A 70-year-old male presented with a 5-year history of intermittent fever and a more recent 2-week history of behavioral changes and severe headaches. Imaging showed evidence of basilar meningitis and hydrocephalus. Cerebrospinal fluid analysis found lymphocytic pleocytosis with low glucose and high protein, consistent with tuberculous meningitis. The patient was started on empiric anti-tuberculosis treatment given the clinical suspicion while further diagnostic tests were pending. Tuberculous meningitis requires a prolonged multi-drug treatment regimen to reduce the risk of complications like hydrocephalus, infarctions, and neurological deficits.

1. Case study

2. CaseA 70year old male NKCM came with the complain ofLow grade fever -5yrs –on & offSevere Headache-15-20dysBehavioural changes- 2wks

3. According to the attendant (son) he has been ill on & off since the past 5-6yrs when he used to develop a low grade intermittent self resolving fever. It was sudden & non specific happening bout 1-3dys & the fever free period varied from weeks to months. Now since the past few weeks he had a headache which wasn’t relieved by anything. He also was restless & disoriented. His talk & behaviour was odd to the family so they brought him for treatment. He was labelled as having dementia since the past year. He was a smoker *quit since some years* & had a persistent dry cough. No history of vomiting, Night sweats, loss of consciousness or loss of function but on/off nausea present. Past hx- Pulmunary TB diagnosed on CXR/Sputum test 2yrs ago took ATT for only 2 weeks Hernia repair & Hemorrhoidectomy -6-7yrs ago. Social History- Contact Hx of TB from work collegue. Family History- not significant.

4. InvestigationsCBCHb-12.1, Pcv-37, TLC-5.9, Plt-267UCENa-142, K-3.4, Co3-21, Cl-103,Urea-44, Crt-0.84 SGPT- 10, RBS-91Urine D/RPH-5.5, Protein- 10mg/dl, Sp.grav-1.025, Rbs-numerous, Blood-3+, pus-2, Epi-2, Bacteria-few

5. CSF-D/RVolume-10mlColorless, clearGlucose-43 ( Serum Rbs-83)Protein-87Rbc-64, 000cu/mmWbc- 200cu/mm ------Neu- 6, Lymp-92, Mono-2ESR-32AFB –veCXR- Fibrosis.

6. CT scan showing basilar & Vascular enhancement

7. CT showing ventricular dilatation

8. TB Meningitis

9. Clinical featuresPrinciple presentaion is subacute febrile illness that progresses through three discernible phases:

10. Choroid tubercles on opthalmoscopy -multiple, ill-defined, raised yellow-white nodules (granulomas) of varying size near the optic diskCXR abnormalities- single or multiple lesions

11. Atypical features:Meningitic syndrome rapidly progressing-suggesting acute infectionDementia over months or years- personality change, social withdrawal, loss of libido, and memory deficitsEncephalitic course with stupor, coma, and convulsions without overt signs of meningitis

12. Clinical stagesIt is useful for prognosis and therapyStage I patients are lucid with no focal neurologic signs or evidence of hydrocephalus. Stage II patients exhibit lethargy, confusion; may have mild focal signs, such as cranial nerve palsy or hemiparesis.Stage III represents advanced illness with delirium, stupor, coma, seizures, multiple cranial nerve palsies, and/or dense hemiplegia.

13. Pathogenesis & suseptibilityFollowing primary infection or late reactivation TB elsewhere in the body scattered tubercles are established in the brain, meninges, or adjacent bone. Subcortical or meningeal focus from which bacilli gained access to the subarachnoid space is the critical event for development of tuberculous meningitis .More common in miliary TB because of higher chance of forming Juxta ependymal meningitis. Meningitis can develop as a complicatin of primary infection in infants/children Due to chronic reactivation bacillemia in older adults immune deficiency caused by aging, alcoholism, malnutrition, malignancy, or human immunodeficiency virus (HIV) infectionHead trauma may also lead to destabilization of an established quiescent focus resulting in meningitis

14. The spillage of tubercular protein into the subarachnoid space produces an intense hypersensitivity reaction due to a dense gelatinous exudate, giving rise to inflammatory changes. Proliferative arachnoiditis, most marked at the base of the brain, produces a fibrous mass involving cranial nerves and penetrating vessels. Vasculitis with resultant thrombosis and infarction involves vessels that traverse the basilar or spinal exudate or are located within the brain substance itself. Multiple lesions are common and a variety of stroke syndromes may result, involving the basal ganglia, cerebral cortex, pons, and cerebellum.Communicating hydrocephalus results from extension of the inflammatory process to the basilar cisterns and impedance of CSF circulation and resorption. Obstruction of the aqueduct develops less frequently, from contraction of exudate surrounding the brain stem or from a strategically placed brain stem tuberculoma.

