Aug 19 (Reuters) - Manchester United and Scotland great Denis Law has been diagnosed with Alzheimer"s and vascular dementia, the 81-year-old said in a statement on Thursday. Striker Law, who won the Ballon d"Or in 1964 and is third on United"s all-time list of corers with 237 goals in 404 matches behind Bobby Charlton and Wayne Rooney, said that the road ahead would be "hard, demanding, painful and ever changing. "I"m at the point where I feel I want to be open about my condition. I"ve been diagnosed with "mixed dementia", which is more than one type of dementia, in my case... Alzheimer"s and vascular dementia," Law said on United"s website. "This has been an extremely difficult year for everyone and the long periods of isolation have certainly not helped." Law described the disease as "incredibly challenging" and that he had witnessed many friends go through it. "You hope that it won"t happen to you, even make jokes about it whilst ignoring the early signs because you don"t want it to be true," Law added. "You get angry, frustrated, confused and then worried, worried for your family, as they will be the ones dealing with it. However, the time has come to tackle this head on, excuse the pun. "I recognise how my brain is deteriorating and how my memory evades me when I don"t want it to and how this causes me distress in situations that are beyond my control." Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Ken Ferris Our Standards: The Thomson Reuters Trust Principles.