Dementia is
the loss of a person's cognitive, or intellectual, function. those
conscious mental tasks that we perform every waking second of
every day, from remembering our name to performing complicated
mathematical calculations. Memory is one of the most essential
cognitive functions, and it is the often the first and most crucial
one that dementia impairs. Dementia also affects problem-solving
ability, decision making, judgment, our ability to orient ourselves
in space, and our ability to put together simple sentences and
understand and communicate with words. It is also often associated
with personality change. Dementia is a permanent, progressive
disease that affects mostly the elderly. People who suffer from
dementia eventually are unable to take care of themselves and
require round-the-clock care.
Vascular dementia:
Is the second most common cause of dementia, accounting for about
20 per cent of all cases by itself and up to another 20 per cent
in combination with Alzheimer’s
Disease. It usually affects people between the ages of 60
and 75 and is slightly more common in men than women. Vascular
dementia is a term for dementia associated with problems in the
circulation of blood to the brain (cerebrovascular disease). It
encompasses a wide range of diseases or disorders, the principal
feature of which is loss of intellectual abilities.
Binswanger's Disease
Binswanger’s Disease is a subcortical vascular dementia
which was once considered rare but is now being reassessed, and
may be relatively common. As with other vascular dementias, it
is associated with stroke-related changes. It is the ‘white
matter’ deep within the brain that is affected. It is caused
by high blood pressure, thickening of the arteries and inadequate
blood flow.
Symptoms often include slowness and lethargy, difficulty walking,
emotional ups and downs and lack of bladder control early in the
course of the disease, with gradually progressive dementia developing
later. Most people with Binswanger’s disease have or have
had high blood pressure.
Multi-Infarct
Dementia:
Among the
different types of vascular dementia that have been identified,
multi-infarct dementia
(MID) is probably the most common. MID is caused by a number of
small strokes, called ministrokes. These strokes may be silent
in that no one may be aware they have occurred, but they can be
seen on various brain scans. Sometimes the brain is damaged but
not dead as a result of inadequate blood flow. This is called
ischaemia. If ischaemia is severe, it causes an infarct. Some
people also incorrectly use MID as a term for all types of vascular
dementia.
Differential
Diagnosis
Some disorders have similar symptoms. The clinician, therefore,
in his diagnostic attempt has to differentiate against the following
disorders which need to be ruled out to establish a precise diagnosis.
Sometimes
people experience symptoms that resemble dementia but are perfectly
normal or associated with some other illness. Forgetfulness, for
example, is something that can happen at any age. Isolated incidents
of temporary memory loss or other temporary cognitive impairments
are not considered dementia. A person, who has never been fully
competent and has always had dementia-like symptoms, unless the
symptoms progress, does not have dementia.
Cause:
There are
50 different causes of dementia, including neurological disorders
such as Alzheimer's disease,
vascular disorders such as multi-infarct disease, inherited disorders
such as Huntington's disease, and infections such as HIV.
The most common
cause of dementia is Alzheimer's
disease. It is estimated that as many as 50% to 70% of all
people who suffer from dementia have Alzheimer's.
However, some researchers suspect that this may be an overestimate
due to the tendency for people to too quickly assume that if an
elderly person is showing signs of dementia then they must have
Alzheimer's. Diagnostic tests, ranging from neuropsychological
exams to brain imaging studies, are essential for identifying
the cause of dementia. Some forms of dementia are treatable, or
partially treatable. A proper diagnosis allows for a more accurate
prognosis and also helps prepare friends and family to cope better
with the situation.
The most common
causes of dementia include degenerative neurological diseases
such as Alzheimer's, Parkinson's
and Huntington's; vascular disorders as when multiple strokes
in the brain lead to what is called multiple-infarct dementia;
infections that affect the central nervous system, for example,
dementia complex caused by the HIV virus and Creutzfeldt-Jakob
disease; chronic drug use; depression ("pseudodementia");
and certain types of hydrocephalus, an accumulation of cerebrospinal
fluid in the ventricles of the brain that can result from developmental
abnormalities, infections, injury, or brain tumors.
