Are there any differences between adult-onset cerebellitis and childhood cerebellitis?

Acute cerebellitis (AC), a rare inflammatory disorder of the cerebellum, is primarily associated with infectious, post-infectious, and autoimmune mechanisms. It predominantly affects children and typically follows a benign and self-limited course. This study, the largest case series to date focusing exclusively on adult-onset AC, reveals distinct clinical, laboratory, and imaging characteristics compared to the pediatric AC literature. We included 16 patients (mean age of 39.5 years) who met the clinico-radiological features of AC. The causes of AC in this study were varied, encompassing paraneoplastic, post-infectious, infectious, anti-GAD-related, and hemophagocytic lymphohistiocytosis etiologies. The most common symptoms were altered consciousness, dysarthria, ataxia, vomiting, fever, headache and seizures. All cases showed bilateral cerebellar involvement on MRI, predominantly affecting the cerebellar cortex. Hemorrhage within cerebellar lesions was observed in three patients. Outcomes were often severe, with 56% of patients experiencing severe sequelae and 31% mortality. This study highlights the distinct characteristics and potential for severe outcomes in adult AC, emphasizing the need for a comprehensive diagnostic approach.