Outcomes of persons with blastomycosis involving the central nervous system

Abstract

Blastomyces dermatitidis is a dimorphic fungus which is potentially life-threatening if central nervous system (CNS) dissemination occurs. Sixteen patients with proven or probable CNS blastomycosis are presented. Median duration of symptoms was 90 days; headache and focal neurologic deficit were the most common presenting symptoms. Magnetic resonance imaging (MRI) consistently demonstrated an abnormality, compared to 58% of computed tomography scans. Tissue culture yielded the pathogen in 71% of histology-confirmed cases. All patients who completed treatment of an amphotericin B formulation and extended azole-based therapy did not relapse. Initial nonspecific symptoms lead to delayed diagnosis of CNS blastomycosis. A high index of suspicion is necessary if there is history of contact with an area where B. dermatitidis is endemic. Diagnostic tests should include MRI followed by biopsy for tissue culture and pathology. Optimal treatment utilizes a lipid-based amphotericin B preparation with an extended course of voriconazole.