Chapter 17: Motor Speech Disorders in Adults
During every second a person is talking, approximately _______________ neuromuscular contractions and relaxations occur in the speech muscles (i.e. muscles of the respiratory, phonatory, resonatory, and articulatory systems)
140,000
ANARTHRIC (ANARTHRIA)
A complete or near complete loss of the ability to articulate speech
APRAXIA OF SPEECH (SPEECH APRAXIA, VERBAL APRAXIA, ACQUIRED APRAXIA)
A deficit in the neural motor planning or programming of the articulatory muscles for voluntary movements for speech, in the absence of muscular weakness, that primarily affects articulation and prosody - is caused by damage in the region of the posterior inferior left frontal lobe in or around Broca's area
DYSARTHRIA
A general term for a collection of neurological speech disorders characterized by weakness and incoordination in the muscles that control respiration, phonation, resonation, and articulation. (All of these systems are important for swallowing)
MYASTHENIA GRAVIS
A neuromuscular disorder is more commonly seen in women than men, characterized by chronic fatigue and muscle weakness, especially in the facial and articulatory muscles, resulting in dysarthria - an incidence of approximately 1 case per 10,000 population - begins in women in their 30s, in men usually in their 60s
PLATEAU
A patient's general leveling off of improvement in rehabilitation, after which gains are slower and less easily documented; often the reason for discharging from rehabilitation.
AMYOTROPHIC LATERAL SCLEROSIS (ALS)
A rare, rapidly progressive degenerative disease of motor neurons that control movement of all muscle systems, including the speech systems - commonly called Lou Gehrig's disease - usually begins in the middle age, with the age of initial symptoms occurring as early as the 40s and as late as the 70s - males are affected more than females - There is no known medical treatment for this disease
ORAL APRAXIA (NONVERBAL APRAXIA, FACIAL APRAXIA, BUCCOFACIAL APRAXIA)
Difficulty with volitional nonspeech movements of the articulators (e.g., puffing the cheeks, clicking the tongue, whistling, or smiling) - individuals with this may exhibit groping of the articulators or inconsistent trial-and-error attempts. - Individuals are usually confused, frustrated, embarrassed, and sometimes even amused by their difficulty with seemingly easy tasks - they may automatically and spontaneously complete any of these movements and be unaware they just performed them
FLACCID DYSARTHRIA
Disease/Disorder- Bulbular palsy, myasthenia gravis Site of Lesion- Lower motor neuron Speech Characteristics- Audible inspiration, hypernasality, nasal emission, breathiness
ATAXIC DYSARTHRIA
Disease/Disorder- Cerebellar or Friedrich's ataxia Site of Lesion- Cerebellum Speech Characteristics- Phoneme and syllable prolongation, slow rate, abnormal prosody
HYPERKINETIC DYSARTHRIA
Disease/Disorder- Huntington's chorea, dystonia Site of Lesion- Extrapyramidal system Speech Characteristics- Imprecise articulation, prolonged pauses, variable rate, impaired prosody
MIXED DYSARTHRIA
Disease/Disorder- Multiple sclerosis, amyotrophic lateral sclerosis Site of Lesion- Multiple motor systems Speech Characteristics- Dependent on motor systems affected
HYPOKINETIC DYSARTHRIA
Disease/Disorder- Parkinson's disease Site of Lesion- Extrapyramidal system Speech Characteristics- Monoloudness, monopitch, reduced intensity, short rushes of speech
SPASTIC DYSARTHRIA
Disease/Disorder- Pseudobulbar palsy Site of Lesion- Upper motor neuron Speech Characteristics- Imprecise articulation, slow rate, harsh voice quality
A foundational therapy for apraxia of speech is
Drill (the systematic practice of specifically selected and ordered exercises
AUTOMATIC SPEECH
Over-learned sequences of words that can be recited without much conscious thought, such as counting to 10, saying the days of the week, months of the year, and the alphabet; and singing some songs (e.g., the birthday song)
The focus of treatment is
Speech intelligibility - Clinicians attempt to reduce patients' impairments by increasing physiological support for speech - for example, increasing range of motion, muscle tone, strength, and rate of movement of the articulators
DIFFERENTIAL DIAGNOSIS
The process of narrowing possibilities and reaching conclusions about the nature of a deficit
TREMORS AT REST
Tremors that occur when the head, limbs, hands, or fingers are not intentionally being moved; when movement is initiated, the tremors subside until the body part is again no longer moving
Phonation characteristics of dysarthria
When muscles of the phonatory system are weak, the vocal folds may have unilateral or bilateral paresis or paralysis that prevents normal valving of the air stream from the lungs - This weakness results in mild to severe breathiness of the voice
