Retired US Supreme Court Justice Sandra Day O'Connor revealed this week that she has been diagnosed with the "beginning stages of dementia, probably Alzheimer's disease."

Day O’Connor, 88, was the first woman appointed to the Supreme Court, in 1981, by then President Ronald Reagan, who also developed Alzheimer’s.

Revered as a trailblazer, Day O'Connor inspired generations of female lawyers. On the court she was regarded as a moderate conservative and often held the swing vote on controversial social issues.

Chief Justice John Roberts praised Day O'Connor as a "towering figure and a role model not only for girls and women, but for all those committed to equal justice under law."

Roberts said that while he was sad to hear of O'Connor's diagnosis, he "was not at all surprised that she used the occasion of sharing that fact to think of our country first."

Advocate

Day O’Connor retired from the bench in 2006, in part to care for her husband who also developed Alzheimer's and she became an advocate for those suffering from the disease.

She also worked in retirement to encourage young people to engage with civics and to “make civic learning and civic engagement a reality for all".

"I will continue living in Phoenix, Arizona surrounded by dear friends and family," Day O’Connor wrote in her statement yesterday.

'Final chapter'

"While the final chapter of my life with dementia may be trying, nothing has diminished my gratitude and deep appreciation for the countless blessings of my life."

O'Connor concluded the statement with her signature and a sign-off of "God bless you all."