15. Ventricular dilatation is present (asterisks), as well as inflammatory exudate in the ambient cistern (black arrows) and multiple foci of vasculitis-associated subacute, ischemic necrosis

16. DiagnosisCerebrospinal fluid examination:Protein 100-500mg/dl Glucose <45 mg/dL (80%)Initial stages PMN predominance later changed to lymphocytic dominance.

18. Culture: (87% diagnostic)CSF specimens for M. tuberculosis. The demonstration of acid-fast bacilli (AFB) in the CSF is the effective means for an early diagnosis. Minimum of 3 lumbar punctures be performed at daily intervals. Polymerase chain reaction: nucleic acid-based amplification test (NAAT) relies upon the polymerase chain reaction (PCR) is 60% sensitive in rapid detection of M. tuberculosis in CSF. Recommended whenever clinical suspicion is sufficiently high for empirical therapy or AFB is negative.

19. Neuroradiology: CT & MRI are helpful in detection. CT can present the extent of basilar arachnoiditis, cerebral edema and infarction, and the presence and course of hydrocephalus.Hydrocephalus combined with marked basilar enhancement is indicative of advanced meningitic disease and carries a poor prognosis. Marked basilar enhancement correlates well with vasculitis and, therefore, with a risk for basal ganglia infarction.

20. Interferon-gamma release assay (IGRA) using specific tuberculous antigens is a rapid, specific and sensitive method for the detection of tuberculous infection. The high interferon-gamma concentration in the CSF increases further after the antigen stimulation, suggesting theoretically the presence of tuberculous antigen-specific T cells.

21. DIFFERENTIAL DIAGNOSISBased on CSF findings of Glucose, Protein & lymphocytic pleocytosis, Subacute or chronic meningitis syndrome caused by cryptococcosis, Granulomatous fungal infections, brucellosis, and neurosyphilis.Parameningealsuppurative infection, (eg, sphenoid sinusitis, brain abscess, or spinal epidural space infection.Herpes encephalitis

22. TreatmentThe mainstay of treatment for TB is clinical suspicion & starting of empirical therapy. First line drugs — Isoniazid (INH), rifampin (RIF), and pyrazinamide (PZA) are bactericidal, can be administered orally all having good meningeal penetration.

23. First line drugs

24. Recommended regimen Intensive phase (Initial 2months) — A four drug regimen that includes INH, RIF, PZA, and either EMB or STM Continuation phase (7-10m) — INH and RIF alone if the isolate is fully susceptible.Duration of therapy —9 to 12 months in drug-sensitive infections. If PZA is omitted or cannot be tolerated, treatment should be extended to 18 months.

25. Glucocorticoid regimenDexamethasone — A total dose of 8 mg/day for children weighing <25 kg; 12 mg/day for adults and children >25 kg, for 3 weeks, then tapered off gradually over the following 3 to 4 weeks. Prednisone — A dose of 2 to 4 mg/kg per day for children; 60 mg/day for adults, for 3 weeks, then tapered off gradually over the following 3 weeks.

26. Second line drugsAminoglycosides: e.g., amikacin (AMK), kanamycin (KM);Polypeptides: e.g., capreomycin, viomycin, enviomycin;Fluoroquinolones: e.g., ciprofloxacin (CIP), levofloxacin, moxifloxacin (MXF);Thioamides: e.g. ethionamide, prothionamideCycloserine (the only antibiotic in its class);p-aminosalicylic acid (PAS or P).

27. OthersMacrolides: e.g., clarithromycin (CLR);Linezolid (LZD);Thioacetazone (T);Immunomodulators- cytokine-based therapy but more research needed for other cytokines and chemokines that may enhance both the mycobacterial killing activity of effector cells and the restriction of bacterial intracellular multiplication

28. Surgical InterventionPatients with hydrocephalus may require surgical decompression of the ventricular system by shunt.

29. ComplicationsHydrocephalusInfarctionsComa/stuporMotor deficits-CN palsies, hemiparesis , Seizures, Mental impairmentAbnormal behaviorBrain damageHigh morbidity and mortality

30. Take home message Start ATT empirically when suspicion of TBCounsel the patient for medication/side effectsComplete the courseFollow up

31. The End