DIAGNOSING AND TREATING ACQUIRED (ADULT) APRAXIA OF SPEECHDon FreedOctober 14, 2014CSHA Hot TopicsChildren’s Hospital of Central California

AOS Defined

Apraxia of speech is a phonetic-motoric disorder of speech production. It is caused by inefficiencies in the translation of well-formed and filled phonologic frames into previously learned kinematic information used for carrying out intended movements. These inefficiencies result in intra- and interarticulator temporal and spatial segmental and prosodic distortions. It is characterized by distortions of segment and intersegment transitionalization and coarticulation resulting in extended durations of consonants; vowels; and time between sounds, syllables and words. These distortions are often perceived as sound substitutions and as the misassignment of stress and other phrasal and sentence-level prosodic abnormalities. Errors are relatively consistent in location within the utterance and invariable in type. It is not attributable to deficits of muscle tone or reflexes, nor to primary deficits in the processing of sensory (auditory, tactile, kinesthetic, proprioceptive), or language information. In its extremely infrequently occurring isolated form, it is not accompanied by the above mentioned deficits of basic motor physiology, perception, or language.

McNeil, Robin, and Schmidt (2009)

Key Elements of This AOS Definition1. When our cognitive system selects a word for

speech production, the word’s phonological representations are combined to form a phonological word “frame.”

2. In cases of AOS, correct phonological frames are poorly transformed into speech movements.

3. This results in speech that has timing and movement errors for sounds, syllables, and words.

4. The timing problem causes speech that is slow, with lengthened productions of vowels, consonants, or both.

5. In addition, the timing problem causes pauses between phonemes, syllables, words, and phrases.

Key Elements of This AOS Definition6. The movement problem causes distorted

productions of vowels and consonants.7. These distortions can sometimes sound like

phoneme substitutions, but they actually are distortions of the correct target sound (however, real substitutions can occur in AOS).

8. These timing and movement problems contribute significantly to prosody errors in connected speech.

9. On repeated utterances, articulation errors in AOS are generally consistent for type of error (distortion, substitution, omission) and for location.

10. AOS errors are not caused by muscle, sensory, or language deficits.

11. Pure AOS is very rare.

Primary Clinical Characteristics of AOSThe following six behaviors are strongly indicative of apraxia of speech when, as a group, they are present in a patient’s speech (Wambaugh, Duffy, McNeil, Robin, & Rogers, 2006): The patient demonstrates prosody abnormalities. The patient has a slow speech rate characterized by

lengthened productions of vowels, consonants, or both. The patient has a slow speech rate with pauses between

phrases, words, syllables, or phonemes. These pauses may often be filled with a schwa.

The patient produces consonants and vowels that are distorted.

The patient has phoneme substitutions that also are distorted.

The patient demonstrates articulation errors during repeated utterances that generally are consistent for type of error (omission, distortion, substitution) and for location.

Nondiscriminative Clinical Characteristics of AOS

The following behaviors only are suggestive of AOS when they are found in a patient’s speech because they also can be found frequently in other disorders, such as fluent aphasia. By themselves, these behaviors should not be used to make the diagnosis of apraxia of speech:

The patient has short periods of error-free speech.

The patient’s automatic, overlearned speech (e.g., counting 1 to 10) is produced better than propositional speech (e.g., describing the prior day’s activities).

The patient self-corrects errors and shows other signs of error awareness.

Nondiscriminative Clinical Characteristics of AOS (cont.)

The patient has difficulty initiating speech.

The patient’s speech errors increase as word length increases.

The patient has perseverative errors or movements.

The patient demonstrates articulatory groping, either visually, audibly, or both.

Clinical Characteristics Usually Found in Other DisordersThe following behaviors are more likely to be found in other disorders and therefore should not be used to make the diagnosis of apraxia of speech:The patient demonstrates a difference between

expressive and receptive speech and language abilities.

