Former Alberta premier Ralph Klein is suffering from a form of dementia that is robbing him of the ability to speak, say reports.

Rod Love, a former Klein aide and longtime friend to the former premier, confirmed to The Canadian Press the 68-year-old former premier has been diagnosed with dementia.

"For the greatest political communicator of our generation, it's tough to see," said Love.

"I've spent 30 years of my life with him so it's a bit of a shock."

Klein's wife Colleen told the Calgary Herald in an interview that her husband was diagnosed last Friday with frontal temporal dementia, consistent with primary progressive aphasia. The diagnosis came after months of tests and visits with specialists.

The aphasia has left Klein unable to speak more than just a few short words and phrases. Colleen Klein says her husband now has trouble focusing on reading, spends much of his day napping, and has problems with his memory.

Just four months ago, the Kleins confirmed the former premier also suffers from the smoking-related lung disease, emphysema.

Love said the dementia is in the early stages.

"He's got good days. I had lunch with him six weeks ago. Some of the boys took him down to Palm Springs for a little break during the winter a couple of months ago, so he's got good days and he's got days that aren't so good."

Although frontal temporal dementia, or FTD, accounts for only two to five per cent of all dementia cases, it is the second-most common form of dementia, after the much more well-known Alzheimer's disease.

Unlike Alzheimer's, FTD affects middle-aged adults, typically between the ages of 45 and 65.

The disease also affects the brain quite differently than Alzheimer's. Alzheimer's affects the memory primarily, by destroying cells throughout the brain. FTD on the other hand, actually causes the front lobes of the brain, which control speech and behaviour, to shrink.

Dr. Morris Freedman, the head of neurology of Baycrest Centre for Geriatric Care in Toronto and the medical director of the Ross Memory Clinic at Baycrest says primary progressive aphasia can be difficult to diagnose. There is no blood test or brain scan that can pinpoint it and diagnosis is typically based on evaluating symptoms.

He says while there are different syndromes within the condition, all of them are progressive, meaning symptoms will worsen with time.

"This disease can go six, seven, eight years. Some people with this disorder progress very rapidly and some progress a lot slower. There is variability. So you can't predict what's going to happen a year ago in an individual case. But you can predict – if the diagnosis is correct -- that it's going to get worse," he told CTV.ca.

Unlike Alzheimer's disease, patients in the early stages of FTD often have no problems with daily functions and know where they are and what day it is.

In the later stages, those with FTD start to develop symptoms typically associated with Alzheimer's, like confusion, forgetfulness and repetitive behaviour.

Later, the disease leads to movement problems or swallowing difficulties. The patient may become wheelchair- or bed-bound, putting them at risk of infections or pneumonia. While the disease itself isn't fatal, its consequences can be, says Freedman.

There is no cure or treatment for FTD, although some medications can help manage some of the behavioural changes.

The cause of FTD is unknown, but there does seem to be a genetic component involved in at least some of the cases. In fact, there is a 40 per cent chance that Klein has a family relative with FTD.

Klein led the Progressive Conservative Party to four consecutive majorities beginning in 1993. He stepped down in late 2006.