Dysarthria in Communication
types of dysarthria affect the articulation of consonants,
causing the slurring of speech. In very severe cases, vowels
may also be distorted. Intelligibility varies greatly
depending on the extent of neurological damage.
Hypernasality is frequently present as are problems with
respiration, phonation and resonance.
You will recall
that it is due to damage to the pyramidal tract. This
direct, mono-synaptic tract is predominantly facilitatory.
That means its cell bodies send impulses that result in
movement, along its axons. The principle result of damage is
difficulty with fine motor movements. This is due to
exaggerated stretch reflexes, resulting in increased muscle
tone and incoordination. All of the cranial nerves except
VII and XII are stimulated bilaterally by the cortico bulbar
tracts. Bi-lateral lesions on those tracts result in a much
more severe dysarthria than unilateral lesions. However,
unilateral lesions on a cortico-bulbar tract will affect
cranial nerves VII (facial movement) and XII (tongue protrusiont).
Since the other cranial nerves recieve signals from both
cortico-bulbar tracts, the muscles they innervate are barely
affected. Thus, one would not expect problems with the lips,
cheecks, throat, velum, or larynx. With bi-lateral
cortico-bulbar lesions all of the above, and more, would be
quality is harsh. Sometimes the voice of a patient with
spastic dysarthria is described as strained or strangled
(Duffy, 1995). Pitch is low, with pitch breaks occurring in
Hypernasality typically occurs, but
is usually not severe enough to cause nasal emission.
of loudness are sometimes noted in the speech of patients
with spastic dysarthria.
According to Duffy (1995) range of
movement, tongue strength, speech rate and voice onset time
for stops are reduced. There is an increase in phoneme to
phoneme transitions, in syllable and word duration, and in
voicing of voiceless stops.
above, hyperkinetic dysarthria is usually thought to be due
to lesions of the basal ganglia. Its predominant symptoms
are associated with involuntary movement. There may be
unilateral or bilateral damage.
with spastic dysarthria, vocal quality may be described as
harsh, strained, or strangled. Voice stoppages may occur in
dysarthria associated with dystonia.
Hypernasality is common.
voluntary speech movements are made there is often a
super-imposition of involuntary movements. Speech can range
from total lack of intelligability to a mild problem. There
are many syndromes, several of which are described above,
associated with this problem.
with Parkinson's disease, It is due to a lesion in the
substantia nigra; however, it can also result from
anti-psychotic medications, frequent blows to the head and
other etiologies described above. According to Ferrand and
Bloom, 1997, in order for normal muscle movement to occur
dopaminergic and cholinergic (ACh) pathways must be in
Hoarseness is common in Parkinson's
patients. Also, low volume frequently reduces
Hypernasality may occur
Monopitch and monoloudness may occur.
Pallilalia, or the compulsive repetition of syllables, is
production pattern of patients with Parkinson's disease is
sometimes described as articulatory undershoot.
Bradykinesia (reduced speed of
muscles) associated with Parkinson's disease causes
difficulty in the initiation of voluntary speech. This can
result in delay in starting to talk as well as very slow
speech. According to Duffy (1995), there may be freezing of
movement during speech. Rigidity can also occur.
Additionally, Parkinson's patients have reduced loudness,
imprecise consonant production, reduced pitch variability
and festinating speech. The latter can result in extremely
fast speech together with short rushes of speech (Ferrand
and Bloom, 1997).
This disorder is
due to damage to the cerebellar control circuit. According
to Duffy (1995), it can affect respiration, phonation,
resonance and articulation, but its characteristics are most
pronounced in articulation and prosody.
quality may be harsh. As loudness may vary excessively, and
increased effort is evident, ataxic speech is sometimes
described as explosive speech.
Hypernasality is not common, but may
Patients with ataxic dysarthria tend
to place equal and excessive stress on all syllables spoken.
The term scanning speech has been used in the past to
describe this prosodic pattern. (The name was originally
used by Charcot in reference to the speech of a patient who
spoke very slowly and paused after each syllable). The label
is no longer applied to ataxic dysarthria in order to avoid
confusion as it has been used to describe a variety of
different speech problems.
dysarthric speech could be described as slurred. However,
due to the incoordination caused by cerebellar lesions,
ataxic speech sounds especially slurred. Patients sound
almost inebriated. Gait is affected in the same way.
According to Duffy (1995), it is a breakdown in motor
organization and control. The result is slowness and
inaccuracy in range, force, timing, and direction of
This results from
damage to the lower motor neurons (cranial nerves) involved
X is damaged, voice will be affected as this nerve
innervates the intrinsic musculature of the larynx.
