It is being described by charities as a once in a lifetime opportunity. 

The dementia summit called by Prime Minister David Cameron takes place on December 11 and for the first time,  the health ministers from the G8 countries will gather at Downing Street to discuss a global and united approach to tackling the disease.
And on Monday, Alzheimer’s societies from the G8 nations will each hand a letter to their respective health ministers begging them not to squander this opportunity.
 
The Alzheimer’s Society in the UK said it was a “unique opportunity for international leaders”.  

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It is calling for a collaborative global action plan on dementia research, a significant increase in funding for that research, and help in attracting, developing and retaining the best scientists, clinicians and care professionals.

It is certainly the first time a prime minister has used the presidency of the G8 to take action on a single disease. 

And it follows his Challenge on Dementia in England campaign which has pledged major improvements in dementia care and research by 2015.
 
There is, of course, no cure for dementia and the few treatments that do exist have limited value.
 
All of this at a time when dementia is on the increase.  By  2020, it is estimated one million people in the UK will be diagnosed with the disease.

And there is an even more startling fact -  so high now is the global cost of caring and treating those with dementia – that if it were a country – it would be the 18th largest economy in the world.
 
 For those affected by the disease, this summit represents a step forward not least in raising awareness. 

We spoke to Jill Batty and her husband Dominic, who was diagnosed with Alzheimer’s 10 years ago. 

Mrs Batty, of north London,  says there is a stigma attached to it.  She compares it to the way people thought of cancer 20 years ago. 
 
“Breast cancer wasn’t talked about so much,” she says.  “It was almost as if people feared catching it.  But now most people know someone who has had it, they are likely to survive and this is because so much effort and money has been put into research and treatment.
 
“We need that for dementia,” she said.
 
Mr Batty was once a dentist.  An intelligent, witty man.  His cognitive decline has been relatively slow but it has still been hard for the family. 

“Some people call it dead but living.  The man you fell in love with is not there anymore,” Mrs Batty said.
 
Just occasionally, during a time with the couple, you did get a glimpse of the man he once was.  With the words in front of him, he sang Winter Wonderland for Us. 

Later, at a respite centre in Kentish Town, run by the Alzheimer’s Society with the help of volunteeers, he played the piano.
 
It was not faultless but it was somehow beautiful because of the mistakes. 

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We were able to have a conversation of sorts, a chat about the weather and how much he preferred cooler to warmer temperatures.  He told me how humid it had been in Malaya where he was posted for his National Service.
 
Later, though, he would not remember that conversation.  And that is the way it always is now.  He could recite a Shakespearian sonnet, but he could not remember what he had had for breakfast.
 
He can no longer watch films or read a book but now and then he will dip into Pride and Prejudice and read a few paragraphs.
 
It is not, Mrs Batty says, how they had planned their retirement.  “You never think it is going to happen to you,” she said.  

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