Berlin - Dementia has many facets. Memory loss and personality changes are among the most typical.

People affected by dementia behave differently than their loved ones are used to, and it's not uncommon for the loss of intimacy to be the the worst thing about the condition. In the advanced stages of the disease, the victim cannot recognize their spouse or their children. Sometimes the caregiver is mistaken for the partner.

"They orientate themselves based on behaviour," said Rosemarie Drenhaus-Wagner of the a Berlin-based initiative for relatives of people with Alzheimer's disease. "When loved-ones take on care giving tasks, then they are perceived as the caregivers or nurses."

Professor Rolf Hirsch, head physician at a large hospital in Bonn, is familiar with such situations.

"I was working in a hospital ward when a dementia patient received a visit from his wife," said Hirsch. "But he didn't recognize her and pointed to another patient, introducing her as his wife."

For loved-ones, it's often a bitter experience when grandpa, grandmother or another elderly relative doesn't recognize them any more.

Grandchildren often are mistaken for the patient's own children, said Drenhaus-Wagner. Dementia illnesses are often accompanied by gradual disorientation. At first, dementia patients have difficulty correctly estimating the timeline of their life. In the end, orientation fades with respect to places, situations and other people.

Even the ability to hold a conversation can be lost, said Klaus Kruesmann, a member of the board of Germany's Alzheimer's society in Hamburg.

"Dementia patients often live in their own world, which has little to do with their loved-ones," said Kruesmann.

They often remember their childhood, but not the most recent 30 years, said Hirsch. Thus, they often express the wish to "go home," which to them is the place where they were as children. Hirsch recalls a patient who walked 10 kilometres to the town he was born in after deciding the present location was just too strange for him.

The present and the past are no longer clearly separable for people with dementia. Experiences from far in the past are projected into the present time, which can irritate loved-ones, said Drenhaus-Wagner.

"I once knew of a dementia patient who insisted on going to the basement every time she heard the sound of a vacuum cleaner," said Drenhaus-Wagner. She confused the noise with the sound of the sirens that blared during the war warning of an air strike.

In such cases it doesn't help to try continually to convince the person that their perception is wrong, said Hirsch. Sometimes a dementia patient regularly misplaces something that he wants nothing to do with, and the partner reminds them about it with the same regularity. When that occurs, an argument is unavoidable. But when dealing with someone who has dementia, you cannot win an argument.

A typical misunderstanding arises over the belief that the dementia patient could "learn" to remember again, if he or she is told over and over again to do something, said Kruesmann.

"But that just makes dementia patients angry because they feel like they are being nagged," said Kruesmann. Praising a dementia patient for doing something correctly is always better than reproaching them. (dpa)