The term Mild Cognitive Impairment (MCI) is used to describe a level of memory loss that is somewhere between normal aging and dementia. As discussed at the 7th Annual Mild Cognitive Impairment Symposium, symptoms vary widely among people diagnosed with MCI. These symptoms can be cognitive (involving memory and thinking) or psychiatric.
Researchers at a 2003 international conference on diagnosis of MCI agreed on the following categories for classification of cognitive symptoms:
Amnestic vs. Non-Amnestic MCI
In Amnestic MCI, the most noticeable symptom is difficulty remembering things. But the “cognitive” in Mild Cognitive Impairment involves more than remembering what your friend told you yesterday, or whether you paid the power bill. It also includes language, decision-making and visuospatial abilities, as well as attention. When some or all of these abilities are decreased, but memory is intact, it’s called Non-Amnestic MCI.
Single Domain MCI vs. Multi-Domain MCI
In Single Domain MCI, a person has problems with one type of cognition only. Perhaps he has developed difficulties with language, but is more “normal” in other areas. Or maybe his memory has declined, but he has no problems in other areas. Multi-Domain MCI simply means the person has problems in more than one area.
As you’ll see in the next few reports, researchers use these classifications to look for patterns in Mild Cognitive Impairment. Understanding any patterns may lead to better diagnosis and treatment of MCI, and help predict whether people diagnosed with MCI will develop dementia.
In addition to memory loss and other cognitive problems, some people with Mild Cognitive Impairment have psychiatric symptoms. Dr. Liana Apostolova, Assistant Professor in Neurology at University of California Los Angeles (UCLA), gave an overview of these symptoms at the Symposium.
Behavioral symptoms are common in people diagnosed with MCI, she said. These symptoms are similar to those seen in people with Alzheimer’s, and can include:
Recent work done at UCLA appears to show that men have these symptoms more than women, and younger patients have them more than older patients. There doesn’t seem to be much difference in the prevalence of psychiatric symptoms in Amnestic MCI versus Non-Amnestic MCI.
Psychiatric symptoms can of course be addressed with therapy, medications and family education, Dr. Apostolova said, but deserve a closer look because they may indicate that a patient is at risk for developing dementia. Separate studies have shown that anxiety, apathy and agitation in people with MCI are all associated with an increased risk.
Whether or not you have been diagnosed with MCI, depression may also increase your risk of dementia. It’s not known if treating depression lowers that risk.
These studies show that psychiatric symptoms are common among people with MCI, but they don’t explain what the relationship is. Do changes in the brain that cause problems with memory and thinking also cause depression, for example? Or does depression actually contribute to cognitive problems? During the Friday morning Q & A session at the Symposium, Dr. Yonas Geda of Mayo Clinic said their studies show that older people with memory problems normal for their age plus depression have a higher risk of developing MCI if they have the APOE4 gene variation. Perhaps depression interacts with other factors to influence the rate of cognitive decline.
In the next report in this series, I’ll summarize MCI Symposium presentations on the diagnosis of MCI.