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For further information, see CMDT Part 35-36: Tuberculous Meningitis
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Essentials of Diagnosis
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Gradual onset of listlessness and anorexia
Fever, headache, vomiting, and seizures common
Cranial nerve abnormalities typical
Tuberculous focus may be evident elsewhere
Cerebrospinal fluid shows several hundred lymphocytes per microliter, low glucose, and high protein
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General Considerations
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Onset usually gradual
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
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Differential Diagnosis
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Fungal and other granulomatous meningitides
Syphilis
Carcinomatous meningitis
Tuberculous meningitis 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
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The spinal fluid is frequently yellowish, with increased pressure, 100–500 cells/mcL (0.1–0.5 × 109/L) (predominantly lymphocytes, though neutrophils may be present early during infection), increased protein, and decreased glucose (Table 32–2)
Acid-fast stains of cerebrospinal fluid usually are negative, and cultures also may be negative (sensitivity less than 50%)
Nucleic acid amplification tests allow for rapid diagnosis, when positive
The tuberculin skin testing and interferon-gamma release assays do not distinguish between active and latent tuberculosis and may be negative in the presence of CNS infection
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