JAMA PATIENT PAGE | Neurology
Alzheimer Disease Alzheimer disease is a common cause of dementia in older adults. Causes of Alzheimer Disease
Brain changes in Alzheimer disease
Development of Alzheimer disease is related to 2 abnormal proteins in the brain called β-amyloid and tau, which are toxic to nerve cells (neurons) in the brain. The buildup of these proteins in neurons eventually leads to neuron death, worsened brain function, and symptoms of dementia. Dementia is a term used to describe a decline in mental abilities including memory, language, and logical thinking. The exact trigger for Alzheimer disease is unknown. It tends to run in families, meaning there is a genetic component. More than 30 genes have been identified that may be involved in Alzheimer disease. Three genes have been found to be passed down from parent to child in a “dominant” manner, with about half of children of an affected parent also eventually developing Alzheimer disease. Alzheimer disease symptoms usually occur after age 65 years, but often, the types of Alzheimer disease that run in families occur earlier.
HEALTHY
Cerebral cortex
Shrinkage of cortex
Enlarged ventricles
Hippocampus Brain nerve cells
Shrinkage of hippocampus Damaged and dying nerve cells
Tau tangles
Symptoms The symptoms of dementia from Alzheimer disease range from mild to very severe. • Symptoms of mild Alzheimer disease include problems with memory of recent events (often the earliest symptom), misplacing items, getting lost in a familiar place, trouble completing complex tasks such as paying bills, and mood and personality changes. • Symptoms of moderate Alzheimer disease include worse memory loss and confusion, worse mood and personality changes, which can include hostility or paranoia, not recognizing family members and friends, and needing help with activities such as getting dressed or going to the bathroom. • Symptoms of severe Alzheimer disease include losing the ability to speak and complete dependence on others for all day-to-day activities. Normal aging also causes some degree of memory loss. It is important not to confuse normal age-related changes in mental functioning with dementia. Changes from normal aging should not cause problems with day-to-day activities.
Amyloid plaque
tests or tests of spinal fluid can also help detect the abnormal proteins that collect in the brain, but these are not always done.
Treatment There is currently no cure for Alzheimer disease. Current medications can slow the progression of the disease but cannot reverse it. Other medications can be used to treat problems with sleep, anxiety, or depression that develop along with Alzheimer disease. This is an area of active research. Several clinical trials are currently under way to investigate new classes of medications, such as antibodies targeted directly against the β-amyloid protein.
FOR MORE INFORMATION
Testing for Alzheimer Disease Diagnosis of Alzheimer disease involves various tests for brain function, referred to as neuropsychological testing. Brain imaging is usually also done, both to look for signs of Alzheimer disease and to rule out other conditions that can cause similar symptoms. Blood tests are usually done to rule out other problems, such as thyroid diseases or vitamin deficiencies, that may cause symptoms of dementia. Blood Author: Jill Jin, MD, MPH Sources: National Institute on Aging Stevens L. Alzheimer disease [JAMA Patient Page]. JAMA. 2001;286(17):2194. Langa KM, Levine DA. The diagnosis and management of mild cognitive impairment: a clinical review. JAMA. 2014;312(23):2551-2561.
1488
SEVERE ALZHEIMER DISEASE
• National Institute on Aging www.nia.nih.gov/alzheimers To find this and previous JAMA Patient Pages, go to the Patient Page link on JAMA’s website at jama.com. Many are available in English and Spanish.
The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate in most instances, but they are not a substitute for medical diagnosis. For specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied noncommercially by physicians and other health care professionals to share with patients. To purchase bulk reprints, call 312/464-0776.
JAMA April 14, 2015 Volume 313, Number 14 (Reprinted)
Copyright 2015 American Medical Association. All rights reserved.
Downloaded From: http://jama.jamanetwork.com/ by a Nanyang Technological University User on 05/21/2015
jama.com
Alzheimer Disease Alzheimer disease is a common cause of dementia in older adults. Causes of Alzheimer Disease
Brain changes in Alzheimer disease
Development of Alzheimer disease is related to 2 abnormal proteins in the brain called β-amyloid and tau, which are toxic to nerve cells (neurons) in the brain. The buildup of these proteins in neurons eventually leads to neuron death, worsened brain function, and symptoms of dementia. Dementia is a term used to describe a decline in mental abilities including memory, language, and logical thinking. The exact trigger for Alzheimer disease is unknown. It tends to run in families, meaning there is a genetic component. More than 30 genes have been identified that may be involved in Alzheimer disease. Three genes have been found to be passed down from parent to child in a “dominant” manner, with about half of children of an affected parent also eventually developing Alzheimer disease. Alzheimer disease symptoms usually occur after age 65 years, but often, the types of Alzheimer disease that run in families occur earlier.
HEALTHY
Cerebral cortex
Shrinkage of cortex
Enlarged ventricles
Hippocampus Brain nerve cells
Shrinkage of hippocampus Damaged and dying nerve cells
Tau tangles
Symptoms The symptoms of dementia from Alzheimer disease range from mild to very severe. • Symptoms of mild Alzheimer disease include problems with memory of recent events (often the earliest symptom), misplacing items, getting lost in a familiar place, trouble completing complex tasks such as paying bills, and mood and personality changes. • Symptoms of moderate Alzheimer disease include worse memory loss and confusion, worse mood and personality changes, which can include hostility or paranoia, not recognizing family members and friends, and needing help with activities such as getting dressed or going to the bathroom. • Symptoms of severe Alzheimer disease include losing the ability to speak and complete dependence on others for all day-to-day activities. Normal aging also causes some degree of memory loss. It is important not to confuse normal age-related changes in mental functioning with dementia. Changes from normal aging should not cause problems with day-to-day activities.
Amyloid plaque
tests or tests of spinal fluid can also help detect the abnormal proteins that collect in the brain, but these are not always done.
Treatment There is currently no cure for Alzheimer disease. Current medications can slow the progression of the disease but cannot reverse it. Other medications can be used to treat problems with sleep, anxiety, or depression that develop along with Alzheimer disease. This is an area of active research. Several clinical trials are currently under way to investigate new classes of medications, such as antibodies targeted directly against the β-amyloid protein.
FOR MORE INFORMATION
Testing for Alzheimer Disease Diagnosis of Alzheimer disease involves various tests for brain function, referred to as neuropsychological testing. Brain imaging is usually also done, both to look for signs of Alzheimer disease and to rule out other conditions that can cause similar symptoms. Blood tests are usually done to rule out other problems, such as thyroid diseases or vitamin deficiencies, that may cause symptoms of dementia. Blood Author: Jill Jin, MD, MPH Sources: National Institute on Aging Stevens L. Alzheimer disease [JAMA Patient Page]. JAMA. 2001;286(17):2194. Langa KM, Levine DA. The diagnosis and management of mild cognitive impairment: a clinical review. JAMA. 2014;312(23):2551-2561.
1488
SEVERE ALZHEIMER DISEASE
• National Institute on Aging www.nia.nih.gov/alzheimers To find this and previous JAMA Patient Pages, go to the Patient Page link on JAMA’s website at jama.com. Many are available in English and Spanish.
The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate in most instances, but they are not a substitute for medical diagnosis. For specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied noncommercially by physicians and other health care professionals to share with patients. To purchase bulk reprints, call 312/464-0776.
JAMA April 14, 2015 Volume 313, Number 14 (Reprinted)
Copyright 2015 American Medical Association. All rights reserved.
Downloaded From: http://jama.jamanetwork.com/ by a Nanyang Technological University User on 05/21/2015
jama.com
