Chapter 6: Motor Speech Disorders: Apraxia of Speech and Evaluation of Motor Speech Disorders

motor speech disorders

are disorders involving the effective manufacture, refinement, transmission, and execution of motor plans for speech

speech

the sounds made with the vocal and articulatory structures to verbally produce words

language

the actual words produced

cognitive or language disorder

the presence of a motor speech disorder does not necessarily imply the presence of what?

apraxias and dysarthrias

what are the two major categories of motor speech disorders?

praxis

means to move or to move

a

means without

apraxia of speech

a lack of movement or action for speech production

an acquired disorder of speech originating from an inability to create and sequence motor plans or speech

inability to put together motor plans for speech

various kinds of apraxia

the inability to move limbs, eyes, and oral structures

for speech and swallowing

acquired and developmental apraxia of speech

what are the two subcategories of apraxia of speech?

acquired apraxia of speech

a type of apraxia that results from some form of brain damage

developmental apraxia of speech

a type of apraxia that results from an unknown etiology

apraxia of speech

an inability to create and sequence the neural impulses necessary to create appropriate motor movements for speech

individual’s brain has lost the ability to produce plans that tell the muscles used to produce speech how to contract with the appropriate range, force, and timing to produce normal speech

construction of appropriate motor plans for the articulators to produce nonspeech actions

what remains unaffected in apraxia of speech?

some level of aphasia (typically nonfluent)

what does apraxia of speech usually co-occur with?

inferior posterior left hemisphere

where is the damage to apraxia of speech typically?

broca’s

what type of aphasia is most often seen with apraxia of speech?

apraxia of speech in SLP terms

a neurologic speech disorder reflecting an impaired capacity to plan or program sensorimotor commands necessary for directing movements that result in phonetically and prosodically normal speech. it can occur in the absence of physiologic disturbances associated with the dysarthrias and in the absence of disturbance in any component of language

characteristics of apraxia of speech

effortful speech, awareness of speech areas, self-repairs, struggle and frustration, limited prosody (music of speech is reduced), slowed rate, groping movements of the articulators

dysarthria

what does a motor speech disorder typically co-occur with?

motor speech programmer

a network of neural structures that contribute to the function of creating appropriate motor plans for speech

broca’s area, supplementary motor cortex, primary motor cortex, basal ganglia, and cerebellum are involved in the appropriate productions

speech characteristics of those with apraxia of speech

effortful and lots of struggle/frustration, articulation errors, limited prosody, slowed rate, visible groping about the tongue, lips, and mandible, aware of speech errors which leads to slowed rate, self-repairs, and inconsistent errors (islands of intact articulation)

because the decreased rate of speech they adopt to avoid errors

why do those with apraxia of speech have limited prosody?

to assume the appropriate articulatory position for production of a certain phoneme or word

why do those with apraxia of speech move their tongue, mandible, and lips to inaccurate and outrageous positions?

the severity of the disorder

what is the impact that apraxia of speech has on the speech of an individual determined by?

mild case of apraxia of speech

individual experiences barely any noticeable articulation difficulties that can be easily disguised as normal and appropriate difficulties with articulation

moderate severity of apraxia of speech

individual might continually struggle to articulate appropriately

severe case of apraxia of speech

an individual might be able to produce only a handful of words appropriately and will usually experience extreme difficulty producing appropriate speech

profound cases of apraxia of speech

individual can be completely mute with the inability to produce even a single phoneme

articulation errors of those with apraxia of speech

are inconsistent and include various sound-level errors: phoneme substitution (tat for cat), phoneme distortions, and voice-onset errors

on the first phoneme of a word

articulation errors of those with apraxia of speech often occur where?

the phonemes or phoneme combinations that require greater motor planning abilities (like dog vs tornado)

they require more more muscles

which word are more difficult to produce?

