Thursday, 1 September 2011

CBS ( not the News you want)

Charles Bonnet syndrome (CBS) is a condition that causes patients with visual loss to have complex visual hallucinations, first described by Charles Bonnet in 1760. It is a common condition among people who have lost their sight. It causes people who have lost their vision to see things that aren’t really there, known as visual hallucinationsCBS can be distressing, but the hallucinations are usually not permanent. Many people experience hallucinations for a year to eighteen months before they become a lot less frequent.

The visual hallucinations caused by CBS can take many forms, ranging from simple shapes and dots of colours, simple patterns, straight lines or a network of branches, to detailed pictures of people, animals, insects, landscapes and buildings. When you have lost a large amount of your vision it may be difficult to see everyday things, but you may find that your CBS hallucinations are very detailed, and much clearer than your normal vision. The images can appear ‘out of the blue’, lasting for just a few minutes or in some cases, several hours. At times, the hallucinations will fit alongside the background you are looking at, giving them an understandable feeling of being real, like seeing cows in a field when the field is actually empty or seeing a fence across the pavement. At other times, they will seem totally unreal, like seeing fantasy images such as dragons.

My grandmother suffered from this in her early 90s and was quite concerned she was descending into madness. For her it took the form of fields of flowers or dogs and animals fighting and tearing each other limb from limb. Doctors explained it was part of Macular degeneration and offered little relief. Eventually after a fortnight, it righted itself and the brain re-adjusted. I read about it again in V S Ramanchandran's book, Phantoms of the Brain where it was suggested that the cartoonist/author James Thurber (one of my heroes) may have suffered from this as a result of his continuing vision problems and his injury during childhood... perhaps a catalyst for his wild imagination.
Burn brightly, Pete

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