Noninfectious Causes of Chronic Meningitis
| Causative Agents | CSF Formula | Helpful Diagnostic Tests | Risk Factors and Systemic Manifestations |
|---|---|---|---|
| Malignancy | Mononuclear cells, elevated protein, low glucose | Repeated cytologic examination of large volumes of CSF; CSF exam by polarizing microscopy; clonal lymphocyte markers; deposits on nerve roots or meninges seen on myelogram or contrast-enhanced MRI; meningeal biopsy | Metastatic cancer of breast, lung, stomach, or pancreas; melanoma, lymphoma, leukemia; meningeal gliomatosis; meningeal sarcoma; cerebral dysgerminoma; meningeal melanoma or B cell lymphoma |
| Chemical compounds (may cause recurrent meningitis) | Mononuclear or PMNs, low glucose, elevated protein; xanthochromia from subarachnoid hemorrhage in week prior to presentation with “meningitis” | Contrast-enhanced CT scan or MRI; cerebral angiogram to detect aneurysm | History of recent injection into the subarachnoid space; history of sudden onset of headache; recent resection of acoustic neuroma or craniopharyngioma; epidermoid tumor of brain or spine, sometimes with dermoid sinus tract; pituitary apoplexy |
| Primary inflammation | |||
| CNS sarcoidosis | Mononuclear cells; elevated protein; often low glucose | Serum and CSF angiotensin-converting enzyme levels; biopsy of extraneural affected tissues or brain lesion/meningeal biopsy | CN palsy, especially of CN VII; hypothalamic dysfunction, especially diabetes insipidus; abnormal chest radiograph; peripheral neuropathy or myopathy |
| Vogt-Koyanagi-Harada syndrome (recurrent meningitis) | Mononuclear cells | Recurrent meningoencephalitis with uveitis, retinal detachment, alopecia, lightening of eyebrows and lashes, dysacousia, cataracts, glaucoma | |
| Isolated granulomatous angiitis of the nervous system | Mononuclear cells, elevated protein | Angiography or meningeal biopsy | Subacute dementia; multiple cerebral infarctions; recent zoster ophthalmicus |
| Systemic lupus erythematosus | Mononuclear or PMNs | Anti-DNA antibody, antinuclear antibodies | Encephalopathy; seizures; stroke; transverse myelopathy; rash; arthritis |
| Behçet's syndrome (recurrent meningitis) | Mononuclear or PMNs, elevated protein | Oral and genital aphthous ulcers; iridocyclitis; retinal hemorrhages; pathergic lesions at site of skin puncture | |
| Chronic benign lymphocytic meningitis | Mononuclear cells | Recovery in 2-6 months, diagnosis by exclusion | |
| Mollaret's meningitis (recurrent meningitis) | Large endothelial cells and PMNs in first hours, followed by mononuclear cells | PCR for herpes; MRI/CT to rule out epidermoid tumor or dural cyst | Recurrent meningitis; exclude HSV-2; rare cases due to HSV-1; occasional case associated with dural cyst |
| Drug hypersensitivity | PMNs; occasionally mononuclear cells or eosinophils | Complete blood count (eosinophilia) | Exposure to nonsteroidal anti-inflammatory agents, sulfonamides, isoniazid, tolmetin, ciprofloxacin, penicillin, carbamazepine, lamotrigine, IV immunoglobulin, OKT3 antibodies, phenazopyridine; improvement after discontinuation of drug; recurrence with repeat exposure |
| Granulomatosis with polyangiitis (Wegener's) | Mononuclear cells | Chest and sinus radiographs; urinalysis; ANCA antibodies in serum | Associated sinus, pulmonary, or renal lesions; CN palsies; skin lesions; peripheral neuropathy |
| Other: multiple sclerosis, Sjögren's syndrome, monogenic autoinflammatory disorders, and rarer forms of vasculitis (e.g., Cogan's syndrome) | |||
Abbreviations: ANCA, antineutrophil cytoplasmic antibodies; CN, cranial nerve; PMNs, polymorphonuclear cells.