/s and /l/

which sounds displayed with greater difficulty among these individuals?

islands of intact articulation

individual may struggle and then suddenly a phrase or whole sentence flows with no errors, then back to reduced rate, limited prosody, etc

when articulation errors are varied and inconsistent

errors of speakers with apraxia vary widely even among one individual’s productions of the same utterance

articulatory difficulties

anticipatory substitutions (knowing cat ends in t but saying it earlier like tat), consonant and vowel distortions, perseverative substitutions (repeat a sound/word inappropriately), phoneme additions (saying stat for sat), phoneme prolongations (saaaat for sat), phoneme substitutions (tat for cat), and voicing errors (manner and place intact, but not the voicing and the voicing that comes in pairs)

lesion sites for apraxia of speech

largely debated

left hemisphere at or around the inferior-posterior frontal lobe (broca’s area), left parietal lobe in conjunction with lesion at the left frontal lobe, lesion to the parietal or frontal cortex or the subcortex underlying the frontal cortex, at the precentral gyrus of the anterior insula, and/or broca’s area and other structures involved in motor planning

etiologies of apraxia of speech

any process or event that damages the left inferior-posterior frontal lobe, stroke involving occlusion to left MCA, generalized head trauma, and focal head trauma (like surgical removal of tumor or aneurysm near broca’s area)

primary progressive apraxia of speech

is a neurodegenerative condition in which patients display a slow onset of apraxia of speech that gains in severity over time as a result of continued atrophy of the lateral premotor cortex and the supplementary motor area

individuals evolved into a condition of degeneration of the premotor cortex, prefrontal cortex, primary motor cortex, basal ganglia, midbrain, and corpus callosum

progressive supranuclear palsy

what does the clinical presentation of primary progressive apraxia of speech pattern of degeneration resemble?

buccofacial-oral apraxia

aka nonverbal apraxia or oral apraxia

is an inability to program and carry out any volitional movements of the tongue, cheeks, lips, pharynx, or larynx on command

individuals are able to accomplish the same actions automatically in a natural context but not on command (like asking a man to pucker his lips to kiss but he cant unless he is leaning in to kiss his wife)

volitional speech can also be affected, whereas more formulaic utterances might be left unimpaired

ideomotor apraxia

the inability to program motor movements for pantomiming gstures and for the use of tools despite possessing the knowledge of how the tools are used and their function

ex: individual can explain the purpose of a hairbrush and how to brush one’s hair, but if given a hairbrush they are unable to accomplish the task on command but the same person can wake up and automatically brush their hair in a natural context of standing in front of a bathroom mirror

ideational apraxia

an inability to conceptualize a task, formulate motor plans required for the task, or hold in memory the idea of the task long enough to accomplish it successfully

individuals can perform individual components of a task but lack the ability to perform a series of actions sequentially to accomplish an entire act

ex: if handed a hairbrush, an individual may be able to raise the brush to their head but then be unable to accomplish the remaining actions necessary to brush their hair

cannot perform the task volitionally or automatically

individuals with ideational apraxia cannot perform the task volitionally or automatically whereas those with ideomotor apraxia perform well automatically and spontaneously, but not on command

what is the difference between ideational and ideomotor apraxia?

hemiplegia

half body paralysis

hemiparesis

half body weakness

hemiplegia/hemiparesis

occurs with apraxia of speech and is contralateral to the cerebral hemisphere where the lesion is located (usually the right hand)

affects individuals written expression since its usually on the dominant writing hand and apraxia affects verbal expression

hyperreflexia

a likely result of damage to the motor areas of the brain that produces apraxia of speech is also concomitant damage to the UMNs, which transmit extrapyramidal impulses of reflex regulation to the brain stem and spinal cord

without these impulses to inhibit overactive release of reflexes, many inappropriate reflexes are released and others are made hyperactive

may co-occur with apraxia of speech

dysarthria

a lesion at or near motor areas of the left frontal lobe that produces apraxia of speech is also likely to damage descending motor tracts (UMNs) located in the same vicinity, producing this

yes

can you have apraxia of speech and buccofacial apraxia/ideomotor apraxia at the same time?