The patient has transposition errors on phonemes or syllables. “Vellitision” for television (a type of error more common in conduction aphasia, for example).

The patient has anticipatory articulation errors. “Papple” for apple (a type of error more common in fluent aphasia).

Note: The presence of limb apraxia or nonverbal oral apraxia does necessarily indicate a diagnosis of apraxia of speech.

Clinical Characteristics Ruling Out Apraxia of SpeechThese three behaviors are exclusionary characteristics; they do not occur in the speech of patients with apraxia of speech. Their presence in a patient’s utterances indicate that apraxia of speech would not be the correct diagnosis.The patient demonstrates a fast rate of

speech.The patient has a normal rate of speech.The patient demonstrates normal

prosody.

Assessment of AOSThere is no widely accepted,

published, standardized test for adult AOS.

Many current researchers use a collection of informal assessment tasks to detect the speech errors of AOS in their participants.

For example, Wambaugh has repeatedly used the following assessment tasks in her recent AOS research:

Assessment of AOS (cont.)(a) The Increasing Word Length (thick-

thicker-thickening) and Repeated Trials (repeat target word 3x) subtests of the Apraxia Battery for Adults—Second Edition

(b) narrative and procedural discourse tasks

(c) Assessment of Intelligibility of Dysarthric Speech

(d) consonant production probe (e) sentence repetition task(f ) multisyllabic word repetition task.

Assessment of AOS (cont.)Hegde and Freed’s (2011) informal AOS

assessment recommended the following tasks detecting this disorder:

Repeating multisyllabic wordsRepeating phrasesRepeating sentencesReciting overlearned sequences (e.g.,

days of week, counting 1-20)Increasing word length Repeated trials (3x)Comparing AMRs and SMRsConnected speech sample

Assessment of AOS (cont.)In general, these types of informal tasks

seem to be effective in evoking the core speech errors of AOS.

To make the most accurate diagnosis of AOS, a number of researchers report that they are looking for the speech errors that are on the “McNiel checklist”:

Slow rate of speechProlonged segment/intersegment durations Distortions/distorted sound substitutionsErrors consistent in type and locationProsodic abnormalities

Differential Diagnosis: AOS and Fluent AphasiaPatients with apraxia of speech often have

anterior brain damage and right hemiparesis. Patients with aphasia who produce literal paraphasias often have posterior brain damage and do not have hemiparesis.

Patients with apraxia of speech usually have a co-occurring Broca’s aphasia. Patients who produce literal paraphasias usually have Wernicke’s or conduction aphasia.

Patients with apraxia of speech usually have disturbed prosody, often because they are frequently stopping or slowing their speech as they search for correct articulatory positions. Patients with aphasia usually produce their literal paraphasic errors in a flow of speech that has normal prosody.

Differential Diagnosis: AOS and Fluent AphasiaPatients with apraxia of speech may have

difficulty initiating speech because they are searching for the correct articulatory position of the first phoneme in an utterance. Patients with aphasia who produce literal paraphasias typically do not have as much trouble initiating an utterance.

The phoneme and syllable substitutions in apraxia of speech are usually close to the intended sounds. For example, a /b/ might be substituted for a /d/. The substitutions in literal paraphasias can be far off target from the intended sounds, such as a nasal consonant being used in place of a stop consonant, or perhaps even a vowel being substituted for a consonant.

Differential Diagnosis: AOS and Fluent AphasiaPhoneme distortions often are present in cases of

apraxia of speech; they are rare in the speech of patients with literal paraphasias.

Self-initiated efforts at fixing articulation errors usually do not result in improvements in apraxia of speech. In cases of literal paraphasia, these self-repair efforts often can result in improved articulation.

In apraxia of speech, patients often have prolonged transitions when moving from phoneme to phoneme and from word to word (even when the words are articulated correctly); they also often prolong vowels in multisyllabic words and sentences. Patients with literal paraphasias demonstrate much more normal movement transition times in their speech.

