brain, spinal cord, and nerve disorders
Dementia
Introduction
Dementia is a slow, progressive decline in mental function including memory, thinking, judgment, and the ability to learn. Typically, symptoms include memory loss, problems using language and doing activities, personality changes, disorientation, and disruptive or inappropriate behavior. Symptoms progress so that people cannot function, causing them to become totally dependent on others. Doctors base the diagnosis on symptoms and results of a physical examination and mental status tests. Blood and imaging tests are used to determine the cause. Treatment focuses on maintaining mental function as long as possible and providing support as the person declines. (See also Overview of Delirium and Dementia .) Dementia occurs primarily in people older than 65. Dementia, particularly the disruptive behavior that often accompanies it, is the reason for more than 50% of admissions to nursing homes. However, dementia is a disorder and is not a part of normal aging. Many people over 100 do not have dementia. Dementia differs from Delirium , which is characterized by an inability to pay attention, disorientation, an inability to think clearly, and fluctuations in the level of alertness. Dementia affects mainly memory, and delirium affects mainly attention. Dementia typically begins gradually and has no definite beginning point. Delirium begins suddenly and often has a definite beginning point. (also called age-associated memory impairment) cause some decline in short-term memory and slowing in learning ability. Memories are retrieved more slowly. These changes, unlike dementia, occur normally as people age and do not affect the ability to function and do daily tasks. Such memory loss in older people is not necessarily a sign of dementia or early Alzheimer Disease . However, the earliest symptoms of dementia are very similar. Mild cognitive impairmentcauses greater memory loss than age-associated memory impairment. It may also impair the ability to use language, think, and use good judgment. However, it, like age-associated memory impairment, does not affect the ability to function or do daily tasks. Up to half of people with mild cognitive impairment develop dementia within 3 years. Subjective cognitive declinerefers to a continuing decline in mental function that the affected person notices but that is not identified by standardized tests for mild cognitive impairment. People with subjective cognitive decline perform normally on such tests. However, these people are more likely to develop mild cognitive impairment and dementia. Dementiais a much more serious decline in mental ability and one that worsens with time. People who are aging normally may misplace things or forget details, but people who have dementia may forget entire events. People who have dementia have difficulty doing normal daily tasks such as driving, cooking, and handling finances. Rapidly progressive dementiais a group of dementias that progress faster than other dementias. typically within 1 to 2 years. The most obvious early symptom of these dementias is rapidly decreasing mental function. Memory is lost. People have difficulty using language. They also have difficulty planning, solving problems, handling complex tasks (such as managing a bank account), and using good judgment (called executive function). Other symptoms of rapidly progressive dementias include disruptive behavior, personality changes, mood disorders, psychosis, problems sleeping, and problems walking. Levels of alertness and awareness may be altered. Their limbs may shake and/or jerk involuntarily. The most common cause of rapidly progressive dementia is a Overview of Prion Diseases . Other common causes include autoimmune and paraneoplastic encephalitis. Sometimes other types of dementias progress faster than is typical. They include Depression None In some types of dementia (such as Alzheimer Disease ), the level of acetylcholine in the brain is low. Acetylcholine is a chemical messenger (called a neurotransmitter) that helps nerve cells communicate with one another. Acetylcholine helps with memory, learning, and concentration and helps control the functioning of many organs. Other changes occur in the brain, but whether they cause or result from dementia is unclear. Dementia is a disorder, not a part of normal aging. Many people over 100 do not have dementia. 