Cerebellopathy secondary to anti-peroxidase antibody-mediated toxicity. A special case of Hashimoto encephalopathy

Abstract Objective The aim of this case report is to highlight the importance of recognizing uncommon causes of cerebellar involvement. Case presentation A 45-year-old woman with no medical history who presented gait instability that appears suddenly and evolves rapidly in two weeks, causing frequent falls. Neurological examination revealed an inability to walk due to severe ataxia, accompanied by global hypotonia, appendicular dysmetria, opsoclonus and dysarthria. We studied this patient with cerebellar syndrome, obtaining as relevant findings global cerebellar atrophy in MRI (magnetic resonance imaging) and especially, considerably elevated levels of antibodies against thyroid peroxidase (TPO). The patient was treated with high doses of intravenous methylprednisolone for 5 days. Six months after diagnosis and in treatment with low doses of prednisone, the patient is asymptomatic. Conclusion We must considerer the cerebellar involvement secondary to steroid responsive encephalopathy associated with autoimmune thyroiditis (SREAT) in a patient in whom other more frequent causes of isolated cerebellar disease have been ruled out.