 Dysarthria
is a speech disorder that is due to a weakness or incoordination
of the speech muscles. Speech is slow, weak, imprecise or
uncoordinated. It can affect both children and adults.
"Childhood dysarthria" can be congenital or acquired. It is
often a symptom of a disease, such as cerebral palsy, Duchenne
muscular dystrophy, myotonic dystrophy, Bell palsy. In both
adults and children, it can result from head injury.
In adults, dysarthria is can be caused by stroke,
degenerative disease (Parkinson's, Huntington's, amyotrophic
lateral sclerosis, multiple sclerosis, myasthenia gravis),
infections (meningitis), brain tumours, and toxins (drug or
alcohol abuse, lead poisoning, carbon monoxide, etc.).
In order for speech to be clear, a number of
subsystems must work together. A weakness in any one of the
systems can result in dysarthria. So can an incoordination
between systems. The lungs (respiratory subsystem) supply the
air necessary to power the speech system. The voice box or
larynx (laryngeal) sets the air vibrating and creates voice. The
soft palate (velopharyngeal) acts a door between the oral and
nasal cavities and channels air to one or both cavities
resulting in different sound quality. The lips, tongue, teeth,
and jaw (articulatory) move to further channel and shape the
sounds into the various vowels and consonants.
If the respiratory subsystem is weak, then
speech may be too quiet and produced one word at a time. If the
laryngeal system is weak, speech may be breathy, too quiet and
slow. If the velopharyngeal subsystem is not working, speech may
sound too nasal or nasal sounds may be misssing. If the
articulatory subsystem is not working, speech may sound slurred,
may have many errors and may be slow and laboured.
Therapy for dysarthria focuses on maximizing
the function of all systems. Compensatory strategies are often
used. Individuals with dysarthria may be advised to take
frequent pauses for breath, to over-articulate, or to pause
before important words to make them stand out. If there is
muscle weakness, they may benefit from performing oro-facial
exercises. This helps to strengthen the muscles of the face and
mouth that are used for speech.
For some people, speech is not a viable
option. Alternative or augmentative systems are frequently used.
These can be low tech or high tech. An example of a low tech
system would be an alphabet board. The individual points to
letters to spell out messages. "Pic-syms" are picture symbols,
black and white line drawings with print that can be combined on
a communication board or book. The individual points to the
appropriate picture or combination of pictures to communicate.
High tech systems include computers and voice output devices. A
regular computer keyboard, monitor and word processor can be
used to type out and display messages. Programs that predict
words and sentences can speed up this method of communicating.
Some indivduals are unable to read and have a computer system
that uses symbols - they select a symbol and the printed word is
produced. Voice output systems are similar to the computer
setups already described but rather than having the printed word
as output, the spoken word is produced. Simple devices have the
ability to let an individual access a limited number of
pre-recorded phrases by pushing the appropriate key. More
complex systems allow for creative productions. Any of these
systems can be used as a back-up by individuals who do have some
functional speech. There are times when it is too tiring or too
time-consuming to use speech. Then the alternative system is
used.
Most dysarthric speakers need more time to get
their message across. It helps to allow them extra time and to
listen face to face. When you haven't understood what they've
said, it's better to say so than to pretend you have understood.
It helps to repeat the part that you did understand as a
question, so they only have to repeat the part you didn't get.
For example, if you hear "I would like a XX", rather than saying
pardon and getting a repetition that may sound the same, try
asking "You would like a... ?" with rising inflection, or "What
would you like?" If a person is using an augmentative device,
consider it to be valid and equal to speech. Don't insist that
they "say it" if you have understood they message they sent by
the augmentative system.
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