TY - JOUR T1 - A 50-year-old with rapid neuropsychiatric deterioration and choreiform movements JF - Practical Neurology JO - Pract Neurol DO - 10.1136/practneurol-2016-001481 SP - practneurol-2016-001481 AU - Graham Andrew Mackay AU - Stewart Campbell AU - Ravi Jampana AU - Jonathan Cavanagh Y1 - 2017/01/23 UR - http://pn.bmj.com/content/early/2017/01/23/practneurol-2016-001481.abstract N2 - 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.Question 1What should you do now?Obtaining a collateral history is essential in establishing baseline function in people presenting with neuropsychiatric disturbance. This can help us focus on the differential diagnoses and plan for investigation. It can also avoid repeating previous investigations.The admitting team contacted his brother, his next of kin. The patient was an unemployed ex-builder. One year earlier, he had consulted a movement disorder doctor with a high-frequency tremor and brief involuntary movements. Investigations at this time included a normal MR scan of the brain and routine blood tests, including thyroid function tests and serum calcium. In the 2 months before admission, his family had noticed occasional repetitive conversation. However, he still lived independently and attended training courses. His agitation and disorientation had developed over the 24 hours before presentation. There was no family history of dementia or of involuntary movements.Question 2What is the differential diagnosis?Question 3What initial investigations would you plan?Causes of cognitive impairment and chorea (Box 1).Urine screening for illicit drugs was negative. The following were normal: blood film, renal function, serum calcium, thyroid function tests and serum C-reactive protein; serum antistreptolysin O titres were negative. Urinalysis was normal. MR scan … ER -