To be ill in any way is unpleasant. But to have an illness that others find funny, as Linda Walker from Newcastle has discovered, is intolerable. For 60 years, the retired university administrator had spoken quite naturally as a Geordie, when suddenly in March she suffered a stroke and found herself irrevocably reprogrammed to talk with a Jamaican accent.
Walker suffers from a rare neurological condition, known as foreign accent syndrome, in which the patient's ability to articulate words is impaired by damage to speech centres in the brain.
It may be of some comfort to Walker and the 49 other recorded sufferers of foreign accent syndrome to know that they are not alone. In rare cases, damage to the brain can cause a number of other conditions in which sufferers display symptoms that are as odd as they are unusual.
After Alan Davies and his wife Christine survived a car accident in 1995, Alan became convinced that the woman he loved had actually been killed and replaced with an identical, but inadequate, likeness. This is classic Capgras's syndrome. "You think the person you see is an impostor," says Dr David Enoch, emeritus consultant psychiatrist at the Royal Liverpool university hospital. "The patient will say the man who is visiting her looks like her husband, talks like her husband, has the eyes of her husband, the gestures of her husband, but is not her husband."
In some cases, damage to the front of the temporal lobe and the amygdala can disrupt a person's ability to tell what category of thing they are dealing with, often causing them to misidentify objects as food or sexual partners. Classic cases of Kluver-Bucy syndrome involve sufferers compulsively eating both food and household objects, and trying to have sex with inappropriate people, animals and things.
Alien hand syndrome
Peter Sellers made this condition famous (but funnier than it is for its sufferers) with his portrayal of Dr Strangelove. After brain surgery or a stroke, which may have separated the right and left halves of the brain, the patient continues to experience sensation in both of their hands, but finds that one of them is acting of its own accord. The hand can perform complex and often aggressive actions, including undoing buttons and tearing off clothes. Some sufferers have even reported that the hand has tried to strangle them in the night.