Differential Diagnosis: AOS and Fluent AphasiaAn overall slow speech rate for phrases

and sentences is found in cases of apraxia of speech, even when the words are produced correctly. In cases of literal paraphasias, the speech rate is within normal limits during error-free utterances.

When patients with apraxia of speech attempt to increase their speech rate, phoneme production errors also increase, often quite noticeably. Patients with literal paraphasias usually can increase their speech rate and maintain accurate phoneme production.

Treating AOS:

Sound Production Treatment

Types of AOS TreatmentsArticulatory kinematic—use of modeling, repetition,

and artic placement (e.g., 8-Step Continuum and SPT).

Rate and rhythm—decreases artic timing errors by contolling rate of speech (e.g., using metronome or computer to set an optimal rate of speech).

AAC—creates a comprehensive communication system for the patient using writing, gestures, pictures, and drawing or using a specialized electronic device.

Intersystemic facilitation and reorganization treatment—supplement speech with a stronger communicative ability, such as combining good gesturing skills with limited verbal output.

Sound Production Treatment (SPT)SPT is an articulatory-kinematic

treatment.It combines the following elements

into its treatment steps:modeling-repetitionminimal contrast practice (sometimes) integral stimulationarticulatory placement cueingrepeated practice verbal feedback

Sound Production Treatment (SPT)SPT was developed about 15 years ago. It is based on prior AOS tx, and motor learning

research, such as using blocked and random practice and reduced feedback schedules.

“SPT has received more extensive and systematic study than any other specific treatment for AOS.” (p. 815)

“SPT has been shown to improve articulatory accuracy of consonant production in words, phrases, and sentences for trained and untrained items****.” (p. 815)

**** Response generalization to untrained phonemes has been minimal.

Maintenance of tx effects has been demonstrated out to 10 weeks, with a slow decline after that.

Wambaugh and Mauszycki (2010)

Sound Production Treatment (SPT) Here is a recommended procedure for getting started with

SPT for a patient with AOS: Complete your assessment of the patient’s speech and

determine which phonemes are most in error. (In order of difficulty, affricates are typically the hardest, then fricatives, then stops, nasals, semivowels, and vowels. Also, back sounds are usually more difficult than front sounds.)

Determine the utterance length where your patient’s productions of the target phonemes begin to breakdown (e.g., monosyllabic words, multisyllabic words, phrases, or sentences).

Choose three difficult phonemes for treatment. Develop about 30 tx stimuli for each phoneme at the

“breakdown” utterance length. Include the target sound in the initial, medial, and final positions (as appropriate).

Note: If you are working at the monosyllabic word level, you will need to create a minimal pair tx stimulus for each word.

Why Include the Minimal Pairs?“The minimal contrast tasks used in SPT

require production of words in which target contrasts are minimally different (e.g., shock-sock; conical-comical). It is believed that the use of minimal contrast pairs provides a context for practicing and refining the movement patterns necessary to distinguish among minimally different sounds and that such practice is important when errors are the result of a movement programming disorder.” (p. 450)

Duffy (2013)

Sound Production Treatment (SPT) Sound Production Treatment Hierarchy (Minimal Pair

Version) 1. Therapist says word and requests repetition.

◦ (a) If correct, request additional repetitions (5 times*) and go to next item.

◦ (b) If incorrect, give feedback and say, “Now let’s try a different word” and produce minimal pair word and request a repetition.

If correct, give feedback and say, “Now let’s go back to the other word” and go to #2 with the target word.

If incorrect, give feedback, attempt with integral stimulation up to 3 times, then go to #2 with the target word.

2. Therapist shows the printed letter of the target sound, says word, and requests repetition.◦ (a) If correct, request addition repetitions (5 times) and

go to the next item. ◦ (b) If incorrect, go to #3.

Sound Production Treatment (SPT) 3. Therapist uses integral stimulation: “Watch me,

listen to me, say it with me” up to three times.◦ (a) If correct, request addition repetitions (5 times)

and go to the next item. ◦ (b) If incorrect, go to #4.

