Dementia and Alzheimer Disease
Alzheimer Disease is the most common form of dementia.
Is it Alzheimer disease or Normal Aging?
Alzheimer disease is a form of dementia characterized by the gradual loss of several important mental functions. It is, by far, the most common cause of dementia in older persons. As we age, we all experience some changes in mental functioning. The most well characterized change with aging is a loss of short term memory. We may remember vividly what transpired on our wedding day or the first day at college, but can't remember where we just parked the car or where we just placed our keys. From time to time, we may forget the names of acquaintances. However, the changes that occur with Alzheimer disease are much more serious changes than those that occur with aging: forgetting the names of close friends or family members, having trouble speaking or doing simple tasks or paranoid behavior.
Dementia is a medical term used to describe a number of conditions
characterized by the gradual loss of intellectual functions.
Diagnostic Criteria (Created by the National Institute of Neurological
and Communicative Disorders and Stroke and the Alzheimer Association)
The development of multiple cognitive (mental) deficits manifested by both of the following:
1. Memory impairment
2. One or more of the following cognitive (mental) disturbances:
A. Aphasia (language difficulties)B. Apraxia (impairment of the ability to conduct motor activities)C. Agnosia (failure to recognize or identify objects)D. Disturbances in intellectual functioning (planning, organizing, abstracting)
Pre-Senile Dementia vs. Senile Dementia
Alzheimer disease was first described in a 52 year old woman. Up until two decades ago, it was believed that Alzheimer disease was a condition of younger, 50-60 year old, individuals and that the intellectual deterioration seen in much older persons was caused by another condition called senile dementia. For many years, the term Senile Dementia of the Alzheimer Type was associated with these individuals. However, we know now that Alzheimer disease can occur at a wide variety of ages and in fact is much more common in the very old.
Delirium is an acute condition which features confusion, disorientation, memory loss and agitation. Except for its rapid onset, it can resemble dementia. Delirium can be caused be a wide variety of medical conditions including drug overdose, infections, and metabolic disturbances. It occurs much more frequently in older persons, particularly those that are hospitalized or undergo surgery. It usually occurs rapidly and disappears with time or with adequate treatment of the underlying condition. It features marked fluctuations in intellectual functioning as well as visual and auditory hallucinations. Since a number of drugs can cause intellectual impairment and delirium, it is critical to evaluate the drugs given to older persons during hospitalization.
Distinguishing Between Delirium and Dementia
| Delirium | Dementia | |
| Onset | Sudden | Gradual |
| Course | Level of awareness fluctuates, usually worse at night | Slow progressive decline |
| Duration | Hours to weeks | At least 1 to 2 years |
| Affect | Confusion, fear, bewildered | Flat or indifferent |
| Cause | Usually medical illness or drugs (e.g. post-surgical anesthesia, sleeping medications) | Usually Alzheimer's disease or multiple infarcts |
| Treatment | Determine underlying cause and treat. Provide support until delirium resolves. | Treatment when appropriate, environmental modifications, behavioral management, caregiver support. |
Other Conditions that Cause Dementia Besides Alzheimer Disease
A number of other medical conditions can resemble Alzheimer disease. Many of these conditions have treatments that can decrease or even cure the dementia. Therefore, a good history and physical examination as well as a few blood tests may be necessary to eliminate these conditions before a diagnosis of Alzheimer disease is made. Here are a few of these conditions. Click on the condition you wish to learn more about.
Depression
Many older depressed persons can have signs and symptoms that resemble
Alzheimer disease such as memory problems, intellectual impairment,
faulty decision making and poor judgement. Furthermore, the difficulties
with sleep and the poor nutrition that accompany depression can produce
a decline in intellectual functioning. To learn more about depression
in the elderly, you can click on the following:
Adverse drug responses are extremely common as we age. Many health care providers do not spend the time to review the medications that you are taking before prescribing new medicines. Therefore, as we age, we acquire more and more medications that can produce side effects. One side effect of many medications is impaired mental functioning. Furthermore, as we age, we many metabolize medicines more slowly and therefore the amount of certain medicines in our blood stream may rise to levels where they interfere with mental functioning. Thus, any evaluation for dementia should include a careful examination of the prescription as well as non-prescription medications that the patient is taking.
Multi-infarct dementiaDementia can be produced by multiple small strokes. In fact, it is
very difficult to distinguish multi-infarct dementia from Alzheimer
disease. Multi-infarct dementia may feature signs and symptoms of strokes
localized to one side of the body and may progress in a more step-wise
fashion. Furthermore, these individuals may have had a previous stroke
or TIA (Transient Ischemic Attack, which may act like a stroke but which
resolves quickly usually over a period of hours). To learn more about
strokes and TIAs, you can click on the following:
Many patients with Parkinson disease have intellectual impairments.
