Adult-onset cerebellitis differs significantly from its pediatric form. In adults, post-infectious causes are less common, with paraneoplastic and infectious origins being more prevalent. Additionally, cerebellitis can sometimes be the first sign of an undiagnosed malignancy. Unlike the acute onset often seen in children, adults may experience a more gradual progression of symptoms. The prognosis is generally poorer in adults, highlighting the critical need for prompt diagnosis and treatment to improve patient outcomes.