Mild Cognitive Impairment (MCI)

Photo by Flood. 

As people get older, they experience age-related changes to their memory: i.e., they take longer to store and retrieve information, their attention is compromised when multitasking, and they take longer to retrieve the desired name, date, place or specialized word.  Sometimes older adults too readily fear that they have early stage of Alzheimer's disease (AD). Usually, these changes to memory are just normal signs of aging.
But what if the memory problems seem more serious?  Is it Alzheimer's disease?  Maybe, maybe not.
Yes, as people age, their risk for AD and other forms of dementia does increase. About 5% of those ages 65 to 74 have AD; the rate increases to about 50% for those 85 plus. Yes, symptoms of AD can often mask as normal changes to memory. Some disregard atypical memory changes, which postpones a diagnosis until people move beyond the early stage and into the mid-stage of the disease. (For a fuller overview of various stages of memory performance, see this list at alz.org.)

However, older adults with memory problems should first consider the possibility they have Mild Cognitive Impairment (MCI).   The Alz.org document 2012 Alzheimer's Disease Facts and Figures reports this prevalence: "Studies indicate that as many as 10 to 20 percent of people age 65 and older have MCI" (p. 9).  Furthermore, only a small percentage (15%) seek medical advice about MCI. Of those who do seek treatment, half will develop dementia in 3-4 years.  Clearly, older adults and their loved ones need a greater awareness of MCI as a distinct diagnosis.
MCI is a diagnosis that indicates greater memory problems than those associated with normal aging but fewer memory problems than required for a diagnosis of dementia (Alzheimer's disease being the most common form of dementia).   MCI is an "in between" diagnosis of sorts, but the majority of those with  MCI do not progress to dementia.
In combined studies (see Mitchell et al 2009) over a 10 year period, only 1/3 of those with MCI progressed to dementia.  The others either maintained the MCI diagnosis or returned to normal memory capabilities for their age and education.  By another measure, the annual conversion rate from MCI to dementia falls between 5% and 10%. 
People suspect AD over MCI primarily because Alzheimer's disease was established over a century ago as a clinical diagnosis in 1906.  Many haven't heard of MCI yet. Or MCI is ignored as a possibility until major memory problems appear.  Today's most employed definition of MCI began in the 1990s when Dr. Ronald C. Petersen and colleagues established the Petersen guidelines for diagnosing MCI.
MCI has many causes and is still coming into focus for the medical community. Consequently, the diagnostic guidelines are still in flux.  Here is a list of symptoms by Ghetu et al from their 2010 article appearing in Clinical Geriatrics. The authors constructed this list by looking at the available scholarship on defining MCI and presenting the most commonly recurring criteria:  

• Self-reported memory complaint, preferably corroborated by an informant

• Objective memory impairment

• Preserved general cognitive function

• Intact activities of daily living (ADL) with minimal impairment in instrumental functions

• Not meeting criteria for dementia 

When someone has MCI, they are a little more confused a little more often than others with the same age and education level, but they can still meet the day-to-day demands of self-care and social function.
Examine this list that shows MCI-type concerns but recognizing that these are not as severe as a dementia symptom:

• Losing items more often, but not showing paranoia that others are stealing these items.  
• Taking longer to recall information, but eventually finding the right word, even an hour later. 
• Forgetting a doctor's appointments, but remembering where the office is located. 
• Getting off track when interrupted, but eventually returning to the task. 
• Needing to take notes more often, but remembering to consult those notes. 
• Confusion at times about the day of the week, but knowing the season and the year.  
• Forgetting some minor details of a day trip to the next county, but remembering going on a trip. 
• Struggling to manage more complex financial matters, but managing to balance a checkbook. 

If a few "senior moments" from the above list seem familiar, dementia is probably not the problem. But if several of these milder memory problems appear together and with more frequency, there is cause to suspect MCI. 
If you are concerned about changes to memory for you or a loved one, work with a doctor.  Diagnosing memory problems involves a combination of tools: 1) observations by a family member or someone with day-to-day contact (called an informant by clinicians), 2) short cognition tests that can be performed in a doctor's office in 7 or fewer minutes 3) more involved cognition tests such as the MMSE performed by a memory specialist, and 4) blood tests.  With mild memory problems, doctor's rarely order images of the brain such as an MRI, PET or CT scan unless there is a family history of AD  or another exceptional reason.
There's a lot to manage as people age, but memory concerns can be a little tricky to diagnose.  There is a fine line between age-related changes, mild cognitive impairment and pre-dementia symptoms. Memory experts especially value the role of taking the same clinically established cognitive tests (such as the MMSE) over a period of months and years.  Consider asking your general practitioner for a baseline cognition test by age 65 even if it only establishes normal cognition levels. Having that baseline score can prove useful if more serious memory problems appear later. 
Related:
On the Tip of the Tongue
Is It Delirium or Dementia
Hospital-Induced Delirium
Age-Related Changed to How We Write