4. Therapist provides verbal articulatory placement cues appropriate to error. Therapist elicits production using integral stimulation.◦ (a) If correct, request addition repetitions (5 times)

and go to the next item. ◦ (b) If incorrect, go to next item.

*Provide feedback for accuracy for approximately 3 of the 5 productions

Note: the hierarchy is response-contingent (subsequent steps are used only upon incorrect production) and does not reverse directions.

Sound Production Treatment (SPT) Sound Production Treatment Hierarchy

(Multisyllabic Word, Phrase, or Sentence Version) 1. The SLP provides a verbal model of the target word and

requests a repetition. If correct, ask for 5 repetitions and then present next item. If wrong, go to #2.

2. The SLP indicates the printed letter(s) representing the target sound, instructs the participant to attend to this sound, provides another model, and requests a repetition. If correct, ask for 5 repetitions and then present next item. If wrong, go to #3.

3. The SLP says, “watch me, listen to me, say it with me” (i.e., integral stimulation) and attempts simultaneous production for a maximum of three times. If correct, ask for 5 repetitions and then present next item. If wrong, go to #4.

4. The SLP provides articulatory placement cues appropriate to the sound production error and then repeats the procedures used in the previous step.

5. The SLP presents the next item.

Sample Treatment Stimuli ListsSample Stop List (Monosyllabic words

and minimal pairs)Buy -- WhyBee -- We

Bite -- WhiteBay -- WayBore -- War

Beep -- Weep Ben -- When

Bill -- WillBoo -- WooBait -- Wait

Sample Treatment Stimuli ListsSample initial affricate list (Phrases)

Charmed lifeCharley horseJump the gun

Chit chatChick flickJust in timeChow downJudge not

Jam packedChannel surfing

Sample Treatment Stimuli ListsSample Stop List (Sentences)

Pat buys a big bike.Ted keeps bad dogs.

Deb makes pumpkin pie.Bobby’s key is gold.Cook bakes a cake.Dotty picks a cat.

The puppy eats bugs.The boat docks today.

Dad packs the bag.Todd is a good boy.

Sample Treatment Stimuli ListsSample Fricative List (Sentences)

Susan is shy.She finds fuzz.Soda is fizzy.

The zoo is fun.My shoes seem stiff.

Sue fills the vase.Something falls off.

The shell is thin.Cindy is special.The view is fine.

Sample Treatment Stimuli ListsSample Mixed Consonants (Sentences)

Sue eats cheese for lunch.We give Cindy a lift.

Jane is your good friend.Very few people see Jim.You choose the first one.Toast is good for lunch.

I sometimes go with John.This book is very funny.

Chew your food carefully.Charlie never sees that show.

References Dabul, B. (2000). Apraxia battery for adults (2nd ed.). Austin,

TX: Pro-Ed. Duffy, J. R. (2013). Motor speech disorders: Substrates,

differential diagnosis, and management (3nd ed.). St. Louis: Elsevier Mosby.

Hedge, M. N., & Freed, D. B. (2011). Assessment of communication disorders in adults. San Diego, CA: Plural Publishing.

McNeil, M. R., Robin, D. A., & Schmidt, R. A. (2009). Apraxia of speech: Theory and differential diagnosis. In: M. R. McNeil (Ed.), Clinical management of sensorimotor speech disorders (2nd ed.). New York: Thieme.

Wambaugh, J., Duffy, J., McNeil, M., Robin, D., & Rogers, M. (2006). Treatment guidelines for acquired apraxia of speech: A synthesis and evaluation of the evidence. Journal of Medical Speech-Language Pathology, 14(2), xv–xxxiii.

Wambaugh, J. & Mauszycki, S. (2010). Sound ProductionTreatment: Application with severe apraxia of speech, Aphasiology, 24:6-8, 814-825