This is the first evidence of cortical calcification in patients with an APP mutation other than the Iowa mutation. We discuss the radiological, cerebrospinal fluid, and clinical phenotype of patients carrying these mutations in the literature.

An 84-year-old woman who received 2-month oral metronidazole therapy (500 mg 3 times daily) for Clostridium difficile-associated diarrhea was hospitalized for falls. Clinical examination revealed moderate dysarthria and cerebellar ataxia. MRI performed at admission showed bilateral fluidattenuated inversion recovery (FLAIR) symmetric hyperintense lesions in cerebellar dentate nuclei, superior colliculi, and periaqueductal gray matter (figure). Biological investigations showed no vitamin B 1 , B 9 , or B 12 deficiency. Dysarthria and gait disturbance resolved within days after interruption of the metronidazole treatment. Metronidazoleinduced encephalopathy must be considered whenever a patient on metronidazole experiences a subacute cerebellar syndrome.