Developmental Apraxia of Speech

Developmental apraxia of speech (DAS) is a childhood communication disorder that involves the
difficulty or inability to voluntarily complete the motor movements required for the production
of speech. This may involve coordinating and planning the movements of the tongue, lips, jaw,
and palate that are necessary for speech intelligibility. DAS is usually more common in boys
than girls and occurs in 1 to 10 children per 10,000 cases.

Apraxia of speech can sometimes be confused with a developmental expressive
speech/language delay. However, it is important to distinguish between the two. A true
developmental expressive language delay occurs when there is a significant gap between a
child’s strong receptive language abilities and their weaker expressive language abilities which
are usually below age expectations. In other words, the child has the ability to understand
language but has great difficulty expressing his/her thoughts and ideas. Similarly, children with
Apraxia have intact receptive language skills with diminished expressive language abilities.
However, children with Apraxia also exhibit many, if not all, of the following characteristics:

Language problems may also be associated with DAS. Such areas of difficulty can
include reduced or inadequate vocabulary skills, incorrect use of syntax, organization and
sequencing, and inappropriate use of social language. These difficulties in language can be
further connected to academic problems in reading, writing, and spelling.

Although children with DAS have difficulty planning and sequencing motor movements
for speech production, oral-motor structure and function is within normal limits. There is no
associated weakness of facial and speech muscles with apraxia. If oral motor weakness exists,
the weakness may be indicative of dysarthria rather than apraxia.

There has been some recent debate with regards to apraxia and phonology. They are very
similar to each other and the debate lies within the diagnosis. Please refer to the following chart
for their similarities and differences (Elaine D. Schneider lecture 2004):

A speech-language pathologist is a qualified professional who can diagnose and treat
children with apraxia. However, it is important to differentiate between language disorders and
apraxia to avoid misdiagnosis. Davis and Velleman (2000) noted that the child’s speech
inventory should be analyzed for limited consonant and vowel inventory, flat or monotone vocal
quality, and/or the lack of consistent speech patterns. Further assessment of apraxia can include
articulation and phonological performance on standardized tests such as Kaufman Speech Praxis
Test (KSPT) for children (Kaufman, 1995). Speech motor functions should also be assessed to
address fluency, prosody, and nasality. Non-speech motor functions assess the child’s oral
structure/function and oral/limb movements. A language assessment should also be completed
to assess the child’s level of comprehension and expression, in addition to their level of
intelligibility of speech in conversation.

Traditional approaches for treatment of apraxia include the training of sound sequencing
with multiple repetitions and various types of cues (visual and tactile), developing correct
articulatory postures (lip and tongue movements) by using a mirror for imitation and visual
feedback, and sensory training to increase oral awareness. Intervention for children with apraxia
focuses on improving the planning, sequencing, and coordination of the speech muscles (ASHA,
2006). Treatment for apraxia usually begins with imitation of vowel and consonant
combinations. Therapy typically begins with sounds that the child can already produce (usually
developmental sounds) and progresses into a treatment hierarchy beginning with imitation of
syllables, then increasing to words, phrases, sentences with many repetitions to establish a
successful motor plan for speech production. Velleman and Strand suggest beginning with CV
(consonant-vowel: BA) word structures for one class of sounds (e.g. bilabials- /b, p, m/) then
slowly changing the movement pattern into another class of sounds (e.g. alveolars- /t, d, n, l/). It
can be at the discretion of the speech pathologist to proceed from the CV word structure to a
CVC word structure for one class of sounds. The main goal of beginning with small word
structures and slowly increasing to larger ones is the idea of developing and refining a motor
pattern for speech production.

For more information on apraxia, please visit the following websites:
www.apraxia-kids.org
www.apraxia.org
www.professional.asha.org