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Dementia
What Is Dementia?
| Dementia is the progressive decline in cognitive
function due to damage or disease in the brain beyond what might be
expected from normal aging. Particularly affected areas may be memory,
attention, language and problem solving, although particularly in the
later stages of the condition, affected persons may be disoriented in
time, not knowing what day, week, month or year it is, not knowing
where they are not knowing who they are. |
Types of Dementia
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According to the cause, dementia may either be:
Primary dementia
is found in about 80 to 90 percent of cases and is caused by
pathological changes in the brain cells or cerebral vessels. While
these changes are also apparent in secondary dementia, these are the
result of other diseases. This is true in 10 to 20 percent of cases.
Secondary
dementia usually follows diseases alike brain tumors or
multiple head injuries that can lead to subdural hematoma (the
accumulation of blood in the skull). Not a few boxers have died because
of this. An unrecognized infection can also cause secondary dementia.
Formerly, the culprit here was syphilis but now all eyes are on Lyme
disease - a frequent cause of dementia.
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Causes of Dementia
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One of the biggest risk factors for
most types of dementia is age. Although some forms of dementia may
affect those under 50 – some even occur in children – the risk of
dementia occurrence increases rapidly as people age. For example, the
number of people with Alzheimer's disease doubles every five years
after the age of 65, according to the National Institute of
Neurological Disorders and Stroke (NINDS). However, it is important to
note that dementia is not part of the normal aging process. Some people
have a long lifespan and experience only a very slight mental decline.
Another important risk factor for many forms of dementia is genetics
and family history. Some forms of dementia can be traced to genetic
abnormalities. This is the case with Huntington’s disease, which is
passed from parent to child through a gene mutation. Additionally,
people who have a sibling or parent with Alzheimer's disease are more
likely to develop the disease themselves. This risk is even greater if
more than one member of the family has been diagnosed with Alzheimer's
disease. The specific relationship between genetics and dementia is
still being studied.
Some
causes of dementia include:
1. Stroke:
A stroke is a life-threatening event in which part
of the brain is deprived of adequate oxygen (hypoxia). Also known as a
cerebrovascular accident (CVA) or a “brain attack,” a stroke occurs
when a blood vessel in the brain bursts or becomes clogged by a blood
clot or other mass. This prevents oxygen and nutrients from traveling
to nerve cells in the affected area of the brain. These nerve cells can
die within minutes, and the area of the body they control can cease to
function. In many cases, this damage is permanent, especially if the
patient is not treated immediately. Stroke is the most common cause of
vascular dementia..
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2.
Brain injury: Dementia may occur following a traumatic
head injury, depending on which part of the brain is affected. Repeated
concussions (such as those sustained while boxing) increase the risk
for dementia pugilistica, a form of dementia that can also result in
Parkinson-like symptoms.
3.
Malnutrition or metabolic disorders: Malnutrition is
defined as the deficiency in one or more vital nutrients. Many people
are malnourished without realizing it, especially if they do not eat a
balanced diet. Deficiency in any of the B vitamins may result in
dementia. Some people are unable to absorb or metabolize certain
vitamins or minerals, which may lead to dementia. In some cases,
treatment for malnutrition or metabolic disorders may reverse the
dementia.
4.
Infections: Some infections, especially those that cause
high fever, can cause many of the symptoms of dementia. These are often
resolved once the infection has been treated. Infections that directly
affect the brain, such as human immunodeficiency virus (HIV) and
meningitis, can result in more severe and possibly permanent brain
damage and dementia. An untreated infection with the sexually
transmitted disease syphilis can lead to tertiary syphilis, which can
include symptoms of dementia.
5.
Medication reactions: Some medications can cause memory
loss and other symptoms of dementia as a side effect. These may include
medications used to treat depression, seizures or Parkinson’s disease.
Additionally, some medications interact with other substances to
produce symptoms similar to dementia. People who experience symptoms of
dementia should inform their physician of all medications they are
taking. They should also consult with their physician about any vitamin
supplements, topical treatments or over-the-counter products they are
taking.
6.
Drug and alcohol use: Abusing most illegal drugs may lead
to symptoms of dementia, which can normally be resolved once the
substances are removed from the body. Severe alcohol abuse, especially
heavy drinking followed by sudden withdrawal, can lead to a permanent
form of dementia called Wernicke-Korsakoff disorder.
7.
Poisoning: Some substances such as lead and mercury can
cause dementia if people are exposed to unsafe levels. Mercury
poisoning is generally associated with broken thermometers or working
in a thermometer factory. Lead poisoning is more common and can occur
after exposure to lead-based paint used in older homes, breathing
contaminated air or eating contaminated food.
8.
Brain tumor or lesion: Tumors or brain lesions, which can
cause pressure to build up in the brain, can disrupt the function of
neurons. This can lead to symptoms of dementia. In certain cases,
removal of the tumor or lesion can restore cognitive function, although
sometimes the damage may be permanent.
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Clinical Features of Dementia
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Symptoms of dementia can be classified as either
reversible or irreversible depending upon the etiology of the disease.
Less than 10% of all dementias are reversible. Dementia is a
non-specific term that encompasses many disease processes, just as
fever is attributable to many etiologies.
Early symptoms of dementia often consist in changes in
personality, or in behavior. Often dementia can be first evident during
an episode of delirium. There is a higher prevalence of eventually
developing dementia in individuals who experience an acute episode of
confusion while hospitalized.
