Dementia -- Topic Overview What is dementia? dementia is impairment of brain functions such as memory,reasoning, and judgment http://my.webmd.com/hw/healthy_seniors/uf4985.asp
Extractions: Topic Overview Dementia is impairment of brain functions such as memory, reasoning, and judgment so severe that it affects a person's ability to function at his or her usual level. The severity of dementia depends on the number and location of brain cells (neurons) that are damaged or destroyed. Memory loss is the most common symptom of dementia. People also may have difficulty using or understanding words or become lost in previously familiar places. They may have difficulty performing tasks that require organization, such as balancing a checkbook or making a grocery list and going shopping. Dementia also can cause depression , irritability, or other behavior and personality changes.
Extractions: Complex Pathology, Confusing Symptoms A lthough the average brain weighs only three poundsaccounting for just 2 percent of the weight of a 150-pound personit consumes 20 percent of the bodys oxygen and receives 20 percent of the bodys blood supply. Events that interfere with the brains blood supply pose a serious threatits cells can survive without oxygen for only three to five minutes. When brain cells die, their death disrupts the mental or physical function controlled by the area where the damage occurs. Evolving Ideas about a Complex Disorder Medical thinking about vascular dementia has changed considerably over the past few decades. At one time, doctors attributed almost all mental impairment associated with old age to "hardening of the arteries" in the brain. As scientists gained deeper understanding of other dementing illnesses, Alzheimers gradually earned recognition as the most common dementia, and vascular dementia was considered the second most frequent. Experts now acknowledge that neither the frequency nor the characteristics of vascular dementia are well understood. Several professional bodies have developed different sets of criteria for diagnosing the disorder, making it difficult to estimate its frequency with any precision. Estimates found in recent scientific literature indicate that vascular dementia accounts for anywhere from one-tenth to one-third of dementia cases