Fungal infection

Most are medically treated conditions that do not require neurosurgical intervention. They tend to present either with chronic meningitis or brain abscess. Some of the more common ones or those of particular relevance to neurosurgery include:

1. cryptococcosis:

a) cryptococcal meningitis

b) cryptococcoma (mucinous pseudocyst):rare

2. candidiasis: the most common fungal infection of the CNS, but rarely diagnosed before autopsy. Very rare in healthy individuals. Most are C. Albicans

a) candidal meningitis: the most common CNS infection;

b) parenchymal infection: candida brain abscesses are rare

c) following ventricular shunt placement: almost all fungal VP shunt infections are due to Candida spp. ¹⁾

3. aspergillosis: may be associated with a cerebral abscess in organ transplant patients

4. coccidiomycosis: caused by the dimorphic fungus Coccidioides immitis. Endemic in southwest- ern U.S. (including San Joaquin Valley in southern California), Mexico, and Central America. Usually presents as meningitis, with rare reports of parenchymal lesions ²⁾

5. mucormycosis (phycomycosis): usually occurs in diabetics

see also Fungal infection in pediatric neurosurgery.

Fungal infections of the central nervous system (CNS) were considered rare until the 1970s. This is no longer true in recent years due to widespread use of corticosteroids, cytotoxic drugs and antibiotics. Immunocompromised patients with underlying malignancy organ transplantations and acquired immune deficiency syndrome are all candidates for acquiring fungal infections either in meninges or brain. A considerable number of cases of CNS fungal infections even in immunocompetent hosts have been reported. A vast array of fungi may cause infection in the CNS, but barring a few, most of them are anecdotal case reports.

Cryptococcus neoformans, Candida albicans, Coccidioides immitis. Histoplasma capsulatum are common causes of fungal meningitis; Aspergillus spp, Candida spp, Zygomycetes and some of the melanized fungi are known to cause mass lesions in brain.

Few fungi like C. neoformans, Cladophialophora bantiana, Exophiala dermatitidis, Ramichloridium mackenzie, Ochroconis gallopava are considered as true neurotropic fungi. Most of the fungi causing CNS infection are saprobes with worldwide distribution; a few are geographically restricted like Coccidioides immitis. The infections reach the CNS either by the hematogenous route or by direct extension from colonized sinuses or ear canal or by direct inoculation during neurosurgical procedures ³⁾.

see Cryptococcosis.

Fungal Infections of the Central Nervous System Pathogens, Diagnosis, and Management