A 62-year-old woman presented with acute onset ataxia with multiple falls, dysarthria, diplopia, and blurred vision that started 3 days prior to presentation. She had left face angioedema couple days after her flu inoculation 6 weeks prior to presentation. Her exam revealed normal mental status, scanning speech, bilateral dysmetria and ataxia as well as left-sided facial palsy, square wave jerks and hyperreflexia. CSF showed 30 RBC, 17 WBC, normal glucose, and elevated protein of 68 mg/dl. No infectious etiologies were identified. MRI brain showed infratentorial leptomeningeal enhancement with T2 hyperintensities in the both cerebellar hemispheres. Anti-GQ1b antibodies were 51 IV (negative < 30 IV) and anti-GAD65 antibodies were also weakly positive only in serum, 0.12 nmol/L (negative < 0.02 nmol/L). 

We demonstrated prominent cerebellar imaging findings and good recovery in a patient with anti-GQ1b and mild anti-GAD65 seropositive autoimmune encephalitis. Our case is the first reported double positive autoimmune encephalitis with features of BBE and direct cerebellar involvement