Central nervous system tuberculosis

Concurrent cerebral infarction and intracranial tuberculoma induced by the carotid plaque complicated with miliary tuberculosis

Cerebrovascular complications of central nervous system tuberculosis (TB) are predictors of poor prognosis and adverse outcomes. These complications are mainly intracranial arterial involvement, with occasional venous involvement. Here, we present a 67-year-old woman with concurrent cerebral infarction and intracranial tuberculoma induced by the carotid plaque complicated by miliary tuberculosis. Mycobacterium tuberculosis was observed on the luminal side of the carotid plaques in pathological specimens. Treatment with anti-TB drugs alone would likely not cure the patient, as M. tuberculosis would continue to disseminate. Endarterectomy could directly remove the embolic source, and a complete cure was achieved.

Comparative diagnostic utility of metagenomic next-generation sequencing, GeneXpert, modified Ziehl-Neelsen staining, and culture using cerebrospinal fluid for tuberculous meningitis: A multi-center, retrospective study in China

Background

Early diagnosis of tuberculosis meningitis (TBM) remains a great challenge during clinical practice. The diagnostic efficacies of cerebrospinal fluid (CSF)‐based mycobacterial growth indicator tube (MGIT) culture, modified Ziehl–Neelsen (ZN) staining, Xpert MTB/RIF, and metagenomic next‐generation sequencing (mNGS) for TBM remained elusive.

Methods

A total of 216 adult patients with suspicious TBM were retrospectively enrolled in this multi‐cohort study. The diagnostic performances for MGIT, modified ZN staining, Xpert MTB/RIF, and mNGS using CSF samples were evaluated.

Results

Uniform clinical case definition classified 88 (40.7%) out of 216 patients as the definite TBM, 5 (2.3%) patients as probable TBM cases, and 24 (11.1%) patients as possible TBM cases. The sensitivities of MGIT, modified ZN staining, Xpert MTB/RIF, and mNGS for TBM diagnosis against consensus uniform case definition for definite TBM were 25.0%, 76.1%, 73.9%, and 84.1%, respectively. Negative predictive values (NPVs) were 66.0%, 85.9%, 84.8%, and 90.1%, respectively. The sensitivities of MGIT, modified ZN staining, Xpert MTB/RIF, and mNGS for TBM diagnosis against consensus uniform case definition for definite, probable, and possible TBM were 18.8%, 57.3%, 55.5%, and 63.2%, respectively. Negative predictive values (NPVs) were 51.0%, 66.4%, 65.6%, and 69.7%, respectively. mNGS combined with modified ZN stain and Xpert could cover TBM cases against a composite microbiological reference standard, yielding 100% specificity and 100% NPV.

Conclusion

Metagenomic next‐generation sequencing detected TBM with higher sensitivity than Xpert, ZN staining and MGIT culture, but mNGS cannot be used as a rule‐out test. mNGS combined with Xpert or modified ZN staining could enhance the sensitivity of diagnostic tests for TBM.

A study of glutamate excitotoxicity in seizures related to tuberculous meningitis

BACKGROUND AND PURPOSE

Glutamate is a neurotransmitter that regulates approximately half of the nervous system, along with the sensory system. Glutamate excitotoxicity is related to seizures but its role in TBM-related seizure has not been reported to our best knowledge. It is proposed to report plasma glutamate level and its receptors in TBM patients with seizures and correlate with the type of seizures, Magnetic Resonance Imaging (MRI) findings, and outcome.

METHODS

TBM was diagnosed clinically with MRI as well as cerebrospinal fluid examination. TBM-related seizures have been categorized into early (< 1 month) or late (> 1 month) seizures. Six months outcome was defined using modified Rankin Scale as good (mRS ≤ 2) or poor (mRS > 2). Plasma glutamate was measured by ELISA, along with NR1, NR2A, and NR2B receptors using Real Time Polymerase Chain Reaction (RT-PCR) and have been correlated with seizure, MRI abnormalities, and outcome.

RESULTS

A total of 29 (53.7%) patients developed seizures (early-09, late-20). Glutamate (P < 0.0001), NR1 (p ≤ 0.0001), NR2A (p ≤ 0.0001), and NR2B (p ≤ 0.0001) were higher than the controls. In TBM patients with seizures, plasma glutamate (p = 0.01), NR1 (p = 0.03) and NR2A (p = 0.001) were significantly higher than those without seizures. Plasma glutamate level and all three receptor genes expression were higher during seizures and improved on cessation of seizure compared to the baseline. These markers correlated well with MRI findings and determined the outcome. ROC curve was used to estimate the diagnostic accuracy of the markers. The result indicated that NR2A gene was the best predictor followed by glutamate and NR1 gene.

CONCLUSION

Our results highlight the role of glutamate and its receptors in TBM-related seizures and outcomes.

Spine MRI: A Review of Commonly Encountered Emergent Conditions

Over the last 2 decades, the proliferation of magnetic resonance imaging (MRI) availability and continuous improvements in acquisition speeds have led to significantly increased MRI utilization across the health care system, and MRI studies are increasingly ordered in the emergent setting. Depending on the clinical presentation, MRI can yield vital diagnostic information not detectable with other imaging modalities. The aim of this text is to report on the up-to-date indications for MRI of the spine in the ED, and review the various MRI appearances of commonly encountered acute spine pathology, including traumatic injuries, acute non traumatic myelopathy, infection, neoplasia, degenerative disc disease, and postoperative complications. Imaging review will focus on the aspects of the disease process that are not readily resolved with other modalities.

Giant Cerebral Tuberculoma Masquerading as Malignant Brain Tumor - A Report of Two Cases

Giant cerebral tuberculoma is an uncommon but serious form of tuberculosis. We report two patients who had a single, large lesion on magnetic resonance imaging (MRI) of the brain. Both patients underwent neurosurgery for the excision of the mass lesion as neuroimaging findings were suggestive of a brain tumor. Tuberculoma was later diagnosed on histopathological examination. We want to highlight that cerebral tuberculomas can mimic malignant brain tumors, as the clinical, laboratory, and radiologic features of cerebral tuberculomas are nonspecific.

