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Dysarthria in Adults

Dysarthria can result from congenital conditions, or it can be acquired at any age as the result of neurologic injury, disease, or disorder. The scope of this page is limited to acquired dysarthria in adults.


See the Dysarthria Evidence Map for summaries of available research on this topic.

Dysarthria refers to a group of neurogenic speech disorders characterized by "abnormalities in the strength, speed, range, steadiness, tone, or accuracy of movements required for breathing, phonatory, resonatory, articulatory, or prosodic aspects of speech production" (Duffy, 2013, p. 4).

These abnormalities are due to one or more sensorimotor problems—including weakness or paralysis, incoordination, involuntary movements, or excessive, reduced, or variable muscle tone (Duffy, 2013).

Dysarthria can adversely affect intelligibility of speech, naturalness of speech, or both. It is important to note that intelligibility can be normal in some speakers with dysarthria. Dysarthria may also co-occur with other neurogenic language, cognitive, and swallowing disorders.

The predominant framework for differentially diagnosing dysarthria is based on a perceptual method of classification (Darley, Aronson, & Brown, 1969a, 1969b, 1975). This method relies primarily on the auditory perceptual attributes of speech that point to the underlying pathophysiology. The perceptual attributes are used to characterize the dysarthrias and, along with pathophysiological information, can help identify underlying neurologic illness.

The primary types of dysarthria identified by perceptual attributes and associated locus of pathophysiology (Duffy, 2013) are as follows:

  • Flaccid—associated with disorders of the lower motor neuron system and/or muscle
  • Spastic—associated with bilateral disorders of the upper motor neuron system
  • Ataxic—associated with disorders of the cerebellar control circuit
  • Hypokinetic—associated with disorders of the basal ganglia control circuit
  • Hyperkinetic—associated with disorders of the basal ganglia control circuit
  • Unilateral upper motor neuron—associated with unilateral disorders of the upper motor neuron system
  • Mixed—various combinations of dysarthria types (e.g., spastic-ataxic; flaccid-spastic)
  • Undetermined—perceptual features are consistent with a dysarthria but do not clearly fit into any of the identified dysarthria types

See Distinguishing Perceptual Speech Characteristics and Physical Findings by Dysarthria Type.

Although dysarthria is present in many neurologic diseases, its true incidence and prevalence is not fully known. Estimates and ranges vary based on the location of lesion, the nature and course of the underlying condition, and the assessment criteria used. Estimates of the prevalence of dysarthria associated with some common neurologic conditions are as follows:

  • Stroke: It is estimated that 8%–60% of individuals with stroke present with dysarthria (Bogousslavsky, Melle, & Regli, 1988; Flowers, Silver, Fang, Rochon, & Martino, 2013; Jani & Gore, 2014; Kumral et al., 1988; Lawrence et al., 2001; Safaz, Kesikburun, Adigüzel, & Yilmaz, 2016; Teasell, Foley, Doherty, & Finestone, 2002; Vidović, Sinanović, Sabaskić, Haticić, & Brkić, 2011).
  • Traumatic brain injury: Approximately 10%–65% of individuals with traumatic brain injury have dysarthria (Mitchell, Bowen, Tyson, Butterfint, & Conroy, 2017; Safaz, Alaca, Yasar, Tok, & Yilmaz, 2008; Sarno, 1980; Sarno, Buonaguro, & Levita, 1986; Yorkston, Honsinger, Mitsuda, & Hammen, 1989).
  • Parkinson's disease: It is estimated that dysarthria affects approximately 70%–100% of individuals with Parkinson's disease (Hartelius & Svensson, 1994; Ho, Iansek, Marigliani, & Bradshaw, 1998; Logemann, Fisher, Boshes, & Blonsky, 1978; Müller et al., 2001).
  • Multiple sclerosis: Between 25% and 50% of individuals with multiple sclerosis present with dysarthria at some point during the course of their disease (Darley, Brown, & Goldstein, 1972; Hartelius, Runmarker, & Andersen, 2000; Hartelius & Svensson, 1994; Yorkston, Beukelman, Strand, & Hakel, 2010).
  • Amyotrophic lateral sclerosis: Dysarthria can be observed as an initial sign in up to 30% of individuals with amyotrophic lateral sclerosis, with almost all individuals developing dysarthria in later stages (Chen & Garrett, 2005; da Costa Franceschini & Mourão, 2015; Traynor et al., 2000).

