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.

Tuberculosis revisted: classic imaging findings in childhood

Tuberculosis (TB) remains one of the major public health threats worldwide, despite improved diagnostic and therapeutic methods. Tuberculosis is one of the main causes of infectious disease in the chest and is associated with substantial morbidity and mortality in paediatric populations, particularly in low- and middle-income countries. Due to the difficulty in obtaining microbiological confirmation of pulmonary TB in children, diagnosis often relies on a combination of clinical and radiological findings. The early diagnosis of central nervous system TB is challenging with presumptive diagnosis heavily reliant on imaging. Brain infection can present as a diffuse exudative basal leptomeningitis or as localised disease (tuberculoma, abscess, cerebritis). Spinal TB may present as radiculomyelitis, spinal tuberculoma or abscess or epidural phlegmon. Musculoskeletal manifestation accounts for 10% of extrapulmonary presentations but is easily overlooked with its insidious clinical course and non-specific imaging findings. Common musculoskeletal manifestations of TB include spondylitis, arthritis and osteomyelitis, while tenosynovitis and bursitis are less common. Abdominal TB presents with a triad of pain, fever and weight loss. Abdominal TB may occur in various forms, as tuberculous lymphadenopathy or peritoneal, gastrointestinal or visceral TB. Chest radiographs should be performed, as approximately 15% to 25% of children with abdominal TB have concomitant pulmonary infection. Urogenital TB is rare in children. This article will review the classic radiological findings in childhood TB in each of the major systems in order of clinical prevalence, namely chest, central nervous system, spine, musculoskeletal, abdomen and genitourinary system.

Absence of posterior pituitary bright spot in adults with CNS tuberculosis: A case-control study

INTRODUCTION

Current diagnostic methods used in Central Nervous System Tuberculosis (CNS TB) are limited by the paucibacillary nature of this form of tuberculosis. Posterior pituitary bright spot (PPBS) refers to an area of T1 hyperintensity in the posterior pituitary in MR imaging of the brain. It is found in 80-90% of healthy children and adults. In children with CNS TB, nearly half have absence of PPBS. This finding has not been described in adults. Our study looked for absence of PPBS in MR imaging and its association with CNS tuberculosis.

OBJECTIVE

To study prevalence of the absence of PPBS in patients with CNS tuberculosis when compared to a control group of normal patients.

METHODS

This was a retrospective case-control study of 100 patients with CNS tuberculosis and 200 controls (matched in 1:2 ratio) of patients with normal MRI brain. The MRI images were presented to a blinded radiologist in a randomised sequence to report for absence of PPBS. The data was subsequently analysed to look for association of absence of PPBS with CNS tuberculosis.

RESULTS

Absence of PPBS (cases (47%), controls (8.5%)) was significantly associated with CNS tuberculosis in (Odds ratio-7.90, 95%CI 4.04-15.44, P-value<0.0001). The specificity, sensitivity, positive predictive value and positive likelihood ratio are 91.5%, 47%, 73.4% and 5.53 respectively. Adding of absence of PPBS as an additional radiological feature in diagnosis of CNS TB increased the sensitivity from 77% to 84%.

CONCLUSION

Absence of PPBS is significantly associated with CNS tuberculosis and could be a relatively simple diagnostic aid in the diagnosis of CNS tuberculosis.

Tuberculous Encephalitis May Be Undetectable on Magnetic Resonance Imaging but Detectable on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography

Neurotuberculosis (NT) continues to be a global health problem with severe morbidity and mortality. The manifestations of NT are well-known and encompass forms such as meningitis, tuberculomas, military tuberculosis, ventriculitis, and brain abscess. Data of all patients with central nervous system tuberculosis who underwent magnetic resonance imaging (MRI) and/or 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) were analyzed. Over a 7-year period (2014-2021), we encountered three patients who had dense neurological deficits and 18F-FDG PET-CT results suggesting focal cortical encephalitis. 18F-FDG PET-CT demonstrated focal hypermetabolism involving focal-regional areas of the left hemisphere that corresponded to clinical deficits in two of the three patients. Follow-up 18F-FDG PET-CT showed improvement in cortical hypermetabolism in all three patients that corresponded with clinical improvement. MRI of the brain with contrast showed subtle leptomeningeal enhancement in these areas, along with other features of NT, but it could not detect cortical involvement. A literature review also revealed some previous descriptions that seemed to be consistent with tuberculous encephalitis (TbE). TbE seems to be a distinct subset of NT and may coexist with other features of NT or disseminated tuberculosis. It may be detected by 18F-FDG PET-CT even when brain MRI does not show any evident abnormality to explain a focal neurological deficit. 18F-FDG PET-CT can be considered during the evaluation and monitoring of NT to detect TbE. The presence of TbE may affect the prognosis and treatment duration of NT.

[Central nervous system tuberculosis : don't miss the diagnosis !]

