Fungal Infections of the Central Nervous System

This article summarizes current knowledge on the epidemiology, clinical presentations, diagnosis, and management of selected fungal infections of the central nervous system (CNS). Key syndromes, differential diagnoses, and therapeutic interventions according to host immune status and exposure are reviewed.

Advancements in imaging of the brain and spinal cord, and molecular DNA and antigen-based laboratory diagnostics afford improved sensitivity for CNS mycoses. Newer therapeutic strategies may improve outcomes if provided early and host immunosuppression is abrogated. Adjunctive corticosteroid use for disabling neuroinflammation and cerebral edema in the setting of microbiological control may be considered. In addition, nonspecific presentations and absence of fevers in patients without human immunodeficiency virus suggest that screening for Cryptococcus meningitis be performed in all patients with subcortical dementias using a simple CSF or serum antigen test.

CNS fungal infections comprise a wide spectrum of clinical syndromes, including abscesses, meningitis/meningoencephalitis, focal masses, stroke/vasculitides, immune reconstitution inflammatory syndrome (IRIS), and spinal pathologies such as arachnoiditis. The main etiologies include Aspergillus, Cryptococcus, Candida, Mucorales, dematiaceous molds, and dimorphic endemic fungi, with the route of acquisition being respiratory or traumatic inoculation with subsequent spread hematogenously or contiguously. Proper management focuses on early effective antifungal therapy and surgery for large or compressive mass lesions. While adjunctive recombinant cytokine or growth factor use has been supported in certain hosts with refractory infections, IRIS-like reactions may occur, suggesting alternative approaches such as high-dose pulse corticosteroids followed by taper.