Pediatric Tubercular Meningitis

• Etiology: Mycobacterium tuberculosis via hematogenous spread
• Imaging CT: Hyperdensity and enhancement of basilar meninges
• Imaging MRI:
  — Stages are 1) Cerebritis – non-specific edema and ill-defined enhancement, 2) Solid granulomatous – enhancing nodules and surrounding edema, 3) Central caseation – central T2 hypointensity with peripheral enhancement, 4) Involution – calcified lesions
  — Basilar meningitis
  — Parenchymal extension via Virchow Robin spaces
  — Multiple small ring enhancing tuberculomas at gray-white junction (often in parietal lobe) via hematogenous spread
• DDX:
• Complications:
  — 95% of cases seen as meningitis
  — Tuberculoma seen in 5%
  — Tuberculous abscess seen in 1%
  — Tuberculomas and tuberculous abscesses favor posterior fossa in children as opposed to adults
• Treatment:
• Clinical:
  — Most common cause of subacute meningitis in developing world
  — 0.5-2% of cases involve CNS
  — 30% have concomitant manifestations of tuberculosis outside of central nervous system

Radiology Cases of Tubercular Meningitis