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; sarcoma; cerebral dysgerminoma |
| 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. Enhancement and clumping of nerve roots of the cauda equina in arachnoiditis/pachymeningitis | 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 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; meningeal biopsy may be necessary if confined to small vessels. VZV PCR in blood and biopsy tissue | 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 |
| Neonatal-onset multisystem inflammatory disorder | Mononuclear and PMNs | Gain of function mutation in NLRP3 gene leading to elevated IL-1β | Recurrent fever, urticaria, arthralgia, sensorineural hearing loss, papilledema, increased ICP |
| IgG4-related hypertrophic pachymeningitis | Mild lymphocytic pleocytosis in some cases; normal to mildly increased protein; normal glucose | Serum IgG4 levels frequently elevated; ESR and C-reactive protein; meningeal biopsy shows swirling “storiform” fibrosis with lymphocytic infiltrates, obliterative phlebitis and IgG4+ plasma cells | Headache; seizures; focal symptoms from dural involvement in spinal cord/nerve roots, clivus, periorbital, vestibular, and brainstem structures. Systemic IgG4-related disease can involve many tissues including pancreas, thyroid, lungs, and retroperitoneum |
| Other: multiple sclerosis, Sjögren's syndrome, and rarer forms of vasculitis (e.g., Cogan's syndrome) | |||