With the number of people being diagnosed with Alzheimer's disease and dementia, most of us have a general understanding of the effects the illness can have on loved ones. But there's a lesser known form of dementia that can be equally as devastating. And it's striking people at a much younger age.

Brian Hayden plays a round of solitaire on the computer, but the hand he's been dealt in life is anything but fun and games. The 62-year-old has fronto-temporal dementia -- a condition that attacks the front part of the brain responsible for personality, speech, and some aspects of memory.

Terry Hayden, Brian's wife, explains that Brian doesn't reason the way most people do. "Brian has a very small vocabulary. He has lost his cognitive thinking. He can't think through problems or anything like that."

People with fronto-temporal dementia, or FTD, also experience behavioral changes. They often become socially withdrawn, compulsive or repetitive in their actions. And, sometimes, they engage in behaviour that some may feel is inappropriate.

FTD is classified under the general umbrella of Alzheimer's disease -- But unlike those who suffer from Alzheimer's, people with FTD are diagnosed much younger. Most patients are only in their 50's or 60's when they receive their diagnosis.

Dr. Andrew Kirk is a neurologist who treats people with FTD. "I've certainly seen people in their 50's where it wasn't really recognized that they have an illness. They've lost their jobs they no longer have insurance, or they had to retire early."

At this point, the cause of fronto-temporal dementia remains unknown -- and there is no cure. Something Dr. Kirk says is frustrating.

"We have to tell people we don't have a cure for this. We don't really have things that will help slow it down and all we can do is try to help with the symptoms. It's quite a difficult illness," says Dr. Kirk.

The illness is difficult for doctors--- and difficult for patients and their families.

"It's hard watching what's happening," says Terry Hayden. "I know it's harder on me than him because he doesn't know."

Hayden says dealing with her husband's illness has been a lonely experience. There isn't a lot of support for patients and their caregivers. But like many in her situation, what keeps her going is the love she feels for the man she's been married to for 40 years.

"Oh I love him. He's a sweet person and I wouldn't ever think it different," says Hayden.

There are signs of FTD that could signal an onset of the disease. One of the first signs is a significant change in a person's ability to think or their ability to function.

Sometimes the difficulty for families is that people with fronto-temporal dementia don't recognize anything is wrong. They think everything is normal. So a good place to start for a loved one is to address the issue with their family doctor and go from there.