What is Multi-Infarct Dementia?
Multi-infarct dementia (MID) is a common cause of memory loss in the elderly. MID is caused by multiple strokes (disruption of blood flow to the brain). Disruption of blood flow leads to damaged brain tissue. Some of these strokes may occur without noticeable clinical symptoms. Doctors refer to these as "silent strokes." An individual having a silent stroke may not even know it is happening, but over time, as more areas of the brain are damaged and more small blood vessels are blocked, the symptoms of MID begin to appear. MID can be diagnosed by an MRI or CT of the brain, along with a neurological examination. Symptoms include confusion or problems with short-term memory; wandering, or getting lost in familiar places; walking with rapid, shuffling steps; losing bladder or bowel control; laughing or crying inappropriately; having difficulty following instructions; and having problems counting money and making monetary transactions. MID, which typically begins between the ages of 60 and 75, affects men more often than women. Because the symptoms of MID are so similar to Alzheimer’s disease, it can be difficult for a doctor to make a firm diagnosis. Since the diseases often occur together, making a single diagnosis of one or the other is even more problematic.
Is there any treatment?
There is no treatment available to reverse brain damage that has been caused by a stroke. Treatment focuses on preventing future strokes by controlling or avoiding the diseases and medical conditions that put people at high risk for stroke: high blood pressure, diabetes, high cholesterol, and cardiovascular disease. The best treatment for MID is prevention early in life – eating a healthy diet, exercising, not smoking, moderately using alcohol, and maintaining a healthy weight.
What is the prognosis?
The prognosis for individuals with MID is generally poor. The symptoms of the disorder may begin suddenly, often in a step-wise pattern after each small stroke. Some people with MID may even appear to improve for short periods of time, then decline after having more silent strokes. The disorder generally takes a downward course with intermittent periods of rapid deterioration. Death may occur from stroke, heart disease, pneumonia, or other infection.
What research is being done?
The National Institute of Neurological Disorders and Stroke (NINDS) conducts research related to MID in its laboratories at the National Institutes of Health (NIH), and also supports additional research through grants to major medical institutions across the country. Much of this research focuses on finding better ways to prevent, treat, and ultimately cure the vascular dementias, such as MID.