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.