We are presented a 35-year-old patient with no previous relevant medical history who was admitted to the emergency department for fever, altered mental status and diffuse abdominal pain. Initial evaluation failed to the demonstrated the presence of thoracic or abdominal deep infection. The clinical course was marked by a deterioration of the neurological condition. The cerebral MRI showed diffuse and extensive involvement of the brainstem and cerebellar hemispheres associated with hydrocephalus consistent with tuberculous meningoencephalitis. Antituberculous therapy was started with some delay but no clinical improvement was achieved and the patient died.

Extrapulmonary involvement in pediatric tuberculosis

Tuberculosis in childhood is clinically challenging, but it is a preventable and treatable disease. Risk factors depend on age and immunity status. The most common form of pediatric tuberculosis is pulmonary disease, which comprises more than half of the cases. Other forms make up the extrapulmonary tuberculosis that involves infection of the lymph nodes, central nervous system, gastrointestinal system, hepatobiliary tree, and renal and musculoskeletal systems. Knowledge of the imaging characteristics of pediatric tuberculosis provides clues to diagnosis. This article aims to review the imaging characteristics of common sites for extrapulmonary tuberculous involvement in children.

Worsening of longstanding headaches, dizziness, visual symptoms · Dx?

The clinical presentation and imaging studies of central nervous system tuberculosis are often indistinguishable from those of patients with malignant neoplasms or metastatic disease. Biopsies may be necessary to distinguish tuberculomas from other intracranial lesions such as pyogenic abscesses or necrotic tumors.

[MRI features of ventricular system tuberculosis]

OBJECTIVE

To study the MRI features of ventricular system tuberculosis.

METHODS

Nineteen patients with ventricular system tuberculosis in our hospital from Mar. 2009 to Sep. 2014 were retrospectively identified. Their clinical features and cranial MRI characteristics were reviewed.

RESULTS

There were 13 males and 6 females, aged from 15-81 years(mean 37±16). Eight patients had intraventricular tuberculosis, with 5 long striped or irregular shaped intraventricular tuberculosis and 3 with ventricular tuberculoma. Six patients had tubercular ependymitis and 5 had intraventricular tuberculosis along with tubercular ependymitis. The lesions of 14 patients were in the lateral ventricle; 13 in occipital or temporal horn of lateral ventricle, 9 complicated by tubercular meningitis, and 10 complicated by brain tuberculoma. The lesion of 5 patients were in the fourth ventricle, 5 in the postmedian of the fourth ventricle, 5 complicated by tubercular meningitis and 4 complicated by hydrocephalus. There were 4 cases with ring-enhancement and 15 with heterogeneous enhancement. Ten cases were complicated by peripheral edema.

CONCLUSIONS

The diagnosis of ventricle system tuberculosis is difficult due to its low incidence. The site, cranial MRI characteristics, the patterns of enhancement and complications have certain specificity and are useful in the diagnosis of ventricular system tuberculosis.

REVIEW OF THE CLINICAL, COMPUTERIZED TOMOGRAPHY SCAN AND/OR MAGNETIC RESONANCE IMAGING FINDINGS OF INTRACRANIAL TUBERCULOMA IN AN ETHIOPIAN TEACHING HOSPITAL

ACKGROUND

Ethiopia is one of the countries that has high burden of all forms of tuberculosis and there is no published report on computerized tomography scan and/or magnetic resonance imaging of intracranial tuberculomas. Objective : to review the clinical, computerized tomography and/or magnetic resonance imaging features of intracranial tuberculoma.

METHODS

retrospective review of patient’s medical records of patients operated for intracranial mass that had computerized tomography and/or magnetic resonance imaging brain scans and had histopathological diagnoses, at Tikur Anbessa Specialized Hospital between January 2009 and June 2013.

RESULTS

Of 222 operated cases of intracranial mass subjected to histopathological test 29 (14.6%) were found to have tuberculomas, 28 (14.1%) had caseous necrosis and one was a tuberculous abscess, in 25 cases imaging was available for review and were included in the study . There were 15 males and 10 females with age range being 2 to 65 years and with the Median age being 13 years. Twenty patients had computerized tomography and five patients had magnetic resonance imaging. Seizure 15/25 (60%) and headache 11/25 (44%) were the commonest presentation. Solitary or confluent large lesions were seen in 12/25 (48%) of patients. 14/25 (56%) of the lesions had their size between 2 cm and 5 cm. Majority of the lesions 15/25 (60%) were in the frontal and parietal lobes. The lesions were isodense on CT in 18/25 (72%) of the pre-contrast studies and 21/25 (84%) showed ring or rim enhancement after intravenous administration of the contrast medium.

