Clinicoradiological features of tuberculous meningitis in patients over 50 years of age

Tuberculous meningitis in the elderly

OBJECTIVE

Although the elderly population remains at high risk for tuberculosis, studies addressing tuberculous meningitis (TBM) in this age group are scarce. The present study aimed to evaluate the spectrum and outcome of geriatric TBM and document differences between older and young patients.

METHODS

A prospective cohort study was conducted in the adult TBM patients admitted at PGIMER, Chandigarh (India). Consecutive older patients aged 60 years and above were enrolled from January 2019 to December 2020, and young adults aged 18-59 years were enrolled from July 2019 to December 2019.

RESULTS

Fifty-five older patients with a mean age of 66.6 years and 73 young patients with a mean age of 35.1 years were enrolled. At admission, older patients were more likely to have altered mental status (96.4% vs. 78.1%, P = 0.003) and advanced disease with British medical research council staging 2 or 3 (98.2% vs. 89.0%, P = 0.043); however, headache (38.2% vs. 67.1%, P = 0.001), vomiting (18.2% vs. 35.6%, P = 0.030) and fever (80.0% vs. 91.8%, P = 0.052) were less common. Cerebrospinal fluid (CSF) abnormalities were less marked in older patients, with a significant difference in median total cells (70 vs. 110/µl, P = 0.013). Hydrocephalous and infarct were common neuroimaging abnormalities in both groups; however, tuberculomas were significantly less in the elderly (15.1% vs. 35.2%, P = 0.012). Older patients had a significantly low survival rate (56.4% vs. 76.7%, P = 0.021).

CONCLUSION

Significant differences in clinical, CSF and radiological characteristics exist between elderly and young TBM patients, with survival remains dismal in the elderly.

Imaging in Differentiating Cerebral Toxoplasmosis and Primary CNS Lymphoma With Special Focus on FDG PET/CT

OBJECTIVE. The purpose of this article is to present a brief review of literature evaluating different imaging modalities with special focus on ¹⁸F-FDG PET/CT in differentiating cerebral toxoplasmosis and primary CNS lymphoma. CONCLUSION. Differentiating cerebral toxoplasmosis and primary CNS lymphoma is crucial in the care of patients with HIV infection. Delayed diagnosis can lead to considerable morbidity and mortality. The reference standard for diagnosis is biopsy and histopathologic examination. Biopsy has disadvantages due to its invasive nature and associated complications. Noninvasive imaging can be an alternative to biopsy for differentiation of toxoplasmosis and primary CNS lymphoma. Despite advances in MRI techniques, prophylaxis of opportunistic infection, and treatment of HIV infection, clinical situations continue to arise in which the diagnosis is not clear. In these instances, molecular imaging can be helpful.

Dural masses: meningiomas and their mimics

Meningiomas are the most common dural tumour. They are regularly being seen as an incidental finding on brain imaging and treated conservatively. However, there are many other dural masses which mimic their appearances, including primary neoplastic processes, metastases, granulomatous diseases and infection. While some of these are rare, others such as metastases and tuberculosis arise relatively frequently in practice. Although not pathognomonic, key features which increase the probability of a lesion being a meningioma include intralesional calcifications, skull hyperostosis, local dural enhancement and increased perfusion. It is important to have an awareness of these entities as well as their main imaging findings, as they have a wide range of prognoses and differing management strategies. This review outlines several of the most important mimics along with their imaging findings on both standard and advanced techniques with key features which may be used to help differentiate them from meningiomas.

