Transient prosopagnosia resulting from a cerebral gas embolism while diving

A 33-year-old male was diving in excess of 50 metres of water in a marine tunnel at a remote location off the west coast of Scotland when he ran out of air. He made an emergency ascent and was recovered unconscious on the surface; he was not breathing, had no pulse and had missed a significant amount of decompression. Following resuscitation he was transferred by helicopter to the Dunstaffnage Hyperbaric Unit where he received hyperbaric oxygen therapy for a cerebral arterial gas embolism. He made a quick recovery but during the treatments he demonstrated a number of neurological abnormalities including visual disturbances which were diagnosed as prosopagnosia, the inability to recognise faces. The effects were transient and the patient went on to make a full recovery. Prosopagnosia is a rare affliction and this is thought to be the first reported that appears to have occurred as a direct result of a diving accident. The case is described in detail and prosopagnosia is reviewed.