Tuberculous meningitis in children treated with streptomycin and P.A.S

The current global situation for tuberculous meningitis: epidemiology, diagnostics, treatment and outcomes

Tuberculous meningitis (TBM) results from dissemination of M. tuberculosis to the cerebrospinal fluid (CSF) and meninges. Ischaemia, hydrocephalus and raised intracranial pressure frequently result, leading to extensive brain injury and neurodisability. The global burden of TBM is unclear and it is likely that many cases are undiagnosed, with many treated cases unreported. Untreated, TBM is uniformly fatal, and even if treated, mortality and morbidity are high. Young age and human immunodeficiency virus (HIV) infection are potent risk factors for TBM, while Bacillus Calmette-Guérin (BCG) vaccination is protective, particularly in young children. Diagnosis of TBM usually relies on characteristic clinical symptoms and signs, together with consistent neuroimaging and CSF parameters. The ability to confirm the TBM diagnosis via CSF isolation of M. tuberculosis depends on the type of diagnostic tests available. In most cases, the diagnosis remains unconfirmed. GeneXpert MTB/RIF and the next generation Xpert Ultra offer improved sensitivity and rapid turnaround times, and while roll-out has scaled up, availability remains limited. Many locations rely only on acid fast bacilli smear, which is insensitive. Treatment regimens for TBM are based on evidence for pulmonary tuberculosis treatment, with little consideration to CSF penetration or mode of drug action required. The World Health Organization recommends a 12-month treatment course, although data on which to base this duration is lacking. New treatment regimens and drug dosages are under evaluation, with much higher dosages of rifampicin and the inclusion of fluoroquinolones and linezolid identified as promising innovations. The inclusion of corticosteroids at the start of treatment has been demonstrated to reduce mortality in HIV-negative individuals but whether they are universally beneficial is unclear. Other host-directed therapies show promise but evidence for widespread use is lacking. Finally, the management of TBM within health systems is sub-optimal, with drop-offs at every stage in the care cascade.

The chemotherapy of tuberculous meningitis in children and adults

Literature dealing with antituberculosis chemotherapy of tuberculous meningitis (TBM) in adults and children is reviewed and recommendations made for the chemotherapy of TBM. Publications relating to the chemotherapy of TBM were reviewed which contribute to understanding the efficacy of different drugs and regimens in TBM treatment. The established classification of disease severity into stages I (no neurological signs and fully conscious), II (patients conscious but with neurological signs) and III (comatose or stuporous or with severe pareses) was used to compare regimens of isoniazid (INH), para-amino salicylic acid and streptomycin (INH regimens) used up to approximately 1970 with those using INH and rifampicin (RMP), supported by pyrazinamide and ethambutol or streptomycin (RMP regimens). Mortality in studies at all disease stages in adults or adults and children, with the children not distinguished, following INH regimens (12.4%, 25.2% and 55% at stages I, II and III respectively) did not differ significantly from that following introduction of RMP regimens (9.7%, 22.2% and 56% at stages I, II and III respectively), In studies of children only, mortality fell significantly following the introduction of RMP to 0%, 5.9% and 28.2% in children at stage I, II and III having been 10.2%, 22.3% and 49.4% respectively with INH regimens (P = 0.006). Following RMP regimens of 6 months duration, only 2 (1%) relapses occurred amongst 197 patients, after RMP regimens of 9-24 months only 1 (0.16%) relapse was recorded amongst 632 patients. Where INH resistance rates are <4% a directly observed INH, RMP, pyrazinamide and ethambutol for 2-months followed by INH and RMP for 4 months is recommended. If directly observed therapy cannot be practiced treatment duration should be extended to at least 9 months; if the risk of INH resistance or multidrug resistance is higher, the use of ethionamide and a fluoroquinolone and possibly cycloserine is recommended and pyrazinamide should be continued for full treatment duration. The penetration of RMP, ethambutol and streptomycin into cerebrospinal fluid is poor; higher dosages of RMP should be considered.

Tuberculous meningitis--clinical and laboratory review of 100 patients

In developing countries tuberculous meningitis is a difficult infection to differentiate from other central nervous system (CNS) infections. This paper presents the history, physical findings, laboratory data, and clinical course of 100 patients who were admitted to a special ward and had CSF cultures positive for Mycobacterium tuberculosis. Fifty-four patients were comatose when admitted and 76 had meningeal signs. Mean admission CSF values were WBC 531, glucose 23 mg/dl, and protein 166 mg/dl. Only two CSF AFB smears were positive. Sixty-one percent of the chest X-rays taken were consistent with pulmonary tuberculous and 39% were normal. Twenty-four patients died within the first week after admission, before the clinical diagnosis was made and anti-tuberculous therapy could be started. Fifty-three of 76 patients given antituberculous therapy died. Neurologic sequelae developed in 48% of the survivors. The high mortality and morbidity rates in this patient-group were due to the severity of illness on admission and the predominance of children (54%).