Signs and symptoms of dysarthria include perceptual speech characteristics and physical signs that vary by dysarthria type (see Distinguishing Perceptual Speech Characteristics and Physical Findings by Dysarthria Type). Dysarthria can alter speech intelligibility and/or speech naturalness by disrupting one or more of the five speech subsystems—respiration, phonation, articulation, resonance, and prosody.

Perceptual Speech Characteristics

Perceptual speech characteristics are grouped below by the subsystem that contributes most to the feature, recognizing that it is difficult to associate some characteristics with specific subsystems. For example, reduced loudness may be a laryngeal problem for some individuals and a respiratory problem for others. In addition, due to the interactive nature of the speech subsystems, disruptions in one subsystem can have an impact on others. For example, impairments in respiration, phonation, articulation, and/or resonance may be responsible for prosodic deficits.

Respiration (Breathing)

  • Short phrases
  • Reduced loudness
  • Monoloudness
  • Excessive loudness variation
  • Loudness decay
  • Forced expiration/inspiration

Phonation (Laryngeal)

  • Pitch level (too low/too high)
  • Monopitch
  • Pitch breaks
  • Aberrant voice quality (roughness, breathiness, strain; or harsh, hoarse, strain)
  • Diplophonia
  • Vocal flutter
  • Voice tremor
  • Voice stoppages
  • Audible inhalation/inhalatory stridor
  • Grunt at ends of phrases

Articulation

  • Imprecise consonants
  • Distorted vowels
  • Irregular articulatory breakdown
  • Articulatory blurring

Resonance (Velopharyngeal)

  • Hypernasality
  • Denasality or hyponasality (oral resonance on nasal consonants)
  • Audible nasal emission/nasal snort

Prosody

  • Aberrant rate (too fast/too slow/accelerating/variable)
  • Short rushes of speech
  • Reduced stress
  • Excessive and equal stress
  • Prolonged intervals
  • Inappropriate silences

Physical Signs

Physical signs may include the following:

  • Muscle wasting
  • Abnormal muscle tone at rest
  • Fasciculations
  • Tremor (e.g., head, jaw, lip, tongue, velum)
  • Weakness (e.g., tongue, lower face, velum)
  • Involuntary movements (e.g., head, jaw, face, tongue, velum)
  • Abnormal reflexes (e.g., hypo- or hyperactive gag reflex, jaw jerk, sucking or snout reflexes)

Many neurologic illnesses, diseases, and disorders—both acquired and congenital—can cause dysarthria. Listed below are examples of some specific etiologies, grouped into broad categories (Duffy, 2013).

  • Congenital—cerebral palsy, Chiari malformation, congenital suprabulbar palsy, syringomyelia, syringobulbia
  • Degenerative diseases—amyotrophic lateral sclerosis, Parkinson's disease, progressive supranuclear palsy, cerebellar degeneration, corticobasal degeneration, multiple system atrophy, Friedreich's ataxia, Huntington's disease, olivopontocerebellar atrophy, spinocerebellar ataxia, ataxia telangiectasia
  • Demyelinating and inflammatory diseases—multiple sclerosis, encephalitis, Guillain-Barré and associated autoimmune syndromes, meningitis, multifocal leukoencephalopathy
  • Infectious diseases—acquired immune deficiency syndrome (AIDS), Creutzfeldt-Jakob disease, herpes zoster, infectious encephalopathy, central nervous system tuberculosis, poliomyelitis
  • Neoplastic diseases—central nervous system tumors; cerebral, cerebellar, or brainstem tumors; paraneoplastic cerebellar degeneration
  • Other neurologic conditions—hydrocephalus, Meige syndrome, myoclonic epilepsy, neuroacanthocytosis, radiation necrosis, sarcoidosis, seizure disorder, Tourette's syndrome, Chorea gravidarum
  • Toxic/metabolic diseases—botulism, carbon monoxide poisoning, central pontine myelinolysis, heavy metal or chemical toxicity, hepatocerebral degeneration, hypothyroidism, hypoxic encephalopathy, lithium toxicity, Wilson's disease
  • Trauma—traumatic brain injury, chronic traumatic encephalopathy, neck trauma, neurosurgical/postoperative trauma, skull fracture
  • Vascular Diseases—stroke (hemorrhagic or nonhemorrhagic), Moyamoya disease, anoxic or hypoxic encephalopathy, arteriovenous malformations

Speech-language pathologists (SLPs) play a central role in the screening, assessment, diagnosis, and treatment of persons with dysarthria. The professional roles and activities in speech-language pathology include clinical services (diagnosis, assessment, planning, and treatment); education, administration, and research; and prevention and advocacy. See ASHA's Scope of Practice in Speech-Language Pathology (ASHA, 2016b).

