Abnormal diffusion-weighted imaging findings in an adult patient with acute cerebellitis presenting with a normal magnetic resonance imaging.

Acute cerebellitis is an unusual central nervous system complication of infectious disease often due to viral etiology. Diagnosis is aided by neuroimaging studies, actually by magnetic resonance imaging in the first place, which shows increased signal intensity on T2-weighted images. However, conventional magnetic resonance imaging may be unrevealing in some of the cases, and additional workup such as single photon emission computed tomography and diffusion-weighted imaging may be required. We present a case of acute cerebellitis in a 35-year-old woman diagnosed by diffusion-weighted imaging.