LONDON: The daughter of British former prime minister Margaret Thatcher tells how her mother's dementia has left her struggling to remember the simplest facts in book extracts published yesterday.

Ms Carol Thatcher wrote that, on her worst days, her mother struggles to finish sentences but shows occasional glimpses of her old self, particularly when talking about her time in Downing Street.

THAT DAY OF DISBELIEF 'I almost fell off my chair. Watching her struggle with her words and her memory, I couldn't believe it. She was in her 75th year but I had always thought of her as ageless, timeless and 100 per cent cast-iron damage-proof. The contrast was all the more striking because, until that point, she'd always had a memory like a website.' - The day Ms Thatcher realised her mother's memory was failing

OMINOUS SIGNS EMERGE 'From the fateful day of our lunch, tell-tale signs that something wasn't quite right began to emerge. Whereas previously you would never have had to say anything to her twice, because she'd already filed it away in her formidable memory bank, Mum started asking the same questions over and over again, unaware she was doing so.' - The author describes how tell-tale signs of her mother's illness emerged

BARRED FROM 'OTHER WORLD' 'I had to learn to be patient, a quality I admit is in short supply. I also had to learn she had an illness and that it wasn't personal. That's the worst thing about dementia: It gets you every time. Sufferers look and act the same but beneath the familiar exterior, something quite different is going on. They're in another world and you cannot enter.' - The author on how she learnt to deal with her mother's illness

'I had always thought of her as ageless, timeless and 100 per cent cast-iron damage-proof,' Ms Thatcher wrote in her memoir, A Swim-On Part In The Goldfish Bowl, which was serialised in the Mail on Sunday newspaper.

Mrs Thatcher, nicknamed the Iron Lady, was Britain's first and so far only female premier and was in office as head of a Conservative government between 1979 and 1990.

The book is believed to be the first time a family member has spoken publicly of her condition.

Ms Thatcher says she first noticed her mother's memory was failing over lunch in 2000 - a decade after she had left power.

Mrs Thatcher, then 75, got confused between Bosnia and the Falklands during a conversation about the war in the former Yugoslavia, she wrote.

She wrote she 'almost fell off her chair' seeing her mother struggle with her words and her memory. 'I couldn't believe it,' she wrote.

Ms Thatcher goes on to describe how tell-tale signs of dementia then began to emerge.

'Whereas previously you would never have had to say anything to her twice, because she'd already filed it away in her formidable memory bank, Mum started asking the same questions over and over again, unaware she was doing so.

'It might be something innocuous - such as 'What time is my car coming?' or 'When am I going to the hairdresser?' - but the fact she needed to repeat them opened a new and frightening chapter in our lives.'

Now aged 83, Mrs Thatcher gave up speaking in public in 2002 on the advice of her doctors after a series of small strokes.

Ms Thatcher described how she had to learn to be patient and that her mother 'had an illness and that it wasn't personal'.

'That's the worst thing about dementia: It gets you every time,' she wrote.

'Sufferers look and act the same but beneath the familiar exterior, something quite different is going on. They're in another world and you cannot enter.

'Much of my mother's daily life was affected. Timing became a particular concern. If I said, 'Oh, do relax, Mum. The car won't be here for 10 minutes,' she'd jump up, hook her handbag over her arm and say, 'Ten minutes? I'll go down now' as if I'd said 30 seconds.'

Ms Thatcher also wrote of how her mother keeps forgetting that she lost her husband Denis to pancreatic cancer in 2003.

'I had to keep giving her the bad news over and over again,' she wrote.

'Every time it finally sank in that she had lost her husband of more than 50 years, she'd look at me sadly and say 'Oh' as I struggled to compose myself.

' 'Were we all there?' she'd ask softly.'

Ms Thatcher also recalled how when a friend asked her mother about Soviet leader Mikhail Gorbachev, 'she snapped back into Iron Lady mode and was utterly engaging'.

Mrs Thatcher briefly returned to the limelight in September last year when she visited Downing Street as a guest of Prime Minister Gordon Brown.

He praised her as a 'conviction politician'.

AGENCE FRANCE-PRESSE

This article was first published in The Straits Times on Aug 25, 2008.