The prevalence, characteristics and outcome of seizure in tuberculous meningitis

Seizures are a common finding in patients with tuberculous meningitis (TBM), and associate with four times increased risk of death and neurological disability, especially in children. It has been reported that brain inflammation, diffuse neuronal injury, and reactive gliosis may all contribute to the pathogenesis of seizures in TBM. Early seizure onset may be associated with meningeal irritation and cerebral oedema; while, the late seizures are usually due to infarction, hydrocephalus, tuberculoma and paradoxical response. Moreover, recurrent uncontrolled seizures can evolve to status epileptics resulting in an increased risk of chronic epilepsy and poor prognosis. Therefore, this review aimed to assess the frequency of seizures in patients with TBM, and discuss the etiologies, mechanisms, and characteristics of seizures in TBM. Besides, we have searched the literature to identify the prognostic factors for chronic epilepsy after TBM.

Tuberculous Myelopathy Associated with Longitudinally Extensive Lesion: A Clinicoradiological Review of Reported Cases

Acute transverse myelitis is an inflammatory disorder of the spinal cord in which there is no evidence of spinal cord compression. Longitudinally extensive transverse myelitis (LETM) is a specific subtype of acute transverse myelitis that usually affects three or more vertebral levels and produces marked neurological deficits. While the most-common cause of LETM is neuromyelitis optica or neuromyelitis optica spectrum disorder, there are rare cases of other causes mimicking this condition, including tuberculosis (TB). We sought to review the clinicoradiological features of TB myelopathy associated with longitudinally extensive lesion, which may mimic LETM, in the English literature. We searched the PubMed, Google Scholar, Web of Science, and Scopus databases for relevant articles using search terms including “longitudinally extensive transverse myelitis,” “tuberculosis,” “TB spinal cord,” and various combinations of these expressions. Full-text papers were selected without limiting the publication year. We also examined the reference lists of key papers to identify further articles that are potentially relevant. We found 10 cases in 7 papers describing TB myelopathy associated with longitudinally extensive lesion. The demographics, clinical features, relevant cerebrospinal fluid findings, and radiological findings were compiled and summarized. TB myelopathy associated with longitudinally extensive lesion is very rare, with no documented prevalence. Early and accurate diagnosis is important since the condition is potentially treatable.

Comparative evaluation of loop-mediated isothermal amplification (LAMP) assay, GeneXpert MTB/Rif and multiplex PCR for the diagnosis of tubercular lymphadenitis in HIV-infected patients of North India

BACKGROUND

Tubercular lymphadenitis (TBLA) is one of the most common extrapulmonary manifestations of tuberculosis in patients with HIV. With several other pathological conditions presenting as lymphadenitis and lack of consensus regarding a gold standard test, the diagnosis of TBLA remains a challenge for the clinician.

OBJECTIVES

and design: In this study, we have assessed the potential of loop-mediated isothermal amplification (LAMP) test for the diagnosis of TBLA in HIV-infected patients. The study group included samples collected by fine needle aspiration (FNAC) of lymph nodes from 24 HIV-infected patients with TBLA. A composite reference standard was used to identify cases of TBLA based on clinical suspicion, results of cytology, AFB smear, MGIT culture, GeneXpert MTB/RIF, multiplex polymerase chain reaction (MPCR) and subsequently clinical response to antitubercular therapy. These tests were also carried out in 26 control samples of lymph node FNAC from HIV-infected patients with non-tubercular lymphadenitis.

RESULTS

LAMP assay was positive in 19/24 TBLA cases and yielded a sensitivity of 79.17% with 100% specificity. Cytology was suggestive in 18/24 (75%) TBLA cases. GeneXpert MTB/RIF assay correctly identified 16/24 TBLA cases, but the test did show one false positive result reducing its specificity. MPCR had the highest sensitivity of 91.67% as it correctly identified 22/24 cases and showed no false positive result.

CONCLUSION

The current study highlights the potential of LAMP test for the specific diagnosis of tubercular lymphadenitis in FNAC samples from HIV-infected patients, especially when cytology is either non-conclusive or non-available. Though MPCR had a higher sensitivity than LAMP assay, the added advantages of low cost, minimal technical expertise and simplicity of procedure make LAMP assay a suitable diagnostic test in resource-limited settings.

Diagnosis and management of intracranial tuberculomas: about 2 cases and a review of the literature

Central nervous system tuberculosis is a major cause of morbidity and mortality in developing countries. Intracranial tuberculoma is rare and is one of the most severe cases of tuberculosis. We present two cases. The first one is about a girl of 7 years, followed for 5 months for lymph nodes tuberculosis on anti-TB treatment that presents generalized tonic-clonic seizures associated with progressive intracranial hypertension syndrome. Brain MRI has objectified necrotic nodules in left hemisphere. The surgical approach of the lesions was direct with complete excision. The diagnosis of tuberculoma was confirmed by anatomopathological examination. The second case is about a 6-year-old girl with no particular medical history, which presents for three months progressive and treatment-resistant cervico-occipital headaches associated with walking difficulties. The MRI objectified left cerebellar tumor process interpreted preoperatively as medulloblastoma. The patient was operated on intraoperative, appearance was that of a nodular lesion. Anatomopathological examination confirmed the diagnosis. The intracranial tuberculoma is an unusual variety of the central nervous system tuberculosis and remains a topical issue in Morocco. The prognosis depends on prompt diagnosis, quality of surgical resection and anti-TB treatment. The diagnostic confirmation is histological and should therefore be evoked infront of any intracranial process mimicking a brain tumor.

Oxidative and endoplasmic reticulum stress in tuberculous meningitis related seizures

BACKGROUND AND PURPOSE

High oxygen consumption and high polyunsaturated fatty acid content in the brain may render it vulnerable to oxidative stress and endoplasmic reticulum (ER) stress. We report the role of these parameters in tuberculous meningitis (TBM) patients with seizures and correlate these with clinical radiological, and laboratory findings.

METHODS

Serum oxidative stress markers ; Catalase, Superoxide dismutase (SOD), Glutathione (GSH), Protein-carbonyl, Malonaldehyde (MDA) were measured using spectrophotometer and ER stress markers-ATF4, CHOP, XBP1 and GRP-78 using RT-PCR in TBM patients, 29 with seizures, 20 without seizures and 20 matched controls. In 10 patients, sequential estimation of oxidative stress and ER stress markers was also measured.

