Question category: Neurology
A 24 year old female has been being treated for depression and anxiety. She now presents with worsening of her mood and memory difficulties. She has noticed pain in her legs and feeling her legs jerking. You notice she has an ataxic gait and some odd choreiform movements and occasional myoclonic jerks. She is referred for an MRI which shows high signal in the posterior thalamus. An EEG reveals no abnormalities. What is the likely diagnosis?