The following roles are appropriate for SLPs:

  • Screening individuals who present with possible dysarthria and determining the need for further assessment and/or referral for other services
  • Conducting a culturally and linguistically relevant comprehensive assessment of speech, language, and communication in the context of the individual's unique complaints and functional needs
  • Diagnosing the presence of dysarthria, and establishing its severity, characteristics, and functional impact
  • Referring to, and collaborating with, other professionals to determine etiology of dysarthria, if not already known, and to facilitate access to comprehensive services
  • Determining probable prognoses for improvement or progression of the dysarthria
  • Making decisions about the management of dysarthria in collaboration with the patient, family, and interprofessional treatment team. See ASHA's resources on person- and family-centered care and interprofessional education/interprofessional practice (IPE/IPP)
  • Developing culturally and linguistically appropriate treatment plans, providing intervention and support services, documenting progress, and determining appropriate service delivery approaches and dismissal criteria
  • Counseling persons with dysarthria and their families and caregivers regarding communication-related issues and providing education aimed at preventing further complications related to dysarthria
  • Consulting and collaborating with other professionals, families and caregivers, and others to facilitate program development and to provide supervision, evaluation, and/or expert testimony, as appropriate
  • Providing prevention information to individuals and groups known to be at risk for etiologies associated with dysarthria, as well as to individuals working with those at risk
  • Advocating for individuals with dysarthria and their families at the local, state, and national levels
  • Educating other professionals on the needs of persons with dysarthria and the role that SLPs play in meeting those needs
  • Remaining informed of research in the area of dysarthria, helping advance the knowledge base related to the nature and treatment of this disorder, and using evidence-based practice to guide intervention

As stated in the Code of Ethics (ASHA, 2016a), SLPs who serve this population should be specifically educated and appropriately trained to do so. SLPs who diagnose and treat dysarthria must possess skills in the differential diagnosis and management of motor speech disorders. They must have specialized knowledge of

  • neuroanatomy and neural functions related to craniofacial, laryngeal, and respiratory musculature and how they interact during speech production;
  • how each subsystem (articulation, phonation, respiration, resonance, and prosody) can contribute to the perception of normal or abnormal speech;
  • the principles of speech motor control and motor learning; and
  • appropriate evidence-based assessment and intervention techniques.

See the Assessment section of the Dysarthria Evidence Map for pertinent scientific evidence, expert opinion, and client/caregiver perspectives.

Screening

Screening for dysarthria is pass/fail. It does not provide a diagnosis or a detailed description of the severity and characteristics of speech deficits associated with dysarthria but, rather, identifies the need for further assessment.

Screening may result in recommendations for

  • dysarthria assessment and/or
  • referral for other examinations or services.

Dysarthria Assessment

Assessment of individuals with suspected dysarthria should be conducted by an SLP using both standardized and nonstandardized measures (see assessment tools, techniques, and data sources).

The goal of the dysarthria assessment is to

  • describe perceptual characteristics of the individual's speech and relevant physiologic findings;
  • describe speech subsystems affected (i.e., articulation, phonation, respiration, resonance, and prosody) and the severity of impairment for each;
  • identify other systems and processes that may be affected (e.g., swallowing, language, cognition); and
  • assess the impact of the dysarthria on speech intelligibility and naturalness, communicative efficiency and effectiveness, and participation.

See, for example, Duffy (2013) and Lowit and Kent (2010).

The severity of the disorder does not necessarily determine the degree of disability. Speech-related disability will depend on the communication needs of the individual and the comprehensibility of his or her speech in salient contexts.

Consistent with the World Health Organization's (WHO) International Classification of Functioning, Disability, and Health (ICF) framework (ASHA, 2016b; WHO, 2001), the assessment identifies and describes

  • impairments in body structure and function, including underlying strengths and weaknesses in speech production and verbal/nonverbal communication;
  • the individual's limitations in activity and participation, including functional status in communication, interpersonal interactions, self-care, and learning;
  • contextual (environmental and personal) factors that serve as barriers to, or facilitators of, successful communication and life participation; and
  • the impact of communication impairments on quality of life and functional limitations relative to the individual's premorbid social roles and abilities and the impact on his or her community.

See Person-Centered Focus on Function: Dysarthria [PDF] for an example of assessment data consistent with ICF.

