Description

Mild cognitive impairment (MCI) is the stage between normal cognitive aging and more serious dementia.  During MCI, there are significant enough cognitive changes taking place, such that the changes are noticeable to the person affected and/or observers; however, the individual remains generally independent in activities of daily living (e.g., driving, financial and medication management, shopping and cooking).

MCI does not always lead to dementia and may remain stable over time or revert to normal cognition if reversible causes (e.g., disrupted sleep, mood/anxiety, medications, vitamin deficiencies, etc.) are treated. However, people with MCI may be at an increased risk of later conversion to dementia, in which further cognitive decline occurs and causes marked impairment in activities of daily living. Although it is still not clear, it has been suggested that individuals with Non-Amnestic MCI may be more likely to develop Vascular Dementia, Frontotemporal Dementia, or Dementia with Lewy Bodies, while individuals with Amnestic MCI may be more at risk of developing Alzheimer’s disease.

Symptoms

MCI is classified into four subtypes:

1. Amnestic MCI, Single Domain: Memory is the primary domain affected, with minimal to mild change in other cognitive domains. A person with Amnestic MCI may begin to forget important information/details that would previously have been recalled easily, such as recent conversations, recent events, and trouble remembering upcoming engagements.
   
   
2. Amnestic MCI, Multidomain: Memory is the primary domain affected, but other cognitive domains (e.g., language, decision-making, judgment, visuospatial/visuoperceptual abilities, etc.) are also impacted.
   
   
3. Non-Amnestic MCI, Single Domain: Affects one cognitive domain that does not involve memory (e.g., language, decision-making, judgment and reasoning, visuospatial/visuoperceptual abilities, etc.)
   
   
4. Non-Amnestic MCI, Multidomain: Affects two or more cognitive domains, neither of which involves memory.

Diagnosis

MCI is a clinical diagnosis, typically diagnosed by a physician or neuropsychologist. Diagnosis of MCI is based on the following criteria:

1. Problems with memory or other cognitive functions (noticed by the individual and an observer)
2. Relative cognitive decline over time
3. Overall cognitive function and activities of daily living generally aren’t impaired
4. Mental status testing (based on brief bedside cognitive evaluations and more detailed neuropsychological testing) shows a mild level of impairment for age and educational history.
5. Diagnosis is not dementia

Your physician may refer you for a comprehensive medical work-up including:

1. Blood work to rule out reversible causes of cognitive changes (e.g., hypothyroidism or vitamin B-12 deficiency).
2. Structural scan (brain MRI or head CT) to assess for a structural cause for cognitive changes, such as a brain tumor or stroke.
3. EEG to assess for abnormalities in your brain waves or in the electrical activity of your brain that may suggest focal or diffuse dysfunction.

Treatment

Like in the case of dementia, there is currently no cure for MCI and drugs approved to treat symptoms of Alzheimer’s disease have not shown any lasting benefit in delaying or preventing eventual progression to dementia, although as with dementia, the goal remains to stabilize cognitive changes for as long as possible. In addition to medications, this may be achieved through regular moderate physical activity, social and cognitive stimulation, and diet (specifically, adherence to the Mediterranean diet, characterized by high intake of whole grains, legumes, vegetables, and fruits, only moderate consumption of alcohol, and a high monounsaturated-to-saturated fat ratio).

In the case of reversible etiologies, your physician may prescribe vitamin B-12 replacement, recommend adjustments in thyroid medications, refer you for a polysomnogram/sleep study (to rule out a sleep disorder), refer you for psychotherapy and/or psychiatric treatment, or recommend adjustments in medications. 

Useful Links

UCSF Memory and Aging Center
Alzheimer’s Association
AARP
This Caring Home