Tubercular Meningitis In Children 

What is Tubercular Meningitis (TBM)?

Tuberculosis can involve many parts of the body. CNS Tuberculosis can have multiple forms. The most serious complication of TB in children. TBM Occurs in 0.3% of untreated TBIs in children. According to Nelson, the peak age is 6 months to 4 years.

Risk Factors

• Infants
• Immunosuppression
• Protein Energy Malnutrition (PEM)
• Contact with TB patient
• Recent measles infection

Pathophysiology of TBM

Also read: Acute Disseminated Encephalomyelitis

Clinical Stages of TBM

Stage 1

Lasts for up to 1-2 weeks. The child will have a fever, irritability, malaise, and headache but no focal deficits. Sometimes, in infants, there is a loss of recently acquired milestones in patients.

Stage 2

Abrupt onset of CNS features in the form of vomiting and meningeal signs. Meningeal signs: nuchal rigidity, kernig sign & brudzinski sign Seizures and CN Palsy, Hypertonia. Focal neural deficits can occur.

Stage 3

It is called the CNS complication stage. So, the patients will develop features like hemiplegia/paraplegia, hydrocephalus, hypertension, and decorticate posturing due to the involvement of the vital center, which can lead to death. Poor prognosis. Sequelae are frequently seen in this stage.

Also read: Autoimmune Encephalitis in Pediatrics: Symptoms

Diagnosis of TBM

IOC: CSF analysis by lumbar puncture (ventricular CSF may be normal despite having tubercular meningitis; it is because the site of maximum pathology is usually beyond the fourth ventricle, usually in the basal cistern area). On CSF analysis, pressure is elevated, and the cell count is also elevated modestly at 10-500/μL. Lymphocytic predominance is seen. However, some in early stage 1 may have few neutrophils. CSF protein content is significantly high in TBM, 400 to 5000 mg/dL, because these patients have hydrocephalus and spinal block. CSF glucose: <40 mg/dL. Appearance: Clear, but sometimes it is a pellicle/cobweb formation. CSF: For a ZN stain and culture, at least 5 to 10 ml of CSF should be used. ZN stain-positive AFB in 30% of cases, culture-positive in 50-70% of cases. Adenosine deaminase (ADA): Elevated; cut off: >10 mL

Neuroimaging

Contrast CT is the initial investigation.

Findings include: hydrocephalus, basal cistern exudates (radiological hallmark), and leptomeningeal enhancement by contrast → Maximum in Sylvian fissure region. Sometimes, there are cerebral infarcts or ischemic changes. Rarely: Co-existing tuberculomas (cortex & thalamus)

Other Investigations

Chest X-ray: Positive finding in 33 to 60 % of cases.

Mantoux test: Positive results in 30 % of cases.

Others: Wherever TB focus is suspected.

Also read: TICS in Children

Treatment of TBM

Supportive management: Fever control, ABC, seizure control, and managing elevated ICP.

ATT: Mainstay of treatment

2 months of intensive therapy—HRZE. 10 months of continuation—HRE

Steroids: decrease inflammation, reduce the complication rate, and show better resolutions of exudates. Dexamethasone is used at 0.6 mg/kg/day for 8–12 weeks. (IAP 2022 → 8 weeks)

Alternative therapy: according to IAP 2022, oral prednisolone (1-2 mg/kg/day). If a patient develops hydrocephalus, then surgery is recommended.

Past SS MCQ

Indications of steroids TBM (IAP 2022)

Definite indications (must be used): TBM, TB Pericarditis, TB Uveitis, Addison's Disease, & Military TB with alveoli-capillary block. Possible indications (may be used): endobronchial TB, laryngeal TB, bronchial compression, pleurisy with severe respiratory distress, mediastinal compression syndrome, TB-related IRIS (Immune Reconstitution Inflammatory Syndrome).

Prognosis in TBM

It is related to age, stage, and presentation.

• Therapy in stage 1: >90% recovery with little/no sequelae.
• Therapy in stage 2: 80% survive, but 50% have sequelae.
• Therapy in stage 3: 50% survive, but 80% have sequelae.
• Comas, at presentation, usually have a terrible prognosis.
• Age <1 year and has a severe disease.
• Sequelae include Cortical blindness, epilepsy, residual FNDs, low IQ, and endocrinopathies like DI.

Also read: Newer Antiepileptics In Pediatrics-  Eslicarbazepine And Lacosamide

WHO Update 2021 

For treatment of TBM: An intensive (6-month) regimen based on a meta-analysis of comparative studies is now proposed as an alternative to the standard 12-month regimen for treating TB meningitis TBM. Usual therapy: 2 HRZE + 10 HRE. Alternate: 6 HRZE

Points to remember in Tuberculoma

• A tumor-like mass resulting from the aggregation of caseous tubercles resembles a brain tumor.
• Infratentorial in children, supratentorial in adults.
• Usually single, rarely multiple.
• It can produce fever, headache, vomiting, seizures, and FNDs.
• Associated with a positive Mantoux test, but CXR is normal.
• CECT/MRI: Extensive contrast enhancement with a ring-like pattern.
• Respond to ATT: Steroids are needed to decrease cerebral edema.
• The onset of hydrocephalus is early compared to other CNS infections.
• The initial fever in stage 1 is usually subacute or insidious, but the onset of stage 2 is acute and dramatic.
• Higher Chances of CNS vasculitis, focal deficits, optic atrophy, and extrapyramidal complications than other CNS infections.
• Infants have more severe presentations.
• Nelson says: If any basilar meningitis + hydrocephalus/stroke/CN palsy→ start ATT if no other cause is found.

Also read: Rett Syndrome- Clinical Features And Management

Hope you found this blog helpful for your NEET SS Pediatrics Neurology Preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.