<prompt> A 10-month-old child presents with 2 weeks history of fever, vomiting and alteration of sensorium. Cranial CT scan reveals basal exudates and hydrocephalus, the most likely etiological agent is:Mycobacterium tuberculosisCryptococcus neoformansListeria monocytogenesStreptococcus pneumoniae  <response>: - History suggests the diagnosis of Tuberculous meningitis caused by Mycobacterium tuberculosis - It is one of the most severe forms of TB Pathogenesis: Primary infection - Bacillemia - Seeding of meninges RICHs FOCI- Rupture -Tubercular meningitis Clinical features: Stages: 1. Prodromal stage fever, anorexia, vomiting, irritability 2. Focal deficits, seizures, meningeal signs 3. Coma, neurological sequelae Investigations: CNS IMAGING CT Head Basal exudates Image showing basal exudates Hydrocephalus Tuberculoma with perilesional edema CSF STUDY: Opening pressure elevated Cell count - 500mm3 lymphocytic predominance Elevated proteins Low glucose Cob-web coagulum Diagnosis is confirmed if CSF culture PCR is ve for mycobactacterium tuberculosis acid fast bacilli TREATMENT - ATT Steroids 