The primary goal of speech therapy for dysarthria is
to maximize the effectiveness, efficiency, and naturalness of communication
The primary goal of therapy for apraxia of speech is
to maximize the effectiveness, efficiency, and naturalness of communication
Articulation characteristics of dysarthria
When the muscles of the mandible, lips, and tongue are weak, either unilaterally or bilaterally, there can be decreased range of motion, strength, coordination, adn rate of movement. - This weakness results in distorted, imprecise consonants that can have mild to severe effects on speech intelligibility
Resonation characteristics of dysarthria
When the muscles of the resonatory system are weak, unilateral, or bilateral paresis of the soft palate prevents it from making normal contact with the posterior pharyngeal wall, which can result in hypernasality
Respiration characteristics of dysarthria
When the muscles of the respiration system (diaphragm, chest, and abdominal muscles) are weakened by damage to the CNS, patients have difficulty achieving adequate inspirations and having controlled, steady, and prolonged expirations for normal speech - this weakness can result in low vocal intensity and speech that is limited to short phrases.
MULTIPLE SCLEROSIS (MS)
a debilitating disease in which the body's immune system slowly destroys the protective sheath (myelin) that covers the nerves - This damage interferes with the communication between the brain and the muscles and organs of the body - is most often seen in females between 20 to 40 years of age, but it can occur at any age - there is no known cure for this, although medical management can modify the course of the disease and treat its symptosm
The previously described signs and symptoms are noted, and when appropriate,
a diagnosis of apraxia of speech is made
Because speech is normally such an automatic process,
a sudden disturbance requires immediate attention.
When dysarthria is suspected,
a thorough evaluation of the speech systems (respiratory, phonatory, resonatory, and articulatory) is completed, with emphasis on the oral mechanism
A diagnosis of a motor speech disorder is made
after a thorough evaluation of a patient's motor speech abilities - sometimes evaluation results are unambiguous and a clear diagnosis can be made - more commonly, several interpretations are possible, and the clinicians have to rank these possibilities
Speech apraxia is the result of
an impaired ability to plan (program), sequence, coordinate, and initiate motor movements of the articulators, which can also affect voluntary initiation of swallowing.
Speech compensatory approaches attempt
to reduce the impact of the dysarthria on speech by providing alternative methods of communication while not actually reducing the severity of the underlying neuromotor deficits - for example, if an individual has inadequate respiratory support for speech, the clinician may teach the person methods for best using the breath support he has available to produce speech, such as taking more breaths during the production of an utterance
Nonspeech compensatory strategies may be
used with individual with severe dysarthria, such as AAC systems
Individuals who have motor speech disorders are often
very aware of the difficulty they have being understood, and attempts to communicate can be fraught with frustration
Many individuals with apraxia of speech benefit from
watching their face and articulators in a mirror while they are talking. - The visual feedback helps compensate for their lack of awareness of the placement of their articulators and where they want to move them.
When the adjacent precentral gyrus or the pyramidal tract is also damaged,
weakness can contribute to impaired speech intelligibility. - there may be distorted speech sounds in the absence of damage to the precentral gyrus
The physiological, perceptual, and acoustic characteristics of motor speech disorders are
well-described in literature; however, the psychosocial consequences are only beginning to receive attention
Because of the various types of dysarthria (spastic, ataxic, flaccid, hyperkinetic, hypokinetic, mixed)
what is an appropriate treatment for one type may not be at all appropriate for another type - for example, clinicians may attempt to strengthen weakened muscles of respiration, phonation, and articulation for hypotonic or flaccid muscles, but use relaxation techniques for hypertonicity or spasticity
Adults who were very effective communicators, and who might have even made their living based on their verbal skills, may find that
without those skills, they can no longer compete in the marketplace or enjoy socializing with colleagues, friends, and family - What they may have taken pride in for decades-their verbal skill- no eludes them and they feel isolated.
