Multi-infarct dementia (MID) is the second most common cause of dementia after Alzheimer disease in people over age 65. MID usually affects people between ages 55 and 75. More men than women have MID.
MID is caused by a series of small strokes.
A stroke is an interruption in or blockage of the blood supply to any part of the brain. A stroke is also called an infarct. Multi-infarct means that more than one area in the brain has been injured due to a lack of blood.
If blood flow is stopped for longer than a few seconds, the brain cannot get oxygen. Brain cells can die, causing permanent damage.
When these strokes affect a small area, there may be no symptoms of a stroke. These are called silent strokes. Over time, as more areas of the brain are damaged, the symptoms of MID appear.
Not all strokes are silent. Larger strokes that affect strength, sensation, or other brain and nervous system (neurologic) function can also lead to MID.
Symptoms of dementia may also be caused by other types of disorders of the brain One such disorder is Alzheimer disease. Symptoms of Alzheimer disease can be similar to those of MID. MID and Alzheimer disease are the most common causes of dementia, and may occur together
Symptoms of MID may develop gradually or may progress after each small stroke.
Symptoms may begin suddenly after each stroke. Some people with MID may improve for short periods, and then decline after having more silent strokes.
Early symptoms of dementia can include:
Difficulty performing tasks that used to come easily, such as balancing a checkbook, playing games (such as bridge), and learning new information or routines
Getting lost on familiar routes
Language problems, such as trouble finding the name of familiar objects
Losing interest in things you previously enjoyed, flat mood
Personality changes and loss of social skills
As dementia worsens, symptoms are more obvious and the ability to take care of oneself declines. Symptoms may include:
Change in sleep patterns, often waking up at night
Difficulty doing basic tasks, such as preparing meals, choosing proper clothing, or driving
Forgetting details about current events
Forgetting events in your own life history, losing awareness of who you are
Having delusions, depression, or agitation
Having hallucinations, arguments, striking out, or violent behavior
Having more difficulty reading or writing
Having poor judgment and loss of ability to recognize danger
Using the wrong word, not pronouncing words correctly, or speaking in confusing sentences
Withdrawing from social contact
Nervous system (neurologic) problems that occur with a stroke may also be present.
Exams and Tests
Tests may be ordered to help determine whether other medical problems could be causing dementia or making it worse, such as:
Call the health care provider if symptoms of multi-infarct dementia occur. Go to the emergency room or call the local emergency number (such as 911) if there is a sudden change in mental status. This is an emergency symptom of stroke.
Control conditions that increase the risk of hardening of the arteries (atherosclerosis) by:
Moorhouse PA, Rockwood K. Vascular cognitive impairment. In: Fillit HM, Rockwood K, Woodhouse K, eds. Brocklehurst's Textbook of Geriatric Medicine and Gerontology. 7th ed. Philadelphia, Pa; 2010:chap 55.
Joseph V. Campellone, M.D., Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.