An Elderly Case of Acute Cerebellitis after Alleged Vaccination

Acute cerebellitis (AC) is a benign and self-limiting inflammatory disease. It typically occurs as a primary infectious or postinfectious disorder. Although AC mostly presents in early childhood, it can appear in adult. A 66-year-old man admitted to our hospital because of limb and gait ataxia. Three weeks ago, he took an influenza vaccination. There was no abnormality on brain MRI with contrast enhancement, but Technetium-99m hexamethyl propylene amine oxime-single photon emission computed tomography (HMPAO-SPECT) showed markedly cerebellar asymmetry, suggesting hypoperfusion in the right cerebellum. Influenza vaccination can cause AC in the elderly and brain HMPAO-SPECT imaging is more useful than MRI in identifying patients with AC.