Immunotherapy Responsive Recurrent Post-Infectious Ataxia Associated With Recurrent Gene Variant.

Objectives: We detail a case of recurrent, postinfectious, cerebellar ataxia associated with a likely pathogenic previously documented gene variant in .

Methods: The patient was identified after her second hospitalization for postinfectious cerebellar ataxia. Genetic testing was performed after discharge.

Results: An 11-year-old girl with 1 prior episode of self-resolving parainfectious acute cerebellar ataxia at age 4 years presented with acute-onset ataxia, dysarthria, and gait instability in the setting of influenza A infection. The patient had CSF pleocytosis but negative influenza PCR and antibody detection in the CSF. Because of clinical deterioration, she received empiric IV methylprednisolone without improvement. She was subsequently administered IVIg and improved dramatically over the subsequent 7 days. The patient was found to have a rare de novo gene (c.3028G>A, p.(Glu1010Lys)) variant previously reported in the literature. The variant was analyzed to have a Combined Annotation Dependent Depletion score of 33 and Polyphen-2 score of 1.0 and was determined to be likely pathogenic according to American College of Medical Genetics PP3 and PM2 criterion.

Discussion: Recurrent episodes of cerebellar ataxia are an especially rare occurrence, and genetic testing may be warranted in these individuals. It is possible that immunotherapy with IVIg may augment clinical outcomes in those with pathogenic gene variants.