At one time, senile dementia was the catch-all term used to describe symptoms of cognitive decline that were considered normal signs of aging. Now researchers know that dementia is not the name of one condition and is not considered a normal part of aging. Rather, there are more than 80 forms of dementia, according to NYU Langone Medical Center's Center of Excellence on Brain Aging. Each form of dementia represents a collection of symptoms that can be caused by a variety of different brain disorders.
What Is Dementia?
Age-related cognitive decline that causes delayed information processing and some memory loss is normal; dementia occurs when a disease process damages or destroys brain cells, or causes a loss of normal communication between these cells. Different types of dementing disorders are categorized by which area of the brain is affected and whether or not the condition is progressive.
What Is Multi-Infarct Dementia?
Multi-infarct dementia (MID) is the second most common form of dementia after Alzheimer's Disease. Unlike MID and other forms of dementia, Alzheimer's Disease is not secondary to another physical, psychological, or neurological condition. Alzheimer's Disease is a progressive form of dementia that is a result of damaged neurons (brain cells).
MID is a type of vascular dementia that results from multiple small or "mini" strokes cutting cut off blood flow to the brain. Without a constant supply of oxygenated blood, brain cells die, leaving isolated, damaged areas of the brain known as infarcts. MID affects more men than women. If you have a history of hypertension (high blood pressure), stroke, or transient ischemic attack (TIA), you may be at higher risk of developing MID.
Symptoms
Loss of concentration, attention, short-term memory, judgment, motor skills, and ability to use language may appear with MID. Other symptoms may include wandering or getting lost in familiar places, walking quickly with a shuffle-like step, laughing or crying for no reason, loss of bowel or bladder control, and problems performing monetary transactions. Because of the isolated nature of MID infarcts, only one or two of these functions may be affected and motor skills are often lost on only one side of the body. Although the symptoms are similar to those of Alzheimer's disease, they can affect the body differently.
Unlike Alzheimer's Disease, which comes on gradually, MID appears rather suddenly and cognitive function deteriorates quickly in a series of steps, with more symptoms developing after each stroke. Alzheimer's Disease and MID may occur simultaneously, however, and under these circumstances, a clear diagnosis can be difficult.
Treatment
There is no treatment for MID other than treating the underlying conditions that can lead to more strokes and further cognitive decline. This means treating and controlling hypertension, high blood cholesterol, cardiovascular disease, and diabetes.
Sources:
National Institute of Neurological Disorders and Stroke: Dementia: Hope Through Research May 2012 Web July 2012
http://www.ninds.nih.gov/disorders/dementias/detail_dementia.htm#1909019213
National Institute of Neurological Disorders and Stroke: Multi-infarct Dementia Information Page
http://www.ninds.nih.gov/disorders/multi_infarct_dementia/multi_infarct_dementia.htm
Padovani, Al., et al. "Patterns of Neuropsychologic Impairment in Mild Dementia: A Comparison Between Alzheimer's Disease and Multi-Infarct Dementia." ACTA Neurologica Scandinavica 1995:92;33-42 Web July 2012
http://iacoboni.bol.ucla.edu/pdfs/ActaNeurolScan_Padovani_v92p433.pdf
Stanford School of Medicine: Vascular Dementia Web July 2012
http://scmd.stanford.edu/t_vascular.html
