysis of patients with TBM-like cerebrospinal fluid changes will help improve the diagnostic accuracy of the disease and reduce misdiagnosis and underdiagnosis.

Autoimmune glial fibrillar acidic protein astrocytopathy mimicking tuberculous meningitis

Autoimmune glial fibrillar acidic protein (GFAP) astrocytopathy typically presents as acute or subacute meningoencephalitis with or without myelitis. We describe a case of autoimmune GFAP astrocytopathy that mimicked tuberculous meningitis. A man in his 70s was referred to our hospital with lethargy persistent for 2 months, appetite loss for 1 month and fever with headache for 10 days. The cerebrospinal fluid test revealed lymphocytic pleocytosis with elevated adenosine deaminase (ADA). Laboratory investigations ruled out microbial and neoplastic causes. Empirical therapy for tuberculous meningitis combined with corticosteroid improved the patient's condition. Culture for Mycobacterium tuberculosis failed to show microbial growth despite 1 month of incubation. The cerebrospinal fluid was examined for GFAP antibody and returned positive result. Antituberculous agents were discontinued, and corticosteroid was administered until patient's symptoms resolved completely. Thus, clinicians should consider autoimmune GFAP astrocytopathy as one of the differential diagnoses of lymphocytic meningitis with elevated ADA.

Associations of hyponatremia and SIADH with increased mortality, young age and infection parameters in patients with tuberculosis

BACKGROUND AND OBJECTIVE

Hyponatremia and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) are associated with and can be caused by tuberculosis (TB) through meningitis by locally invading the hypothalamus, adrenal, or pituitary glands or possibly through ectopic ADH production. This study assessed the association of TB mortality with hyponatremia and SIADH in a large cohort of a university hospital in Austria.

METHODS

This retrospective study enrolled patients with hyponatremia and patients diagnosed with TB from 01/2001-11/2019 to assess the prevalence of TB in hyponatremia and TB morbidity and mortality in patients with and without hyponatremia. Sex, age, microbiological results, laboratory tests and comorbidities were analysed and used to calculate survival rates.

RESULTS

Of 107.532 patients with hyponatremia (0.07%) and 186 patients with TB (43%), 80 patients were diagnosed with both-hyponatremia and TB. Only three TB patients had SIADH, precluding further SIADH analysis. In hyponatremia, young age and high CRP levels showed significant associations with TB diagnosis (p<0.0001). Survival rates of patients diagnosed with TB with moderate to profound hyponatremia were significantly lower than those without hyponatremia (p = 0.002).

CONCLUSION

In this study of a large cohort from a tertiary care hospital in a non-endemic area of TB, 0.07% of patients presenting with hyponatremia, but especially younger patients and patients with high CRP values, were diagnosed with TB. Crucially, patients with moderate to profound hyponatremia had a significantly higher mortality rate and thus required increased medical care.

Role of Caspase- 3, TNF-α, and IL6 mRNA Expression in Intracranial Tuberculoma

The development of tuberculoma is a process of inflammation, necrosis, and apoptosis. Therefore, the pro-inflammatory cytokines and apoptosis biomarkers are likely to play an important role. In this study, we report the expression of TNFα, IL6, and caspase-3 at the mRNA level in the patients with tuberculous meningitis (TBM) and compare these biomarkers in the patients with and without tuberculoma. A total of 134 patients with TBM and 35 matched healthy controls were included. The clinical, cerebrospinal fluid (CSF), and cranial magnetic resonance imaging (MRI) findings were noted. The mRNA expression of TNFα, IL6, and caspase-3 in peripheral blood mononuclear cells was evaluated by reverse transcriptase polymerase chain reaction. On cranial MRI, 89 (64.2%) patients had tuberculoma, and their level of consciousness, severity of meningitis, CSF findings, and blood counts were not significantly different from those without tuberculoma. Patients with tuberculoma had a higher expression of TNFα and IL6 compared to the controls, but had lower expression compared to the patients without tuberculoma. TNFα expression positively correlated with the expression of caspase-3, but not with IL6. Twenty-five (18.6%) patients died: 12 (13.5%) in tuberculoma and 13 (28.9%) in the non-tuberculoma group. Death was related to higher expression of TNFα and caspase-3. The lower expression of TNFα and IL6 in intracranial tuberculoma suggests that these patients are unlikely to be benefited with TNFα blockers.

