Cognitive impairment and memory loss associated with histoplasmosis: a case study

Histoplasmosis is a rare disease caused by inhalation of the fungus Histoplasma capsulatum. It can spread via cerebral circulation to the central nervous system as a manifestation of a disseminated infection; particularly in patients with immune suppression, which can result in isolated ring-enhancing lesions and inflammation in the brain. Of the reported disseminated histoplasmosis cases (approximately 1 in 2000 per year), only 5-20% have evidence of central nervous system involvement. This paper reviews a single case study of a 57-year-old female diagnosed with disseminated CNS histoplasmosis. Patient's complaints included reduced short-term memory, word-finding problems, and difficulty organizing, making decisions, getting lost while driving, recalling names, retaining information while reading, and slowed processing speed. There was also a history of mild depression and anxiety. Direct testing revealed deficits in multiple cognitive domains including complex attention, processing speed, semantic fluency, visual scanning, motor speed, set-shifting, naming, nonverbal memory, and verbal memory. Neuropsychological deficits suggest cortical and subcortical brain dysfunction, including anterior, temporal, and mesial-temporal regions. This case illustrates the need for neuropsychologists to understand histoplasmosis, the related pathophysiology, and the neuropsychological impact; particularly with the potential for delayed progression.