When PSP finally defeated Eugenie in 2007, it was the end of a desperate – yet far from unique – story. She was 60.

Eugenie was my mum's twin. Mum and extended family supported and cared for Eugenie as PSP took hold. The support and advice of the PSP Association was invaluable in making Eugenie's final years as comfortable as possible, as well as helping the family cope then recover.

PSP is a brain-degenerative disorder with no cure. It is rarer and does not have the profile of its more familiar cousin Alzheimer's, and, as a result does not receive as much support. There is limited research into the condition and diagnosis often takes months, causing damage to families and sufferers as symptoms can be destructive.

I am running the London Marathon… in Eugenie's memory; to support the PSP Association's aim to speed up diagnosis; as a massive hug to my amazing mum who still misses her twin every day – and who did everything in her power to make the end of Eugenie's life as wonderful as life should be.

Many thanks for any sized donation, it will all make a huge difference.

Ed