Dementia can affect language, comprehension, motor
skills, short-term memory, ability to identify commonly used items,
reaction time, personality traits, and executive functioning. Even
without signs of general intellectual decline, delusions are common in
dementia (15-56% incidence rate in Alzheimer's type, and 27-60%
incidence rate in multi-infarct dementia). Often these delusions take
the form of monothematic delusions, like mirrored
self-misidentification.
Elderly people can also react with dementia-like
symptoms to surgery, infections, sleep deprivation, irregular food
intake, dehydration, loneliness, change in domicile or personal crises.
This is called delirium, and many if not most dementia patients also
have a delirium on top of the physiologial dementia, adding to the
symptoms.
The delirium can go away or greatly improve when treated
with tender care, improved food and sleeping habits, but this does not
affect the alterations in the brain. Affected persons may also show
signs of psychosis or depression. It is important to be able to
differentiate between delirium and dementia.
Proper differential diagnosis between the types of
dementia will require, at the least, referral to a specialist, e.g. a
geriatric internist, geriatric psychiatrist or neurologist. However,
there are some brief 5-15 minute tests that have good reliability and
can be used in the office or other setting to evaluate cognitive status.
Except for the treatable types listed above, there is no
cure to this illness, although scientists are progressing in making a
type of medication that will slow down the process.
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Diagnosis
People who are concerned about a decline in cognitive
function, including memory loss or unusual changes in mood or behavior
should consult their physician as soon as possible.
- Diagnosis will usually begin with a medical history
and a physical examination. People are encouraged to keep a log of
their symptoms to report to their physician. A physician may also ask
family members or close friends about the nature of the patient’s
symptoms. During the medical history, the physician may ask questions
related to the patient’s dietary habits and use of alcohol in order to
establish potential causes of dementia that can be reversible. During
the physical examination, the physician will likely assess neurological
function by testing the patient’s reflexes, balance and coordination.
- A physician may conduct a mental status examination
to assess the patient’s stage of dementia. During the exam, the
physician may ask the patient a variety of questions aimed at testing
the patient’s awareness of surroundings, problem solving skills and
memory skills. Examples of items on the test may include:
- Situational questions such as “What year is it?” or
“What is the address of this office?”
- Remembering and recalling a short list of items (e.g.
a ball, a pencil, a dog)
- Counting backwards or spelling a word backwards
- Naming familiar objects in the room as the physician
points to them
- Following simple instructions or writing a simple
sentence. This test can also be used after diagnosis to
evaluate the progression of dementia in the patient.
- Additionally, blood and urine tests may be performed
to test for conditions that cause dementia. These may include tests for
vitamin deficiencies, poisoning or infections. A sample of spinal fluid
may also be taken using a spinal tap to test for infections of the
brain or spine.
- Imaging tests, such as magnetic resonance imaging
(MRI) tests and computed axial tomography (CAT) scans may be used to
identify signs of brain abnormalities that may be the result of injury,
stroke or a tumor. This enables physicians to identify the underlying
cause of the dementia or to take steps towards preventing potential
causes of dementia (e.g. strokes). However, imaging tests have
limitations and are unable to identify many of the brain abnormalities
that are the hallmark of progressive dementias such as the plaques and
tangles of Alzheimer's disease and the Lewy bodies of Lewy body
dementia.
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Treatment
Treatment for dementia often relies on treating the
underlying cause. If dementia is caused by medication interactions or
drug or alcohol abuse, it may be possible to reverse the dementia by no
longer taking the medication or substance. In some cases, dementia
caused by a brain tumor or lesion may be treated and resolved by
removing the tumor or lesion. However the damage the tumor or lesion
caused to brain tissues and function can be permanent.
In the case of progressive dementias or dementias that are caused by
brain injury, there is rarely a cure. However, there are treatment
options available that can minimize or stabilize patients’ symptoms and
in some cases delay the necessity of nursing home care.
There are certain medications that a physician may prescribe to try to
reduce the symptoms of dementia. Some of these medications are designed
to maintain the levels of a neurotransmitter in the brain called
acetylcholine, which is important for brain function. Other medications
work to regulate the function of the neurotransmitter glutamate, which
is important for learning and memory.
Behavioral or psychiatric symptoms due to dementia may first be treated
with non-drug methods. This usually includes identifying the trigger
for the symptoms and attempting to resolve it. Many times this involves
making adjustments to the environment that the patient lives in – for
example, simplifying the environment or increasing the time between
stimulating events (e.g. bath-time, getting dressed).
In addition to non-drug methods, a physician may recommend certain
medications to control behavioral or psychiatric symptoms. It is
important that these medications be used according to physician
instructions. People with dementia are more likely to experience severe
side effects from these medications than other people. Medications that
may be prescribed for patients with behavioral or psychiatric symptoms
include:
Antidepressants to treat depression and low moods
Anti-anxiety medications to treat anxiety or verbally disruptive
behavior
Anti-psychotic medication to treat hallucinations, delusions or
aggression
Sedatives to treat sleep problems
Some companies market herbal supplements as alternative treatment
methods for dementia. However, in most cases, these treatments have not
been thoroughly tested. In addition, unlike prescribed medication, they
have not been approved and are not regulated by the Food and Drug
Administration (FDA). It is important to discuss the use of alternative
treatment methods with a physician before they are started. Some
alternative remedies could interact with prescribed medication or lead
to more serious health complaints.
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