What is Dementia?
Dementia is a decline in
cognitive function. It may affect memory, thinking, language, judgment, and
behavior. To be considered dementia, mental impairment must affect at least two
brain functions. It may also cause personality changes.
Dementia is not a disease. It may
be caused by a variety of illnesses or injuries. Mental impairment may range
from mild to severe. Some dementias are progressive, which means they get worse
over time. Some dementias are treatable or even reversible. Some experts
restrict the term dementia to irreversible mental deterioration.
What Causes Dementia?
Dementia can be caused by degeneration of neurons (brain cells), or by disturbances in other
body systems that affect how neurons function.
Several conditions can cause dementia, including diseases of the
brain. The most common such causes are Alzheimer’s disease and vascular
that neurons gradually degenerate (cease to function or function
inappropriately and eventually die). This impacts the neuron-to-neuron
connections, called synapses, which are
how messages are passed along in your brain. This “disconnect” can
result in a range of dysfunction.
Some of the more common causes of dementia include:
- Alzheimer’s disease
- Parkinson’s disease with dementia
- vascular dementia
- medication side effects
- chronic alcoholism
- certain tumors or infections of the
Another cause is frontotemporal lobar degeneration, which is a blanket term for a
range of conditions that cause damage to the frontal and temporal lobes of the
brain. They include:
- Pick’s disease
Other Causes of Dementia
Dementia may also be caused by
- structural brain disorders
- normal-pressure hydrocephalus (increased pressure on the brain due
to the buildup of cerebrospinal fluid)
- subdural hematoma (a collection of blood on the surface of the
- metabolic disorders
- vitamin B-12 deficiency
- kidney and liver disorders
- toxins, such as lead
Some of these dementias may be reversible. This is one of the many
reasons why it is important to see your doctor and get a medical workup as soon
as symptoms develop.
Isn’t Forgetfulness a Normal Part of Aging?
absolutely normal to forget things once in a while. Memory loss by itself does
not mean you have dementia. However, there is a difference between occasional
forgetfulness and forgetfulness that is cause for serious concern.
Potential red flags for dementia include:
- forgetting who someone is
- forgetting how to do common
tasks (such as how to use the telephone or find your way home)
- Inability to comprehend and/or retain information that has been
Seek medical attention if you experience any of the above.
Getting lost in familiar settings (driving to the supermarket, for
example), is often one of the first signs of dementia.
How Common Is Dementia?
Manual states that approximately five percent of people aged 65 to 74 years
and 40 percent of people older than 85 years have some form of dementia.
number of people diagnosed with and/or living with dementia is increasing. This
is at least in part due to increasing life expectancy. By 2030, the size of the
population 65 years of age and older in the U.S. will have increased from 37
million people (in 2006) to an estimated 71.5 million, according to the U.S.
What Research is Being Done?
all over the world are working hard to gain a better understanding of the many
different aspects of dementia. This might help to develop preventive measures
(such as a vaccine), improved early detection diagnostic tools, better and
longer-lasting treatments, and even cures.
For example, a vaccine known as a bapineuzumab jab is currently in
its final phase of testing. Though it
cannot cure dementia or related disorders, this vaccine has been shown to
prevent, and in some cases reverse, the buildup of amyloid plaques in the
brain. Amyloid plaques—which
are the hallmark of Alzheimer’s disease—are dense, mostly insoluble (not
dissolvable) clumps of protein fragments that deposit a highly damaging gunky
substance outside and around the
brain’s nerve cells.
Scientists are also investigating genetic factors, various
neurotransmitters, the role of inflammation, factors that influence programmed
cell death in the brain, the roles of tau (a protein found in neurons of the central nervous system),
and the possible roles of oxidative stress (i.e., chemical reactions that can
damage proteins, DNA, and lipids/fats inside cells) in the development of
dementia. Such research can help doctors and scientists better understand what causes
dementia, and in turn, how best to treat and possibly prevent the disorder.
also increasing evidence that lifestyle factors, such as getting regular
exercise and maintaining social connections, may be effective ways to decrease
the risk of developing dementia.