RESULTS

In comparison to controls, TBM patients had significant difference in the expression of oxidative stress and ER stress markers. Serum MDA (P=0.02), protein-carbonyl (P < 0.01) were significantly higher and SOD (P=0.02) and GSH (P < 0.01) significantly lower in the patients with seizures compared to those without seizures. The ER stress markers were insignificantly elevated in TBM patients with seizures. On sequential evaluation, oxidative stress and ER stress markers increased following seizures and returned to baseline at the time of discharge.

CONCLUSION

The results suggest some role of oxidative stress and ER stress in TBM, but do not predict its outcome.

Tuberculosis of the Central Nervous System

PURPOSE OF REVIEW

This article details the epidemiology and clinical manifestations of central nervous system (CNS) tuberculosis (TB), provides guidance for diagnostic imaging and CSF testing, and recommends treatment strategies for tuberculous meningitis and other forms of CNS TB, illustrating key aspects of diagnosis and management with case presentations.

RECENT FINDINGS

Although improvements in our understanding of the pathogenesis and management of CNS TB have occurred over the past 50 years, the emergence of multidrug-resistant and extensively drug-resistant TB, the advent of acquired immunodeficiency syndrome (AIDS), and the subsequent availability of highly active antiretroviral therapy that can produce the immune reconstitution inflammatory syndrome have complicated the diagnosis and treatment of CNS TB. Advances in diagnostic assays promise to increase the speed of diagnosis as well as the percentage of people with a confirmed rather than a presumptive diagnosis. Advances in precision medicine have identified polymorphisms in the LTA4H gene that influence the risk for inflammation in patients with tuberculous meningitis.

SUMMARY

CNS TB continues to be a major cause of morbidity and mortality, with the majority of people affected living in low-income and middle-income countries. Newer diagnostic assays promise to increase the speed of diagnosis and improve appropriate selection of antituberculous therapy and anti-inflammatory medications. Despite these advances, CNS TB remains difficult to diagnose, and clinicians should have a low threshold for initiating empiric therapy in patients with presumptive infection.

Seizures in tuberculous meningitis

OBJECTIVE

We report the frequency of seizure, its possible mechanisms and effect of seizure on the outcome of tuberculous meningitis (TBM).

METHODS

Seventy-nine patients with TBM admitted during 2014-2017 were evaluated. The seizures were categorized as per International League Against Epilepsy as well as into early (within 1 month of meningitis) and late (>1 month) seizure. The possible association of seizures was recorded and the outcome was assessed using modified Rankin Scale (mRS ≤ 2 as good, and mRS > 2 as poor).

RESULTS

The median age was 27 (18-76) years and 43 (54.4%) of whom were females. Tuberculous meningitis was definite in 31 (39.2%) and highly probable in the remaining. Seizures occurred in 27 (34.2%): early onset in 8 (29.6%) and late in 19 (70.4%) patients. The seizures were focal in 11(13.9%), focal to bilateral in 9 (11.4%), generalised tonic clonic in 7 (8.9%) and status epilepticus in 6 (7.6%) patients. Early seizures were associated with meningeal irritation and late seizures with tuberculoma, infarction and hyponatremia (P = 0.01). Seizure did not affect the mortality but were associated with worse six months outcome (P = 0.03).

CONCLUSION

Seizures occurred in 34% patients with TBM and were associated with poor outcome at six months.

Utility of pyrosequencing for rapid detection of tubercular meningitis (TBM) and associated susceptibility directly from CSF specimens

Tubercular meningitis (TBM) is a serious form of tuberculosis (TB). The diagnosis of TBM & susceptibility/resistance is difficult as TB MGIT culture lacks sensitivity & timeliness. Timely and accurate diagnosis of the TBM is the need of the hour for initiation of appropriate therapy. We have exploited pyrosequencing to detect TB and associated Multi/extensively drug resistant (MDR/ XDR-TB) directly from Cerebrospinal Fluid (CSF) specimens.

Progress on Diagnosis of Tuberculous Meningitis

Central nervous system (CNS) disease caused by Mycobacterium tuberculosis (MTB) is highly devastating. Tuberculous meningitis (TBM) is the most common form of CNS tuberculosis (TB). Rapid, sensitive, and affordable diagnostic tests are not available. Ziehl-Neelsen (ZN) stain has a very low sensitivity in cases of TBM, the sensitivity rates is of about 10-20%.The detection rate can be improved by taking large volume CSF samples (>6 ml) and prolonged slide examination (30 min). Culture of MTB from the CSF is slow and insufficiently sensitive. The sensitivity is different, which varies from 36% to 81.8%. The microscopic observation drug susceptibility (MODS) assay was recommended by the World Health Organization in 2011. The sensitivity is 65%, which is more sensitive and faster than CSF smear. Commercial PCR assays were found to be insensitive at detecting MTB in CSF samples. Many research provided the value of ADA on the TBM diagnosis. Interferon-gamma release assays (IGRAs) are not recommended for diagnosis of active TB disease. Imaging is essential in diagnosis and showing complications of CNS TB. Thwaites criteria and the Lancet consensus scoring system (LCSS) were developed to improve the diagnosis of TBM. Clinicians will continue to make judgment based on clinical examination, inflammatory CSF examinations, imaging studies, and scoring systems.

Cerebral hemorrhage due to tuberculosis meningitis: a rare case report and literature review

Tuberculosis (TB) is a common disease to threaten human health. TB of the central nervous system (CNS) is rare but the most serious type of systemic TB because of its high mortality rate, serious neurological complications and sequelae. In this case report, we describe a woman who presented with walking instability, intracerebral hemorrhage and leptomeningeal enhancement due to tuberculosis meningitis. The patient had no significant medical history and the initial clinical symptoms were walking instability. On analysis, the cerebrospinal fluid was colorless and transparent, the pressure was more than 400 mm H₂O, there was lymphocytic pleocytosis, increased protein, and decreased glucose levels present. No tuberculosis or other bacteria were detected. The patient's brain computed tomography image showed intra-cerebral hemorrhage (ICH) and contrast magnetic resonance imaging showed ICH in the right frontal lob, and leptomeningeal enhancement. CNS TB is rare but has a high mortality rate. As this disease has no unique characteristics at first presentation such as epidemiology and obvious clinical manifestation, a diagnosis of CNS TB remains difficult.

