There was a time, and it wasn't that long ago, when the word dementia was nearly synonymous with Alzheimer's disease.

Dementia is now a far more complicated realm.  There are 48 kinds, including variations of Alzheimer's, Lewy body, and frontotemporal dementias, Tam Cummings, a gerontologist from Texas, told 400 family and professional caregivers last week. They all have fatal, untreatable brain destruction in common, but their symptoms and courses are different.

Cummings urged family members to ask their doctors more questions — as many questions as they might ask if the diagnosis were cancer.  Knowing more, she said, may help them understand and cope with the memory lapses, confusion, delusions, falls, depression, and stubbornness that often accompany dementia.

She was among the speakers at the Alzheimer's Association's annual Southeastern Pennsylvania dementia conference at the Valley Forge Casino Resort. They talked about how dementia progresses, how to deal with problem behavior, and how caregivers can take care of themselves while caring for a loved one or client who needs constant help over many years.

A recurring theme: People with dementia have brain damage that limits what they can do and how they can think.  It's those around them who have to change.

There's no point in begging Mom to just try a little harder to remember that name. Attempting to have a rational discussion about whether you really did steal her purse is a waste of time.  If people with dementia are being obstinate or aggressive, it's up to caregivers to try to figure out whether there is an explanation that their loved one can no longer communicate: Are they in pain? Are they afraid? Were the instructions too complicated? Have perceptual changes made the environment look dangerous to them?

As Jeanne Bryant, a Philadelphia woman who has cared for her mother and is now helping her aunt, put it: "The one thing we have to remember is they will not come into our life anymore. We have to go into theirs."

Cummings told the crowd that "your loved one's reality is your reality."  Many people with dementia lose more recent memories until all that's left is a version of an earlier time of their lives.  In later stages, they may be living in the 1950s.  An aged mother may now think that her daughter is her mother. She thinks her parents are still alive.  Her husband is some old guy who won't leave her house.

"We don't tell people that Mom and Dad died 20 years ago," Cummings said.  "It just makes them grieve again."

Caregivers can take some solace in knowing that whatever irritating behavior they're dealing with now will change as the disease progresses.

But she suggested taking several relaxing deep breaths before contemplating the other side of that reality.  The changes will mean the dementia is getting worse.  Many will come to hope that their family members die of something else before dementia makes them mute and incontinent.