Dr. Victor M. Pedro
Department of Clinical Sciences, University of Bridgeport, Bridgeport, Connecticut, U.S.A.
A case study is described of a 7-year-old right-handed Caucasian male with moderate to severe developmental apraxia of speech. Mother developed gestational diabetes during third trimester, pregnancy otherwise normal. Anoxia noted at birth or shortly thereafter, also breast-feeding difficulty observed during infancy. Intelligence testing at age 3 revealed a moderate receptive language delay and significant delays to expressive language skills and speech articulation. Diagnosed with pronounced farsightedness and bilateral stigmatisms with suspected color blindness at age 6. Prior to age 7, while speech-language skills improved somewhat, difficulties with expressive grammar and speech intelligibility worsened. A fear of loud noises became more pronounced. Motor coordination deficits were noted. Difficulty in understanding and following directions was observed. Intelligence and performance tests registered in the low range for mathematics, reading, written language and expression, and oral expression areas. At age 7 years 1 month, a single area of testing, picture vocabulary, revealed a relative strength in the low average range. After three years of special education interventions with no significant improvement in any measurable area of function, a multimodal approach using techniques aimed at facilitating inter-hemispheric communication was provided. At completion of the Cortical Integrative Therapy program, significant improvements were observed in ability to read and reading comprehension, mathematics, written and oral expression, and motor coordination.
KEY WORDS: apraxia, apraxia of speech, breast-feeding, speech delays, Cortical Integrative Therapy
Apraxia results when sounds do not easily form into words. To produce even the simplest words, a complex coordination of lips, tongue, and throat muscles as mediated by neural processes is required. Acquired apraxia occurs in adults, often as a result of a stroke or other experiential trauma. Acquired apraxia differs significantly from developmental apraxia (Maassen B., 2002). Developmental apraxia, referred to variously as developmental verbal apraxia, developmental dyspraxia, developmental verbal dyspraxia (Thoonen G. et al), childhood apraxia of speech, and most commonly developmental apraxia of speech (DAS), occurs in children and is resultant from a coordination deficit involving those muscles used in producing speech or language. While it often manifests as a severe communication disorder, speech-language pathology literature supports the idea that DAS also can be exhibited in children with only mildly disordered articulation (Hall P.K., 1989). Debate continues as to whether a given motor speech disorder (especially apraxia of speech and stuttering) should be understood at the phonologic level, the motoric level, or both of these (Kent R.D., 2000). Although the etiology and pathology of DAS are unknown, it has often been described in a neurological context despite convincing evidence of vocal or lateralized brain lesions (Bornman et al, 2001). It has long been known that DAS is probably not due to a congenital or an acquired speech defect in Broca’s motor speech area or adjacent brain area of the left hemisphere (Kornse et al, 1981), yet family pedigrees may be indicative of developmental apraxias. In one recent study of apraxic children, 13 of 22 children (59%) had, at least, one affected parent (Lewis et al, 2004). Hearing in DAS children is often judged to be relatively normal, but auditory processing deficits can occur (Groenen P. et al, 1996) especially deficits and idiosyncrasies involving auditory and phonetic perception of vowels (Maassen B. et al, 2003). The practice of “bridging,” making the transition from one sound to another or from one word to the next, as a reflection of the child’s ability to generate hierarchical linguistic structures, may also be affected (Velleman S.L., 1994). In fact, DAS is primarily a spectrum disorder without definite behaviors identifying its presence. Jaffe pointed out that in describing DAS, all symptoms and signs need not be present to diagnose it, nor must one typical sign or symptom be present in order to establish the diagnosis (Jaffe, 1984). Instead, a child is identified as having apraxia if he/she exhibits a number of characteristics that are highly indicative of apraxia. These may include a decreased ability to imitate speech, slowed production of rapid, repetitive consecutive oral movements, difficulties in initiating speech movements, severely limited consonant and vowel repertoire with fricative errors, impaired production of sound sequencing, specific difficulty in sequencing of syllables, syllable omissions (Velleman S.L. et al, 1999), planning of syllables (Nijland L. et al, 2003), the integrity of the syllable (Marquardt T.P. et al, 2002), form and motion coherence processing (O’Brien J. et al, 2002), inconsistent and unusual errors, and depressed expressive language skills relative to receptive abilities. DAS is distinguishable from so-called “functional” defective articulation when this is manifested as a discrete and singular deficit (Williams et al, 1981). Children may have difficulty speaking longer words or sentences. Terms such as isochrony, syllable segregation, scanning speech, and staccato-like rhythmic quality have been used to characterize the temporal regularity that may be a core feature of apraxia of speech (Shriberg L.D. et al, 2003). Diagnostic criteria used to identify DAS have been at the center of controversy for decades (Forrest K., 2003). The disorder may be present into adulthood (Poole J.L. et al, 1994), although the phenotype for DAS changes with age. Language disorders persist in these children despite partial resolution of articulation problems.
Language development is often delayed with a late onset of first words resulting in infants and toddlers being labeled as ‘silent babies’ followed by a late combination of two-word sentences. Language development is also atypical, in that there is sometimes a prolonged use of single words for multiple meanings. Parents have reported that words are ‘lost’ and that children increase their use of gestures (Love, 1992). Children may speak unevenly or very slowly. Great variability in speech production patterns may exist with any population of DAS children (Marquardt et al, 2004), although it has long been known that adult speakers with acquired apraxia of speech and child speakers with developmental apraxia of speech systematically reduce linguistic complexity and simplify the production of consonants (Klich et al, 1979). DAS can effect a child’s perception and production of rhyme (Marion M.J. et al., 1993). Accuracy in producing linguistic stress can also be effected in DAS populations (Munson B. et al, 2003) as well as co-articulation patterns suggesting an underlying language expressive deficit (Nijland L. et al, 2002). The accuracy of articulatory movements of speech in a group of first graders has also been studied, providing additional insights about speech production patterns in children (Qvarnstrom et al, 1993). Children with DAS are also at risk for reading and spelling problems (Lewis B.A. et al, 2004).
DAS may also manifest as oral motor deficits including feeding problems in infants. For instance, sucking and oral groping behaviors may be affected, later manifested as motor programming deficits in school-age children (Nijland L. et al, 2003) which can affect motor sequencing strategies in such populations (David K.S., 1985). In addition, DAS can engender other language or learning problems, hyperactivity, and motor coordination problems involving movement. The latter can be indicated by trophic limb changes such as asymmetric hands and feet observed in clumsy children (Iloeje S.O., 1988). A seminal study of Nigerian children with developmental apraxia revealed by neurological examination a higher incidence of abnormality, principally dysdiadochokinesia, among clumsy children (Iloeje S.O., 1987). Other studies have linked DAS with limited manual dexterity (Kornse D.D. et al, 1981) and with the specific diagnosis of developmental coordination disorder (Miyahara M. et al, 1995). In fact, it is now well established that children with DAS have difficulties with coordination (Chia S.H., 1997) and that language development and motor performance in the clinical diagnosis appear to follow a similar course of maturation (LeNormand M.T. et al, 2000). Motor impairment and evidence of proprioceptive deficits in Asperger syndrome individuals appear to be similar (Weimer A.K. et al, 2001).
The therapeutic process is a mix of technique and insight and effective clinicians are able to blend theory with practice. This is especially true in the area of DAS. Children with the symptom complex of apraxia are a challenge to any therapy program (Helfrich-Miller K.R., 1994).