Gerry Anderson, 83, has been fighting the disease for the last eighteen months or so. He admitted that he feels like he has “lost” his freedom.
Speaking to BBC Berkshire, Mr Anderson said, "I don't think I realised at all. It was my wife Mary who began to notice that I would do something quite daft like putting the kettle in the sink and waiting for it to boil.
“Finally I was persuaded to go and see the doctor and eventually I was confronted with the traditional test - a piece of paper with drawings on it, taking a pencil and copying them."I thought 'Why are they doing this? A child could do this'.
"I started to get in a muddle. That's when I began to realise that there was something wrong."
The success of Thunderbirds shot Anderson’s brand of puppetry to international fame in the 60s and 70s, after being filmed on Slough Trading Estate in Berkshire and was first broadcast in 1965.
Anderson’s biggest successes following Thunderbirds included Stingray, Captain Scarlett And The Mysterons and Joe 90.
Mr Anderson and his son Jamie will be taking part in the Windsor Memory Walk in October in support of the Alzheimer's Society, with walks set to take place across the country.
The Society said in a statement that they were “grateful” for Mr Anderson’s contribution.