Acute cerebellopathy as a probable toxic effect of flucytosine

An 87-year old woman with no relevant personal or family history was admitted to the hospital for headache, fever, and confusion over the past week. The vital signs, general and neurological examination were normal. In laboratory tests, the urine, urea nitrogen, glucose, bilirubin, electrolytes, aspartate aminotransferase, creatine kinase, alkaline phosphatase, haematocrit, white-cell count, and platelet were also normal. A lumbar puncture was performed which showed: 60 typical lymphocytes per ml, adenosine deaminase (ADA) activity 6 U ⋅ l⁻¹ (normal under 4 U ⋅ l⁻¹), proteins 75.7 mg ⋅ dl⁻¹, and glucose 13 mg ⋅ dl⁻¹ with a glycaemia of 120 mg ⋅ dl⁻¹. The microbiology study showed staining and a positive culture for Cryptococcus neoformans, and an antigen titre of 1/2080. The serology for HIV infection was negative, and other predisposing factors for this fungal infection, such as immunological defects, a lymphoreticular malignancy and sarcoidosis were excluded. A CT scan of the cranial-thoracic-abdominal regions was normal and tumour markers were absent.