It’s Tuesday afternoon, and you’re stood at your COW (computer on wheels) trying to figure out why all your notes from this morning’s take have disappeared. You stare at the screen for several minutes before the computer dies and you take that as a sign you should have a break.

Just as you’re about to leave for a quick lunch after a tough day on call, Mohamed a 68 year old man is rushed in at 17:35, unable to speak. His worried wife tells you he’s been like this since about 13:45 and has not been able to lift his left arm or leg.

She reports that normally he’s quite healthy, and only takes something for cholesterol.

The paramedic who brought him in reports that an ECG taken on the way showed Atrial Fibrillation, but when you ask the nurse to redo it there’s nothing but Sinus Tachycardia.

What investigation would you do next?