Jade Rolph's mother, Zoe, was living with her husband Lloyd on the houseboat they had built – their dream retirement in mind – when she found herself unable to operate a canal lock.
More difficulties followed, with tasks Zoe, then aged 48, had previously managed with ease – driving, finding things – and the couple became concerned.
Eight years on, Zoe is in the advanced stages of Alzheimer's disease. She lives in a specialist nursing home, her needs too great for her family to manage themselves.
There are around 500,000 people in the UK living with Alzheimer's (two-thirds of all dementia cases). Zoe is one of the 5 per cent diagnosed under the age of 65. Jade, 29, believes that raising awareness of early-onset Alzheimer's could make the experience of other affected families easier.
"It is a particularly difficult diagnosis at a young age," she says. "My parents were still working and reliant on their incomes. They didn't have big pension pots. I was at university and enjoying building an adult relationship with my mum, but some who get the disease are still caring for young children."
It was about 18 months before her mother was diagnosed that Jade first began to worry. On visits home from university, she noticed changes. "I am an only child and we had always got on very well in the family. There was never any conflict. Suddenly, my parents were arguing."
When Jade sought advice from her mother – always a caring and wise confidante – she found her uncharacteristically unresponsive. "I felt she wasn't really listening. I would pour my heart out and get nothing in return. I didn't understand what was happening."
Dementia was initially deemed unlikely because Zoe was so young, but by the time her GP referred her for specialist cognitive tests and signed her off work, the family knew what he suspected. When Alzheimer's was confirmed, a few months later, Zoe had a better idea than most of what to expect.
Working as a carer for the elderly meant that "she knew the horror ahead", says Jade. Her realisation of just how frightened her mother was came when a wad of papers fell out of her handbag one day. It was covered in the clock faces she was asked to draw at the tests. "She was desperately practising in the hope she could mask the deterioration. On a few occasions, when we were alone, she asked me what was going to happen to her."
No one could answer this question precisely, as the experience of Alzheimer's varies, but the family knew that the condition is progressive and incurable. They were also aware that the rate at which the brain is affected is often swifter in those who develop the condition young.
"They had worked hard all their lives and were saving for their retirement on the boat. Dad realised that wasn't going to happen and decided to make the most of the time they had," says Jade. The couple left their jobs (Lloyd was working for the council) and set off to travel the country on their boat. "They had a couple of good years. Mum increasingly needed support, but she was still functioning. It was the lifestyle they loved, and they wanted to preserve it as long as they could. "
When the particulars of life on the boat – chopping wood, navigating locks, restricted space – became too much for Lloyd to manage alongside helping Zoe to wash and dress, the couple reluctantly sold up and moved into a rented home in Cambridgeshire. Jade, who had then finished her degree, moved home to help her parents three years ago.
"Mum's condition deteriorated very quickly. She was incontinent and waking every few hours through the night. Sometimes she believed Dad was trying to kill her and became hysterical and aggressive. It was terrifying." In 2011, after a number of emergency hospital admissions, Zoe was sectioned. Doctors realised that her situation at home was unsustainable and dangerous, and took her into psychiatric care.
It was, Jade recalls, a very difficult time. "We agreed to it because rationally we knew we weren't coping. It was the right decision, but it still felt as if we were giving up on Mum a bit. Everything seemed beyond our control."
After spending 18 months on an assessment ward, Zoe was moved into a nursing home. Lloyd is there almost every day and Jade visits twice a week. Zoe no longer speaks and appears largely unaware of her surroundings.
"The mum I knew has gone and I do look back and miss her. I feel cheated of our adult friendship, but I try to focus on the positive," says Jade. "She doesn't know who I am, but she recognises me as friendly and she often smiles when I arrive. That is the only response I get but it is special.
"I spend two hours telling her what is going on in my life. It is quite therapeutic. I can still talk to her, which means a lot to me, and I hope that, whether or not she can process what I am saying, the human voice is comforting for her."
Last year, Zoe stopped swallowing – often the final stage of Alzheimer's. Her family were told she would die within days. Lloyd and Jade planned the funeral, but then Zoe made an unexpected recovery. "We have confronted the future, which was probably helpful. We don't know how long she has left but we realise we need to make the most of the present."
They have found new ways to share experiences with Zoe. Listening to a CD together – "she will tap her foot along" – and offering foods that she enjoys. "Her food is puréed as she cannot really chew, but it is always clear what she enjoys. Chocolate mousse and Love Hearts sweets are favourites."
Lloyd is now Jade's main worry. "He is 57, working full time, facing retirement on his own with little money, and he is incredibly lonely. He has a very limited social life. Sometimes people tell him to move on, and it makes him angry. He takes his marriage vows very seriously. I see him in limbo."
Jade now works in corporate fundraising for the charity Alzheimer's Research UK, something that helps combat her feelings of helplessness in the face of her mother's illness.
She believes that raising understanding of Alzheimer's, and money for research, is vital. "Everyone has heard of Alzheimer's, but they usually know surprisingly little," says Jade. "When I told people about Mum, they often just thought it meant a bit of forgetfulness."
Dr Simon Ridley, head of research at the charity, believes this lack of awareness makes diagnosing and supporting younger sufferers particularly difficult. Symptoms may be missed, or mistaken for other problems such as stress or depression.
"While some symptoms can be similar to those of late-onset Alzheimer's, the disease can also reveal itself in more unusual ways. This can make it more difficult for individuals, families and doctors to recognise," he says. Alongside memory problems and confusion, symptoms might include changes in personality and behaviour, and problems with language and vision.
Alzheimer's Research UK is currently funding a research project at University College London, that aims to learn more about the causes and development of early-onset Alzheimer's.
Jade is confident that research will eventually lead to treatments to prevent Alzheimer's or freeze the process of brain-cell death. This optimism alleviates her own fears of developing the condition – though it is very rarely hereditary. "Alzheimer's colours my whole life. It is my only real fear."
She accepts that advances will come too late for her mother. "That is very hard, but seeing what has happened to her makes it feel even more important that we make this happen."
For further information and to read Jade's blog, go to www.alzheimersresearchuk.org or call 0300 111 5555