**12. Prognosis of tuberculous meningitis**

TBM prognosis depends on two factors: age of the patient and the stage of the disease at which the treatment began. Without treatment, the prognosis is fatal. In stage 1, a 100% cure rate is expected. Even with optimal therapy, mortality varies between 30–50%, and the incidence of neurological sequelae is 75–80%, especially in stage 3 [59]. In contrast, most patients diagnosed with stage 3 who survive have permanent disabilities: blindness, deafness, paraplegia, mental retardation and diabetes insipidus. Infants and young children have a poor prognosis compared to older children [60–62]**.**

#### **13. Conclusions**

TBM is a severe form of extrapulmonary tuberculosis with a high mortality rate due to the delay in diagnosis and adequate treatment. In the absence of an early

diagnosis and treatment, tuberculous meningitis is characterized by high mortality (20–50%) and increased morbidity (20–30%). The diagnosis of TBM remains difficult as its presentation is non-specific and may mimic other causes of chronic meningoencephalitis. Cytological and biochemical analysis of the cerebrospinal fluid is the cornerstone for diagnosis, but there are often diagnostic difficulties in differentiating tuberculous meningitis from nontuberculous. Although the culture for mycobacteria from CSF remains the gold standard for the diagnosis of TBM, the diagnosis is often delayed due to the long time interval until cultures are obtained. Therefore, it is necessary to discover new rapid tests that optimize the diagnosis of TBM. The new molecular biology tests and those based on gamma interferon release have improved the prognosis through a faster diagnosis and promptly initiated anti-tuberculosis treatment. New studies on the pathogenesis of MTB would be necessary for a better understanding of the therapeutic mechanisms needed to improve the prognosis.

The optimal duration of antituberculosis treatment has not been established precisely, varying in different studies and recommendations. The discovery of new classes of drugs active on M.tuberculosis is imperative considering the growing number of patients diagnosed with multidrug-resistant TB (MDR-TB) or even extensively drugresistant TB (XDR-TB). MTB in patients with HIV infection raises serious treatment problems due to drug interactions, the possibility of immune reconstruction syndrome and the more frequently unfavorable evolution, toward complications and death.

The role of corticosteroid treatment in MTB is controversial, the duration of treatment has not been clearly established, and their role in preventing complications and sequelae is not well defined.

More studies are needed to establish the role of surgical treatment, the optimal timing of surgery and the best method for the treatment of hydrocephalus.
