Treatment of Meningitis with Lymphocytic Pleocytosis and Hypoglycorrhachia
Immediate Empiric Antibiotic Therapy is Required
The most appropriate treatment is D. Ceftriaxone and vancomycin, with the critical addition of ampicillin to cover Listeria monocytogenes, which characteristically presents with lymphocytic predominance and low glucose. 1, 2
Why This CSF Pattern Demands Broad Bacterial Coverage
The combination of slightly low glucose (hypoglycorrhachia) and lymphocytic pleocytosis does not exclude bacterial meningitis—this is a critical pitfall that leads to delayed treatment and increased mortality 2. This CSF pattern can occur in:
- Partially treated bacterial meningitis (prior antibiotics) 3, 2
- Listeria monocytogenes meningitis (classically presents with lymphocytic predominance) 1, 2
- Early bacterial meningitis (up to 20% of bacterial meningitis cases lack significant pleocytosis early in disease) 2
- Tuberculous meningitis (though this typically has more profound hypoglycorrhachia) 2
The Required Empiric Regimen
Core Triple Therapy:
- Ceftriaxone 2g IV every 12 hours (or cefotaxime 2g IV every 6 hours) 3, 1
- Vancomycin 60 mg/kg/day IV divided every 6 hours to cover penicillin-resistant Streptococcus pneumoniae 1, 4
- Ampicillin 2g IV every 4 hours is essential because lymphocytic predominance with low glucose raises concern for Listeria 1, 2, 5
Adjunctive Dexamethasone:
- Dexamethasone 10mg IV every 6 hours should be administered immediately, either shortly before or simultaneously with the first antibiotic dose 3, 1, 2
- Continue for 4 days if pneumococcal meningitis is confirmed or probable 3
- Stop if another cause is identified 3
Why Each Answer Choice is Correct or Incorrect
A. Acyclovir - Incorrect
- Acyclovir treats viral meningoencephalitis (HSV, VZV) 2
- While viral meningitis can present with lymphocytic pleocytosis, the low glucose strongly suggests bacterial or tuberculous etiology, not viral 2
- Viral meningitis typically has normal glucose 2
B. Steroid - Partially Correct but Insufficient
- Dexamethasone is indeed indicated as adjunctive therapy, not monotherapy 3, 1, 6
- Steroids alone without antibiotics would be catastrophic in bacterial meningitis 3
C. Meropenem - Not First-Line
- Meropenem has proven efficacy in bacterial meningitis with 78% cure rates 7
- However, it is not recommended as initial empiric therapy by major guidelines 3, 1
- Reserved for specific situations: nosocomial meningitis, post-neurosurgical infections, or documented resistant organisms 7
D. Ceftriaxone and Vancomycin - Correct but Incomplete
- This combination is the standard empiric regimen for community-acquired bacterial meningitis 3, 1, 6
- However, ampicillin must be added when lymphocytic predominance is present due to Listeria risk 1, 2, 5
Critical Timing Considerations
Antibiotics must be initiated within 1 hour of presentation 1, 2. Delay in treatment is strongly associated with death and poor neurological outcomes 1. Do not delay antibiotics for:
Common Pitfalls to Avoid
Assuming viral meningitis based on lymphocytic predominance alone—bacterial causes including Listeria present identically 2
Omitting ampicillin in patients with lymphocytic CSF—this is the classic presentation of Listeria meningitis 1, 2
Using ceftriaxone monotherapy—vancomycin is essential for pneumococcal coverage in the era of resistant strains 1, 8, 9
Delaying treatment to "rule out" bacterial meningitis—up to 20% of bacterial meningitis cases have minimal pleocytosis early 2
Duration and Monitoring
- Continue antibiotics for 10-14 days for pneumococcal meningitis if confirmed 2
- Continue for 21 days for gram-negative bacillary meningitis or Listeria 10, 2
- If cultures remain negative at 48-72 hours with inadequate clinical response, strongly consider tuberculous meningitis and add appropriate therapy 2