My dad, Nigel, was diagnosed with Corticobasal Degeneration in 2018. We had never heard of this disease. It was a bewildering time, and continues to be a disorientating and deeply sad experience.

CBD is a rare brain disease caused by the loss of nerve cells in the brain. Together with a similar condition, PSP, it affects about 10,000 people in the UK. 50% of people living with CBD or PSP are incorrectly diagnosed at first.

The disease is dismantling my dad piece by piece, and he knows it is happening to him. I want to run this marathon now with his knowledge. When I told him last week that I am doing it, and asked him what he thought, he whispered, 'Bonkers'.

I am so grateful for your support of me in this challenge, my first marathon, and in fundraising for PSPA, the only UK charity dedicated to improving the lives of people living with PSP and CBD. We've used their services and they've been able to connect us with other people around the world living with this disease or supporting others who do.

I hope you never have a personal experience of CBD, but just knowing what it is could be of use to someone you know or love in the future.