It’s common sight at a football match to see a player suffer a severe blow to the head and wander for several minute in daze. Spectators remark that the player ‘has no idea where he is’, and that may indeed be so. He has suffered concussion. According to the blows severity, it may be mild, with not much more than a view of flashing stars and lights before the eyes, or it may be long lasting.
Severe concussion may cause unconsciousness accompanied by memory loss, or amnesia. The footballer may not recall the injury itself or details of the game. Usually, a bout of amnesia doesn’t last long. In any case, somebody suffering a severe head blow should see a doctor to remove doubts about possible fracture. If amnesia persists for a week or more, specialist help is essential. It could be a sign of serious brain damage.
The brain has an impressive array of defences. It is the body’s best-protected organ. First, it is guarded by the skull, the bony skeleton of the head. The skull is extremely strong. That is why most broken skulls are what is known as closed, or simple, fractures, in which the broken pieces stay in place. Depressed fractures, in which the pieces are displaced, are more serious, because fragments may pierce the brain’s outer covering. Fortunately, the are more rare.
Inside the skull, the entire brain and the spinal cord are guarded, like delicate instruments in transit, in several layers of packaging. Outside comes the tough and leathery dura mater. Beneath that are two other strong membranes, the arachnoid and pia mater, which are cushioned in fluid.
Despite these safeguards, if the brain receives a severe blow, its regions concerned with memory may be temporarily or permanently damaged. Until normal service resumes, a victim may be unable to store new information.
Amnesia is caused not only by blows but by Alzheimer’s disease, encephalitis, strokes and brain tumours. Heavy and persistent drinking also affects the memory, as does the process of growing older.