One of the acquired language disorders is dementia. Dementia, as
referred by Owen, Cummings and Benson, is a kind of disorder that is
characterized by intellectual decline due to chronic neurogenic causes that can
affect several aspects of mental activities including language, memory,
cognition and the processing of visual-spatial information. According to
Diagnostic and Statistical Manual 5 (DSM-V), it is stated, “Dementia is the
development of multiple cognitive deficits that include memory impairment and
at least one of the following: aphasia, apraxia, agnosia or a disturbance in
executive functioning”. Since 1990s, developing countries were expected to have
higher rate of dementia like in China who had seen a doubling in the prevalence
of Alzheimer disease alongside its rapid development (Mathers & Leonardi,
2000). In general population, Alzheimer disease has become among six leading causes
of death in United States and it is also projected that by 2050, 1.6 million of
43% of older adults’ death will be due to Alzheimer disease. Plus, Owen also
stated that Alzheimer’s disease accounts for over 50% of the dementia cases and
may affect 20 million people worldwide.
Etiologies
The most common etiologies of
dementia include progressive disease and terminal illnesses. These etiologies
can be divided into cortical, subcortical and mixed categories. The division is
made based on the areas of the brain that they affect the most. For cortical
dementias, they are created generally by the degeneration of the cerebral
cortex. On the other hand, subcortical dementias are created by the
degeneration of subcortical structures while the mixed dementias result from
pathologic changes to the cortex and subcortex.
Characteristics
of dementia
People with dementia may be observed by the progress of their
functional skills that range from low to rapid decline as dementia is
characterized by the progressive decline of the mental activities. Dementia can
be progressing from mild to moderate and severe deficits.
Individuals with mild dementia may depict forgetfulness even in
basic information like their identity and in common routines like eating,
dressing and basic hygiene. They also suffer memory problems as they tend to
misplace items, miss appointments or forget familiar phone numbers. For speech
and language, at this stage, people with dementia are usually lacked of
vocabularies making them less likely to perform in verbose conversation and to
have problem in naming and word retrieval which so called anomia. Despite of
difficulty in remembering information, their language comprehension, pragmatics
and social skills are well preserved. Plus, they have intact motor function
allowing them to walk, eat and use the bathroom like other people do.
The next stage is moderate dementia. People with this level of
dementia exhibit poor attention and are increasingly disoriented in time and
place. They often forget the current time and get lost in a familiar
environment such as home. Other than having poor memory, people at this stage
of dementia do experience language difficulties in word-finding and repetition
due to reduced vocabularies. They also have problem in abstract thinking that
they hardly understand metaphors, sarcasms and humour. However, at this stage,
their motor skills are still adequate for walking and eating, although
restlessness is likely.
The final stage is severe dementia. At this stage, the language
skills are profoundly compromised. There will be frequent repetitions and
jargon and limited meaningful communication. In fact, their comprehension
skills are severely impaired.
Characteristics
of Alzheimer’s disease
Apart of all etiologies, Alzheimer disease is the most common one
that leads to dementia. It often results in dementia that the symptoms of
dementia and Alzheimer’s disease are almost the same. The cause of Alzheimer’s
disease is unknown but may be combination of genetic and environmental factors
where nerve fibers degenerate resulting in brain atrophy that may decrease
brain weight as much as 20 percent (Kemper, 1984; Koo & Price). The most
obvious changes that accompany Alzheimer’s disease are memory problem where
long-term memory is intact initially but deteriorates by time as the disease
progresses. Meanwhile, Alzheimer’s disease affects the speech and language
according to level severity.
During the initial stage, the
difficulties involve word-retrieval, off-topic conversations and comprehension.
Later, they will start to develop paraphasia especially in semantic aspect of
language. For example, they tend to use the incorrect word to refer to
something that has related characteristic with something else like using “sudu”
(spoon) to refer to “garfu” (fork).
Next, during the middle stage, people with Alzheimer’s disease may
exhibit reduced repetition span, speech sound and intelligibility, and the
ability of reading and writing. Due to language comprehension problem, they tend
to produce empty speech with grammatical simplification. In addition, they also
show phonological aphasia in which they substitute a word with nonword that
preserves at least half of the segments or syllables of intended word. In final
stage, their language and speech is characterized by severe naming and
syntactic errors, jargon, echolalia, logoclonia, palilalia and dysarthria.
Reference
1. M., M., S., A., M., & D. (2018).
Dementia, Alzheimer’s Disease, and Mortality after Hemodialysis Initiation.
Clinical Journal of the American Society of Nephrology, 13, 1341-1347.
2. M.H. Manasco
(2014) Introduction to Neurogenic Communication Disorders (1st Ed.).
Jones & Barlett Learning.
3. Owens, R.E.,
Mertz, D.E, Haas,A. (2003). Introduction to Communication Disorders: A Lifespan
Perspective (2nd ed. ). Boston: Pearson, Allyn and Bacon.
4. Laura M.J,
Erin E. Redle (2006). Communication Sciences And Disorders: A Clinical
Evidence-Based Approach ( 3rd Ed.) Boston: Pearson.
