RESUMO
Acute cerebellitis is a well recognized complication of varicella zoster virus (VZV) infection in children. It has been described in adults in the setting of virus reactivation with a preceding herpes zoster rash, but it is exceedingly rare in adults who are not elderly or immunocompromised, particularly in the absence of a rash. To our knowledge, there has been only one reported case of acute cerebellitis in an immunocompetent adult less than age 65 with virological confirmation of acute VZV infection. We describe a 59-year-old immunocompetent man who presented with acute truncal ataxia without rash and was diagnosed with VZV cerebellitis, supported by anti-VZV IgM and anti-VZV IgG antibodies in the serum and a positive VZV polymerase chain reaction in cerebrospinal fluid. He had robust improvement with intravenous acyclovir treatment and was free of neurologic disability at two month follow-up. This case highlights the importance of virological evaluation in patients with acute ataxia, even in the absence of typical features of infection.