Our Mum, Pat, is fortunate to have lived a very healthy life; and having worked as a primary school teacher for over 30 years she enjoyed the first few years of her retirement gardening, walking and travelling the world. She's an incredible woman: Clever, funny, an awesome cook and young at heart - but 12 years ago in her early 70's she started to behave differently.

The first thing I noticed was she gradually lost her empathy which for a doting, tactile mum of four seemed odd. Our puzzle loving Mum also seemed to lose her sense of logic with simple tasks proving really challenging. She started to dress out of character - not really dressing for the seasons or taking as much care of her appearance. After several years and 3 trips to a memory clinic she was diagnosed with a rare condition called Frontotemporal Dementia, which is characterised by a change in personality rather than memory loss. The memory loss came later.

By the time her memory had noticeably started to fade, she had daily carers visit her at home, but she would turn them away, as our independent Mum didn't understand there was an issue. Three years ago, when this was no longer feasible we feared for her safety; so moved her into a residential home specialising in dementia care.

Some days mum thinks she's a little girl and asks after her parents; other times she is a young Mother worrying about her small children. Sometimes she is still a school teacher and believes that the other care home residents are her class. "Id love to retire but I'm so busy and the children here need me..." she says, with such conviction, that even I'm convinced. Its important not to correct a Dementia patient as it causes more distress; so even my kids have become adept at going along with Nanny's stories and actually do so with greater ease than most adults.

We still see glimpses of Mum through her sense of humour and beautiful smile; but watching someone close to you gradually lose their cognitive abilities, independence and sense of identity can lead to a profound sense of grief. She can no longer engage in meaningful conversations, remember shared experiences, or recognise her own children.

Whilst Mum is well looked after...I wouldn't wish this on any family, and I am invested in any research that can help understand and seek to prevent this cruel disease. On July 5th I will therefore be walking 26 miles of the Cotswold Way to raise money for the Alzheimer's Society - and would be most grateful if you can support me by sponsoring me for this heartfelt cause.