Fungal Infections of the Central Nervous System

Abstract

Although the most common origin of central nervous system (CNS) infections is bacteria, the role of fungi should not be overlooked; these infections have received much interest in recent years. Fungal diseases have a significant morbidity and mortality. Clinical presentations may be acute and fulminant or chronic and gradually progressive. CNS involvement usually takes the form of either meningitis or intraparenchymal granuloma or abscess. Most patients are immunocompromised hosts, although immunocompetent subjects can also be infected. Aspergillosis, candidiasis, and mucormycosis are almost exclusively seen in immunocompromised or severely debilitated individuals. Cryptococcosis occurs in both previously healthy and immunocompromised patients; blastomycosis and histoplasmosis commonly concern healthy subjects. Diagnosis is often difficult and is usually made by serologic testing, histological examination, and mycologic culture. Patients may require surgical support for biopsy (definitive diagnosis), management of intracranial hypertension, spinal cord decompression, and CSF shunting. Treatment is primarily medical, however, with long-term courses of antifungal drugs and control of the underlying disease. The patient’s initial clinical condition and the potential concomitant diseases are the strongest predictor of clinical outcome. This chapter focuses on the fungal infections most pertinent to neurosurgical practices: aspergillosis, blastomycosis, candidiasis, cryptococcosis, histoplasmosis, and mucormycosis (zygomycosis).