Occasionally, only one vocal fold is paralyzed. If the fold
is paralyzed in an adducted position, the voice will sound
harsh and have low volume. If the fold is paralyzed in the
abducted position, this will cause breathiness along with a
reduction in loudness. Bilateral vocal fold paralysis is
more common than unilateral paralysis. When the folds are in
an abducted position, the voice is breathy and inspiratory
stridor may be noted. (Of course, paralysis of both vocal
folds in a completely adducted position would constitute a
medical emergency; the airway would be closed off).
Hypernasality will occur if the
muscles involved in velar elevation have been affected.
Frequently, velar movement is reduced sufficiently to cause
Monopitch and monoloudness may both
result from vocal fold paralysis.
Muscles affected by flaccid paralysis
may begin to atrophy or lose mass over time. Also, lack of
innervation may cause fasciculations or twitching of muscle
fibers. These movements are especially visible in the
tongue; its surface may dimple as if worms were moving
beneath its skin.
paralysis of the oral structures may be noted. The affected
side of the mouth may sag, causing drooling, while it will
be drawn to the unparylized side The jaw will deviate toward
the weakened side while the tongue moves toward its stronger
will vary depending on whether the upper or lower motor
neurons remain most intact. For example, if upper motor
neurons are most damaged initially, the voice will sound
harsh. However, if lower motor neurons are most affected,
the voice will sound breathy.
According to Netsell (1984, as cited
in Halperen, 1986), a number of factors influence the
prognosis of dysarthric patients. Among them are:
Neurological status and
by bilateral subcortical lesions, brain stem lesions or
degenerative diseases like ALS have the poorest
In general, the
younger the patient, the better the prognosis. Children are
especially likely to have a good outcome, because of neural
receive treatment, especially coordinated speech, medical,
physical and behavioral treatment have a better outcome than
those who do not.
Personality and Intelligence
Patients who were
purposeful and optimistic before injury have a better
prognosis than those who were not. Those who kept their
minds "active" have a better prognosis than do those who did
patients who receive support form family members and/or
friends have a more favorable prognosis than those who
Dysarthria is treated differently
depending on its severity. Patients with a mild or moderate
form of the disorder can be taught to use strategies that
make their speech more intelligible. Before compensation is
attempted every effort should be made to improve
physiological support for articulation, resonance and
respiration. Patients with mild to moderate dysarthria will
be able to continue to use speech as their primary mode of
communication. Patients whose dysarthria is more severe,
however, may have to learn to use alternative forms of
Dworkin (1991 p.188) recommends the
following sequence of treatments for spastic dysarthria that
with some cautions may be used with other types such as
hyperkinetic , hypokinetic and flaccid. For hyperkinetic and
ataxic dysarthrias, Dworkin feels that in most cases
muscular tone reduction and muscular strengthening exercises
may not be necessary. For flaccid dysarthria muscular tone
reduction would not be required :
labial, and mandibular musculature tone reduction
labial, and mandibular musculature strengthening
labial, and mandibular force physiology training
stimulation in various contexts.
Severe Dysarthria/Cerebral Palsy
Adaptation of the
Bobath Method in Remediation of Dysarthria
adapted the Bobath method of physical therapy for the
remediation of dysarthria in children and adults with cerebral palsy.
Since cerebral palsy results from upper neural lesion
problem it can present with any of the dysarthrias mentioned
above, except flaccid which is caused by lesions on the cell
bodies or axons of cranial nerves. The methods Crickmay
advocates make sense to me. It is as timely now as when it
was first published. The Bobath method has three main
stages. In the first stage the patient's abnormal and
pathological reflexes are inhibited. In the second stage
more developmentally mature movements are facilited. In the
third stage movements are put under the voluntary control of
the patient. It is a important that the speech therapist
have guidance and assistance from a physical therapist
before he/she initiates remediation.
In order to
normalize muscle tone the patient is placed in a reflex
inhibiting posture (RIP) which he/she has become accustomed
to while in physical therapy. Two postures that tend to have
normalizing effects are the prone (extended spine and flexed
elbows-lying on your stomach while leaning on your elbows),
and the supine (hips and knees extended, shoulders flexed
-held by therapist, and head back-chin held. In inhibiting
abnormal speech reflexes the therapist should go from gross
to fine. Head control, the ability to lift and turn the head
is a prerequisite for speech. Crickmay suggests that the
individulal be in a supine position with legs and arms at
his/her sides and hips and legs flexed. This is a good time
to work on desensitize the face/articulators. Remember we
are talking about desensitizing the speech mechanism because
when you manipulate the tongue and lips the child may react
with spasms. Crickmay suggests that you help the patient build
up tolerance by holding him/her in the RIP while gently and
carefully touching and moving the hypersensitive face. Since
the mouth is the most sensitive he/she should start with
facial areas furthest from the mouth and work in towards the
mouth. The patient will resist and try to break out of the
RIP. He/she should be held gently but firmly so that he/she
can build up a tolerance and permit the speech pathologist to
manipulate the speech mechanism. The time taken for this to
happen is quite variable-from a few days to several
The patient learns
to lie quietly in an RIP keeping the face free of abnormal
movement. When facial grimacing occurs it can be usually
controlled by the fingertips. Those with spasticity often
have an open mouth, lips drawn back grin. Crickmay suggests
flexing the head forward to inhibit the extensor spasm, and
close the patients mouth.
