-Tuberculous meningitis occurs in persons of all ages

-After primary infection in the lungs, blood-borne bacilli travel to the meninges 

Symptoms & Signs 

-Gradual onset with headache, fever, irritability, vomiting, nuchal rigidity, neck stiffness, cranial nerve palsies 

-Meningeal involvement is prominent at the base of the brain, affecting the pons and optic chiasm, leading to cranial nerve (especially III, IV, and VI) palsies, which results in visual impairment and diplopia 

Diagnosis 

-Cornerstone of diagnosis: Lumbar puncture 

-CSF obeys the ‘500 rule’: Lymphocytic pleocytosis fewer than 500, protein less than 500 mg/dL; glucose less than 45 mg/dL 

-Pathology: Basal meningeal, white gelatinous exudate containing mononuclear cells  

Treatment 

Treatment with isoniazid, rifampin, and pyrazinamide

All three penetrate the cerebrospinal fluid wall 

Add corticosteroids for hydrocephalus.