Causes
of Vascular Dementia:
Vascular dementia can be caused in several different ways. Most
commonly there is blockage of small blood vessels (arteries) deep
within the brain. When any part of the body is deprived of blood,
which carries oxygen and nutrients, it dies - this is called an
infarct. When brain tissue dies it is also called a stroke. Blockages
may be caused by build up of plaque on the inside of the arterial
wall or by clots which have broken off, jamming a smaller tributary
upstream. Clots can also result from abnormal heart rhythms, or
other heart pathology, or can form on the inside of the major
cartoid arteries that run up the side of the neck and supply the
brain.
Other Conditions
Relating to the Cause of Dementia:
HIV related
dementia
Parkinson's Disease
Down's Syndrome
Huntington's Disease (HD)
Transmissible Dementias
Creutzfeldt-Jakob Disease
Kuru
Gerstmann-Straussler-Scheinker disease
Treatment:
Because vascular dementia is caused by strokes, the risk factors
for vascular dementia are the same as those associated with stroke,
high blood pressure, diabetes, high cholesterol and heart disease.
To a large extent, these risk factors are controllable, unlike
the only solidly established risk factors for Alzheimer’s
disease, age, family history and Down
syndrome and Apolipoprotein E status.
While no treatment can reverse damage that has already been done,
treatment to prevent additional strokes is very important. To
prevent additional strokes, medicines to control high blood pressure,
high cholesterol, heart disease and diabetes can be prescribed.
However,
a few causes of dementia are treatable. Treatable causes include
normal pressure hydrocephalus,
brain tumors, and dementia due to metabolic causes. However, many
of the disorders associated with dementia are progressive, irreversible,
degenerative conditions.
Sometimes
aspirin or other drugs are prescribed to prevent clots from forming
in the small blood vessels. Drugs can also be prescribed to relieve
restlessness or depression or to help the person with vascular
dementia sleep better. In some cases, surgery known as carotid
endarterectomy may be recommended to remove blockage in the carotid
artery, the main blood vessel to the brain.
Counseling
and Psychotherapy [
See Therapy Section ]:
The provision
of a safe environment, control of aggressive or agitated behavior,
and the ability to meet physiologic needs may require monitoring
and assistance in the home or in an institutionalized setting.
This may include in-home care, boarding homes, adult day care,
or convalescent homes.
Visiting nurses or aides, volunteer services, homemakers, adult
protective services, and other community resources may be helpful
in caring for the person with organic brain syndrome. In any care
setting, there should be familiar objects and people. Lights that
are left on at night may reduce disorientation. Behavior modification
may be helpful for some people in controlling unacceptable or
dangerous behaviors. This consists of rewarding appropriate or
positive behaviors and ignoring inappropriate behaviors (within
the bounds of safety). Reality orientation, with repeated reinforcement
of environmental and other cues, may help reduce disorientation.
Family counseling may help in coping with the changes required
for home care.
Pharmacotherapy
[ See
Psychopharmacology Section ] :
The goal of
treatment is to control the symptoms of dementia. Treatment varies
with the specific disorder. Hospitalization may be required for
a short time. The underlying causes should be identified and treated,
including treatment for reversible organic lesions (such as tumors).
Correction of coexisting medical and psychiatric disorders often
greatly improves mental functioning. Medications may be required
to control aggressive or agitated behaviors or behaviors that
are dangerous to the person or to others. These are usually given
in very low doses, with adjustment as required. Medications that
may be considered for use include:
Anti-Psychotics.
Beta Blockers if dementia is related to central nervous system
lesions.
Serotonin-Affecting Drugs - lithium, trazodone, buspirone, clonazepam.
Dopamine Blockers.
Carbamazepine.
Fuoxetine, Imipramine.
Stimulant drugs - such as methylphenidate- may improve mood.