CONCLUSION

Tuberculoma, more frequently, presented with non-specific clinical findings and chronic seizure disorder and comonly occurred in young patients and often seen infratentorialy. It is often complicated with hydrocephalus in the pediatric age group. Computerized tomography scan and/or magnetic resonance imaging features are not different from reports from other countries.

Patient taking chemotherapy for a small cell lung cancer: not every cerebral nodule is a metastasis: the tree that hides the forest

We report the case of a 53- year-old man in whom the diagnosis of small cell lung cancer (SCLC) was made by the biopsy of a mass of the right trapezius muscle. A tumor was revealed on flexible bronchoscopy which pathological study showed tuberculosis (TB). Chest computed tomography (CT) scan revealed findings related to the SCLC associated to micronodules and nodules compatible with pulmonary TB. Cerebral CT scan revealed a nodule of 4.5 mm in diameter presenting enhancement after contrast material injection thought to be a metastasis. The patient was administered antitubercular treatment. Fiveteen days later, the patient started chemoptherapy with etoposid and carboplatin. A control cerebral CT scan realized after the end of the chemotherapy (2 months and a half of antitubercular treatment) revealed numerous cortical and subcortical infracentimetric nodules with contrast enhancement with a tentorial and subtentorial location considered to be in relation with cerebral miliary TB. The nodule discovered on the first cerebral scan was therefore a posteriori considered to have been of tubercular origin. The PS of the patient rapidly worsened. He presented mental confusion and died in some days.

The imaging appearances of intracranial CNS infections in adult HIV and AIDS patients

The spectrum of pathology affecting the central nervous system (CNS) in patients suffering from acquired immunodeficiency syndrome (AIDS) is broad and comprises predominantly opportunistic infections and neoplasms. It is estimated that approximately one-third of all patients with AIDS develop neurological complications. The organisms responsible for AIDS are human retroviruses: primarily the human immunodeficiency virus type 1 (HIV). In this review we shall focus on the neurological complications of HIV and AIDS which are applicable to the more frequently occurring intracranial infective organisms. Attention will be paid specifically to those CNS manifestations occurring in the adult HIV and AIDS population as infection in the paediatric HIV and AIDS group, although bearing some similarities, demonstrates some important differences.

Paradoxical response to chemotherapy in neurotuberculosis

OBJECTIVE

Our objective was to investigate the paradoxical response and the factors responsible for such an uncommon (but known) response to chemotherapy in neurotuberculosis.

MATERIAL AND METHODS

Ten children with intracranial tuberculomas/neurotuberculosis were retrospectively studied, who were on regular antituberculous chemotherapy. Any deterioration of the neurological condition, increase in the size of the lesion or appearance of new lesions was studied clinically and radiologically during the follow-up period.

RESULTS

An atypical response to chemotherapy was observed from 3 weeks to 1 year of chemotherapy. Four of the 10 children, who were receiving chemotherapy for either post-tubercular meningitis (TBM), hydrocephalus (2) or TBM (2), developed multiple granulomas in 3 and hydrocephalus in 1 case. The remaining 6 children who were diagnosed to have granulomas at their presentation deteriorated at the follow-up despite regular chemotherapy. CT scans were repeated in 7 of 10 cases at the time of neurological deterioration, out of which 5 children showed appearance of new granulomas or abscess(es) and 2 showed an increase in the size of their preexisting granulomas. One patient with faintly enhancing granulomas in the posterior fossa responded to an additional use of steroids. The remaining 9 patients required surgical intervention on account of their neurological deterioration.

CONCLUSIONS

(1) Paradoxical responses to intracranial tuberculoma/neurotuberculosis can occur at any time even up to 1 year during chemotherapy despite a regular standard antitubercular treatment. (2) New granuloma(s) or abscess(es) may appear in children receiving chemotherapy for TBM during the follow-up. (3) Hydrocephalus may also appear despite a regular chemotherapy in treated TBM cases. (4) Immature faintly enhancing tuberculomas have a more likely chance of resolution with antituberculous chemotherapy and glucocorticoids, while a well-formed and probably large-sized (>3 cm) granuloma may have a risk of paradoxical enlargement.

An infant with central nervous system complications of disseminated tuberculosis

A previously well, nine-month-old, Canadian-born, Caucasian infant presented with one month history of cough, irritability, and poor weight gain. Her past medical history was significant for open-heart surgery at age four months, with repair of a ventricular septal defect, closure of an atrial septal defect, and ligation of patent ductus arteriosus. There were no operative complications. Her development was normal for age. She had received her routine immunizations.There was no known infectious diseases contact or exposure to farm animals.

Modern imaging of tuberculosis in children: thoracic, central nervous system and abdominal tuberculosis

Tuberculosis (TB) can affect any organ in the body. Children are a high-risk group for contracting the disease and pose a constant challenge to clinicians with regard to making a definitive diagnosis. Radiologists are playing a more active role in diagnosing TB, and armed with more accurate diagnostic investigations such as CT and MRI, they must face the cost implications as well as technical limitations. This review aims to guide the reader through the modern imaging techniques useful for diagnosing TB of the thorax, central nervous system and abdomen in children. The more specific features of each modality in the particular anatomical regions are highlighted.