Infektionen

In diesem Kapitel werden zunächst die für die Neurointensivmedizin wesentlichen bakteriellen Infektionen (Meningitis, spinale und Hirnabszesse, Spondylodiszitis, septisch-embolische Herdenzephalitis) abgehandelt, die trotz gezielt eingesetzter Antibiotika und neurochirurgischer Therapieoptionen noch mit einer erheblichen Morbidität und Mortalität behaftet sind. Besonderheiten wie neurovaskuläre Komplikationen, die Tuberkulose des Nervensystems, Neuroborreliose, Neurosyphilis und opportunistische Infektionen bei Immunsuppressionszuständen finden hierbei besondere Berücksichtigung. Der zweite Teil dieses Kapitels behandelt akute und chronische Virusinfektionen des ZNS sowie in einem gesonderten Abschnitt die HIVInfektion und HIV-assoziierte Krankheitsbilder sowie Parasitosen und Pilzinfektionen, die in Industrieländern seit Einführung der HAART bei HIV zwar eher seltener, aber mit zunehmender Globalisierung auch in unseren Breiten immer noch anzutreffen sind.

Adult tuberculous meningitis in Qatar: a descriptive retrospective study from its referral center

BACKGROUND

Tuberculous meningitis is the severest and commonest form of central nervous system tuberculosis causing high mortality and morbidity. We aim to study the clinical, biochemical, and radiological characteristics of tuberculous meningitis in adult patients in Qatar and to calculate the incidence.

METHODS

A descriptive retrospective 7-year study was conducted at the Hamad General Hospital (the only tertiary referral center and sole health care provider for tuberculosis in Qatar) between the 1st of January 2006 and the 31st of December 2012, to describe the clinical presentation, diagnosis, treatment, outcome, and the incidence of adult tuberculous meningitis in Qatar.

RESULTS

Tuberculous meningitis was diagnosed in 80 patients (65 male, 15 female), with a mean age of 30.3 ± 8.9. The majority of patients (76.3%) were from the Indian subcontinent. The commonest clinical features were fever (79%), headache (71%), and meningism (56%). Cerebrospinal fluid tuberculosis culture was positive in 44% of patients. Almost 39% of patients were in Stage I, 46% in Stage II and 15% in Stage III of the disease. The commonest neuroimaging features were leptomeningeal enhancement (34%) and hydrocephalus (33%). Cranial nerve palsy, limb weakness, and an elevated C-reactive protein were associated with a poorer outcome. Sixty eight percent had complete recovery, 10% had residual neurological sequelae without disability, 17% had disability, and 5% died. The average incidence of tuberculous meningitis over 7 years was 0.9 per 100,000 adult population.

CONCLUSION

The characteristics of tuberculous meningitis were described in our population. Our data indicate that the incidence of tuberculosis meningitis in Qatar has increased. Tuberculous meningitis in Qatar is mainly an imported disease.

Risk assessment of the outcome for cerebral infarction in tuberculous meningitis

INTRODUCTION

Cerebral infarction in tuberculous meningitis is a major risk factor for permanent disability. This study assessed the clinical presentation of tuberculous meningitis and risks factors for cerebral infarction.

OBSERVATION

Thirty-eight adult patients with tuberculous meningitis were studied between 2002 and 2006. Clinical, radiological, and laboratory data of patients with cerebral infarction were compared with those of patients without cerebral infarction. Patients with cerebral infarction were significantly older (65.1 vs 52.1years), had higher risk assessment scores (3.7 vs 2.2), and more often had basal meningeal enhancement on imaging (92.3% vs 60.0%), mild to moderate sequelae (69.2% vs 4%), an overall poor brain outcome (69.2% vs 8%), aspirin prescription (84% vs 8%), and neurosurgical intervention for hydrocephalus (54.0% vs 16.0%). Cerebral infarction patients were also more likely to have experienced doctor-related delays in antituberculosis (61.5% vs 36%) and corticosteroid (61.5% vs 32%) therapy.

DISCUSSION AND CONCLUSION

The Framingham risk score would be an option for tuberculous meningitis patients to access cerebral infarction risk. Contrast-enhanced brain imaging is helpful for exploring basal meningeal enhancement, in order to obtain an early diagnosis. Antituberculosis, corticosteroid, and aspirin therapies should be started immediately when tuberculous meningitis is suspected.