Dysarthria ma have the same etiologies as
aphasia and cognitive disorders (e.g., CVA, TBI, tumor, toxin, degenerative disease).
Motor Speech Disorders often accompany
aphasia, cognitive impairments, or both when the lesion is extensive; however, they can also occur alone
Symptoms of Myasthenia Gravis
appear first and most noticeably in the face - the eyelids begin to droop, double vision occurs, and weakness in the articulators causes slurred speech (dysarthria), dysphonia, and difficulty swallowing - the arms and legs may be affected, making it difficult to comb the hair or stand without wobbling - key diagnostic feature is decreasing muscle function with use adn easy fatigability - with medication, some transmission of nerve impulses can be restored, but this disease cannot be cured.
Apraxia and dysarthria
are frequently seen as problems in the same patient
When only Broca's area is damaged, the speech errors
are not the result of weakness
MOTOR SPEECH DISORDERS
are the result of neurological impairments that affect motor programming and planning, coordination, or strength of the articulators for rapid and complex movements needed for smooth, effortless, and intelligible speech - include apraxia of speech and dysarthria
Individuals with severe apraxxia mmay begin to
avoid talking and feel that the effort and embarrassment are not worth trying to communicate
Some individuals, because of severe difficulty communicating verbally, will
avoid verbal communication as much as possible- not wanting to place the burden of understanding on their listener and not wanting to embarrass themselves
Motor Speech Disorders have a sensory component and , therefore should
be thought of as sensorimotor in nature - not just motor conditions
Limb apraxia is important to speech-language pathologists
because when a patient has a moderate to severe speech apraxia, she may not have sufficient control of finger and hand movements to write, print,or type what she cannot say
Every physical feature of the body can be affected with ALS, including
breathing, swallowing, speaking, and walking
The same neurological insults (e.g., cerebrovascular accidents (CVA's), traumatic brain injury [TBI], degenerative diseases) that cause apraxia and dysarthria
can cause dysphagia (difficulty or discomfort in swallowing, as a symptom of disease) - this is true not only for adults, but also for children
Perceptual evaluations provide the "gold standard" evidence for
clinical differential diagnosis, judgments of severity, many decisions about management, and assessment of functional change
Many patients with apraxia of speech have
combinations of other impairments, such as dysarthria, aphasia, cognitive disorders, and dysphagia, all of which need to be thoroughly evaluated
Certain neuromuscular conditions or disorder are
commonly associated with dysarthria - some of these conditions may be seen in relatively young adults
Each of the speech systems (respiration phonation, resonation, and articulation)
contributes to the characteristics of dysarthria
Every day activities, such as conversation, are
difficult even when voice or speech changes are mild and do not interfere with speech intelligibility
As the [ALS] disease progresses, the speaking rate of mot patients
diminishes - during the last years or months of life, they experience severe communication disorder, with some individuals being anarthric
the weakness and incoordination may have an
effect on all speech systems ranging from minimal to profound, depending on the site and size of the lesion(s) in the brain, cerebellum, or brainstem
Careful visual, auditory, and even tactile perceptual evaluations are
essential, with emphasis on the auditory component
In the earlier stages of MS disease, individuals typically experience
exacerbations of symptoms, which are then followed by partial or complete remission
Patients may be able to say complex, multisyllabic words, yet then
have difficulty with simple, single-syllable words - They often can say sequences of automatic speech, such as counting to 10 and saying the days of the weeks or the months of the year - However, when a patient is trying to say "Thursday" for example, they may not be able to say it alone - they may get a "running start" by starting with "Sunday" and, upon reaching "Thursday", stop and says "That's it"
Apraxia of speech has numerous characteristics that
help identify the disorder, although they do not all need to be present for a diagnosis.
