Tall Stack of Papers
“Getting lost,” says Dr. Carmela Tartaglia, “is not a normal part of the aging process.”
Tartaglia is a scientist with the Tanz Centre for Research in Neurodegenerative Diseases and a cognitive neurologist who sees patients at Toronto Western Hospital’s Memory Clinic. She is sitting in the hospital’s fifth-floor atrium, explaining what the brain tells us about why people with dementia wander.
Most wanderers have Alzheimer’s, which is a dementia-causing disease that disrupts communication among neurons in areas of the brain responsible for memory, thought, language and judgment. The cells wither and die over time, Tartaglia says, “and when lots of cells die, the brain shrinks.” Scientists do not know what causes Alzheimer’s, and currently there is no cure.
They could be circling the block, passing their house multiple times without realizing it.
Early on, the disease targets the hippocampus, which is the horseshoe-shaped chunk of the brain essential for creating new memories. Doctors frequently use this analogy to describe the impact: imagine a tall stack of papers sitting by a window, with those at the bottom containing your earliest memories and those at the top, more recent ones. When Alzheimer’s sets in, the window opens and papers begin blowing off the top. You may forget about the conversation you had an hour ago but remember every detail of your wedding in 1956.
As the disease progresses, more papers blow away and years are lost. A person like James Berry may forget that six months ago he moved in with his daughter and grandsons. He may leave his daughter’s house because he believes he was there for a visit that has come to an end. Or he may flee because he doesn’t recognize the place at all.
But getting lost is not just about forgetting. To know where you are going, you must remember your destination. But to know how to get there, you need not only memory but the ability to navigate — a sense of time and space, and where you fit into it.
Alzheimer’s disease damages important spatial memory centres such as the parietal lobe, impairing our ability to understand where we are in relation to the objects around us. As the disease progresses, people can become disoriented and lost in familiar places, even on their own street. “They could be circling the block,” Tartaglia says, “passing their house multiple times without realizing it.”
The disease also impairs judgment. A person with normal cognitive functioning who becomes disoriented will probably ask for help. “But if your judgment is off,” Tartaglia says, “it doesn’t even come to mind that you should ask somebody.”
The wanderer may not realize how cold it is or how far he has gone. He may not remember to eat or drink. He may not even realize he is lost.