Symptoms
Symptoms of Alzheimer’s disease are divided into two categories
: cognitive, or intellectual, and
psychiatric.
Differentiating them is important so that behavioral problems that are caused by loss of cognitive
functioning are not treated with anti-psychotic or anti-anxiety medications.
The clinical symptoms of Alzheimer’s disease vary
, depending on the type of disease causing it, and
the location and number of damaged brain cells. With Alzheimer’s disease, manifestation of all of these
symptoms is quite probable; with other types of Alzheimer’s disease, it is possible to have some or all of these
symptoms.
Cognitive, or intellectual, symptoms are amnesia, aphasia, apraxia and agnosia.
Amnesia
is defined as loss of memory, or the inability to remember facts or events. We have two types of
memories: the short term (recent, new) and long term (old) memories. Short termmemory is programmed
in a part of the brain called the temporal lobe, while long termmemory is stored throughout extensive nerve
cell networks in the temporal and parietal lobes.
In Alzheimer’s disease,
short termmemory storage is damaged first. Aphasia is the inability to communicate
effectively. The loss of ability to speak and write is called expressive aphasia. An individual may forget words
he has learned, and will have increasing difficulty with communication. With receptive aphasia, an individual
may be unable to understand spoken or written words or may read and not understand a word of what
is read. Sometimes an individual pretends to understand and even nods in agreement; this is to cover up
aphasia. Although individuals may not understand words and grammar, they may still understand nonverbal
behavior, i.e., smiling. Apraxia is the inability to do preprogrammed motor tasks, or to perform activities of
daily living such as brushing teeth and dressing. An individual may forget all motor skills learned during
development. Sophisticated motor skills that require extensive learning, such as job related skills, are the first
functions impaired by Alzheimer’s disease. More instinctive functions like chewing, swallowing and walking
are lost in the last stages of the disease. Agnosia is an individual’s inability to correctly interpret signals
from their five senses. Individuals with Alzheimer’s disease may not recognize familiar people and objects.
A common yet often unrecognized agnosia is the inability to appropriately perceive visceral, or internal,
information such as a full bladder or chest pain
Major psychiatric symptoms include:
Personality changes, depression, and hallucinations & delusions.
Personality changes
can become evident in the early stages of Alzheimer’s disease. Signs include irritability,
apathy, withdrawal and isolation. Individuals with Alzheimer’s disease may show symptoms of depression at
any stage of the disease. Depression is treatable, even in the latter stages of Alzheimer’s disease.
Psychotic symptoms
include hallucinations & delusions, which usually occur in the middle stage of
Alzheimer’s disease. Hallucinations occur in about 25 percent of Alzheimer’s disease cases and are typically
auditory and/or visual. Sensory impairments, such as hearing loss or poor eyesight, tend to increase
hallucinations in the elderly with Alzheimer’s disease. Delusions affect about 40 percent of individuals with
Alzheimer’s disease.
Hallucinations & delusions
can be very upsetting to the person with Alzheimer’s disease. Common
reactions are feelings of fear, anxiety and paranoia, as well as agitation, aggression and verbal outbursts.
Individuals with psychiatric symptoms
tend to exhibit more behavioral problems than those without these
symptoms. It is important to recognize these symptoms so that appropriate medications can be prescribed
and safety precautions can be taken.
Psychotic symptoms
can often be reduced through the carefully supervised use of medications. Talk to your
primary care doctor, neurologist or geriatric psychiatrist about these symptoms because they are treatable.
Dementia Defined
Dementia is a general term that describes a
group of symptoms such as loss of memory,
judgment, language, complex motor skills,
and other intellectual function caused by
the permanent damage or death of the
brain’s nerve cells, or neurons.
One or more of several diseases, including
Alzheimer’s disease, can cause dementia.
Alzheimer’s disease is the most common
cause of dementia in persons over the age
of 65.
It represents about 60 percent of all
dementias. The other most common causes
of dementia are vascular dementia, caused
by stroke or blockage of blood supply,
and dementia with Lewy bodies. Other
types include alcohol dementia, caused by
sustained use of alcohol; trauma dementia,
caused by head injury; and a rare form of
dementia, frontotemporal dementia.
The clinical symptoms and the progression
of dementia vary, depending on the type
of disease causing it, and the location
and number of damaged brain cells.
Some types progress slowly over years,
while others may result in sudden loss of
intellectual function.
Each type of dementia is characterized by
different pathologic, or structural, changes
in the brain, such as an accumulation of
abnormal plaques & tangles in individuals
with Alzheimer’s disease, and abnormal tau
protein in individuals with frontotemporal
dementia.