Former Alberta Premier Ralph Klein has been diagnosed with a progressive form of dementia, a close friend confirmed Friday.

Rod Love, Klein's former chief of staff, told CBC News the condition has slowed Klein's legendary wit and sharp tongue. Because of the illness, his language skills have been impaired.

"He was the great communicator," said Love. "He was one of the best communicators, I think, of our generation, certainly in politics. So to see him now struggle now occasionally to find the right word is obviously something we're not used to."

Klein, 68, was recently diagnosed with fronto-temporal dementia, which can interfere with the ability to sustain a thought, maintain a conversation, read or write. Early signs of a problem can include differences in behaviour and speech, according to the Toronto Dementia Network.

Stelmach 'very saddened' by news

In a statement released Friday, Alberta Premier Ed Stelmach said he was "very saddened" to learn about the diagnosis.

“I only served under one premier, and that was Ralph Klein. He gave me my first opportunity to serve in cabinet, and I cannot thank him enough for his wisdom and advice over the years. To hear now of his dementia diagnosis was a real shock to me.

Former Alberta Premier Ralph Klein, left, receives the Alberta Order of Excellence from Lt.-Gov. Donald Ethell in Edmonton in October 2010. John Ulan/Canadian Press“Ralph has meant a lot to Alberta and Albertans, particularly in his hometown of Calgary where he has long been a local icon. I know that all Albertans will have Ralph and his wife Colleen in their thoughts and prayers as the Kleins continue to face the challenges of Ralph’s condition.

CBC News has not been able to reach the Kleins for comment.

In an interview with the Calgary Herald published Friday, Colleen Klein said she suspected that something besides the lung disease emphysema was affecting her husband. It took two years to get the dementia diagnosis, she said, stressing that he wasn't given any preferential treatment by medical professionals.

“Also, I wouldn’t like to have people thinking he had this condition when he was premier," she said. "It probably started about a year after."

Difficult diagnosis for loved ones

Love still lunches with Klein and visits his home. Klein understands his condition and "is dealing with it," Love said.

"For those who have seen him recently, what you notice is that he has slowed down. In terms of speaking and concentration, he has slowed down," said Love.

"It's difficult for everybody. It's difficult for anyone who has got a friend or parent suffering from this condition."

Klein, a former Calgary mayor, led the Progressive Conservative Party to four consecutive majorities beginning in 1993. He resigned as premier in 2006.