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Purpose: Childhood apraxia of speech (CAS) is diagnosed on the basis of specific speech characteristics, in the absence of problems in hearing, intelligence, and language comprehension. This does not preclude the possibility that children with this speech disorder might demonstrate additional problems., Method: Cognitive functions were investigated in 3 domains: complex sensorimotor and sequential memory functions, simple sensorimotor functions, and nonrelated control functions. Seventeen children with CAS were compared with 17 children with normal speech development at 2 occasions within 15 months., Results: The children with CAS showed overall lower scores but similar improvement at Occasion 2 compared with the typically developing controls, indicating an overall delay in the development of cognitive functions. However, a specific deviant development in sequential abilities was found as well, indicated by significantly lower scores at Occasion 2 as compared with younger control children at Occasion 1. Furthermore, the scores on the complex sensorimotor and sequential memory tasks were significantly correlated with the severity of the speech impairment., Conclusions: These results suggest that CAS involves a symptom complex that not only comprises errors of sequencing speech movements but implicates comorbidity in nonverbal sequential functioning in most children with CAS.

It has long been recognized that from the first months of life auditory perception plays a crucial role in speech and language development. Only in recent years, however, is the precise mechanism of auditory development and its interaction with the acquisition of speech and language beginning to be systematically revealed. This paper presents the results of a series of studies exploring the relevance of electrophysiological measurements for the objective diagnosis of children with language and speech disorders. In the first, retrospective, study, an inventory was made of clinical neurological, neuropsychological, logopedic and neurophysiological findings obtained from 43 children referred to the Paediatric Neurology Centre for the diagnosis of their speech and language deficits. Neurophysiological abnormalities were found in 95% of these children, among these deviant auditory evoked potentials (AEVPs). The second study demonstrated developmental trends in the waveform of the cortical AEVPs up to age 6 years; the implications for longitudinal studies are discussed. Preliminary results from the third study show emerging differences in auditory event-related potentials (AERPs) for young children who are at risk for developmental dyslexia based on their family history. These findings underscore the clinical usefulness of neurophysiological measures for the diagnosis of speech-language disorders. Clinical protocols are further developed and tested.

Research in the field of speech production pathology is dominated by describing deficits in output. However, perceptual problems might underlie, precede, or interact with production disorders. The present study hypothesizes that the level of the production disorders is linked to level of perception disorders, thus lower-order production problems (such as childhood apraxia of speech; CAS) are linked to lower-order perception problems and higher-order production problems (phonological disorder; PD) are linked to higher-order perception problems. For this, various perception tasks were administered (non-word auditory discrimination task, word rhyming task, categorical classification, and discrimination task) in children with CAS, PD, or a mixture. The results show that children with PD only show higher-order perception problems, whereas children with CAS have difficulties on both lower- and higher-order perception tasks. In children with CAS, difficulties at lower-order processes might affect the higher-order processes in development. Furthermore, significant correlations were found between production and perception scores at different levels. Thus, a link between perception and production seems to be evident. [ABSTRACT FROM AUTHOR]

Developmental apraxia of speech (DAS) is generally classified as a 'speech motor' disorder. Direct measurement of articulatory movement is, however, virtually non-existent. In the present study we investigated the coordination between articulators in children with DAS using kinematic measurements. The results of articulatory coordination in CCV and CVC syllable productions showed systematic effects of place of articulation in the relative phase values in normally speaking children. Deviant and more variable relative phase values as found in the children with DAS are an indication of coordination problems. The relative phase values are discussed with respect to phonological vs. motoric involvement. [ABSTRACT FROM AUTHOR]