United Kingdom, May 26 -- Billy Joel's family are "hopeful for his recovery".

The 76-year-old star recently cancelled all forthcoming tour dates after being diagnosed with Normal Pressure Hydrocephalus (NPH), a rare brain condition caused by a build-up of fluid in the brain, but Billy's family are trying to remain optimistic amid his recovery.

Alongside a family photo, Alexis - his wife - said on Instagram: "Thank you for the outpouring of love and support. We are so grateful for the wonderful care and swift diagnosis we received. Bill is beloved by so many, and to us, he is a father and husband who is at the center of our world. We are hopeful for his recovery. We look forward to seeing you all in the future (sic)"

Christie Brinkley, ...