Articulatory abnormalities in athetoid cerebral palsy.

This report presents cinefluorographic data on the articulation of isolated vowels, VCV nonsense utterances, and short sentences by five subjects with athetoid cerebral palsy. Articulatory abnormalities were identified from tracings of vocal tract shapes and from displacement-by-time plots of articulatory events. The most frequent abnormalities were large ranges of jaw movement, inappropriate positioning of the tongue for various phonetic segments (especially because of a reduced range of tongue movement in the anteroposterior dimension), intermittency of velopharyngeal closure caused by an instability of velar elevation, prolonged transition times for articulatory movements, and retrusion of the lower lip. The speech disorder associated with athetosis is considered with respect to a model of motor learning.