Typical Components of the Dysarthria Assessment

The assessment process includes consideration of the individual's hearing and vision status. This may include hearing screening, inspection of hearing aids, and provision of an amplification device, if needed. If the individual wears corrective lenses, these should be worn during the assessment.

The assessment section below is not prescriptive—it outlines the components of a very thorough exam. Some components may not be applicable in all clinical settings.

Case History

  • Medical diagnosis and history
    • Onset and course of symptoms
    • Associated deficits (e.g., language, cognitive-communication, and swallowing, problems)
    • Medical procedures, hospitalizations, prior treatments and their outcomes
    • Other medical and rehabilitation specialty referrals and interventions and their outcomes
    • Medications and potential side effects/symptoms
  • Review of auditory, visual, motor, cognitive, language, and emotional status (if not included as part of the assessment)
  • Education, vocation, and cultural and linguistic backgrounds
  • Patient and family report
    • Awareness, observations, and perspectives
    • Person-specific communication needs
    • Impact of the presenting problem on activities and participation
  • Identification of facilitators of and barriers to communication
    • Extent to which the level of effort for speaking changes in different contexts (e.g., when fatigued, at different times of day, relative to medication schedule)
    • Adaptability in different communication contexts (e.g., in noisy environments, with distractions, with multiple communication partners, with unfamiliar listeners)

Nonspeech Examination

  • Assessment of speed, strength, range, accuracy, coordination, and steadiness of nonspeech movements and assessment of the speech subsystems using objective measures, as available. The following are typically included:
    • Completion of a cranial nerve exam (CN V, VII, IX, X, XI, XII)—to assess facial, oral, velopharyngeal, and laryngeal function and symmetry
    • Observation of facial and neck muscle tone—at rest and during nonspeech activities (Clark & Solomon, 2012)
    • Assessment of sustained vowel prolongation—to determine if there is adequate pulmonary support and sufficient laryngeal valving for phonation
    • Assessment of alternating motion rates (AMRs) and sequential motion rates (SMRs) or diadochokinetic rates—to judge speed and regularity of jaw, lip, and tongue movement and, to a lesser extent, articulatory precision (see Kent, Kent, & Rosenbek, 1987)

Speech Production

  • Vocal quality and ability to change loudness and pitch—to assess laryngeal/phonatory function (see ASHA's Practice Portal page on Voice Disorders)
  • Stress testing—2 to 4 minutes of reading or speaking aloud to assess deterioration over time (can use spontaneous conversation, reading text aloud, or counting)
  • Motor speech planning or programming—repetition of simple and complex multisyllabic words and sentences to determine if apraxia of speech (AOS) is present (see ASHA's Practice Portal page on Acquired Apraxia of Speech)

Prosody—use of variations in pitch, loudness, and duration to convey emotion, emphasis, and linguistic information (e.g., meaning, sentence type, syntactic boundaries); speech naturalness reflects prosodic adequacy

  • Recommendations for speech sampling include the following:
    • Use connected speech (reading and spontaneous speech) to observe variations in pitch, loudness, and duration.
    • Use targeted prosodic tasks, including asking and answering questions; contrastive stress tasks; and reading statements using prosodic variation to express different emotions.

Speech Intelligibility—the degree to which the listener (familiar/unfamiliar) understands the individual's speech; typically reported as a percentage of words correctly identified by a listener

  • Recommendations for speech sampling include the following:
    • Use material unknown to the listener and with low semantic predictability.
    • Include words that provide a sampling of most of the phonemes.
    • Tasks include single-word production and sentence production (recorded and later transcribed by a judge).

Comprehensibility—the degree to which the listener understands the spoken message, given other information or cues (e.g., topic, semantic context, gestures) to enhance communication; typically reported as percentage of words correctly identified by a listener

  • Materials and tasks are similar to those used to assess speech intelligibility.
  • Various cues (e.g., auditory, visual, contextual) are provided to the listener.
  • The speaker's use of comprehensibility strategies or the potential to adopt these strategies can also be assessed during these tasks.

Efficiency—the rate at which intelligible or comprehensible speech is communicated; typically reported as the number of intelligible or comprehensible words per minute

  • Sentence-level materials and tasks are similar to those used to assess speech intelligibility and comprehensibility.
  • Sentences are transcribed by a judge, and the number of correct words per minute are computed.