Because speaking needs to become very conscious, it
is both physically and cognitively demanding - and fatiguing
One of the hallmarks of apraxia of speech is
its inconsistency
Individual may have only motor speech problems and
little to no impairment of language and cognitition
Disfluencies (stutter-like speech) in apraxia of speech have
long been noted in the literature and are considered a "perceptually salient characteristic" of the speech of persons with apraxia.
When speaking, individuals with dysarthria need to
make speech very conscious so their focus is on being heard and understood rather than how quickly they can communicate their messages
The range of motion (ROM), strength, coordination, and rate of muscle movement
may be affected in each of the speech systems, which then has an overall effect on the prosody of speech.
Depending on the severity of the dysarthria, patients an clinicians together
may choose different approaches - for example, patients with mild dysarthria may focus on efficient and natural-sounding speech; patients with moderate dysarthria may choose to work on speech intelligibility and efficacy (i.e., manageable physical effort); and patients with severe dysarthria may emphasize effective and efficient alternative means of communication
Individual disfluencies (particularly word repetitions, repeated movements, and fixed postures) may be
motoric or linguistic; that is, apraxia of speech or Broca's aphasia.
Apraxia therapy often uses a
multimodality approach - that is, auditory, visual, and tactile interventions
When speech muscles are not exercised sufficiently,
muscle strength may further decline (similar to general body deconditioning that occurs when patients are confined to bed)
At other times, Dysarthria has
no clearly identifiable cause.
Some individuals with severe apraxia of speech may have
no functional speech and may benefit from augmentative and alternative communication (AAC) systems
They psychosocial difficulties of motor speech disorders are
not related to age, gender, diagnosis, or employment status
Signs and Symptoms of MS vary depending on the nerve fibers affected, but may include
numbness or weakness in one or more limbs, tingling or pain in parts of the body, tremors and lack of coordination or unsteady gait, fatigue, dizziness, and partial or complete loss of vision - over time, speech, language, cognition, and swallowing may be affected
Patients with speech apraxia also have
oral apraxia (nonverbal apraxia, facial apraxia, buccofacial apraxia)
The important motor function of Broca's area are related to
planning and programming of voluntary movements of the articulators.
Patients with speech apraxia, even though they have some aphasia or cognitive disorders typically
recognize their errors and try to repair them - To their chagrin, the harder they try, the more difficult it is for them to say the intended words - In turn, patients often become frustrated and angry with themselves
A sign system such as American Indian Hand Talk (Amerind)
relies on somewhat universal "natural gestures" (e.g., raising the fingers to the mouth as if eating to represent hunger, food, or eat) may be functional for the person to learn for basic communication.
The restorative approach to treatment of dysarthria attempts to
restore lost motor abilities by reducing the underlying pathologic neuromotor condition that is creating the dysarthria (e.g. weakness, incoordination, spasticity) - Reduction of the underlying pathology thereby reduces the severity of the dysarthria
Therapy for individuals with motor speech disorders focuses on
restoring or compensating for impaired functions, as well as helping the person emotionally adjust to the loss of abilities that cannot be restored
Regardless of demographic characteristics, speakers with motor speech disorders report
restrictions in taking part in communication situations, negative emotions, and change in the number of familiarity with people present in communication encounters
Individuals with severe apraxia of speech may be able to
say a few "stock" (stereotypic) phrases: "I'm fine, How are you?", "I know what I want to say, but I can't say it", or "I know I want to say 'I work in construction', but I can't say it" - In the last example, the person actually says automatically and effortlessly the very word, phrase, or sentence that could not be said when intentionally trying to say it.
The characteristics of apraxia of speech include the following:
- Articulation errors are not the result of muscle weakness or paralysis - Articulation errors are highly variable - Sound errors are more often substitutions than distortions, omissions, or additions - Consonant errors are more common than vowel errors - Errors occur most often on the initial consonant of words - Consonant clusters (e.g. /bl, sp, st, tr/) are more likely to be in error than single consonants - Errors increase with increasing word length (i.e. number of sounds and syllables) - There is trial-and-error "groping" for the correct placement of the articulators to produce sounds, causing the person to look like he is working hard or struggling to talk - Front-of-the-mouth sounds (e.g., /b, d, z/) are more likely to be correct than back-of-the-mouth sounds (e.g, /k, g, ch, sh/) - "Islands" of fluent, error-free words, phrases, and sentences are found amidst effortful, struggling speech - Individuals may perform adequately on isolated articulator movements (e.g., rapid protrusion and retraction of the tongue) but when the complex interactions of the speech systems are added to produce speech, the articulatory system is overtaxed and difficulty becomes apparent.
