Purpose: Children diagnosed with Childhood Apraxia of Speech (CAS) often acquire sounds but have difficulties in putting them together and forming words. This case study deals with the therapeutic challenges and examines a technique called Initial Phoneme Cue (IPC).
Method: A 10 year old girl with Autism Spectrum Disorder (ASD) and CAS had word formation treatment for several years with no results. We compared the use of IPC technique versus regular imitation of CVCV structured words.
Results: The use of IPC resulted in a 97-100% success of word imitation while regular imitation had 0-20% success of word imitation.
Conclusions: The results confirmed our speculation of the efficacy of IPC’s technique within this single treatment process.
Initial phoneme cue (IPC) is a technique that is used for word formation among patients with Childhood Apraxia of Speech (CAS). Not many such techniques have been examined objectively in order to prove their usefulness in treatment of CAS in general let alone in the Hebrew language. An objective investigation of the IPC technique may provide clinical knowledge of the efficiency of the technique and may help in improving the technique’s protocol. The purpose of this study was to assess the effect of the IPC technique of the Verbal Motor Learning (VML) method in teaching word formation among children diagnosed with CAS and Autism. I will begin by defining the CAS condition and scanning different techniques for treating difficulties in word formation and then concentrate on the IPC technique.
Childhood Apraxia of speech (CAS) is a motor-speech disorder that occurs among children. This disorder is different from Apraxia of Speech (AOS) that occurs among adults after a head injury or Cerebral Vascular Accident (American Speech-Language-Hearing Association (1). The updated definition of CAS according to the ASHA is:
“Childhood apraxia of speech (CAS) is a neurological childhood (pediatric) speech sound disorder in which the precision and consistency of movements underlying speech are impaired in the absence of neuromuscular deficits (e.g., abnormal reflexes, abnormal tone). CAS may occur as a result of known neurological impairment, in association with complex neurobehavioral disorders of known or unknown origin, or as an idiopathic neurogenic speech sound disorder. The core impairment in planning and/or programming spatiotemporal parameters of movement sequences results in errors in speech sound production and prosody”
Levelt, Roelofs & Meyer (2) distinguish between three different stages of speech and their pathologies, 1) impairments of lexical access to the word form (classic anomia), 2) phonological encoding (post lexical phonological disorder), and 3) phonetic encoding (apraxia of speech). CAS causes deficits in the production of consonants, vowels and the formation of words. Pronouncing a word built from two open familiar syllables can be a difficult task for a child with CAS (3). A common characteristic of word imitation among children diagnosed with CAS is a difficulty in pronouncing the first syllable of the word (4).
Shriberg et al. (4) identified segmental and supra-segmental characteristics of CAS. The segmental characteristics include (a) an articulatory struggle (groping) particularly on word onsets, (b) trans positional (metathetic) substitution errors reflecting sequencing constraints on adjacent sounds, (c) marked inconsistencies on repeated tokens of the same word type, (d) proportionally increased sound and syllable deletions relative to overall severity of involvement and (e) proportionally increased vowel/diphthong errors relative to overall severity of involvement. The supra-segmental characteristics include (a) inconsistent realization of stress (i.e. prominence on syllables or words), (b) inconsistent realization of temporal constraints on both speech and pause events and (c) inconsistent oral-nasal gestures underlying the percept of nasopharyngeal resonance. All of these characteristics of CAS effects word formation.
Techniques for treating difficulties in word formation
A number of approaches and techniques have been introduced in the literature to deal with word formation. Tomlin (5) suggests forming words by practicing monosyllabic words and when the severity of the apraxia condition decreases the therapist should proceed to practicing multi-syllabic words. Tomlin (5) starts teaching pronunciation by increasing phoneme control up to an 80% success rate of pronunciation. She argues that when the client starts to produce the phoneme correctly he/she will begin to understand the tactile/kinesthetic pattern of the phoneme.
Another approach is the cycles approach (6) which combines various phonological theories including cognitive psychology principles, phonological acquisition research and clinical phonology research. Its main purpose is to improve the speech pronunciation and clarity through planned cycles of pattern pronunciation targets which are based on seven underlying concepts.
There is also a technique that is called Metaphon which is a cognitive-linguistic treatment that aims to increase metalinguistic awareness as a means of improving phonological change and sound production (7). It is based on contrasting speech sounds and properties while emphasizing similarities and differences in sounds. It enables recognizing, matching and classifying sounds according to their features.