Other components of the assessment may include a review of the following, which may lead to further, in-depth assessment of these areas:

  • Language—assess receptive and expressive language skills in oral and written modalities to help distinguish between dysarthria and aphasia. See ASHA's Practice Portal page on Aphasia.
  • Cognitive-Communication—identify aspects of verbal or nonverbal communication that may be affected by disruptions in cognition (e.g., attention, memory, organization, executive function). See ASHA's resources on cognitive-communication.
  • Swallowing—assess swallowing function. See ASHA's Practice Portal page on Adult Dysphagia.

Assessment may result in the following outcomes:

  • Diagnosis of dysarthria and classification of dysarthria type.
  • Clinical description of the dominant auditory-perceptual speech characteristics and the severity of the disorder.
  • Presence of co-morbid conditions, including apraxia of speech, aphasia, cognitive-communication disorder, or swallowing disorder.
  • Statement of prognosis and recommendations for intervention that relate to overall communication adequacy.
  • Development of an intervention or management plan (in collaboration with patient, family, and rehabilitation team), including (a) prosthetic or surgical management or (b) augmentative and alternative communication (AAC), as appropriate. See ASHA's Practice Portal page on Augmentative and Alternative Communication.
  • Identification of relevant follow-up services, including support for individuals with dysarthria.
  • Referral to other professionals as needed (e.g., neurologist, psychologist).

Differentiating Among Dysarthria Types

Given the overlap in speech characteristics and other deficits across the dysarthrias, it may be difficult to determine dysarthria type, particularly when the underlying etiology is unknown (Fonville et al., 2008; Van der Graaff et al., 2009; Zyski & Weisiger, 1987). However, there are a number of distinguishing speech characteristics and physical findings that can be useful in making a differential diagnosis. See Distinguishing Perceptual Speech Characteristics and Physiologic Findings by Dysarthria Type.

Distinguishing Dysarthria From Apraxia of Speech

Listed below are characteristics and comparisons often used to distinguish dysarthria from apraxia of speech (AOS). Some dysarthria types (e.g., ataxic, hyperkinetic, and unilateral upper motor neuron) share some characteristics with AOS and can be difficult to distinguish (Bislick, McNeil, Spencer, Yorkston, & Kendall, 2017; Duffy, 2013).

  • Muscle weakness or spasticity are present in several dysarthria types; AOS does not present with muscle weakness or spasticity unless there is a concomitant dysarthria.
  • Several subsystems can be affected in dysarthria—unlike AOS, which is predominated by articulatory and prosodic deficits.
  • In contrast to AOS, dysarthric speech may present with more consistent error patterns and is generally not influenced by automaticity of speech production, stimulus modality, and linguistic variables (Duffy, 2013).
  • Other apraxic speech characteristics, such as a larger variety of articulatory errors and groping for articulatory postures, are typically not seen in dysarthria.
  • Poorer performance on SMRs than on AMRs in AOS may distinguish it from ataxic dysarthria (Duffy, 2013).

For more information about AOS, see ASHA's Practice Portal page on Acquired Apraxia of Speech.

Distinguishing Dysarthria From Aphasia

Aphasia affects language comprehension and expression in both spoken and written modalities; dysarthria affects only speech production.

When an individual has both dysarthria and aphasia, and verbal expression is significantly impaired, the clinician will need to determine if the problem is motor based or language based—or some combination of the two.

Intelligibility and speech naturalness can be significantly compromised by dysarthria; however, delays during speech and/or attempts by the speaker to revise content might indicate language expression problems associated with aphasia. In such cases, it may be necessary to assess written language expression as well as oral and written language comprehension to make a definitive diagnosis. If deficits are found in these modalities, it is likely that language problems are contributing to verbal expression difficulties (Duffy, 2013). For more information about aphasia, see ASHA's Practice Portal page on Aphasia.

Cultural and Linguistic Factors

When selecting screening and assessment tests, the SLP considers the influence of cultural and linguistic factors on the individual's communication style and the potential impact of impairment on function. Variations in dialect should be taken into consideration before marking phonemes in error if they were not part of the client's repertoire or dialect prior to injury or disease.

The assessment is conducted in the language(s) used by the person with dysarthria, with the use of interpretation services as necessary. See ASHA's Practice Portal pages on Collaborating With Interpreters, Transliterators, and Translators and Bilingual Service Delivery.

Appropriate accommodations and modifications must be made to the testing process to reconcile cultural and linguistic variations. Comprehensive documentation includes descriptions of these accommodations and modifications. Scores from standardized tests should be interpreted and reported with caution in these cases.

