Pratchett suffers Alzheimer's blow

The writer behind the Discworld fantasy books released a statement online reassuring readers that "there's time for at least a few more books yet".

Pratchett, 59, who has sold more than 55 million books around the world, called the diagnosis "an embuggerance".

He said the Alzheimer's lay behind this year's "phantom stroke".

Pratchett was told by doctors in the summer that he had suffered a mini stroke in the past few years, although he had been unaware of it.

The writer had medical tests after having problems with his dexterity and hand-eye coordination.

Pratchett said in a statement: "We are taking it fairly philosophically down here and possibly with a mild optimism.

"For now work is continuing on the completion of Nation (Pratchett's next book) and the basic notes are already being laid down for Unseen Academicals.

"All other things being equal, I expect to meet most current and, as far as possible, future commitments but will discuss things with the various organisers."

Pratchett is most famous for his Discworld series of humorous and satirical fantasy novels. Making Money, the 36th in the series, which began life as a parody of the fantasy genre, was published earlier this year.