Finally, the “System for treatment of developmental verbal apraxia” (8) is a listed patent used to improve word formation among patients diagnosed with apraxia of speech. The system’s kit includes a selected single-syllabic word cards in a specific order that forms a multi-syllabic word, which is also represented on a card. The multi-syllabic word is cut into single-syllabic sections that can be represented as words. The child is required to pronounce each single-syllabic section separately but in order so it superficially creates the multi-syllabic word.
The Initial Phoneme Cue Technique
One of the techniques that promote word forming among CAS patients is called Initial Phoneme Cue (IPC) which involves prompting the first syllable of the word. IPC is usually used as a word retrieval technique for anomia, which is a problem in lexical access to the word form (9,10). Ziegler & Wunderlich (11) found that the IPC technique was beneficial for children with CAS by shortening naming latencies. Hillis (12) argues that IPC can help in word retrieving for patients with Aphasia but the effect diminishes with time.
The IPC contains two kinds of information; auditory and visual. The auditory information leads the patient to the next phonemes of the word. The visual information shows the patient how to pronounce the first phoneme. Visual information from the speaker‘s face enhances intelligibility – in normal hearing conditions and, even more so, in noisy environments (11). Further information of how to exactly perform the IPC technique can be found in the appendix.
Motor learning and speech
Speech involves complex motor movements and is the most complicated timed movement in the body. Each word production involves 100 muscles that need accurate and very fine tuning (13). The general motor learning principles can be applied to motor speech control in order to improve motor speech ability especially among patients diagnosed with CAS.
Knock, Ballard, Robin & Schmidt (14) investigated the application of a principle of motor learning (15), namely random practice and compared it to blocked practice as a mechanism to treat apraxia of speech in two patients, focusing on production of plosives and fricatives. Random practice is claimed to be more beneficial in terms of generalization and maintenance than blocked practice (15). In their study, Knock et al. (14) found that although trained practice sounds improved, there was no generalization to novel responses in either the random or the blocked condition. However, retention was better following random practice than following blocked practice. In addition, performance was less variable in random practice conditions than in blocked practice conditions.
The VML method (16) has been developed over the last 13 years in Israel in the Hebrew language. The beginning of the development was an intuitive field work with a 4 year old autistic child who also had CAS. The method has been expanded over the years using hundreds of different cases in a grounded theory research process (17). There has been subsequent development of treatment and evaluation tools, developing algorithms of the method, collecting data from hundreds of treatment processes and training therapists.
The VML is an organized, structured method that includes evaluation, analysis, techniques and treatment principles that promote speech via motor intervention. The system is based on two basic elements. The first is tactile and kinesthetic cues for every phoneme, syllable and word form. The second element is motor learning principles that enable thorough analysis and influence on the therapist’s decision making process.
The reasoning behind the IPC technique
In Hebrew, most of the words include 2 syllables or more. There are relatively few words built from one open syllable (CV format – consonant + vowel) and a larger group of words built form one closed syllable (CVC format). For a child diagnosed with severe CAS, the production of a single phoneme might be a difficult motor task so a CV format is even harder. A CVC format would require even more capabilities etc. Any combination of two phonemes together is two separate tasks which are difficult. At the beginning of the process the child can’t handle so many motor tasks consecutively. The hierarchical process of the treatment is to build the ability to control the basic motor task (phoneme = consonant or vowel) by creating a motor scheme for each task. The second stage is to put two basic motor tasks together (consonant + vowel) to create a new motor scheme (open syllable, e.g. Ba, Gu, Ta). After creating the open syllable as a solid, controlled motor scheme the patient can move to the next level of putting two syllables together to build a more complex motor scheme. In Hebrew that will be his/her first complex word.
The IPC technique helps the patient to build a motor scheme of the format CVCV. The difficulty in imitating two open syllables is both phonological and motor. In the phonological aspect, the difficulty is to organize the chain of syllables in the correct sequence. A known phenomenon is backwards pronunciation that occurs at 2-3 years of age when the child put the syllables in backwards order. The motor difficulties evolve from the change in the articulator’s way of action and the quick timing needed for that. It can be manifest in different types of errors such as stopping, vowel replacement, vowel drop, consonant replacement etc. Not necessarily the specific error of a syllable pronunciation is syllable based problem if the same single syllable can be pronounced correctly not within the word formation.
In order to practice word formation the ability to pronounce each syllable within the word should be intact. The IPC unique strategy deals with the core problem itself – putting those two sounds together, while offering the precise support needed.
The purpose of this study is to examine the effect of the IPC technique according to the VML’s protocol, in treating word formation among a child diagnosed with CAS.