Table 4.

LABORATORY EVALUATION OF CHRONIC MENINGITIS

Blood Tests	Complete blood count, differential Chemistries, erythrocyte sedimentation rate, antinuclear antibodies HIV serology RPR Consider angiotensin-converting enzyme (ACE), antineutrophilic cytoplasmic antibodies, specific serologies, blood smears
CSF	Cell count with differential, protein, glucose Cytology VDRL Cultures (TB, fungal, bacterial, viral) Stain (Gram, acid fast, India ink) Cryptococcal antigen Oligoclonal bands, lgG index Consider ACE; PCR (viruses, mycobacteria, T. whippelii); histoplasma antigen, immunocytochemistry (T. whippelii and other selected agents); paired antibodies for B. burgdorferi, Brucella, histoplasma, coccidioides, other fungal agents; neoplastic markers
Neuroimaging	Brain MR imaging with contrast Consider CT, spinal MR imaging, angiography
Cultures	Blood (parasites, fungi, viruses, rare bacteria) Urine (mycobacteria, viruses, fungi) Sputum (mycobacteria, fungi) Consider gastric washings, stool, bone marrow, liver (mycobacteria, fungi)
Ancillary	Chest radiograph Electrocardiogram Selected testing (mammogram, CT chest/abdomen, etc.)
Biopsy	Extraneural sites (bone marrow, lymph node, peripheral nerve, liver, lung, skin, small bowel) Leptomeningeal/brain (±special stains)
RPR = Rapid plasma reagin; VDRL = Venereal Disease Research Laboratory.