See the Treatment section of the Dysarthria Evidence Map for pertinent scientific evidence, expert opinion, and client/caregiver perspectives.

Treatment is individualized to address the specific areas of need identified during assessment. It is provided in the language(s) used by the person with dysarthria—either by a bilingual SLP or with the use of trained interpreters, when necessary. See ASHA's Practice portal page on Collaborating With Interpreters, Transliterators, and Translators.

Consistent with the WHO's ICF framework (WHO, 2001), the goal of intervention is to help the individual achieve the highest level of independent function for participation in daily living.

Intervention is designed to

  • capitalize on strengths and address weaknesses related to underlying structures and functions that affect communication across partners, activities, and settings;
  • optimize retention of new motor skills by implementing principles of motor learning (Maas et al., 2008);
  • facilitate the individual's activities and participation by (a) teaching new skills and compensatory strategies to the individual with dysarthria and his or her partner(s) and (b) incorporating AAC strategies if appropriate; and
  • modify contextual factors that serve as barriers and enhance those that facilitate successful communication and participation, including development and use of appropriate accommodations.

For individuals with dysarthria, treatment focuses on facilitating the efficiency, effectiveness, and naturalness of communication (Rosenbek & LaPointe, 1985; Yorkston et al., 2010).

See Person-Centered Focus on Function: Dysarthria [PDF] for an example of functional goals consistent with ICF.

Treatment Approaches

Treatment can be restorative (i.e., aimed at improving or restoring impaired function) and/or compensatory (i.e., aimed at compensating for deficits not amenable to retraining).

Restorative approaches focus on improving

  • speech intelligibility,
  • prosody and naturalness, and
  • efficiency.

Compensatory approaches focus on

  • improving comprehensibility by
    • increasing the speaker's use of communication strategies,
    • improving listener skills and capacity, and
    • altering the communication environment;
  • increasing effective use of AAC options; and
  • increasing use of non-AAC devices.

Treatment is not always restorative or compensatory. Sometimes, it is directed at preserving or maintaining function, such as when an individual has a slowly progressing degenerative disease.

Treatment Options

Below are brief descriptions of treatment options for addressing dysarthria. This list is not exhaustive, and the inclusion of any specific treatment does not imply endorsement from ASHA.

Treatments are grouped into (a) those that directly target the speech-production subsystems and (b) other treatment options, including communication strategies, environmental modifications, AAC, and medical/surgical interventions by other specialists.

Treatment selection depends on a number of factors, including the severity of the disorder, natural history and prognosis of the underlying neurologic disorder, the perceptual characteristics of the individual's speech and his or her communication needs, patient and family preference and engagement, and the presence and severity of co-occurring conditions (e.g., aphasia, cognitive impairment, or apraxia of speech). One or more of these co-occurring conditions might affect the individual's insight into communication limitations, ability to implement compensatory strategies such as conversational repair, or ability to benefit from some treatment approaches.

It can be important to sequence treatments. For example, respiration and phonation are usually targeted initially, but prosthetic management of velopharyngeal dysfunction may be needed first in order to achieve efficient and effective breathing and phonation for speech (Duffy, 2013; Yorkston et al., 2010).

Some treatments have benefits that extend to subsystems other than the one being targeted. For example, improving prosody can benefit naturalness and intelligibility (Patel, 2002; Yorkston et al., 2010), and increased loudness (vocal effort) may induce changes in articulation and resonance (Neel, 2009).

