Acute Cerebellit: Is it always benign?

Introduction: Acute cerebellitis is characterized by an acute or subacute onset of cerebellar ataxia following an infection or vaccination. Here, we present two cases with the different clinical course of acute cerebellitis due to influenza A virus. Case1: An 11-year-old female patient was admitted to the emergency department with the complaints of ataxia and seizures triggered by fever. Truncal ataxia, dysmetria, and dysdiadokinesia were detected in her neurological examination. Cranial MRI imaging was normal. Lumbar puncture could not be performed because of her family approval. Nasopharyngeal swap test was positive for influenza A H1N1. Oseltamivir was completed for 5 days in the treatment. Cerebellar findings were totaly improved on the 7th day of discharge. Case 2: A previously healthy 3.5-year-old female patient was admitted to the emergency department with the complaint of seizures. In her neurological examination, truncal ataxia, titubation were present, and deep tendon reflexes were increased. The cranial MRI revealed hyperintensities in the T2W series and diffusion restriction compatible with acute cerebellitis. Nasopharyngeal swap test was positive for influenza A H1N1. Despite intensive treatment (oseltamivir, cefotaxime, acyclovir, IVIG, steroid and plasmapheresis), the clinical course was fulminant. Additionally, mutism, opslonus and myoclonus were added to clinical picture. At one month later after discharge, there was a minimal improvement in her trunk ataxia, head titubation, opsoclonus and myoclonus. Conclusion: Acute cerebellitis may present as a self-limiting spectrum or, less frequently, may show a fulminant course result in permanent brain damage and sudden death.
Keywords: acute cerebellitis,cerebellar ataxia ,influenza A H1N1,opslonus and myoclonus