Inflammatory Diseases of the Meninges

Neuroimaging is of major importance in all cases of suspected infectious meningitis in order to get quick information about the extent of the disease, typical lesion patterns, and potential complications, such as hydrocephalus, involvement of the underlying brain parenchyma, or vasculitis. In bacterial meningitis, abnormal and asymmetrical enhancement of the leptomeninges and the subarachnoid space is typical. Initial neuroimaging has to rule out infectious foci of the skull base such as purulent sinusitis or mastoiditis. In patients with focal deficits or seizures, MRI is the tool of choice to diagnose vascular or septic complications. Neoplastic, viral, or fungal infections of the CNS may present with similar changes of the meninges; however, fungal meningitis normally causes a thicker and more nodular enhancement. In case of basal accentuation of the leptomeningeal contrast enhancement and conspicuous signal changes in the basal cisterns, one has to consider tuberculous meningitis for differential diagnosis, especially in patients with HIV infection. Non-infectious causes of meningeal enhancement comprise several primary and secondary tumors (e.g., CNS lymphoma, medulloblastoma, or breast cancer), granulomatous diseases, intracranial hypotension, and post-operative changes.

Infektionen

Trotz Weiterentwicklung moderner Antibiotika in den letzten Jahren sind die Letalitätszahlen der bakteriellen (eitrigen) Meningitis weiterhin hoch; Überlebende haben häufig neurologische Residuen. Die ungünstigen klinischen Verläufe der bakteriellen Meningitis sind meist Folge intrakranieller Komplikationen, wie z. B. eines generalisierten Hirnödems, einer zerebrovaskulären arteriellen oder venösen Beteiligung oder eines Hydrozephalus.

Tuberculous meningitis presenting with nonconvulsive status epilepticus

Nonconvulsive status epilepticus (NCSE) is an enduring epileptic condition characterized by alteration in consciousness and continuous ictal discharges on the EEG. Various etiologies have been reported. We describe the case of a 66-year-old woman with altered mental status who was diagnosed with NCSE. A workup to explain the etiology revealed tuberculous meningitis (TBM) with increased cerebrospinal fluid protein and positive tuberculous DNA polymerase chain reaction and interferon-γ assay tests. She was treated according to the status epilepticus protocol with a four-drug anti-tuberculosis regimen to which she responded. TBM is a serious disease with insidious presentation and still constitutes a diagnostic challenge with its various presentations. Among the many presentations of tuberculosis, clinicians should consider NCSE.

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.

Clinical characteristics and treatment delay of cerebral infarction in tuberculous meningitis

BACKGROUND

Cerebral infarction (CI) complicating tuberculous meningitis (TBM) is a major risk factor of permanent disability. The prevention of this complication is an important issue in the quality care of TBM patients.

AIM

Our aim was to evaluate the clinical characteristics of TBM patients with CI.

METHODS

Ninety-one adult patients with TBM were studied between 1999 and 2007. Clinical, neuroradiological and cerebrospinal fluid data of patients with CI were compared with those without CI.

RESULTS

Thirty of the 91 patients had CI, including symptomatic CI occurring before admission in 10 patients, symptomatic CI occurring during hospitalisation in four and silent CI in 16 patients. When compared with non-CI patients, patients with CI were younger and associated with focal weakness on presentation, and had basal meningeal enhancement and hydrocephalus on brain images. Prolonged doctor delays of antituberculosis and steroid therapies, neurosurgical intervention, focal weakness and dementia as sequelae, and poor outcomes were associated with patients with CI than non-CI patients.

CONCLUSION

Contrast-enhanced brain imaging is helpful to explore the basal meningeal enhancement in CI patients, and contributes to early diagnosis and treatment of TBM. Early antituberculosis and steroid therapies may help prevent CI in TBM patients.

