A 50-year-old with rapid neuropsychiatric deterioration and choreiform movements

A 50-year-old man presented acutely to the hospital with behavioural disturbance, choreiform movements and profound nihilistic delusions. He reported recent drug and alcohol abuse, and also apparent involvement in several recent criminal activities, for which he felt he should be punished. He arrived alone at the hospital after a concerned neighbour had called an ambulance. His initial level of agitation prevented formal cognitive testing. However, he was alert, verbally responsive and could obey commands. He was afebrile with normal observations and normal plasma glucose. Although his examination was challenging, the only abnormal neurological findings were bilateral choreiform upper limb movements.