A 19-year-old woman comes to clinic and describes that she is worried by experiences where the usual sounds in the room begin to fluctuate in intensity, almost like they are coming from a radio with the sound being altered. There is no radio present. This lasts for about 10 minutes and then she gets a severe throbbing headache. More commonly, on other occasions she has had the strange experience that her body is changing shape and becoming smaller and that she is farther away from the walls, even though she knows that the room has not actually changed shape. Sometimes this comes with a sensation that time is rushing past. Again she subsequently has a powerful headache that throbs and is usually unilateral. She reports no recent stressful life events and has worked at a supermarket checkout for 15 months. She has a healthy group of friends.