Fungal Infections of the Central Nervous System: A Pictorial Review

Abstract

Fungal infections of the central nervous system (CNS) pose a threat to especially immunocompromised patients and their development is primarily determined by the immune status of the host. With an increasing number of organ transplants, chemotherapy, and human immunodeficiency virus infections, the number of immunocompromised patients as susceptible hosts is growing and fungal infections of the CNS are more frequently encountered. They may result in meningitis, cerebritis, abscess formation, cryptococcoma, and meningeal vasculitis with rapid disease progression and often overlapping symptoms. Although radiological characteristics are often nonspecific, unique imaging patterns can be identified through computer tomography as a first imaging modality and further refined by magnetic resonance imaging. A rapid diagnosis and the institution of the appropriate therapy are crucial in helping prevent an often fatal outcome.

Fluorescence in a cryptococcoma following administration of 5-aminolevulinic acid hydrochloride (Gliolan)

“…Imaging findings of fungal cerebral abscesses are often similar to those of neoplasms, including postcontrast peripheral enhancement. Characteristically, fungal abscesses are multiple in number, located within the basal ganglia and may show a ‘dual-rim sign’ on diffusion-weighted imaging 15. None of these characteristic features were present in our patient, stressing how it ought to remain an important differential diagnosis even in light of atypical imaging patterns.…”

The Neurotropic Black Yeast Exophiala dermatitidis Induces Neurocytotoxicity in Neuroblastoma Cells and Progressive Cell Death

“…Recently, an increasing number of opportunistic mycoses of the central nervous system (CNS) has been reported in healthy individuals and, in particular, in patients with sepsis, prolonged ventilation, oncological therapies, organ transplantation, overuse of antibiotics, HIV patients, and others [41,60]. Opportunistic mycoses of CNS are associated with higher morbidity and mortality [61,62] owing to pathogenic fungi such as Cryptococcus neoformans, which are able to cross the otherwise prohibitive blood-brain barrier [41,63].…”

Antifungal drugs: An updated review of central nervous system pharmacokinetics

“…Acute or subacute fungal meningitis is often caused by yeasts, such as Candida spp. and Cryptococcus spp., but moulds, such as Aspergillus spp., Fusarium spp., and Scedosporium spp., Mucorales, dimorphic fungi ( Blastomyces , Histoplasma , Coccidioides , and Paracoccidioides ), and dematiaceous fungi are also found as pathogens of the CNS 4‐9 …”

“…There is immune control to a limited extent, which the endothelial cells of blood‐brain barrier (BBB) have low expression of leucocyte adhesion molecules, hindering immune cell infiltration into the healthy CNS 10 . However, the inflammatory response in fungal diseases occurs due to the large size of fungal cells, which can occlude meningeal microcirculation, causing a more focal disease, leading to cerebritis and abscess formation, or the involvement of larger vessels, resulting in vasculitis, vascular occlusion, cerebral infarctions or formation of mycotic aneurysms 3,5 . In addition, this response results in deposits of thick, gelatinous exudates containing inflammatory cells, fibrin and haemorrhage, leading to arachnoiditis 4,11 …”