Central nervous system (CNS) infections with the dematiaceous fungus Cladophialophora bantiana (C. bantiana) are extremely rare, with approximately 120 confirmed cases reported as of 2016. C. bantiana is a highly neurotropic and thermotolerant fungus found in soil worldwide. The mode of entry into the CNS remains unknown, but inhalation of fungal spores or subcutaneous trauma have been suggested. Entry of fungal spores can cause cerebral phaeohyphomycosis with the main clinical manifestation of a brain abscess. Symptoms are non-specific and can include headache, fever, hemiparesis, aphasia, visual disturbances, and confusion. C. bantiana cerebral phaeohyphomycosis occurs in both immunocompetent and immunocompromised individuals, with a slightly higher prevalence in immunocompetent males for unknown reasons. Diagnosis is often delayed due to its nonspecific presentation and prevalence in individuals without pre-existing immunological disease. Prognosis is poor, with mortality rates of approximately 70% despite aggressive treatment. Treatment is not standardized but may include several anti-fungal agents and surgical intervention. Case reports documenting the variability seen with cerebral phaeohyphomycosis by C. bantiana can provide valuable insight into this emerging disease. C. bantiana’s neurotropic propensity also warrants cognitive investigation of the disease; however, there are currently limited descriptions of cognitive findings in published case reports of C. bantiana CNS infections.

Here, we describe a case of a 35-year-old immunocompetent, college educated male with a CNS C. bantiana infection, presumably following a fall while biking in Costa Rica. First symptoms included left sided facial palsy, headache, and hand weakness, prompting extensive diagnostic workup, with diagnosis of C. bantiana infection confirmed 8 months after symptom onset. Initial treatment included anti-fungal agents and steroids, but his course of infection was complicated by infectious vasculitis with posterior circulation infarcts and obstructive hydrocephalus requiring ventriculoperitoneal shunt placement two years following the fungal infection diagnosis. The most recent brain MRI revealed encephalomalacia in global periventricular areas, two small masses, likely representing small fungal phlegmons, and enhancing lesions in the upper cervical spinal canal.

The patient reported cognitive changes following the infarcts and shunt placement including difficulties with spatial navigation, following directions, and articulating thoughts. Memory concerns and lapses in judgment were also reported. Results from a neuropsychological evaluation revealed high average baseline intellectual abilities with decrements in visuospatial processing, processing speed, executive functioning, and aspects of memory stemming from his executive dysfunction. At the time, his cognitive profile suggested parietal and frontosubcortical systems disruption meeting criteria for mild cognitive impairment. Two years later, the patient reported continuing cognitive difficulties prompting a follow-up neuropsychological evaluation. Results were similar to his first evaluation, revealing deficits in aspects of visuospatial processing, decreased verbal and visual learning, bradyphrenia and processing speed deficits, and difficulties with visual planning and organization. Minimal anxiety and depression, but increased apathy and executive dysfunction were endorsed on self-report measures.

This case report highlights neurological sequela resulting from CNS infection with C. bantiana, -with a course complicated by subsequent strokes, hydrocephalus, and cognitive impairment-, and contributes additional insight into the relatively limited existing reports of an extremely rare but emerging disease.