| CSF Studies: | ||||
| Normal | Bacterial Meningitis | Viral Meningitis | Fungal/TB | |
| Opening Pressure (cm H2O) | < 15 | ↑↑ | Normal/mild ↑ | Variable |
| Protein (mg/dL) | 15-45 | ↑ | Normal/mild ↑ | ↑ |
| Glucose (mg/dL) | 40-70 | ↓ | Normal | ↓ |
| WBC | 0-8 | ↑↑ (>1000) | ↑ (5-300) | ↑ |
| WBC differential | Even | >80% PMNs | >50% Lymphs, <20% PMNs | 50-80% Lymphs |
| Gram Stain | Normal | 60-90 % + | N/A | 37-87% AFB + |
Differentiate between meningitis and encephalitis:
Brain function: abnormalities of brain function expected with encephalitis: AMS, motor/sensory deficits, speech/movement disorders
*distinction frequently blurred – meningioencephalitis both parenchymal and meningeal process.
Kernig Sign: inability/reluctance to allow full extension of the knee when hip is flexed at 90 degrees.
Brudzinski Sign: spontaneous flexion of the hip during attempted passive flexion of the neck.
*5% sensitivity and 95% specificity!
Characteristic MRI patterns for encephalitis:
- HSV – temporal distribution
- WNV – thalamic distribution
- MS – periventricular (Dawson’s fingers)
Mallaret’s Meningitis: >3 recurrent episodes of HSV2 meningitis
SCVMC IM Chief Resident Blog 