Treatments That Target Speech-Production Subsystems

Respiration
  • Making postural adjustments (e.g., sitting upright to improve breath support for speech)
  • Inhaling deeply before onset of speech utterance (known as preparatory inhalation)
  • Using optimal breath groups when speaking (i.e., for each breath, speak only the number of syllables that can be comfortably produced)
  • Using expiratory muscle strength training to improve strength of the expiratory muscles (the individual blows into a pressure threshold device with enough effort to overcome a preset threshold)
  • Using inspiratory muscle strength training to improve strength of the inspiratory muscles to permit better sustained or repeated inspirations (the individual uses a handheld device that is set to require a minimum inspiratory pressure for inspiration to continue)
  • Using maximum vowel prolongation tasks to improve duration and loudness of speech
  • Using controlled exhalation tasks (air is exhaled slowly over time) to improve control of exhalation for speech
  • Using nonspeech tasks to improve subglottal air pressure and respiratory support (e.g., blowing into a water glass manometer)
Phonation
  • Lee Silverman Voice Treatment (LSVT®; Ramig, Bonitati, Lemke, & Horii, 1994)—an intensive program that targets high phonatory effort to improve loudness and intelligibility
  • Pitch Limiting Voice Treatment (PLVT; De Swart, Willemse, Maassen, & Horstink, 2003)—a program for increasing vocal loudness without increasing pitch
  • Effort closure techniques to increase adductory forces of vocal folds (e.g., pulling upward on chair seat; squeezing palms of hands together)
  • Improved timing of phonation (e.g., initiating phonation at beginning of expiration)
Articulation
  • Phonetic placement techniques (e.g., hands-on, descriptive, pictures) to work on positioning of the mouth, tongue, lips, or jaw during speech.
  • Phonetic derivation techniques (nonspeech to speech tasks such as "blowing" to /u/).
  • Exaggerated articulation (overarticulation) to emphasize phonetic placement and increase precision, sometimes called "clear speech."
  • Minimal contrasts to emphasize sound contrasts necessary to differentiate one phoneme from another.
  • Intelligibility drills in which the individual reads words, phrases, or sentences and attempts to repair content not understood by the listener.
  • Rate modification to facilitate articulatory precision—strategies include
    • pausing at natural linguistic boundaries (e.g., using printed script marked at natural pauses);
    • using external pacing methods such as pacing boards, hand/finger tapping, and alphabet boards;
    • using auditory feedback (e.g., delayed auditory feedback or metronome);
    • using visual feedback (e.g., using computerized voice programs); and
    • using approaches that reduce speech rate without directly targeting it (e.g., increasing loudness, altering pitch variation, altering phrasing or breath patterns).
Resonance
  • Prosthetic management in collaboration with other disciplines (e.g., dentists, prosthodontists)—examples include
    • palatal lift prosthesis and
    • nasal obturator to occlude nasal airflow.
  • Resistance training during speech using continuous positive air pressure (Kuehn, 1997).
Prosody
  • Increasing awareness and ability to control respiration, rate, and pitch to vary emphasis within multisyllabic words and in connected utterances (e.g., using scripts, marked and unmarked passages)
  • Improving intonation by signaling stress with loudness, pitch, or duration
  • Extending breath groups to better align with syntactic boundaries
  • Using contrastive stress tasks to improve prosody and naturalness (e.g., repeating sentence with stress on different word[s])

Other Treatment Options

Communication Strategies

A variety of communication strategies can be used by the individual with dysarthria (speaker) and his or her communication partner to enhance communication when speech intelligibility or efficiency is reduced. These strategies can be used before, during, or after other treatment approaches are implemented to improve or compensate for speech deficits (see, e.g., Duffy, 2013).

Speaker strategies include

  • maintaining eye contact with the communication partner;
  • preparing the communication partner by gaining his or her attention and introducing the topic of conversation before speaking;
  • pointing and gesturing to help convey meaning;
  • looking for signs that the communication partner has or has not understood the message; and
  • effectively using conversational repair strategies (e.g., restating message in different words; using gestures to help clarify message).

Communication-partner strategies include

  • maintaining eye contact with the speaker;
  • being an active listener and making every effort to understand the speaker's message;
  • asking for clarification by asking specific questions;
  • providing feedback and encouragement; and
  • optimizing the ability to hear the speaker and to see the speaker's visual communication cues (e.g., by wearing prescribed hearing aids and glasses during conversations).
Environmental Modification

Environmental modification involves identifying optimal parameters to enhance comprehensibility.

These parameters include

  • reducing background noise (e.g., choose a quiet setting for conversations; turn off TV, radio, and fans);
  • ensuring that the environment has good lighting;
  • improving proximity between the speaker and his or her communication partner; and
  • using face-to-face seating for conversations.
Augmentative and Alternative Communication (AAC)

AAC involves supplementing or replacing natural speech and/or writing.

The two forms of AAC are

  • unaided (e.g., manual signs, gestures, and finger spelling) and
  • aided (e.g., line drawings, pictures, communication boards, tangible objects, speech-generating devices).

Other augmentative supports include voice amplifiers, artificial phonation devices (e.g., electrolarynx devices and intraoral devices), and oral prosthetics to reduce hypernasality.

See ASHA's Practice Portal page on Augmentative and Alternative Communication.

Medical/Surgical Intervention

SLPs may refer the individual to a medical specialist to assess the appropriateness of, or need for, medical interventions.