Central Nervous System Infections in the Critically Ill

Central nervous system (CNS) infections are frequently encountered in the intensive care unit setting and are a significant source of morbidity and mortality. The constantly changing trends in microbial resistance, as well as the pharmacokinetic difficulties in providing effective concentrations of antimicrobials at the site of infection represent a unique challenge to clinicians. Achievement of a successful outcome in patientswith CNS infections is reliant on eradication of the offending pathogen and management of any neurologic complications. This requires an anatomic and physiologic understanding of the different types of CNS infection, diagnostic strategies, associated complications, causative organisms, and the principles that govern drug distribution into the CNS. This article serves as a review of the epidemiology, pathophysiology, diagnosis, and treatment options for a variety of CNS infections, with a focus on those commonly encountered in an intensive care setting.

Evaluation of host Hsp(s) as potential biomarkers for the diagnosis of tuberculous meningitis

OBJECTIVES

Diagnosis of tuberculosis meningitis (TBM) remains challenging in tuberculosis (TB) endemic countries. The need for TB biomarkers arises, in part, from the difficulty of accurately diagnosing TBM with the available methods.

PATIENTS AND METHODS

To explore the potential of host Hsps (Hsp 25, Hsp 60, Hsp 70 and Hsp 90) as an alternative marker in TBM diagnosis, we evaluated cerebrospinal fluid (CSF) sample of TBM (n=49), Pyogenic Meningitis (PM) (n=20), Viral Meningitis (VM) (n=09), Fungal Meningitis (FM) (n=04) and non infectious control (n=79) patients using indirect ELISA.

RESULTS

Out of four Hsps, Hsp 70 and Hsp 90 yields 89% & 88% sensitivity and 82% & 89% specificity, respectively. The positive (PPV) and negative (NPV) predictive values yielded in TBM group for Hsp 70 was 86.27% (73.74-94.27) and 93.51% (85.48-97.83), respectively. For Hsp 90 the obtained PPV was 89.36% (76.88-96.41) and NPV was 91.36% (82.99-96.44). In 86% of TBM patients all the four Hsps were found to be positive and none of the patient was found to be negative for all Hsps in the same group.

CONCLUSIONS

The data presented in the study indicate that host Hsp 70 and Hsp 90 shows good sensitivity and specificity and have potential in the diagnosis of TBM disease. The combined use of all Hsps (Hsp 25, Hsp 60, Hsp 70 and Hsp 90) effectively distinguishes patients with TBM from other disease controls.

Clinical, radiological and laboratory findings in 185 children with tuberculous meningitis at a single centre and relationship with the stage of the disease

Background

A delay in the diagnosis and treatment of tuberculosis meningitis (TBM) may lead to increased mortality and morbidity. The aim of this study was to describe the clinical, radiological and laboratory findings of TBM on a cohort of 185 pediatric patients at a single centre over a 10 year period and to investigate relationship between the stage of the disease.

Methods

The hospital records of 185 TBM children that presented to the Pediatric Clinics of Dicle University Hospital were retrospectively evaluated. The age, gender, family history of tuberculosis, result of Mantoux skin test, status of BCG vaccination, stage of TBM at hospitalization, and clinical, laboratory and radiological features were recorded. Clinical staging of TBM was defined as follows: Stage I, no focal neurological findings and Glasgow Coma Scale (GCS) score 15; Stage II, GCS 15 presenting with focal neurological deficit or all the patients with GCS 10–14; Stage III, all the patients with GCS < 10. Relationships between results and stages of TBM were investigated.

Results

The mean age of the patients was 53.5 ± 44.9 months (4 months–18 years). 121 (65.4 %) of the patients were male and 64 (34.6 %) female. Family history of tuberculosis was defined in 62 (33.5 %) patients. Forty five (24.3 %) children had BCG vaccination scar. Mantoux skin test was interpreted as positive in 35 (18.9 %) patients. Sixty-eight (36.8 %) children were at stage I TBM, 57 (30.8 %) at stage II and 60 (32.4 %) were at stage III on admission. Mean duration of hospitalization was 23.9 ± 14.1 days. Totally, 90 patients (48.6 %) had abnormal chest X-ray findings (parenchymal infiltration in 46 (24.9 %), mediastinal lymphadenopathy in 36 (19.5 %), miliary opacities in 25 (13.5 %), pleural effusion in 2 (1.1 %), and atelectasis in 2 (1.1 %) patients). One hundred sixty seven (90.3 %) patients had hydrocephalus in cranial computerized tomography. There were 24 (13.0 %) patients with positive culture for Mycobacterium tuberculosis and 3 (1.6 %) patients with positive acid-fast bacilli in cerebrospinal fluid. Overall mortality rate was 24 (13.0 %). Among the findings; patients at Stage III had less frequent positive chest X-ray abnormality, miliary opacities and BCG vaccination scar when compared with patients at Stage I and II (p = 0,005; p = 0,007, p = 0.020, respectively).

Conclusions

Children with TBM and positive chest X-ray findings at hospital admission were more frequently diagnosed at Stage I, and BCG vaccination might be protective from the Stage III of the disease.

Radiological Follow-up of a Cerebral Tuberculoma with a Paradoxical Response Mimicking a Brain Tumor

We report a case of a paradoxical response of a tuberculoma in the brain mimicking a brain tumor. A 76-year-old woman presented with a 2 week history of headache, dysarthia, and orthopnea. Brain magnetic resonance images (MRI) revealed two rim-enhancing lesions on the pons and occipital lobe, and chest computed tomography showed randomly distributed miliary nodules. The tentative diagnosis was tuberculosis (TB) of the brain and lung. She complained of right hemiparesis and worsening general weakness after taking the anti-TB medication. On the monthly follow-up images, the enhanced lesions were enlarged with increased perfusion and choline/creatinine ratio, suggesting a high grade glioma. A surgical resection was completed to diagnose the occipital lesion, and the tuberculoma was pathologically confirmed by a positive TB-polymerase chain reaction. The anti-TB medication was continued for 13 months. A follow-up MRI showed decreased size of the brain lesions associated with perilesional edema, and the clinical symptoms had improved. Brain tuberculoma could be aggravated mimicking brain malignancy during administration of anti-TB medication. This paradoxical response can be effectively managed by continuing the anti-TB drugs.

