Fig. (3). Tuberculosis: Spread to the Central Nervous System.
The establishment of Central Nervous System (CNS) tuberculosis occurs after hematogenous dissemination of mycobacteria from the lungs. The mycobacteria invade / traverse the blood brain barrier and get deposited in the CNS. When deposited in large numbers as part of primary tuberculosis in infants / young children, they may cause tuberculosis meningitis and formation of tuberculomas. However, in adults / older children, deposited mycobacteria may not elicit any immune response and cause latent disease until immune recognition / reactivation causes formation of tuberculomas in the CNS. These tuberculomas may later rupture into the cerebrospinal fluid, leading to severe inflammation and tuberculous meningitis.