Management of HIV-associated focal brain lesions in developing countries

BACKGROUND

HIV-associated focal brain lesions (HFBL) are caused by opportunistic infections, neoplasms, or cerebrovascular diseases. In developed countries, toxoplasma encephalitis (TE) is the most frequent cause, followed by primary CNS lymphoma (PCNSL). Guidelines based on these causes however are poorly suited to developing countries, where treatable infections predominate as causes of HFBL.

AIM

To determine a practical approach to the management of HFBL in developing countries.

DESIGN

Case series.

METHODS

Patients (n = 32) were managed based on presumed aetiologies of the focal brain lesions, determined by collating information from CT scans, CSF and blood studies, concurrent non-neurological illness and response to treatment.

RESULTS

The principal presumed cause of HFBL was tuberculosis (69%). The therapeutic response was good in 69% of patients.

DISCUSSION

In developing countries, infections are the predominant cause of HFBL, the principal causes being infections that are endemic to the populations being studied. Empiric treatment based on limited investigations should be directed according to the nature of such infections. A modified algorithm is proposed.

Perfusion magnetic resonance imaging in intracerebral parenchymal tuberculosis: preliminary findings

OBJECTIVES

To study the vascular perfusion patterns of focal intracerebral tubercular lesions using echoplanar magnetic resonance (MR) imaging-derived relative cerebral blood volume (rCBV) maps.

METHODS

Seventeen focal tubercular lesions were evaluated with conventional and perfusion-weighted MR imaging on a 1.5-T MR system. The rCBVs of the center, peripheral wall, and perilesional white matter were calculated from the perfusion MR-derived data. Perfusion MR imaging findings as depicted on the rCBV maps were qualitatively compared with those of conventional MR findings.

RESULTS

Eleven of the 17 lesions demonstrated vascularity greater than that of the contralateral white matter on rCBV maps. The mean of the measured rCBV values of the peripheral wall and center of the lesions was 2.5 +/- 1.42 and 0.33 +/- 0.3 (mean +/- SD), respectively. Most of the hypervascular lesions (8) revealed a concentric peripheral wall having alternating hypointense and hyperintense signal intensity rims surrounding a variable intensity center on T2-weighted images. All the lesions having a nodular enhancing pattern (4) were hypervascular.

CONCLUSIONS

Focal cerebral tubercular lesions can have variable vascularity as shown on perfusion MR-derived rCBV maps. It may be difficult to differentiate hypervascular lesions from cerebral tumors in some patients based on perfusion MR imaging alone.

[Central nervous system tuberculosis with and without HIV infection--clinical, neuroimaging, and neuropathological study]

Clinical data, neuroimaging, and neuropathology of 17 patients with central nervous system tuberculosis were reported. Of this population, 12 were men, 5, women; ages ranged from 23 to 75 years (mean, 46.9). There were three HIV positive patients among them. More than a half of patients had disturbance of consciousness as initial symptom. Neurological signs were variable such as visual acuity loss, hemiparesis, paraparesis, cerebellar ataxia, and tremor, though disturbance of consciousness was the most frequent (36%). Neuroimaging (X-ray CT and MRI) revealed meningeal enhancement (53%), tuberculoma (50%), hydrocephalus, infarction or bleeding and spinal cord tuberculoma. There were three patients who showed paradoxical progression. Eleven patients were performed CSF examination, all of them revealed increased cell count (mean, 206 counts/mm3) and protein (mean, 225 mg/dl), but only 4 patients were positive on bacteriological examination including PCR. Seven patients died and 5 patients were performed autopsy. Neuropathologically, all patients showed a stage of meningitis prominent on basal brain (basal cistern and/or Sylvian fissure). Cell infiltrations including lymphocyte, monocyte, and eosinocyte were most severe around blood vessels, and observed in all cases except one which showed only fibroblast and collagen fibers indicating healed stage. In some cases, there existed epithelioid cells and Langhans giant cells, and in some cases, fibrin exudate. There were three cases having tuberculoma, one HIV case and two non-HIV cases. Center of tuberculoma in non-HIV case was formed by caseous necrosis, and tuberculoma was surrounded by granuloma constituted by epithelioid cells and Langhans giant cells with lymphocyte cell infiltration and proliferation of blood vessels. In contrast, tuberculoma of HIV case did not include granuloma, and was formed with small cells with large nucleus which surrounded arteries. Our studies, as other studies, failed to show any differences between HIV and non-HIV patients clinically, as well as on neuroimaging study. But neuropathological study suggests that mechanism of tuberculoma formation may be different between in HIV positive patients and in non-HIV patients.