Correct Answer: Statement D
The correct statement is (d): In cerebrospinal fluid from a patient with tuberculous meningitis, lymphocytic pleocytosis, elevated protein (albumin), and decreased glucose are found. 1, 2, 3
Analysis of Each Statement
Statement A: Hepatitis as Major Side Effect of Ethambutol - INCORRECT
- Ethambutol's major side effect is optic neuritis/ocular toxicity, not hepatitis 1
- The hepatotoxic anti-tuberculous drugs are isoniazid, rifampicin, and pyrazinamide 1
- Ethambutol can be used with caution even in patients with liver disease, as it is not significantly hepatotoxic 1
Statement B: Arthritis as Side Effect of Rifampicin - INCORRECT
- Arthritis is not a recognized major side effect of rifampicin 1
- Rifampicin's main side effects include hepatotoxicity, drug interactions (reduces efficacy of oral contraceptives and sulphonylureas), and orange discoloration of body fluids 1
- Arthritis/arthralgias are actually associated with pyrazinamide, not rifampicin
Statement C: Isoniazid Maximum Dose of 600 mg - INCORRECT
- The maximum dose of isoniazid is 300 mg daily, not 600 mg 1
- Recommended dosing is 5 mg/kg up to a maximum of 300 mg/day according to IUATLD and WHO 1
- Some sources recommend 10 mg/kg up to a maximum of 300 mg daily, but the ceiling remains 300 mg 1
Statement D: CSF Findings in Tuberculous Meningitis - CORRECT
- Characteristic CSF findings in tuberculous meningitis include lymphocytic pleocytosis, elevated protein, and low glucose 1, 2, 3
- This is the classic triad described in all major guidelines 1, 3
- Specifically: lymphocytic-predominant pleiocytosis (>50% lymphocytes), protein >1 g/L, and glucose <2.2 mmol/L 4, 5
- Early in disease, neutrophils may predominate, but lymphocytes become predominant as disease progresses 4
Statement E: BCG Vaccination in Low Prevalence Countries - INCORRECT
- BCG vaccination is not recommended in countries with low tuberculosis prevalence
- BCG is recommended in countries with high tuberculosis prevalence and high transmission rates
- In low-prevalence settings, BCG vaccination is typically reserved for high-risk individuals only, not given universally
Clinical Pearls for CSF in Tuberculous Meningitis
Key diagnostic features: 3, 4, 5
- Lymphocytic pleocytosis: Usually 10-500 cells/μL with >50% lymphocytes
- Elevated protein: Typically >1 g/L (100 mg/dL)
- Low glucose: <2.2 mmol/L or CSF:serum glucose ratio <0.5
- CSF ADA >6 U/L has 95% specificity and positive likelihood ratio of 10.7 5
Important caveats: 4
- Early in disease (first few days), neutrophils may predominate (>50%), which can be misleading
- Multiple large-volume CSF samples increase diagnostic yield for AFB smear and culture 3
- Treatment should be initiated based on clinical suspicion and characteristic CSF findings, without waiting for culture confirmation 1, 2, 3