Improving Technology to Diagnose Tuberculous Meningitis: Are We There Yet?

Diagnosis of tuberculous meningitis (TBM) remains challenging due to a paucity of high-performance diagnostics. Even those that have reasonable sensitivity are not adequate to 'rule out' TBM. Therefore, a combination of clinical factors alongside microbiological, molecular, and radiological investigations are utilized, depending on availability. A low threshold for starting empiric therapy in the appropriate clinical scenario remains crucial for good outcomes in many cases. Herein, we review the current TBM diagnostics landscape with a focus on limitations frequently encountered, such as diagnostic test performance, cost, laboratory infrastructure, and clinical expertise. Though molecular technologies, particularly GeneXpert MTB/Rif Ultra, have been a step forward, diagnosis of TBM remains difficult. We also provide an overview of promising technologies, such as cerebrospinal fluid (CSF) lactate, a new lipoarabinomannan test (FujiLAM), metagenomic next-generation sequencing, and transcriptomics that may further improve our TBM diagnostic capacity and lead to better outcomes.

Contrast-enhanced weighted-T1 and FLAIR sequences in MRI of meningeal lesions

Magnetic resonance imaging (MRI) is widely used in meningeal lesions due to rapid and accurate diagnosis and prevention of serious complications. The aim of the present study was to compare these two sequences after injection of a contrast agent into meningeal lesions. This is a descriptive-analytical study that was performed in 2018-2020 on patients referred to the radiology ward with detection of any meningeal involvements in the MRI images. In addition to T1-W, FLAIR sequence imaging was also performed. Images were initially evaluated by two expert radiologists and a neurologist. The diagnostic values of the sequences were compared. Overall, a total number of 147 patients with meningeal lesions in their brain MRI entered the study. 57.1% of cases (84 patients) had an infectious etiology and 42.9% (63 patients) had a tumoral etiology. T1-W images without contrast were able to diagnose 78 cases of meningitis (92.8% of them), and FLAIR sequences could diagnose 82 patients (97.6% of them). Without contrast injection on MRI, the diagnostic value of T1-W sequence was higher than FLAIR sequence for tumoral lesions (P < 0.01). The enhancement degree of T1-W was higher for tumoral findings (P < 0.01). In contrast, the enhancement degree of the FLAIR sequence was higher for infectious findings, which was also statistically significant (P = 0.015). FLAIR sequences had 92% sensitivity and 85% specificity for diagnosis of brain inflammatory diseases. Similar analysis showed that T1 sequence had 82% sensitivity and 73% specificity for diagnosis of brain inflammatory diseases.

Neutrophil-Mediated Immunopathology and Matrix Metalloproteinases in Central Nervous System - Tuberculosis

Tuberculosis (TB) remains one of the leading infectious killers in the world, infecting approximately a quarter of the world’s population with the causative organism Mycobacterium tuberculosis (M. tb). Central nervous system tuberculosis (CNS-TB) is the most severe form of TB, with high mortality and residual neurological sequelae even with effective TB treatment. In CNS-TB, recruited neutrophils infiltrate into the brain to carry out its antimicrobial functions of degranulation, phagocytosis and NETosis. However, neutrophils also mediate inflammation, tissue destruction and immunopathology in the CNS. Neutrophils release key mediators including matrix metalloproteinase (MMPs) which degrade brain extracellular matrix (ECM), tumor necrosis factor (TNF)-α which may drive inflammation, reactive oxygen species (ROS) that drive cellular necrosis and neutrophil extracellular traps (NETs), interacting with platelets to form thrombi that may lead to ischemic stroke. Host-directed therapies (HDTs) targeting these key mediators are potentially exciting, but currently remain of unproven effectiveness. This article reviews the key role of neutrophils and neutrophil-derived mediators in driving CNS-TB immunopathology.

