An 84-year-old man in Ireland stunned doctors when scans revealed that he seemed to be missing a large chunk of his brain. Instead of brain tissue, the doctors found a 9 cm (~3.5 inch) pressurized pocket of air where much of his right frontal lobe ought to be. The doctors reported the discovery recently in BMJ Case Reports.
The missing white matter was particularly surprising because the man arrived in the emergency department with afflictions otherwise common for his age. He had been complaining to his regular doctor about repeated falls and feeling unsteady in recent months. When the man added left-sided arm and leg weakness to the list of complaints, his doctor advised him to go to the emergency room, fearing a possible stroke.
Source: Ars Technica – Doctors shocked by 3.5-inch air bubble where part of man’s brain should be