Chronic meningitis.

Chronic meningitis is a syndrome commonly defined by the presence of continuously persistent meningeal inflammation for at least 4 weeks. Presenting neurologic features are often nonspecific, and the list of differential diagnoses is broad. Despite the development of modern molecular diagnostic methods, establishing a specific cause may challenge the acumen of the treating neurologist with clues to the diagnosis residing outside the nervous system and requiring focused investigation. This review discusses selected etiologies illustrating issues in diagnosis and etiologic categories to be considered in the evaluation of this challenging syndrome.