Comparison of amplicor and GeneXpert MTB/RIF tests for diagnosis of tuberculous meningitis

There are no data about the comparative accuracy of commercially available nucleic acid amplification tests (GeneXpert MTB/RIF and Roche Amplicor) for the diagnosis of tuberculous meningitis (TBM). A total of 148 patients with suspected TBM were evaluated, and cultures served as the reference standard. The sensitivities and specificities (95% confidence interval [CI]) for the Amplicor and Xpert MTB/RIF tests were similar: 46 (31-60) versus 50 (33-67) and 99 (93-100) and 94 (84-99), respectively.

Central nervous system tuberculosis

Tuberculosis (TB) has shown a resurgence in nonendemic populations in recent years and accounts for 8 million deaths annually in the world. Central nervous system involvement is one of the most serious forms of this infection, acting as a prominent cause of morbidity and mortality in developing countries. The rising number of cases in developed countries is mostly attributed to factors such as the pandemic of acquired immunodeficiency syndrome and increased migration in a globalized world. Mycobacterium TB is responsible for almost all cases of tubercular infection in the central nervous system. It can manifest in a variety of forms as tuberculous meningitis, tuberculoma, and tubercular abscess. Spinal infection may result in spondylitis, arachnoiditis, and/or focal intramedullary tuberculomas. Timely diagnosis of central nervous system TB is paramount for the early institution of appropriate therapy, because delayed treatment is associated with severe morbidity and mortality. It is therefore important that physicians and radiologists understand the characteristic patterns, distribution, and imaging manifestations of TB in the central nervous system. Magnetic resonance imaging is considered the imaging modality of choice for the study of patients with suspected TB. Advanced imaging techniques including magnetic resonance perfusion and diffusion tensor imaging may be of value in the objective assessment of therapy and to guide the physician in the modulation of therapy in these patients.

Detection of Delta-like 1 ligand for the diagnosis of tuberculous meningitis: An effective and rapid diagnostic method

OBJECTIVE

To investigate the diagnostic value of Delta-like 1 ligand (DLL1) in cerebrospinal fluid (CSF) and serum, in tuberculous meningitis (TBM).

METHODS

Patients with a definite diagnosis of central nervous system infection (TBM, viral meningitis/encephalitis or bacterial meningitis) were prospectively enrolled alongside patients with intracranial metastatic tumour and patients with no diagnosis (who served as controls). DLL1 content in CSF and serum was measured quantitatively by enzyme-linked immunosorbent assay; analyses were blinded.

RESULTS

A total of 173 patients were enrolled: 62 with TBM; 38 with viral meningitis/encephalitis; 26 with bacterial meningitis; 17 with intracranial metastatic tumour; 30 with no diagnosis. CSF DLL1 content was highest for TBM; there were no differences in CSF DLL1 between the other groups. Serum DLL1 content was highest for the TBM and intracranial metastatic tumour groups, with significant differences between the TBM group and the viral meningitis/encephalitis, bacterial meningitis and nondiagnosed groups. There were no differences in serum DLL1 between the viral meningitis/encephalitis, bacterial meningitis and nondiagnosed groups, or between the TBM group and the tumour group.

CONCLUSION

As a new biomarker, DLL1 may be of great clinical importance in the diagnosis of TBM.

Bacterial pathogens

Bacterial infections are frequent complications among patients treated for cancer. The type, severity, and treatment of bacterial infections vary and depend upon the specific malignancy, associated chemotherapies, and transplantation. This chapter discusses commonly encountered bacterial pathogens as well as Nocardia and mycobacteria in patients with cancer and addresses the clinical syndromes and management. Drug-resistant bacteria are becoming an increasingly recognized problem in patients with cancer. Antimicrobial resistance in select gram-positive and gram-negative bacteria are discussed along with the mechanisms of resistance and recommended therapies.

Tuberculosis

Tuberculosis remains a serious health problem worldwide, particularly affecting the poorest in both high-income and developing countries. It was declared a global emergency by the World Health Organization in 1993. Central nervous system (CNS) tuberculosis is caused by mycobacteria belonging to the Mycobacterium tuberculosis complex, and is acquired through inhalation of aerosolized droplet nuclei. Meningitis represents the most frequent and severe form of CNS tuberculosis. Parenchymal CNS involvement can occur in the form of tuberculoma or, more rarely, abscess. Also, damage of the spinal cord, roots, and spine can occur in the form of spinal meningitis, radiculomyelitis, spondylitis, or spinal cord infarction. Diagnosis remains a challenge due to the slow growth of the organisms and the low yield of cerebrospinal fluid cultures, as well as the frequent absence of evidence of infection elsewhere. This results in frequent empirical therapy, based on a combination of four drugs (isoniazid, rifampicin, pyrazinamide and ethambutol) for 2 months, followed by 10 additional months with two drugs (isoniazid and rifampicin) to a total duration of 12 months. Shorter regimens have also been successful, but there have been few controlled trials in patients with extrapulmonary disease. Corticoid therapy seems to be associated with a reduced risk of death, and is usually indicated. Evidence of multidrug resistance requires variable combinations of first- and second-line drugs; fortunately, resistance does not seem to represent a serious threat for CNS tuberculosis at present, but still requires the utmost vigilance.

Diagnostic accuracy of quantitative PCR (Xpert MTB/RIF) for tuberculous meningitis in a high burden setting: a prospective study

BACKGROUND

Tuberculous meningitis (TBM) is difficult to diagnose promptly. The utility of the Xpert MTB/RIF test for the diagnosis of TBM remains unclear, and the effect of host- and sample-related factors on test performance is unknown. This study sought to evaluate the sensitivity and specificity of Xpert MTB/RIF for the diagnosis of TBM.

