Management of Hyperproteinorrachia with Leukocytosis and Normal CSF Glucose
Start empiric intravenous acyclovir immediately (10 mg/kg every 8 hours) along with broad-spectrum antibiotics (ceftriaxone and vancomycin) until bacterial meningitis and HSV encephalitis are definitively excluded by culture and PCR results. 1, 2
Immediate Interpretation of CSF Values
Your CSF shows:
- Glucose 117 mg/dL: Normal to elevated (rules out most bacterial, TB, and fungal infections) 3, 4
- WBC 2,070 cells/µL: Moderate pleocytosis (bacterial meningitis typically shows >2,000 cells/µL but with much higher protein) 3
- Protein 101 mg/dL: Mildly elevated (bacterial meningitis typically shows >220 mg/dL) 3, 4
This pattern strongly suggests viral meningoencephalitis, but partially treated bacterial meningitis and atypical infections cannot be excluded based on CSF alone. 1, 2
Critical Diagnostic Workup Required Immediately
Essential CSF Studies to Send Now:
- CSF PCR for HSV-1, HSV-2, VZV, and enteroviruses (accounts for 90% of viral CNS infections) 1, 2
- CSF bacterial culture and Gram stain (to exclude partially treated bacterial meningitis) 1, 2
- CSF lactate level (if <2 mmol/L, effectively rules out bacterial disease) 1, 2, 4
- CSF cell differential (lymphocytic vs neutrophilic predominance guides diagnosis) 3, 5
Additional Testing Based on Risk Factors:
- TB studies (AFB smear, culture, TB PCR) if immunocompromised, endemic exposure, or risk factors present 3, 2
- Cryptococcal antigen and fungal culture if immunocompromised (note: cryptococcal meningitis can present with completely normal CSF studies) 3, 6
- CSF oligoclonal bands and IgG index if autoimmune/inflammatory conditions suspected 2, 4
Obtain Simultaneous Plasma Glucose:
- Calculate CSF:plasma glucose ratio (normal >0.66) - this is far more informative than absolute CSF glucose alone 4
Empiric Treatment Protocol
Start Immediately (Do Not Wait for PCR Results):
Acyclovir 10 mg/kg IV every 8 hours 3, 1, 7
- HSV encephalitis presents with normal/minimally abnormal CSF in 5-10% of cases 1, 2
- Delays beyond 48 hours significantly worsen outcomes (mortality 70% untreated vs 20-30% with treatment) 1
- Continue for 14-21 days if HSV confirmed 1
Ceftriaxone + Vancomycin (standard meningitis dosing) 1
- Lymphocytic pleocytosis with normal glucose does NOT exclude bacterial meningitis 1
- Partially treated bacterial meningitis, TB meningitis, and listeriosis can present identically 1
- Discontinue once bacterial cultures negative and clinical course supports viral etiology 1
Neuroimaging Requirements
Obtain brain MRI with and without contrast urgently: 2
- Temporal lobe enhancement suggests HSV encephalitis 1, 2
- Basilar meningeal enhancement suggests TB or fungal meningitis 1, 2
- Demyelinating lesions suggest autoimmune disease 2
Follow-Up Strategy
Repeat lumbar puncture in 24-48 hours if: 1, 2
- Initial CSF HSV PCR is negative AND clinical suspicion remains high
- HSV PCR can be negative early in disease course 1, 2
Monitor for acyclovir nephrotoxicity: 1
- Ensure adequate hydration to prevent crystalluria 1
Serial neurological examinations every 4-6 hours until diagnosis established 2
Critical Pitfalls to Avoid
Never assume lymphocytic CSF with normal glucose means "just viral": 1, 4
- TB meningitis, partially treated bacterial meningitis, and listeriosis all present with lymphocytic pleocytosis 1
- Neurobrucellosis commonly shows mild pleocytosis (<50 cells/µL) with only mildly elevated protein and near-normal glucose 8
Never delay acyclovir waiting for HSV PCR results: 1, 2
- If any neurological symptoms present (altered mental status, focal deficits, seizures), start immediately 2
- 5-10% of HSV encephalitis cases have normal/minimally abnormal initial CSF 1, 2
Never rely on CSF glucose alone without plasma glucose: 4
- The CSF:plasma ratio is the critical value, not absolute CSF glucose 4
Consider cryptococcal meningitis even with normal CSF: 6