Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 33-37: Tuberculous Meningitis + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Gradual onset of listlessness and anorexia Fever, headache, vomiting, and seizures common Cranial nerve abnormalities are often present Tuberculous focus may be evident elsewhere Cerebrospinal fluid shows several hundred lymphocytes per microliter, low glucose, and high protein +++ General Considerations ++ Caused by rupture of a meningeal tuberculoma resulting from earlier hematogenous seeding of tubercle bacillus from a pulmonary focus, or may be a consequence of miliary spread + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Usually a subacute or chronic meningitis With listlessness, irritability, anorexia, and fever Followed by headache, vomiting, convulsions, and coma In older patients Headache and behavioral changes are prominent early symptoms Nuchal rigidity and cranial nerve palsies occur as the meningitis progresses Evidence of active tuberculosis elsewhere or a history of prior tuberculosis is present in up to 75% of patients The tuberculin skin test is usually (not always) positive +++ Differential Diagnosis ++ May be confused with any other type of meningitis, but the gradual onset, the predominantly lymphocytic pleocytosis of the spinal fluid, and evidence of tuberculosis elsewhere often point to the diagnosis Chronic lymphocytic meningitis due to Fungi (Cryptococcus, Coccidioides, Histoplasma) Brucellosis Leptospirosis Syphilis Lyme disease HIV infection Neurocysticercosis Carcinomatous meningitis Sarcoidosis Subdural hematoma + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ The spinal fluid is frequently yellowish, with increased pressure, 100–500 cells/mcL (predominantly lymphocytes, though neutrophils may be present early during infection), high protein, and low glucose (Table 30–1) Acid-fast stains of cerebrospinal fluid usually are negative, and cultures also may be negative in 15–25% of cases ++Table Graphic Jump LocationTable 30–1.Typical cerebrospinal fluid findings in various central nervous system diseases.View Table||Download (.pdf) Table 30–1. Typical cerebrospinal fluid findings in various central nervous system diseases. Diagnosis Cells/mcL Glucose (mg/dL) Protein (mg/dL) Opening Pressure Normal 0–5 lymphocytes 45–851 15–45 70–180 mm H2O Purulent meningitis (bacterial)2 community-acquired 200–20,000 polymorphonuclear neutrophils Low (< 45) High (> 50) Markedly elevated Granulomatous meningitis (mycobacterial, fungal)3 100–1000, mostly lymphocytes3 Low (< 45) High (> 50) Moderately elevated Spirochetal meningitis 100–1000, mostly lymphocytes3 Normal High (> 50) Normal to slightly elevated Aseptic meningitis, viral meningitis, or meningoencephalitis4 25–2000, mostly lymphocytes3 Normal or low High (> 50) Slightly elevated “Neighborhood reaction”5 Variably increased Normal Normal or high Variable 1Cerebrospinal fluid glucose must be considered in relation to blood glucose level. Normally, cerebrospinal fluid glucose is 20–30 mg/dL lower than blood glucose, or 50–70% of the normal value of blood glucose.2Organisms in smear or culture of cerebrospinal fluid; counterimmunoelectrophoresis or latex agglutination may be diagnostic.3Polymorphonuclear neutrophils may predominate early.4Viral isolation from cerebrospinal fluid early; antibody titer rise in paired specimens of serum; polymerase chain reaction for herpesvirus.5May occur in mastoiditis, brain abscess, epidural abscess, sinusitis, septic thrombus, brain tumor. Cerebrospinal fluid culture results usually negative. +++ Imaging Studies ++ Chest radiograph often reveals abnormalities compatible with tuberculosis but may be normal + Treatment Download Section PDF Listen +++ +++ Medications ++ Presumptive diagnosis followed by early, empiric antituberculous therapy is essential for survival and to minimize sequelae Even if cultures are not positive, a full course of therapy is warranted if the clinical setting is suggestive of tuberculous meningitis Regimens that are effective for pulmonary tuberculosis (but administered for 12 months) are effective also for tuberculous meningitis (Table 9–15) Rifampin, isoniazid, and pyrazinamide all penetrate into cerebrospinal fluid well The penetration of ethambutol is more variable, but therapeutic concentrations can be achieved, and the drug has been successfully used for meningitis Some authorities recommend the addition of corticosteroids for patients with focal deficits or altered mental status. Dexamethasone, 0.15 mg/kg four times daily for 1–2 weeks, then discontinued in a tapering regimen over 4 weeks, may be used + Outcome Download Section PDF Listen +++ +++ Complications ++ Result from inflammatory exudate primarily involving the basilar meninges and arteries Chronic brain syndrome Seizure disorders Cranial nerve palsies Stroke Obstructive hydrocephalus +++ Prognosis ++ High morbidity and mortality associated with stupor, coma, focal neurologic deficits +++ When to Refer ++ Consultation with a physician experienced in the treatment of tuberculosis is recommended +++ When to Admit ++ Recommended for all suspected cases for initial evaluation and treatment + References Download Section PDF Listen +++ + +Heemskerk AD et al. Intensified antituberculosis therapy in adults with tuberculous meningitis. N Engl J Med. 2016 Jan 14;374(2):124–34. [PubMed: 26760084] + +Khonga M et al. Xpert MTB/RIF Ultra: a gamechanger for tuberculous meningitis? Lancet Infect Dis. 2018 Jan;18(1):6–8. [PubMed: 28919337] + +Prasad K et al. Corticosteroids for managing tuberculous meningitis. Cochrane Database Syst Rev. 2016 Apr 28;4:CD002244. [PubMed: 27121755]