METHODS AND FINDINGS

235 South-African patients with a meningeal-like illness were categorised as having definite (culture or Amplicor PCR positive), probable (anti-TBM treatment initiated but microbiological confirmation lacking), or non-TBM. Xpert MTB/RIF accuracy was evaluated using 1 ml of uncentrifuged and, when available, 3 ml of centrifuged cerebrospinal fluid (CSF). To evaluate the incremental value of MTB/RIF over a clinically based diagnosis, test accuracy was compared to a clinical score (CS) derived using basic clinical and laboratory information. Of 204 evaluable patients (of whom 87% were HIV-infected), 59 had definite TBM, 64 probable TBM, and 81 non-TBM. Overall sensitivity and specificity (95% CI) were 62% (48%-75%) and 95% (87%-99%), respectively. The sensitivity of Xpert MTB/RIF was significantly better than that of smear microscopy (62% versus 12%; p = 0.001) and significantly better than that of the CS (62% versus 30%; p = 0.001; C statistic 85% [79%-92%]). Xpert MTB/RIF sensitivity was higher when centrifuged versus uncentrifuged samples were used (82% [62%-94%] versus 47% [31%-61%]; p = 0.004). The combination of CS and Xpert MTB/RIF (Xpert MTB/RIF performed if CS<8) performed as well as Xpert MTB/RIF alone but with a ∼10% reduction in test usage. This overall pattern of results remained unchanged when the definite and probable TBM groups were combined. Xpert MTB/RIF was not useful in identifying TBM among HIV-uninfected individuals, although the sample was small. There was no evidence of PCR inhibition, and the limit of detection was ∼80 colony forming units per millilitre. Study limitations included a predominantly HIV-infected cohort and the limited number of culture-positive CSF samples.

CONCLUSIONS

Xpert MTB/RIF may be a good rule-in test for the diagnosis of TBM in HIV-infected individuals from a tuberculosis-endemic setting, particularly when a centrifuged CSF pellet is used. Further studies are required to confirm these findings in different settings. Please see later in the article for the Editors' Summary.

Safe Treatment of Seizures in the Setting of HIV/AIDS

OPINION STATEMENT

HIV(+) patients are at increased risk for developing seizures due to the vulnerability of the central nervous system to HIV-associated diseases, immune dysfunction, and metabolic disturbances. In patients with acute seizures, standard protocols still apply with urgent seizure cessation being the priority. Management of the person with established epilepsy who contracts HIV is challenging, but the decision to initiate chronic antiepileptic drug (AED) therapy in an HIV(+) patient is also difficult. Chronic treatment guidelines emphasize the interactions between AEDs and antiretroviral (ARV) medications, but provide no explicit advice regarding when to initiate an AED, what medication to select, and/or the duration of treatment. Epidemiologic data regarding seizure recurrence risk in HIV(+) individuals is not available. The risk of further seizures likely depends upon the underlying etiology for the seizure(s) and patients' immune status and may be increased by the use of efavirenz (an ARV). The issues for consideration include AED-ARV interactions, organ dysfunction, seizure type, and drug side effects, which may worsen or be confused with symptoms of HIV and/or epilepsy. Co-administration of enzyme inducing (EI)-AEDs and ARVs can result in virological failure, breakthrough seizure activity, AED toxicity, and/or ARV toxicity. Where available, the AED of choice in HIV(+) patients is levetiracetam due to its broad spectrum activity, ease of use, minimal drug interactions, and favorable side effect profile. Lacosamide, gabapentin, and pregabalin are also favored choices in patients with partial onset seizures and/or those failing levetiracetam. Where newer AEDs are not available, valproic acid may be the treatment of choice in terms of an AED, which will not cause enzyme induction-associated ARV failure, but its side effect profile causes other obvious problems. In resource-limited settings (RLS) where only EI-AEDs are available, there are no good treatment options and further pressure needs to be placed upon policymakers to address this care gap and public health threat.

Tuberculous meningitis together with systemic brucellosis

We present a case of a 57-year-old woman admitted with findings of meningitis. Cerebrospinal fluid (CSF) tests revealed a pleocytosis together with a low CSF glucose concentration. Empirically, antituberculosis treatment was started. Rose Bengal and Wright tests were performed to exclude brucellosis with central nervous system involvement. These tests were positive in serum but not in CSF. Antibrucellosis treatment with doxycycline and ceftriaxone was started without withdrawing the antituberculosis treatment because of the possibility of simultaneous infection with both tuberculosis and brucellosis agents. Finally, this approach was shown to be correct when tuberculosis was isolated from the culture of CSF. Clinicians in endemic regions for brucellosis should be careful while diagnosing subacute/chronic meningitis. Other possible similar etiologies such as Mycobacterium tuberculosis must be ruled out before attributing the meningitis to brucellosis.

Pathology of tropical diseases

Tropical diseases affecting the central nervous system include infections, infestations, and nutritional deficiency disorders. This article discusses the commonly encountered diseases. The infections include bacterial, mycobacterial, fungal, parasitic, and viral infections with varied clinical manifestations. Imaging sensitivity and specificity for the prediction of the cause of infections has improved with application of advanced techniques. Microbial demonstration and histology remain the gold standard for diagnosis. Understanding the basis of imaging changes is mandatory for better evaluation of images. Nutritional disorders present with generalized and nonspecific imaging manifestations. The pathology of commonly encountered vitamin deficiencies is also discussed.

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

Central nervous system (CNS) tuberculosis (TB) is a devastating infection with high rates of morbidity and mortality worldwide and may manifest as meningitis, tuberculoma, abscess, or other forms of disease. Immunosuppression, due to either human immunodeficiency virus infection or solid organ transplantation, increases susceptibility for acquiring or reactivating TB and complicates the management of underlying immunosuppression and CNS TB infection. This article reviews how immunosuppression alters the clinical presentation, diagnosis, treatment, and outcome of TB infections of the CNS.

Comparative utility of cytokine levels and quantitative RD-1-specific T cell responses for rapid immunodiagnosis of tuberculous meningitis

The rapid diagnosis of tuberculous meningitis (TBM) is problematic. We found in 150 patients with suspected TBM that, similar to RD-1-specific quantitative cerebrospinal fluid (CSF) T-cell responses, unstimulated CSF gamma interferon (IFN-γ) levels when used together with other rapid confirmatory tests (Gram stain and cryptococcal latex agglutination test) may allow the accurate and rapid diagnosis of TBM in a setting in which tuberculosis (TB) and HIV are endemic. In resource-poor settings, a clinical prediction rule (CPR) may be useful to clinicians, and thus the IFN-γ assay may potentially need to be used only when the clinical score is below a prespecified threshold. These preliminary findings will need to be confirmed in further studies.