nonfluent aphasia

apraxia of speech is often a result of lesion at or near broca’s area and the presence of language deficits following that lesion are almost a given

the language deficits take the form of this

apraxia

apraxia of speech vs dysarthria

articulation errors occur more often on longer/complex words

dysarthria

apraxia of speech vs dysarthria

articulation errors are consistent, predictable, and occur on all words in all utterances

apraxia

apraxia of speech vs dysarthria

articulation errors are varied and inconsistent

can produce portions of utterances entirely free from errors (islands of intact articulation)

dysarthria

apraxia of speech vs dysarthria

articulation errors are consistent and predictable

apraxia

apraxia of speech vs dysarthria

have greater difficulty producing less automatic and more volitional utterances, whereas they may produce more automatic, less volitional utterances error free

dysarthria

apraxia of speech vs dysarthria

negatively affect articulation equally across both natural and less natural, more volitional situations 

apraxia

apraxia of speech vs dysarthria

buccofacial-oral apraxia more likely to accompany

dysarthria

apraxia of speech vs dysarthria

buccofacial-oral apraxia less likely to accompany

apraxia

apraxia of speech vs dysarthria

normal muscle strength, muscle tone, and appropriate range of movement of mobile articulators

dysarthria

apraxia of speech vs dysarthria

impaired oral/velopharyngeal muscle strength, abnormal muscle tone, and limited range of motion

apraxia

apraxia vs aphasia

tend to show greater abnormal prosody, more distortions of speech sounds, more articulatory hesitancy and articulatory groping, and more attempts at self-correcting their articulation errors

apraxia

apraxia vs aphasia

errorful production of target words often takes the form of closer approximations than do the errorful attempts at target word production

aphasia

apraxia and this share similarities

both share etiologies (usually stroke) and have similar neuroanatomical regions of origin (left frontal lobe)

aphasia

may mask the presence of apraxia of speech or vice versa

motor speech evaluations and diagnosis

determine the presence and severity of a motor speech disorder such as apraxia and dysarthria

determine the presence and severity of articulatory, resonatory, phonatory, or respiratory problems with speech

the presence of motor speech disorders often implies a problem with nervous system, which may validate a medical-neurological disease

set goals for therapy and determine approach to goals

develop prognosis for recovery of speech

components of motor speech evalution

a case history, an oral motor evaluation with maximum performance tasks, speech tasks that assess error patterns in speech, identification of confirmatory signs to support hypothesized motor speech diagnoses, instrumental measures, and possibly, administration of a formal test of apraxia of speech, dysarthria, and/or intelligibility

case history

review of medical records, interview of patient and caregivers, and interview to observe speech capabilities, or lack thereof

oral motor evaluation

is the examination of the patient’s individual oral structures and articulators and the observation of the nonspeech function of these structures

when SLP asks patient to move the tongue, lips, and mandible so oral cavity can be evaluated

use nonspeech tasks

nonspeech tasks

are used to isolate and test the functioning of any oral structure outside of the context of speech production for strength, mobility, range of motion, and symmetry (range, direction, and rate)

ex includes asking patient to protrude or retract the lips

maximum performance tasks

this tests patient’s maximum limit of ability by comparing patients greatest effort on a task with the knnown average performance rate of unimpaired individuals

include diadochokinetic rates - alternating motion rates and sequential motion rates

alternating motion rates and sequential motion rates

what are the two types of movements in diadochokinetic rates (DDKs)?

alternating motion rates (AMRs)

are simple repetitive motor tasks that are used to test the speed and regularity of movement with which a single syllable can be uttered

the syllables uttered are usually /pʌ/, /tʌ/, and /kʌ/

sequential motion rates (SMRs)

are the rapid repetition of more than one syllable at a time in sequence, they test the individual’s ability to move the articulators rapidly and precisely from one position to the next

includes /pʌtʌ/, /tʌkʌ/, /pʌkʌ/, and /pʌ tʌ kʌ/

speech stress test

a patient is given a book to read aloud or is cued by the SLP to speak continuously for up to 5 minutes to see if the person becomes fatigued and how fatigue affects speech

