Issue 17, Page 4-5: Developmental Verbal Dyspraxia

Developmental Verbal Dyspraxia (DVD), also known as Childhood Apraxia of Speech (CAS) is a motor speech disorder. DVD impairs a child’s ability to plan, sequence and produce precise articulatory movements for speech. Children with DVD have difficulties with accuracy, timing and speed of speech production in the absence of damage to the muscles. The cause of DVD is as yet unknown, and it can occur alongside other developmental disorders.

At the Nuffield Paediatric Speech Clinic, we offer a specialist service where the children are referred for an assessment and diagnosis of their speech.

Below is an excerpt from a conversation with Jack, aged 5 yrs 10 mths, who has DVD:

Jack: “This is a big hospital.”

Jack’s pronunciation of the utterance was heard as: [ di i a bi ho i pel ]

Shula: “Yes, it is. Tell me more about your visit to the farm.”

Jack: “I like animals. I saw a caterpillar, no, no a caterpillar.”

[ I lie a mels. I saw a tatiar no no tapetipa ]

Shula: “Let’s say it together ‘caterpillar’.”

Jack: Ye,[ ta a pi ar ]

It would have been much harder to understand Jack’s message out of context. His speech contains many omissions of sounds, substitutions, and glottal stops. Sequencing sounds and syllables within words is difficult for him and there is a distorted, almost jerky, quality in the rhythm of his speech, with the rate of speech being quite slow. He is not able to produce a target word more accurately when he copies an adult’s production.

How is DVD identified?

• A detailed assessment of speech output is essential
• The importance of a thorough case history cannot be emphasised enough
• Receptive and expressive language and phonological skills need to be assessed, as well, in order to look at the child’s communication holistically.

Because DVD is a speech disorder, children who are not yet producing any verbal output cannot be identified.

What signs do we look for?

From the case history

• Frequently described by parents as a “quiet baby”, did not vocalise very much
• Delayed babble
• Limited range of sounds used in babble
• Late to produce first recognisable words
• Stayed at single word level for a long time
• Late to produce two – word phrases e.g. “My teddy, more bubbles.”
• Unintelligible speech
• Feeding difficulties, sensitive to certain textures, messy eater with food getting smudged over their face (currently or in the past)
• Difficulties copying lip and tongue movements and sequencing these
• Drooling (currently or in the past)
• Difficulties with blowing and sucking
• May have generalised gross motor and fine motor dyspraxia; may have an additional diagnosis of Developmental Coordination Disorder
• Understanding of spoken language is reported to be in advance of expression
• Frustration due to unintelligible speech and not being understood by others
• Family history of speech and/or literacy difficulties

From the speech assessment

The signs of DVD have been controversial amongst speech and language therapists for a long time.

Based on the RCSLT policy statement on DVD the 3 core signs on which there is consensus are:

• Inconsistent errors on consonants and vowels in repeated productions, i.e. child repeats the same word differently each time
• Difficulty transitioning between syllables and sounds (Jack’s speech shows many examples of difficulties in moving from one syllable to the next smoothly and accurately)
• Inappropriate prosody (rhythm, stress and intonation) especially at word or phrase level. For example, placing the stress on the wrong syllable or placing equal stress on all syllables.

In addition, clinical experience and research literature highlight the following speech features:

• Vowel distortions
• Limited range of consonant and vowel sounds, especially compared with the language levels of the child
• Omissions of sounds
• Substitutions of sounds
• Difficulties repeating words
• Difficulties repeating non-words or made up words
• Unusual substitutions which do not necessarily follow a developmental pattern
• Overuse of one sound, known as “favourite articulation”: the child may replace a wide range of consonants, for example, (b,t,d,s,sh) with [g]
• Reduced accuracy and rate in sequencing words and syllables, e.g. if you ask the child “Say digger 5 times” their production may be full of errors and at a slow rate.
• Increased number of errors when words are longer, or phrases are more complex
• Glottal stop insertions and stop insertions and substitutions
• Imitation does not improve accuracy of production, e.g. Jack could not imitate caterpillar
• Unintelligible speech – other people will find the child very difficult to understand, especially out of context
• Difficulty making accurate movements with the mouth and tongue

Treatment

DVD is treatable, but it does require specialist support from an experienced speech and language therapist. Treatment approaches which are based on Motor Learning Principles, for example, the Nuffield Dyspraxia Programme, would be appropriate under the guidance of a speech and language therapist. Phonological skills should be monitored and included in therapy in order to build accurate phonological representations of words.

Children with DVD require regular, direct speech therapy, delivered by a speech and language therapist. Long breaks in therapy between courses do not help generalisation of targets and lead to slow progress, so it is important that practice is maintained between sessions. Frequent practice helps to stabilise the newly learned speech sounds and/or words and repetitive drilling helps motor patterns to become automatic. Teaching Assistants, under guidance from the Speech and Language Therapist, can support this practice effectively in school.

Supporting children with DVD

Most children with DVD attend mainstream schools, however there are frequent educational difficulties and research evidence that confirms a high risk of children with DVD developing literacy difficulties. Unintelligible speech may lead to emotional difficulties and feelings of social isolation in some children and they may withdraw from participation. Gross and fine motor dyspraxia may mean that the child may fall frequently and have difficulties in holding their pencil and handwriting. A child with DVD may use signing to enhance their expression which, if they are the only child in their class who signs, may lead to further feelings of being different from their peers.

Tips to help support children with DVD

• Give your child enough time for them to get their message across and to revise what they have said, using different words
• It may be helpful to discuss with a speech and language therapist whether a communication aid may be appropriate. (This is not to replace the child’s speech, but rather to support and enhance their expression)
• Provide scaffolding to help their understanding of how to formulate sentences
• Pre-teach new concepts and topic vocabulary
• Consider providing a laptop for some children who find pencil grasp very difficult
• An assessment by an occupational therapist may give further information about the child’s profile
• Try and incorporate signing into the class and identify a “buddy” who can sign with the child to avoid the child being the ‘only one’

So how is Jack doing? After his initial assessment at the Nuffield Paediatric Speech Clinic, his parents received a detailed report and a speech therapy programme which could be used in his local therapy sessions. His parents, school and local speech and language therapist are all working together closely to deliver his therapy every day, and we hear that he is making good progress.