Mild cognitive impairment

Mild cognitive impairment (MCI) is a transitional stage between normal age related forgetfulness and dementia.  Age related memory impairment is common after the age of 70 with occasional lapses of memory such as misplacing keys or remembering the name of an old friend that you have not seen for some time.  Majority of elderly population often complain of forgetfulness and not able to remember as well as they used to.

On the other hand people with MCI may in addition to memory impairment, have difficulty with language, judgment, and problem solving with preserved normal functioning.   According to American College of Physicians 20% of the population over the age of 70 have some form of MCI.  MCI can also present with non-memory symptoms such as depression, anxiety, and personality changes that are clearly a change from previous level of functioning.  Although there are various subtypes of MCI, we will focus on the most common form called the amnesic type of MCI.  MCI has been extensively studied and it appears that it is a pre-dementia state leading to Alzheimer’s disease (AD) in a rate of about 20% per year. In other words majority of patients who have a diagnosis of MCI will develop AD within 5 years.   There is a smaller population who develop dementias other that AD and some will remain as MCI and yet others will revert back to normal. The reason for these variations  are not fully understood, but thought to be the type and location of the brain damage, genetic factors as well as presence or absence of Amyloid plaques that are thought to be the initial step in development of AD.  MCI has been studies using Pittsburgh compound B (PIB) that detects amyloid plaques in the brain of the patients destined to develop AD.  In patients with MCI the amyloid plaques are present in smaller proportion as compared to the patients with AD.

The cause or causes of MCI are unknown; however the risk factors appear to be similar to AD, such as age, education, genetic susceptibility such as APO-E positivity and co-morbid medical conditions such as strokes, hypertension, heart disease, diabetes and high cholesterol. So what should you do if you suspect that you may have MCI? The first step is to recognize the pattern of forgetfulness and determine if this is a recurring issue or just an isolated incident. If you notice a pattern that is also verified by others such as friends or family members, then it is time to ask your doctor and start the process of evaluation. Your doctor will determine if it needs further investigation or just follow up.

There are currently no approved medicines for MCI, however in one study Aricept did slow the progression of MCI to AD by about 6 month, the effect was short lived and lasted only about 18 month.  Although there are genetic susceptibilities that play an important role in the development of MCI, one can lower the risk factors such as physical activity, mental stimulation, healthy diet habits, and attending to medical co-morbidities such as hypertension, heart disease, high cholesterol and diabetes.

M. Reza Bolouri, MD