British Infection Society guidelines for the diagnosis and treatment of tuberculosis of the central nervous system in adults and children

SUMMARY AND KEY RECOMMENDATIONS: The aim of these guidelines is to describe a practical but evidence-based approach to the diagnosis and treatment of central nervous system tuberculosis in children and adults. We have presented guidance on tuberculous meningitis (TBM), intra-cerebral tuberculoma without meningitis, and tuberculosis affecting the spinal cord. Our key recommendations are as follows: 1. TBM is a medical emergency. Treatment delay is strongly associated with death and empirical anti-tuberculosis therapy should be started promptly in all patients in whom the diagnosis of TBM is suspected. Do not wait for microbiological or molecular diagnostic confirmation. 2. The diagnosis of TBM is best made with lumbar puncture and examination of the cerebrospinal fluid (CSF). Suspect TBM if there is a CSF leucocytosis (predominantly lymphocytes), the CSF protein is raised, and the CSF:plasma glucose is <50%. The diagnostic yield of CSF microscopy and culture for Mycobacterium tuberculosis increases with the volume of CSF submitted; repeat the lumbar puncture if the diagnosis remains uncertain. 3. Imaging is essential for the diagnosis of cerebral tuberculoma and tuberculosis involving the spinal cord, although the radiological appearances do not confirm the diagnosis. A tissue diagnosis (by histopathology and mycobacterial culture) should be attempted whenever possible, either by biopsy of the lesion itself, or through diagnostic sampling from extra-neural sites of disease e.g. lung, gastric fluid, lymph nodes, liver, bone marrow. 4. Treatment for all forms of CNS tuberculosis should consist of 4 drugs (isoniazid, rifampicin, pyrazinamide, ethambutol) for 2 months followed by 2 drugs (isoniazid, rifampicin) for at least 10 months. Adjunctive corticosteroids (either dexamethasone or prednisolone) should be given to all patients with TBM, regardless of disease severity. 5. Children with CNS tuberculosis should ideally be managed by a paediatrician with familiarity and expertise in paediatric tuberculosis or otherwise with input from a paediatric infectious diseases unit. The Children's HIV Association of UK and Ireland (CHIVA) provide further guidance on the management of HIV-infected children (www.chiva.org.uk). 6. All patients with suspected or proven tuberculosis should be offered testing for HIV infection. The principles of CNS tuberculosis diagnosis and treatment are the same for HIV infected and uninfected individuals, although HIV infection broadens the differential diagnosis and anti-retroviral treatment complicates management. Tuberculosis in HIV infected patients should be managed either within specialist units by physicians with expertise in both HIV and tuberculosis, or in a combined approach between HIV and tuberculosis experts. The co-administration of anti-retroviral and anti-tuberculosis drugs should follow guidance issued by the British HIV association (www.bhiva.org).

Inflammatory Diseases of the Meninges

Neuroimaging is of major importance in all cases of suspected infectious meningitis in order to get quick information about the extent of the disease, typical lesion patterns, and potential complications, such as hydrocephalus, involvement of the underlying brain parenchyma, or vasculitis. In bacterial meningitis, abnormal and asymmetrical enhancement of the leptomeninges and the subarachnoid space is typical. Initial neuroimaging has to rule out infectious foci of the skull base such as purulent sinusitis or mastoiditis. In patients with focal deficits or seizures, MRI is the tool of choice to diagnose vascular or septic complications. Neoplastic, viral, or fungal infections of the CNS may present with similar changes of the meninges; however, fungal meningitis normally causes a thicker and more nodular enhancement. In case of basal accentuation of the leptomeningeal contrast enhancement and conspicuous signal changes in the basal cisterns, one has to consider tuberculous meningitis for differential diagnosis, especially in patients with HIV infection. Non-infectious causes of meningeal enhancement comprise several primary and secondary tumors (e.g., CNS lymphoma, medulloblastoma, or breast cancer), granulomatous diseases, and post-operative changes.