When Mum was young, she was a great runner; she could even beat the boys (which upset them a bit, apparently). I've never been keen on running – not until last year, that is, when I was persuaded to go for a hilly trail run as a way of enjoying some beautiful but more remote parts of the countryside. I gave it a go, loved it, and very quickly it has become part of who I am.

My mum, the real runner, is now in her eighties and suffers from Alzheimer's disease, one of the main forms of dementia.

Imagine a living death, one where your body stays alive but your brain dies, and slowly everything you’ve ever remembered disappears from your mind. The faces, the memories, the history, the laughter and the tears all fade away until all you have left is a basic desire to eat, sleep or defecate. Then, as even these basic needs disappear, you are left in a world of nothing, where you no longer understand anything you see or hear.

This is dementia.

Imagine a living death, one where your treasured parent or loved one slowly disappears in front of your eyes. Where once you could converse and laugh together about the lifetime of memories you share, or marvel at your grandchildren growing up, now you sit in a silent room without any conversation. Dementia offers no hope of comfort for those affected by it; it is an enforced form of bereavement for a living soul.

This is my family's story, and I’d like to raise money for research into this tragic condition in the hope that whatever little money I raise might in some way help to prevent future generations from suffering the pain it causes.

Unlike Mum, I was never a runner in my youth, but now that I’m in my fifties I’m learning to be one. I’ve decided to run the Stirling Marathon in May. I’m hoping that Mum will be there to cheer me on at the end of the 26.2 miles, and I’d like to think that she’ll be proud of me when I cross the line.