drooling, Crickmay recommends teaching the patient to keep
the teeth closed and the tongue tip up against the alvealor
ridge as he/she swallows. The clinician then inhibits any
extraneous movements of cheecks and lips.
To teach a normal
mouth position, Crickmay suggests the following:
Help the patient
close his/her teeth in a normal jaw position. Place one hand
under the patient's chin and hold that position for him/her.
Use the other hand to stroke the patients lips and cheecks
forward in order to relax the face. Chin pressure must be
released gradually in order to permit the patient to assume
control and to experience a closed mouth. Help the patient
gradually increase the time the mouth remains closed.
To reinforce the
closed mouth position negative practice may be used. The
clinician asks the patient to go back the original open
mouth position and then to deliberately assume the new
closed mouth one. Repeated practise will enable the patient
to feel the difference between positions. Using a mirror
during practise will provide visual reinforcement.
In order to
inhibit the infantile sucking reflex, Crickmay recommends
Put the patient in
an RIP. Gently stimulate the lips by touching them with a
straw or finger. Use the other hand to prevent them from
moving into a sucking position. The clinician will have to
control the patient's lips by keeping them in a relaxed
position despite the stimulation. Finally the therapist
should help the child assume control. This can be done by
the clinician removing his/her hand occasionally-gradually
increasing the length of time until the patient can inhibit
the reflex without assistance.
To facilitate the
chewing reflex (a normal reflex, which with sucking and
swallowing is a prerequisite for speech) the clinician can
give hard licorice or chocolate (absent dietary or
swallowing restrictioins). It should be pressed against the
hard palate in order to stimulate chewing. Rubbing the gums
and teeth, front, back and sides, in a rotary motion with a
finger will also help.
independent tongue movement, Crickmay suggests holding the
patient's jaws apart while having him/her raise the tongue
to the alvealor ridge. Next, encourage him/her to produce
/t/, /d/, /l/, and /n/ sounds. Make sure the jaw dosen't
become fixed. It should be immobilized, but given some
freedom of movement. Finally, permit the patient to take
lip movements may be necessary for many patients. The
techniques described above can be used with patients who
have difficulty differentiating lip, tongue, and jaw
movements. That is they cannot make the /r/ sound without
moving both lips and tongue or are unable to make /t/, /l/,
or /n/ sounds without also moving the jaw.
Mild to Moderate Dysarthria
Rosenbeck and La Pointe (1978), and McCaffrey et al (2001,) the goal of therapy for
dysarthria is to help patients achieve compensated
intelligibility. In other words, patients must learn
techniques that help them to make good use of their
remaining physiological capacity to produce understandable
can impair respiration, phonation, resonance and prosody,
therapy will often include compensatory strategies which
address these aspects of speech production as well as
- The most
effective way for most dysarthrics to make themselves
more intelligible is to reduce the rate of their
speech and produce syllables one by
one. Speaking this way will disrupt
intonation patterns and may make the person sound
"robot-like." However, it is the best way to maximize the
clarity of dysarthric speech.
Many patients have difficulty learning to speak slowly. A
pacing board may be helpful for such
patients. Pacing boards are divided into sections and the
patient must tap one section every time he pronounces a
syllable. As the fingers cannot move nearly as rapidly as
the articulators, this should slow the rate of speech
enough to improve intelligibility. After reduced rate has
been established using the board, the client can begin to
count syllables on his fingers. Eventually, he should be
able to maintain the proper rate without counting
syllables at all. A device called a graduated
stick may be used instead of a pacing
board. Graduated sticks have bumps on them at regular
intervals and the client must touch one bump every time
he says a syllable. Metronomes can also be used to slow
speech rate. Patients are taught to pronounce one
syllable per "tick" on the metronome.