These interventions can include, for example,

  • pharyngeal augmentation, pharyngeal flap, or palatal flap to treat velopharyngeal incompetency and improve resonance;
  • laryngeal (vocal fold) augmentation (e.g., autologous fat or collagen), laryngoplasty, or recurrent laryngeal nerve sectioning to improve phonation; and
  • pharmacological management to relieve symptoms of the underlying neurologic condition (e.g., spasticity, tremor) associated with underlying neurologic disease.

Factors Influencing Treatment Decisions

Not all individuals with dysarthria are candidates for treatment. Factors influencing decisions about treatment include the individual's communication needs, his or her motivation, and the presence of other deficits or conditions that can affect communication.

In neurodegenerative disease, treatment is often appropriate. The goal of treatment is to maximize communication at each stage of the disease, not to reverse decline (Duffy, 2013). This may include strategies to conserve energy and minimize fatigue.

Individuals with neurodegenerative diseases will need compassionate counseling to anticipate

  • the potential progression of dysarthria;
  • the corresponding changes in communication; and
  • the types of intervention that might be appropriate at different stages (e.g., AAC, voice banking).

Cultural Factors

Views of the natural aging process and acceptance of disability vary by culture. Cultural views and preferences may not be consistent with medical approaches typically used in the U.S. health care system. It is essential that the clinician demonstrate sensitivity to family wishes when sharing potential treatment recommendations and outcomes. Clinical interactions should be approached with cultural humility.

Service Delivery

See the Service Delivery section of the Dysarthria Evidence Map for pertinent scientific evidence, expert opinion, and client/caregiver perspective.

In addition to determining the optimal treatment approach for an individual with dysarthria, the clinician considers service delivery variables—such as format, provider, dosage, timing, and setting—which may have an impact on treatment outcomes.

Format—refers to the structure of the treatment session (e.g., group and/or individual). Individual treatment may be most appropriate for learning new techniques and strategies. Group treatment provides opportunities to practice techniques and strategies in a naturalistic setting and receive feedback about their effectiveness in improving comprehensibility and overall communication.

Provider—refers to the person providing the treatment (e.g., SLP, trained volunteer, family member, caregiver). In addition to skilled treatment provided by the SLP, family members and other communication partners can be trained by the SLP to provide opportunities for practice, encourage the use of strategies like AAC, and give feedback about performance in functional settings.

Dosage—refers to the frequency, intensity, and duration of service. Dosage may vary depending on individual's type and severity of disease, energy level, motivation, and degree of community support. Individuals with dysarthria may benefit from frequent and intense practice consistent with the principles of motor learning to enhance retention of speech skills (Bislick, Weir, Spencer, Kendall, & Yorkston, 2012; Kleim & Jones, 2008; Maas et al., 2008).

Timing—refers to when intervention is initiated relative to the diagnosis. Early initiation of treatment may be beneficial for learning or relearning motor patterns; however, improvements in comprehensibility using communication strategies are possible at any point. Timing for introducing prosthetic management and/or AAC may vary with the setting, the individual's preferences, and the severity and stage of disease.

Setting—refers to the location of treatment (e.g., home, community-based). Individuals may benefit from a naturalistic treatment environment that incorporates a variety of communication partners to facilitate generalization and carryover of skills.

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Acknowledgements

Content for ASHA's Practice Portal is developed through a  comprehensive process that includes multiple rounds of subject matter expert input and review. ASHA extends its gratitude to the following subject matter experts who were involved in the development of the Dysarthria in Adults page:

  • Deanna Britton, PhD, CCC-SLP
  • Heather M. Clark, PhD, CCC-SLP
  • Joseph R. Duffy, PhD, CCC-SLP
  • Nicole M. Etter, PhD, CCC-SLP
  • Jessica E. Huber, PhD, CCC-SLP
  • Raymond D. Kent, PhD 
  • Mili S. Kuruvilla-Dugdale, PhD
  • Kaitlin L. Lansford, PhD
  • Antje S. Mefferd, PhD, CCC-SLP
  • Amy T. Neel, PhD, CCC-SLP
  • Nancy P. Solomon, PhD, CCC-SLP  

Citing Practice Portal Pages

The recommended citation for this Practice Portal page is:

American Speech-Language-Hearing Association. (n.d.). Dysarthria in Adults. (Practice Portal). Retrieved month, day, year, from www.asha.org/Practice-Portal/Clinical-Topics/Dysarthria-in-Adults/.

Content Disclaimer: The Practice Portal, ASHA policy documents, and guidelines contain information for use in all settings; however, members must consider all applicable local, state and federal requirements when applying the information in their specific work setting.

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