Adenosine Deaminase Levels in CSF of Tuberculous Meningitis Patients

Background

Tuberculosis kills five lakh patients in India every year, out of which 7-12 % are with meningeal involvement. Delay in its diagnosis and in initiation of treatment results in poor prognosis and sequlae in up to 25% of cases. The aim of the present study is to look for a simple, rapid, cost effective, non-invasive and fairly specific test in differentiating tubercular etiology from other causes.

Methods

Forty patients between the age of 6 - 24 months attending hospital with symptoms and signs of meningitis were selected and divided into two groups: tubercular and non-tubercular, depending upon the accepted criteria. CSF was drawn and ADA estimated.

Results

Out of 19 tubercular patients, 18 had CSF ADA at or above the cutoff value while one had below. Out of 21 non-tuberculous patients, two had ADA levels at or above the cutoff value while 19 had below this value. Results of our study indicate that ADA level estimation in CSF is not only of considerable value in the diagnosis of TBM, CSF ADA level 10 U/L as a cutoff value exhibited 94.73% sensitivity and 90.47% specificity in differentiating tuberculous from non-tuberculous meningitis; it also has 90.00% positive predictive value and 95.00% negative predictive value.

Conclusions

It can be concluded that ADA estimation in CSF is not only simple, inexpensive and rapid but also fairly specific method for making a diagnosis of tuberculous etiology in TBM, especially when there is a dilemma of differentiating the tuberculous etiology from non-tuberculous ones. For this reason ADA estimation in TBM may find a place as a routine investigation.

Keywords

Cerebrospinal fluid; Adenosine deaminase; Tuberculous meningitis

Central nervous system infection

This article outlines a practical imaging approach to CNS infection and reviews 5 basic imaging patterns commonly seen: (1) extra-axial lesion, (2) ring-enhancing lesion, (3) temporal lobe lesion, (4) basal ganglia lesion, and (5) white matter abnormality. Opportunistic infections in the setting of HIV are also discussed within the context of these 5 basic imaging patterns. Characteristic imaging features in conjunction with clinical history are also highlighted in order to narrow the differential diagnosis or suggest a specific diagnosis in some cases.

Movement disorders identified in patients with intracranial tuberculomas

INTRODUCTION

movement disorders have been associated with deep brain lesions. This study was performed to describe the frequency and characteristics of movement disorders in patients with intracranial tuberculomas.

METHODS

patients admitted consecutively between 1989 and 2004 to the Neurology Service of Eugenio Espejo Hospital (Quito, Ecuador), with a diagnosis of intracranial tuberculomas. All patients were examined clinically, and laboratory tests and imaging studies performed. Follow-up continued up to one year after the tuberculosis treatment was completed. A nested case-control analysis was performed to compare clinical characteristics, number and location of tuberculomas, between cases with movement disorders and controls.

RESULTS

forty-nine patients with tuberculomas (31.7±20.5 years; males 53.1%) were studied. We found 16 cases (32.6%; 95%CI=19.9% - 47.5%) of movement disorders: chorea (n=7; 43.8%), tremor (n=5; 31.3%), dystonia (n=3; 18.8%) and myoclonus (n=1; 6.3%). Most cases (87.6%) developed early (10.4±5.2 days of hospitalization). On admission, patients with movement disorders showed higher severity of the illness than controls (68.7 vs. 30.3%; p=.01), along with greater motor impairment (75.0 vs. 39.4%; p=.01) and sensitivity impairment (43.8 vs. 9.1%; p=.01). The cases showed higher frequency of multiple tuberculomas (68.7 vs. 36.4%), with deep brain deep (31.3 vs. 21.2%) and more severe motor impairment (25.0 vs. 12.1%).

CONCLUSIONS

our results suggest a causal relationship between tuberculomas and movement disorders. Deep location and multiple tuberculomas may increase the risk of develop movement disorders.

Multiple dural tuberculomas presenting as leptomeningeal carcinomatosis

Objective and Importance. We present the rare occurrence of multiple dural-based tuberculomas mimicking leptomeningeal carcinomatosis in a young immunocompetent patient. Clinical Presentation. A 36-year-old man presented with a 2-month history of generalized epileptic activity and altered perception. Neurological examination was remarkable for bilateral Babinski's sign. Cranial magnetic resonance imaging (MRI) revealed multiple dural-based enhancing lesions with cerebral edema. Intervention. A right frontal craniotomy was performed for diagnosis. Histological examination revealed multiple confluent necrotizing and nonnecrotizing granulomas with giant cells which was consistent with tuberculosis (TB), and the patient was placed on anti-TB therapy for 24 months. Conclusion. To the best of our knowledge isolated diffuse involvement of the dura mater by TB, mimicking leptomeningeal carcinomatosis, as the sole manifestation of disease has not been reported before. Since pachymeningeal TB is rarely suspected when atypical radiological appearance is combined with the absence of systemic disease, biopsy is inevitably required for diagnosis.

Comparison of a clinical prediction rule and a LAM antigen-detection assay for the rapid diagnosis of TBM in a high HIV prevalence setting

BACKGROUND/OBJECTIVE

The diagnosis of tuberculous meningitis (TBM) in resource poor TB endemic environments is challenging. The accuracy of current tools for the rapid diagnosis of TBM is suboptimal. We sought to develop a clinical-prediction rule for the diagnosis of TBM in a high HIV prevalence setting, and to compare performance outcomes to conventional diagnostic modalities and a novel lipoarabinomannan (LAM) antigen detection test (Clearview-TB®) using cerebrospinal fluid (CSF).

METHODS

Patients with suspected TBM were classified as definite-TBM (CSF culture or PCR positive), probable-TBM and non-TBM.