Limb apraxia
- considered the result of damage to the posterior region of the frontal lobe, particularly the left frontal lobe near Broca's area - is seen when a patient cannot perform volitional movements of an arm, hand, or gingers, which affects gestures adn other voluntary movements necessary for activities of daily living (ADL's) - is typically more severe with the hand and fingers than with the arm (for example, a patient is likely to have more difficulty showing you how to snap his fingers, flip a coin, or wind a watch, than showing you how to salute or drink from a class)
Parkinson's Disease (PD)
- is caused by a gradual deterioration of certain nerve centers in the brain that are important in the delicate balance of chemicals needed for transmission of nerve impulses for control of the movement of the body, including the areas - Arms and legs become stiff and do not swing or move in a smooth manner because opposing muscles (e.g., biceps and triceps in the arm) are contracting simultaneously - the face may become masklike with little expression, although the person has all of the same emotions as before the disease emerged - common symptom is tremors at rest (tremors fo the hands or head when the person does not consciously move them)
There are a few standardized assessments for apraxia of speech, including
Apraxia Battery for Adults 2nd Ed. Quick Assessment of Apraxia of Speech Test of Oral and Limb Apraxia
There are a few standardized assessments for dysarthria, including:
Assessment of Intelligibility of Dysarthric Speech (Yorkston, Beukelman & Traynor, 1984 Dysarthria Examination Battery (Drummond, 1993) Frenchay Dysarthria Assessment (Enderby, 1983) Quick Assessment for Dysarthria (Tanner & Culbertson, 1999b)
Six types of dysarthria have been described in literaature
spastic dysarthria ataxic dysarthria flaccid dysarthria hyperkinetic dysarthria hypokinetic dysarthria mixed dysarthria
Patients with motor speech disorders must
speak to improve their disorders
There is consensus that acquired motor disorders change the lives of the speakers experiencing them. For example,
speakers with dysarthria report social isolation and changes in self-identity and social relationships and feelings of perceived stigmatization
A patient may have both
speech apraxia and dysarthria
Therapy for individuas with apraxia of speech should
start as early as possible - Clinicians should carefully select the stimuli (functional words) they want the patient to practice during any one session, implement an orderly progression of therapy tasks (generally from easiest to hardest), and use an intensive and systematic drill
The most common cause of apraxia of speech is
stroke; however, TBI, brain tumors and abscesses, and other causes can result in apraxia
The older the person becomes, the more
susceptible the individual is to the neurological disease and disorders that may result in dysarthria
Speech-language pathologists are likely to see patients with ALS for
swallowing disorders, speech disorders, or both
Once the patient is able to volitionally say the word or phrase correctly, he usually thinks
that he will be able to say it again without difficulty, but his next attempt may be as difficult and off-target as the first attempt
Another fairly common characteristic of speech apraxia is
the ability to fluently use profanity and strings of profane words (even individuals who claim to never use profanity may spontaneously and almost uncontrollably use profane words) This automatic and difficult-to-control behavior is embarrassing to some individuals
Disordered speech is sometimes
the first sign of neurological disease
Of the two motor speech disorders (apraxia and dysarthria), dysarthria is
the more prevalent, primarily because a variety of areas in the central nervous system (CNS) and peripheral nervous system (PNS) may be damaged with this conditions
When apraxia of speech is suspected, the patient's speech and oral mechanism areL
the targets of the evaluation, although an assessment of all speech systems is also appropriate.
Speech-language pathologists become involved with individuals with Parkinson's disease when
their disease begin to affect their speech, swallowing, or both - Dysarthria is the speech disorder associated with Parkinson's disease