I had never thought a lot about mild cognitive impairment, other than that the condition may lead to Alzheimer’s disease. But recently I read a news report that piqued my interest.
First let me tell you about news report on a study by Oregon Health and Science University that found that changes in walking speed among elders could point to the early stages of mild cognitive impairment. This research involved 93 people who were 70 years old and above. These participants all lived alone. At the start of the study, the researchers assessed the participants as to their mental status. They found that 54 did not have cognitive impairment, 31 had non-memory-related mild cognitive impairment while eight had memory-related mild cognitive impairment.
The researchers then installed special infrared sensors in the hallway ceilings of the elders’ homes so they could monitor their walking period. Their analysis found that people who had non-memory related mild cognitive impairment were nine times more likely to be rated as slow walkers than to be moderate or fast walkers. The analysis also found an association between mild cognitive impairment and the amount of fluctuation in walking speed.
This report got me wondering – are there different types of mild cognitive impairment? It turns out that there are. A fact sheet prepared by Washington Regional Medical Center’s Memory Clinic classified mild cognitive impairment into four categories:
- Amnestic mild cognitive impairment – “Amnestic MCI occurs only when memory loss is apparent both subjectively from the person with MCI and/or family member and objectively on formal memory testing,” the fact sheet states. This memory loss can include difficulty remembering names and recent conversations, increased forgetfulness and misplacing items. The person is still able to take care of himself and can function normally in other aspects of life. (This would be memory-related MCI in the study.) Researchers have found that people with this type of MCI progress to Alzheimer’s disease at a rate of 12 percent per year.
- Multi-domain mild cognitive impairment – This type of MCI may involve slight memory impairment. However, the person will display minor cognitive disturbance in other areas such as language, reasoning/judgment and visual perceptual skills. (This category would be non-memory MCI in the study mentioned earlier.) This risk of moving from this type of MCI to dementia is not clearly understood currently. “While Multi-domain MCI can sometimes occur with normal aging, it can also increase one’s risk of converting to Alzheimer’s disease and/or dementia related to cerebrovascular disease (Vascular disease),” the fact sheet stated.
- Single non-memory domain mild cognitive impairment – This type of MCI means that the individual is impaired in an area other than memory, such as language. (This category would be non-memory MCI in the study mentioned earlier.) The risk of someone with this type of MCI progressing into dementia is not clearly understood. “Single-Non Memory MCI can increase one’s risk of developing Vascular dementia, language disorders, dementia with Lewy bodies, and Frontotemporal dementia,” the fact sheet stated.
The website for the University of California, San Francisco’s Memory and Aging Center noted that there’s a higher likelihood of MCI progressing to Alzheimer’s if certain features are evident, including confirmation by a family member or friend of a person’s memory difficulties, poor performance on objective memory testing, and changes in daily tasks, such as hobbies, finances, handling emergencies and personal hygiene. However, UCSF cautions that memory problems do not necessarily have to be MCI. For instance, memory problems that mimic MCI can really be to depression or medications. Therefore, additional testing such as blood work and brain imaging need to be done in order to identify the reason for any memory issues. UCSF recommends that an outside informant such as a family member or friend come be part of the evaluation process to provide input that the individual may forget.