Case 1—A request arrives for an urgent neurosurgical consultation. The urgency is reinforced by several telephone calls. A 12 year old boy with headaches has had a head scan—nowadays more likely magnetic resonance imaging (MRI) than computed tomography—that shows an arachnoid cyst. The parents have been told that the clinical diagnosis of migraine (the scan was performed “just to be on the safe side”) has been changed to something more sinister. The parents are terrified, their fears not at all eased by being referred to a brain surgeon. After all, everyone knows that when doctors talk about a “cyst” they really mean cancer.

The internet is the most potent anxiety provoking system ever devised

Case 2—A 15 year old girl complains of back pain. A neurological examination and various blood and radiological examinations are negative—except for the MRI scan (“I'm sure there'll be nothing, but let's be certain”). The scan shows a mild focal dilatation …