This does not happen to all Parkinson victims, but many do have signs
and symptoms of dementia such as loss of memory, problems with words
or planning and organizing activities. For more information on Parkinson
Disease, you can click on the following:
Some brain tumors can produce intellectual deterioration. It is critical that this condition be diagnosed and treated as early as possible. Many brain tumors, if detected in their earliest stages can be removed with restoration of normal life expectancy as well as a return to intellectual functioning. This is one of the reasons that all patients with signs and symptoms of dementia need a complete neurological examination including a history, physical examination, and certain additional tests. [Back to Conditions]
Increased as well as decreased functioning of the thyroid gland (hyperthyroidism
and hypothyroidism) can produce intellectual impairment. Adequate treatment
of the underlying thyroid conditions can restore mental health to these
individuals.
[Back to Conditions]
One of the major consequences of vitamin B12 deficiency is dementia.
As we age, many individuals have a decrease in their ability to absorb
ingested vitamin B12. As a result, many older individuals suffer from
vitamin B12 deficiency. The detection of vitamin B12 deficiency can
be complicated in those individuals taking folic acid supplements. If
you take in enough folic acid, you will not get the telltale anemia
that is the hallmark of vitamin B12 deficiency, also called Pernicious
Anemia. Since, the government now requires all grains and cereals to
be supplemented with folic acid, this problem may increase in the future.
To learn more about vitamin B12, click on the following:
A subdural hematoma is a leakage of blood from the blood vessels of the brain that can compress the brain itself and cause a variety of neurological signs and symptoms. One of the earliest signs of subdural hematoma may be a loss of intellectual functioning. While the signs and symptoms of a subdural hematoma may progress rapidly, they can also transpire over several weeks. This condition can be cured if treated promptly through an operation that releases the blood and takes the pressure off the brain tissue. [Back to Conditions]
The brain is surrounded by fluid. There are also chambers in the brain called ventricles that are filled with the same fluid. When too much fluid is made or the fluid can not drain properly the fluid can compress the brain and cause signs and symptoms of dementia. This condition, when diagnosed, can be effectively treated with a shunt that directs excess fluid to other parts of the body. This is one of the reasons that all patients with signs and symptoms of dementia need a complete neurological examination including a history, physical examination, and certain additional tests. [Back to Conditions]
SyphilisChronic, long term, untreated syphilis can cause irreversible brain
disease and dementia. In the past, before effective diagnosis and treatment
of syphilis, many individuals developed this dementing brain disease.
Prompt diagnosis and treatment of syphilis will prevent the development
of dementia.
|
Factoid Did you know that Randolph Churchill, the father of the famous English Prime Minister Winston Churchill had syphilitic brain disease? |
Korsakoff's psychosis (brain effects of severe alcoholism)
Chronic long term alcoholism can lead to a condition called Korsakoff's
psychosis which features dementia as well as other symptoms. This condition
does not occur until after many decades of alcohol abuse. To learn more
about alcohol abuse as it relates to aging click on the following:
Jacob-Creutzfeldt Sydrome
Jacob-Creutzfeldt Syndrome is a rare condition which features the rapid
progression of dementia. It is a prion disease caused by an infectious
agent which attacks the brain of affected individuals.. Prion diseases
were called "slow virus" diseases because of the long time
between infection and the display of any signs of symptoms. While Jacob-Creutzfeldt
Syndrome develops spontaneously, it can also be acquired through the
transplantation of human tissues. Several individuals have developed
the disease through administration of growth hormone derived from human
brains and from kidney and eye tissue transplantation.
|
Factoid Two American scientists received Nobel Prizes for their work on Prion diseases: Dr. Carton Guidesek for identifying that these diseases could be transmitted by infection and Dr. Stanley Prusiner who was able to determine the molecular nature of prions. |
HIV (Human Immunodeficiency Virus)
HIV is a viral disease transmitted through sexual contact, intravenous drug use and through contact with human blood. It primarily attacks and weakens the immune system. But it also frequently effects the brain and can produce dementia. HIV infection can be controlled by treatment with several drugs. It is not clear yet that HIV can be totally cured or the dementia totally prevented through this treatment. [Back to Conditions]
Metabolic encephalopathy (poor diabetes control and other metabolic conditions)Poor control of diabetes that results in very high or very low blood
sugar levels can lead to metabolic changes within the brain that produce
delirium. If uncontrolled for long enough time, it can result in a dementia-like
condition called metabolic encephalopathy. To learn more about diabetes
click on the following:
This form of dementia can develop rapidly and can occur at earlier ages than Alzheimer disease. Patients with this condition have balance difficulties and falls, hallucinations and muscular rigidity. This disease features a severe decrease of the brain chemical acetycholine. Treatment with Tacrine and Aricept, which can increase brain acetylcholine levels can be useful in the early stages of this condition. [Back to Conditions]