RESULTS

Of the 150 patients, 84% were HIV-infected (median [IQR] CD4 count = 132 [54; 241] cells/µl). There were 39, 55 and 54 patients in the definite, probable and non-TBM groups, respectively. The LAM sensitivity and specificity (95%CI) was 31% (17;48) and 94% (85;99), respectively (cut-point ≥ 0.18). By contrast, smear-microscopy was 100% specific but detected none of the definite-TBM cases. LAM positivity was associated with HIV co-infection and low CD4 T cell count (CD4<200 vs. >200 cells/µl; p = 0.03). The sensitivity and specificity in those with a CD4<100 cells/µl was 50% (27;73) and 95% (74;99), respectively. A clinical-prediction rule ≥ 6 derived from multivariate analysis had a sensitivity and specificity (95%CI) of 47% (31;64) and 98% (90;100), respectively. When LAM was combined with the clinical-prediction-rule, the sensitivity increased significantly (p<0.001) to 63% (47;68) and specificity remained high at 93% (82;98).

CONCLUSIONS

Despite its modest sensitivity the LAM ELISA is an accurate rapid rule-in test for TBM that has incremental value over smear-microscopy. The rule-in value of LAM can be further increased by combination with a clinical-prediction rule, thus enhancing the rapid diagnosis of TBM in HIV-infected persons with advanced immunosuppression.

Tuberculous meningitis

Tuberculous meningitis is a severe form of extrapulmonary tuberculosis. The exact incidence and prevalence are not known. In countries with high burden of pulmonary tuberculosis, the incidence is expected to be proportionately high. Children are much more vulnerable. Human immunodeficiency virus-infected patients have a high incidence of tuberculous meningitis. The hallmark pathological processes are meningeal inflammation, basal exudates, vasculitis and hydrocephalus. Headache, vomiting, meningeal signs, focal deficits, vision loss, cranial nerve palsies and raised intracranial pressure are dominant clinical features. Diagnosis is based on the characteristic clinical picture, neuroimaging abnormalities and cerebrospinal fluid changes (increased protein, low glucose and mononuclear cell pleocytosis). Cerebrospinal fluid smear examination, mycobacterial culture or polymerase chain reaction is mandatory for bacteriological confirmation. The mortality and morbidity of tuberculous meningitis are exceptionally high. Prompt diagnosis and early treatment are crucial. Decision to start antituberculous treatment is often empirical. WHO guidelines recommend a 6 months course of antituberculous treatment; however, other guidelines recommend a prolonged treatment extended to 9 or 12 months. Corticosteroids reduce the number of deaths. Resistance to antituberculous drugs is associated with a high mortality. Patients with hydrocephalus may need ventriculo-peritoneal shunting. Bacillus Calmette-Guérin vaccination protects to some degree against tuberculous meningitis in children.

Sensitivity, specificity, negative and positive predictive values of adenosine deaminase in patients of tubercular and non-tubercular serosal effusion in India

BACKGROUND

In India, tuberculosis is an endemic disease. Delay in diagnosis results in poor prognosis and fast spread of the disease. The objective of the present study is to look for an effective and acceptable diagnostic test, which may be helpful to initiate early treatment to improve prognosis and reduce spread.

METHODS

Three hundred and thirty patients with pleural, ascitic, meningeal and synovial effusion were selected and divided depending upon the etiology and the involvement of serosal membranes. Serosal aspirated fluid was subjected to biochemical tests and adenosine deaminase estimation. Cutoff taken is above 40 for pleural, peritoneal or synovial fluid and above 10 for CSF.

RESULTS

In cases of pulmonary and extra-pulmonary disease, sensitivity was 92.80% and 94.29%; specificity 90.00% and 92.16%; positive predictive value 92.86% and 89.00%; and negative predictive value 90.00% and 95.92% respectively.

CONCLUSIONS

Adenosine deaminase estimation is not only a fairly sensitive and specific test (more than 90%), helpful in differentiating tubercular from non-tubercular etiology both in pulmonary and extra-pulmonary disease, but is also simple, inexpensive and rapid. For this reason this test may help in early diagnosis, improve the prognosis and reduce spread of disease and sequlae.

KEYWORDS

Adenosine deaminase; Serosal effusion; Tubercular; Non-tubercular; Pulmonary; Extra-pulmonary.

Cerebrospinal T-cell responses aid in the diagnosis of tuberculous meningitis in a human immunodeficiency virus- and tuberculosis-endemic population

RATIONALE

Current tools for the rapid diagnosis of tuberculous meningitis (TBM) are suboptimal. We evaluated the clinical utility of a quantitative RD-1 IFN-gamma T-cell enzyme-linked immunospot (ELISPOT) assay (T-SPOT.TB), using cerebrospinal fluid cells for the rapid immunodiagnosis of TBM.

OBJECTIVES

To evaluate the diagnostic utility of the RD1 antigen- specific ELISPOT assay for the diagnosis of tuberculous meningitis.

METHODS

The ELISPOT assay was evaluated in 150 patients with suspected TBM who were categorized as definite-TBM, probable-TBM, and non-TBM. Culture or polymerase chain reaction positivity for Mycobacerium tuberculosis served as the reference standard. To determine the diagnostic value of the ELISPOT assay, a clinical prediction rule was derived from baseline clinical and laboratory parameters using a multivariable regression model.

MEASUREMENTS AND MAIN RESULTS

A total of 140 patients (81% HIV-infected; median CD4 count, 160 cells/mm(3)) were included in the final analysis. When comparing the definite-TBM (n = 38) and non-TBM groups (n = 48), the ELISPOT assay (cut point of > or =228 spot-forming cells per 1 million mononuclear cells) was a useful rule-in test: sensitivity 58% (95% confidence interval [CI], 41-74); specificity 94% (95% CI, 83-99). However, ELISPOT outcomes improved when other rapid tests were concurrently used to exclude bacterial (Gram stain) and cryptococcal meningitis (latex-agglutination test) within the non-TBM group. Using this approach, the ELISPOT assay (cut point of > or =46 spot-forming cells) was an excellent rule-in test: sensitivity 82% (95% CI, 66-92); specificity 100% (95% CI, 78-100); positive predictive value, 100% (95% CI, 89-100); negative predictive value, 68% (95% CI, 45-86); area under the curve, 0.90. The ELISPOT assay had incremental diagnostic value compared with the clinical prediction rule.

CONCLUSIONS

The RD-1 ELISPOT assay, using cerebrospinal fluid mononuclear cells and in conjunction with other rapid confirmatory tests (Gram stain and cryptococcal latex-agglutination test), is an accurate rapid rule-in test for TBM in a TB and HIV endemic setting.