Chronic Meningitis

Abstract

Purpose of review: This article describes the clinical presentation, diagnostic approach (including the use of novel diagnostic platforms), and treatment of select infectious and noninfectious etiologies of chronic meningitis.

Recent findings: Identification of the etiology of chronic meningitis remains challenging, with no cause identified in at least one-third of cases. Often, several serologic, CSF, and neuroimaging studies are indicated, although novel diagnostic platforms including metagenomic deep sequencing may hold promise for identifying organisms. Infectious etiologies are more common in those at risk for disseminated disease, specifically those who are immunocompromised because of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), transplantation, or immunosuppressant medications. An important step in identifying the etiology of chronic meningitis is assembling a multidisciplinary team of individuals, including those with specialized expertise in ophthalmology, dermatology, rheumatology, and infectious diseases, to provide guidance regarding diagnostic procedures.

Summary: Chronic meningitis is defined as inflammation involving the meninges that lasts at least 4 weeks and is associated with a CSF pleocytosis. Chronic meningitis has numerous possible infectious and noninfectious etiologies, making it challenging to definitively diagnose patients. Therefore, a multifaceted approach that combines history, physical examination, neuroimaging, and laboratory analysis, including novel diagnostic platforms, is needed. This article focuses on key aspects of the evaluation of and approach to patients with chronic meningitis. Specific infectious etiologies and differential diagnoses of subacute and chronic meningitis, including noninfectious etiologies, are addressed.

FIGURE 3-1. Diagnostic evaluation approach for chronic meningitis.

Data from Pruitt A, Continuum (Minneap Minn). © 2012 American Academy of Neurology. Modified with permission from Baldwin KJ, Zunt JR, Neurohospitalist. © 2014 SAGE Publications.

FIGURE 3-2. Patterns of meningeal enhancement in chronic meningitis. A, Dura-arachnoid pachymeningeal enhancement. B, Pia-arachnoid leptomeningeal enhancement.

Reprinted with permission from Smirniotopoulos JG, et al, Radiographics. © 2007 Radiological Society of North America.

FIGURE 3-3

Imaging of the patient in CASE 3-1. Axial postcontrast T1-weighted image showing evidence of a small extraaxial subcentimeter focus of enhancement at the interpeduncular fossa.

FIGURE 3-4

Imaging of the patient in CASE 3-2. Axial T2-weighted MRI (A) and postcontrast T1-weighted MRI (B) images showing a large infiltrating, avidly enhancing process with both right temporal extraaxial and intraaxial components, with associated reactive edema and mass effect. Enhancement abuts the right cavernous sinus and involves the right orbital apex. The mass originates from the right posterior nasal cavity with extension through the expanded pterygopalatine fossa with extension inferiorly into the infratemporal fossa involving the temporalis and lateral pterygoid musculature and superiorly through the foramen ovale.

FIGURE 3-5

Funduscopy of the patient in CASE 3-3 shows dense vitritis, optic disc edema with hemorrhages, serous retinal detachment, and granular retinal lesions.