Are my memory lapses a sign of Alzheimer’s?

By: From: Ask the Doctor
The Globe and Mail August 8, 2006

Question: I am in my late 50’s and I’ve noticed that my memory, and even my ability to concentrate, is not the same as it used to be. How do I tell the difference between memory changes that are a “normal” part of aging and changes that may signify the onset of a dementia such as Alzheimer’s disease?

Answer: These kinds of personal observations regarding reduced memory efficiency and susceptibility to distraction are fairly common as we age. Research into normal aging shows our ability to get information into memory starts to decline gradually beginning as early as our 30’s. So if you’re in your 50s, you might not remember quite as many details from a recently read newspaper article as you could in your 20s. However, your ability to keep the details you have learned is pretty stable throughout adulthood.

The biggest difference between older and younger adults is with the retrieval of stored information. The name or fact is stored in your brain, but you just can’t access it when you need it. Later, when the pressure is off, the information might come to you. This type of failure to retrieve a piece of information at the time you need it, such as remembering someone’s name, is the most common memory complaint associated with aging.

The changes in memory acquisition and retrieval as you age are cumulative and subtle; often many decades will go by before you become aware of these changes. A recent neuro-imaging study, led by Dr. Cheryl Grady at Baycrest’s Rotman Research Institute in Toronto and published in the February 2006 Journal of Cognitive Neuroscience, found that there are age-related differences in brain-memory activity that begin gradually in middle age (between ages 40 and 50). The good news is that the changes are subtle, with relatively little impact on performance level.

The changes in memory activity become more pronounced in older adults (65-plus), and include regions in the brain believed to play a role in our ability to ignore distracting information. These regions show reduced activity when older adults engage in memory tasks, a finding consistent with results from previous studies showing increased susceptibility to distraction as we age. So, you may find you need to turn off the radio when you are engaged in a complex thinking task, such as doing your finances, while the teenager in your life can listen to an iPod while studying for an exam without difficulty.

At what point do memory changes become a cause for concern? Memory mistakes happen to all of us from time to time. We have all experienced going into a room and wondering, “Now, what did I come in here for?” Is making a memory mistake as an older adult potentially more significant than when we are younger? The answer is no. What might speak to significance is whether there seems to be a notable increase in the frequency of everyday memory slips and whether these slips have real consequences.

For example, if you are low on sugar in your cupboard and intend to make a birthday cake, then forgetting to buy the sugar at he grocery store means you have to make another trip. Similarly, forgetting you have a lunch date next week and committing to another activity is okay if you catch the error, but not okay if you stand up your lunch date.

As we age, an increase in memory failures that have consequences, ranging from annoying (repeat trip to the grocery store) to more significant (standing up your lunch date) should grab our attention. You might wonder: Does this signify the onset of Alzheimer’s disease?

First, rule out all other possible causal explanations. A visit to your family doctor can assist in determining whether or not there is a physical explanation for reduced memory function. Consider what is happening in your life. Stress, mood, poor sleep, being preoccupied or distracted: all these can act to reduce memory efficiency.

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