TPO and nervous system disorder: <h4>Background</h4>Pure acute onset chorea without encephalopathy has rarely been reported in anti-thyroid peroxidase (anti-TPO)/anti-thyroglobulin (anti-TG) antibody-related neurologic disorders responsive to steroids (ATANDS).<h4>Case report</h4>We report a 16-year-old female who presented with acute chorea without encephalopathy.