Recent Advances in Fungal Infections of the Central Nervous System: From Etiology to Diagnosis and Management

While the majority of infections in the central nervous system (CNS) are caused by bacteria and viruses, fungi are increasingly being recognized as important pathogens. This is mainly due to the increased awareness of clinicians about these conditions, widespread use of antibacterial agents, a rapid increase in the number of the immunocompromised population, advances in imaging, and the availability of microbiological techniques to confirm the diagnosis from bodily fluids and specimens. Fungal infections have been recognized since early times, but fungal infections of the CNS have mainly been recognized since the 19th century. Fungal infections of the CNS include a wide spectrum of clinical syndromes comprising abscesses, meningitis/meningoencephalitis, focal masses, stroke/vasculitides, immune reconstitution inflammatory syndrome (IRIS), and spinal pathologies such as arachnoiditis. The main etiologies comprise 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. This chapter highlights recent advances in CNS fungal infections caused by different groups of fungal pathogens from etiology to diagnosis and management.