The use of a pacing board, graduated stick or metronome
to slow rate may be referred to as intrasystemic
reorganization. Intrasystemic reorganization for speech
remediation is described by La Pointe and Rosenbeck as
introducing a non speech function into the impaired act
that is not normally used in the impaired act in order to
facilitate speech. This new function is called an
organizer. According to Duffy, 1995 using tongue
protrusion to facilitate the production of interdental
sounds is an example of using a lower level function for
a higher level purpose.
patients should also try to emphasize all
syllables as they speak. This will reduce
should also use greater excursion of the mandible, tongue
and lips to improve production of both consonants and
vowels. The exaggeration of jaw and tongue movements is
the most crucial aspect of this strategy; it may be too
difficult for some patients to increase the amplitude of
their tongue movements.
exaggeration is another compensatory strategy
that improves the intelligibility of dysarthric speech.
Teach the patient to over-articulate in order to
emphasize the sounds that s/he is slighting. (Medial and
final consonants are typically most slighted in running
- If a patient
has difficulty with a particular type of phoneme, the
clinician may have to teach him to use compensatory
placement to produce those sounds. For
example, it the patient has trouble with tongue tip
sounds like /t/, /d/, /n/, /s/ and /z/, he/she could
learn to make them with the blade rather than the tip of
the tongue. If the patient can no longer put his lips
together to make bilabials, he could learn to use his
teeth to contact the lips.
techniques are often used to work with
patients who have problems with either reduced or
excessive loudness. For example, the visipitch could be
used to help Parkinson's patients who speak too softly or
patients with spastic dysarthria who have bursts of very
phrase length is another way to increase the
loudness of a dysarthric's speech. When a patient with
hypokinetic dysarthria stops to take a breath and rest
for an instant between every few words, their vocal
volume usually increases. (Slowing the rate of speech,
which will be the main focus of therapy for dysarthria,
may automatically reduce phrase length and improve the
technique for easy onset of voice, the use
of a breathy voice and Froeschel's chewing
of focusing energy in the oral cavity may all be used to
reduce the strained-strangled vocal quality that occurs
in spastic dysarthria. Patients with this kind of voice
problem are often using hard glottal attack. In this
case, any technique used to ameliorate this problem will
help the patient.
dysarthrics, especially those with the hypokinetic form
of the disorder, may have an excessively breathy voice.
exercises may help a patient who has this
problem by facilitating glottal closure.
dysarthrics speak at an abnormally low pitch. If they
continue to do so for a sufficient length of time, they
may develop a functional voice disorder like nodules. For
this reason, it may be necessary to address the patient's
voice problem although there is usually a trade-off
between improving pitch/intonation and improving
Parkinson's patient with hypokinetic dysarthria cannot learn
to speak more loudly through the use of monitoring
techniques or the use of short phrases, he or she might be
provided with an electro-larynx or computer
hardware/software as a way of increasing vocal
does not effectively reduce the hypernasality that
accompanies most types of dysarthria. Patients can be given
blowing exercises or exercises that contrast nasal sounds
with oral sounds (eg., /n/ vs. /a/). Perceptual training,
such as having the client listen to a tape recording of his
voice, is also used. Froeshel's chewing method may help to
some extent by concentrating energy in the oral cavity. But,
if the velum is paralyzed, none of these techniques will do
anything to alleviate the problem.
is severe, the patient should be referred to an ENT to
explore the possibility of pharyngeal flap surgery or the
use of an obturator and speech bulb prosthesis. (Although
these were developed as treatments for cleft palate, they
could also be used with a dysarthric patient.)
motor exercises may be used in therapy with dysarthric
patients. Programs must also include speech exercises as the
movements involved in speech are different from other types
of oral-motor movements.
addition to the use of the visipitch to monitor loudness
levels, other kinds of feedback are employed in therapy with
- Tactile and
kinesthetic feedback can be used to teach compensatory
- Electromyographic (EMG) feedback
can be used to reduce the hypertonicity of
auditory feedback (DAF) has been used successfully with
Rosenbeck, et al. (1973), developed
an eight step continuum for treating apraxia of speech. This
can be modified for use with dysarthric patients. The
principle modification would be to give dysarthrics several
models of the desired production. With apraxics one model
is given with several opportunities to match it)
Integral stimulation-the therapist
asks the patient to look and listen AND imitate. (watch me
and do the same).
as 1 except the patient is asked to delay the response; then
the therapists silently mimes the response while the patient
is producing the target stimulus.Step 3
Integral stimulation followed by
imitation WITHOUT cues-miming or otherwise.
Integral stimulation with several
successive productions without simultaneous cues or
Printed stimuli are presented by the
therapist without auditory or visual cues followed by
patients production while looking at the written
Written stimuli, with delayed
production after removal of the written stimuli.
therapist elicits a response by asking a question.
playing is used to elicit responses.