Pichet TermsarasabYuvadee PitakpatapeeSteven J. FruchtPrachaya SrivanitchapoomNYU Langone Medical CenterFaculty of Medicine, Siriraj Hospital, Mahidol University2019-08-282019-08-282018-01-01Tremor and Other Hyperkinetic Movements. Vol.8, (2018)216082882-s2.0-85055908838https://repository.li.mahidol.ac.th/handle/20.500.14594/47138© 2018 Termsarasab et al. Background: Myoclonus and tremor are common movement disorder phenomenologies in steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT). Pure ataxia without encephalopathy has rarely been reported. Case report: We report 21- and 40-year-old females who presented with subacute pure ataxia without encephalopathy. After immunotherapies, both exhibited initial improvement of ataxia, and subsequently remained in plateau phase. Discussion: This treatable disorder should be added to the differential diagnoses of progressive cerebellar ataxia, and anti-thyroid peroxidase and antithyroglobulin should be considered as part of the workup. It is crucial not to misdiagnose SREAT presenting with pure cerebellar ataxia as degenerative or spinocerebellar ataxia.Mahidol UniversityMedicineArticleSCOPUS10.7916/D8CZ4QQQ