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.

Central nervous system tuberculosis

PURPOSE OF REVIEW

Central nervous system (CNS) tuberculosis is the most devastating form of tuberculosis (TB), with mortality and or neurological sequelae in over half of individuals. We reviewed original research and systematic reviews published since 1 January 2019 for new developments in CNS TB pathophysiology, diagnosis, management and prognosis.

RECENT FINDINGS

Insight in the pathophysiology is increasing steadily since the landmark studies in 1933, focussing on granuloma type classification, the relevance of the M. tuberculosis bacterial burden and the wide range of immunological responses. Although Xpert/RIF has been recommended by the WHO for extrapulmonary TB diagnosis, culture is still needed to increase the sensitivity of TB meningitis diagnosis. Sequential MRIs can improve understanding of neurological deficits at baseline and during treatment. Pharmacokinetic/pharmacodynamic modelling suggests that higher doses of rifampicin and isoniazid in TB meningitis could improve survival.

SUMMARY

Recent studies in the field of CNS-TB have largely focussed on TB meningitis. The outcome may improve by optimizing treatment dosing. This needs to be confirmed in clinical trials. Due to the important role of inflammation, these trials should be used as the platform to study the inflammatory and metabolomic responses. This could improve understanding of the biology of this disease and improve patient outlook by enabling individualised host-directed therapy.

Imaging of brain tumors in children: the basics-a narrative review

Primary pediatric brain tumors comprise a broad group of neoplasm subtypes that can be categorized based on their histological and molecular features according to the 2016 World Health Organization (WHO) classification of central nervous system (CNS) tumors. The majority of the pediatric brain tumors demonstrate a singular preference for this age group and have a unique molecular profile. The separation of certain tumor entities, including different types of embryonal tumors, low-grade gliomas, and high-grade gliomas, may have a significant impact by guiding appropriate treatment for these children and potentially changing their outcomes. Currently, the focus of the imaging diagnostic studies is to follow the molecular updates, searching for potential imaging patterns that translate this information in molecular profile results, therefore helping the final diagnosis. Due to the high impact of accurate diagnosis in this context, the scientific community has presented extensive research on imaging pediatric tumors in recent years. This article summarizes the key characteristics of the imaging features of the most common primary childhood brain tumors, categorizing them according to the recent WHO classification update, which is based on each of their molecular profiles. The purpose of this review article is to familiarize radiologists with their key imaging features and thereby improve diagnostic accuracy.

Microbiological Testing of Gastric Aspirate Improves the Diagnosis of Pulmonary Tuberculosis in Unconscious Adults with TB Meningitis

Conventional sputum collection for TB diagnosis is difficult in TB meningitis patients since most of them are admitted with decreased consciousness. It is assumed that unconscious patients swallow their sputum; therefore, gastric aspiration can replace sputum collection in unconscious patients. A prospective study was conducted to see whether examining gastric aspirate could increase the diagnosis certainty of pulmonary TB in such subjects. The inclusion criteria were age 18–60 years, decreased level of consciousness, and use of a nasogastric tube. Subjects who had taken antituberculosis drugs for more than 3 days were excluded. Gastric lavage was performed in the morning after an overnight fast. Specimens were examined for direct smear, culture, and rapid molecular testing. Demographic, clinical, chest X-ray, and laboratory data were also recorded. During the study period, 31 subjects were available. The positivity rates for microbiological tests were 19.3%, 41.9%, and 48.4% for smear, culture, and rapid molecular testing, respectively. All positive smears were confirmed by either culture or rapid molecular testing. Gastric lavage can be considered a tool for improving extraneural TB diagnosis in unconscious patients.