5

in a speech stress test, if the speech degrades over ___ minutes or less due to fatigue, this is indicative of pathology

speech tasks

tests verbal repetitions of words, phrases, and sentences, oral reading tasks of various length, and patient’s ability to produce connected and spontaneous speech is assessed (by asking open-ended questions, verbally describing a picture presented, and telling/retelling a story)

confirmatory signs

are any observable physiologic characteristics displayed by the individual that support the SLP’s diagnosis of neurological or motor speech diagnosis

identification of confirmatory signs

signs can range from the presence of abnormal muscle tone (flaccid or spastic), to patterns of paresis/paralysis, to the presence of abnormal reflexes or extraneous involuntary movements

tone

level of contraction that remains in the muscle after it stretches and then relaxes

spasticity

too much contraction in the muscle after relaxation (excess tone)

flaccid

not enough contraction in the muscle after relaxation

instrumental measures

phonatory measures to assess pitch and loudness of voice, range of pitch, and loudness, a regularity of vocal fold frequency and intensity

includes kay elemetric’s visipitch and computerized speech lab

visipitch or computerized speech lab

may include specgrographic analysis of speech to generate useful data about articulation, coarticulation, and voice onset times in speech

formal tests/assessments

assist the SLP in correctly identifying apraxia of speech, dysarthrias, and impact on intelligibility, the provide a standardized and methodical approach to the diagnosis and assessment of severity

apraxia: apraxia battery for adults

dysarthria: frenchay dysarthria assessment (FDA), dysarthria examination battery (DEB), and quick assessment for dysarthria 

intelligibility: assessments of intelligibility in dysarthric speakers (AIDS) and word Intelligibility test

therapy for apraxia of speech

no pharmaceuticals or prosthetics are used to treat (though medications are used to combat any underlying etiologies, such as stroke, that create apraxia of speech)

three approaches: articulatory kinematic therapy, intersystematic reorganization, and alternative/augmentative communication strategies

articulatory kinematic appraches

relies on motor learning theory and neuroplasticity to reestablish motor planning abilities for speech

lost motor abilities can be retrieved or rebuilt by cueing the brain to produce or access the motor plans despite brain damage

relies on motor practice, modeling repetition, and articulatory cueing

motor practice

intensive and repetitive production of target phonemes in isolation or within words or phrases to increase articulatory ability

modeling-repetition

the SLP models the production of the target phoneme, word, or phrase, with instructions for the patient to pay attention to how target word is articulated and attempt to imitate SLP

articulatory cueing

phonetic placement descriptions given by SLP to increase patients awareness and understanding of articulatory movements needed to produce the target word

if the target is /p/, SLP will point to the lips and use a description of the phoneme to cue, “Watch my lips, see how they come together, then open to release air.”

guenther model

developed for stuttering, but is a brain computer interface, enables someone that has no capacity to produce speech, to think a sound and out it comes through the computer

sound production treatment

repeated practice of minimal contrast pairs (like bat vs pat) gives multiple opportunities to modify speech pattern for successful production of target phoneme/words

PROMPT

provides tactile kinesthetic, visual, and auditory cues to elicit production of target phoneme

simultaneous multisensory stimulation in stages, beginning with the concept that the mandible is the platform for all articulatory movements

uses touch and motion cues to the patients head, face, or neck at different points to illustrate: place of articulation, muscles used for phoneme production, level of tension in muscles, voicing, nasality, movement of articulators, timing/speech of movement, and degree of opening mandible

melodic intonation therapy

capitalizes on a patient’’s intact ability to produce melody in spite of loss of speech, teaches reacquisition of language by pairing exaggerated prosodic and melodic components with the production of phonemes and words

intersystematic reorganization

is the facilitation of speech by pairing the actions of an intact system with the actions of the impaired speech system in an effort to facilitate operation of the speech system

pairs a physical act (gesture) with the simultaneous production of the target word (like tapping when saying word)

associative or hebbian learning

pairing a physical act with the production of a target word because initiation of one action primes and increases the likelihood of the initiation of the other

wire together

neurons that fire together ___ ____

augmentative and alternative strategies

can be low tech (like letterboards or pen and paper) or high tech (like speech output devices or smartphone apps)

is employed only in the long term for those with severe or profound levels of apraxia of speech

or may be used as a stop gap to establish functional communication until the individual regains the ability to verbally communicate

jaw (mandible)

is the platform for all articulatory movements