Viking Speech Scale

In my previous blog I have introduced a classification system for young children with CP that was developed to estimate their speech and language development over time. This blog presents another attempt at classifying speech performance in children with CP: The Viking Speech Scale (VSS).

The VSS was developed by an international team around Lindsay Pennington for use in CP surveillance registers to complement information on gross motor performance and manual abilities. Information on speech would help clinicians and researchers to obtain a clearer picture of presence and severity of motor problems that affect communication.

The VSS is intends to be a global measure of speech that captures how speech is produced in daily life. A combination of perceptual characteristics and intelligibility was used as a basis for the scale which comprises 4 levels:

   1. Speech is not affected by motor disorder

   2. Speech is imprecise but understandable to unfamiliar listeners out of context. Loudness
       is adequate; voice may be breathy and harsh; articulation is imprecise but difficulties do
       not affect intelligibility.

   3. Speech is unclear and not usually understandable out of context. Speech can be too loud
       or too quiet; speech can be hypernasal; voice may be harsh; breath control is difficult;
       pitch may change suddenly; only a small range of consonants can be produced.

   4. No understandable speech

The scale was tested using speech samples of 139 children with CP. Their speech was rated by parents and a range of health professionals including speech and language therapists through direct observation or case notes. Feedback was positive and the scale considered being a helpful tool to summarise speech performance of children with CP for clinical reports and research.

Speech and language skills in 4-year old with CP

In my last blog I outlined the results of a study that assessed speech and language performances in 2-year old children with CP. Today’s blog is a continuation of this theme – looking at the speech and language abilities of 4-year olds with CP to find out whether their performances can be classified into groups as well. According to Katherine Hustad, Kristin Gorton and Jimin Lee - the authors of the paper - longitudinal results will help to predict outcomes, and change those outcomes through intervention.

The speech and language classification system employed in the study was developed using existing knowledge as to the nature of CP. Four groups were identified:

1. Children without speech and language problems

2. Children with speech problems, but intact language abilities

3. Children with speech problems and language problems

4. Children who are unable to produce functional speech

Speech and language data from 34 children with CP were collected. The authors measured vowel space, speech rate and language comprehension. They also asked parents to rate the intelligibility of their child’s speech. They then employed statistical procedures to see whether the children’s performances would align with the groups suggested above.

Findings show that children were assigned to the groups mainly based on the results of the speech measures - i.e. speech rate and vowel space. Specifically, it was found that children with speech impairment had a slower speech rate and a smaller vowel space than children without speech problems. Of the two measures speech rate was found to be the stronger indicator for group membership. This makes sense as speech rate performance reflects the integration of all four subsystems (breathing, phonation, velo-pharyngeal function and articulation), whereas vowel space primarily relates to articulation. Language comprehension scores and intelligibility ratings were found to be less predictive of group membership. These findings suggest that speech abilities are the primary determinant for communication profiles in children with CP.

Speech and language skills in 2-year-olds with CP

Children with cerebral palsy are more likely to develop speech and language problems than their peers. In an effort to identify those who may benefit from speech and language therapy to boost communication abilities from an early age, Katherine Hustad and colleagues examined the speech and language skills of 27 toddlers with CP aged 24 to 30 months. The aim of their study was to find out whether children as young as two could be classified into groups on the basis of their speech and language skills.

 

The children’s skills were examined based on parent-child-interaction, parental questionnaires and a language comprehension test. In particular, the authors looked at receptive and expressive skills - reflected in e.g. number of words produced and average length of utterances.

Three groups could be identified:

1.Children who were not yet talking (44%). Children in this group had an active vocabulary of  about three words and primarily used vocalisations to communicate.

2.Children who were emerging talkers (41%). Children in this group used on average 40 words and had begun to combine words.

3.Children who were established talkers (15%). Children in this group showed speech and language skills in line with age expectations.

Group membership was primarily determined by the children’s vocabulary size and ability to combine words. By contrast, receptive abilities did not turn out to be a good indicator for speech and language development as results varied considerably across groups. The study also found that the children’s speech and language abilities were not related to gross motor function. This is important and shows that no conclusion regarding communication skills should be drawn on the basis of gross motor abilities. Overall, the study shows that speech and language delays in children with cerebral palsy can be identified by 2 years of age.

 

Hustad, K., Allison, K., McFadd, E. & A. Riehle, K. (2013). Speech and language development in 2-year-old children with cerebral palsy. Developmental Neurorehabilitation, Early Online.

Can visual feedback help to improve articulation disorders that are resistant to conventional speech therapy?

Speech and language therapy usually relies on auditory feedback (listening to the sounds, words and sentences client and therapist produce) to change speech patterns. A team of Swedish researchers around Ann Nordberg wanted to find out whether visual feedback could help children with CP and dysarthria to change articulation patterns that were resistant to conventional therapy.

The visual feedback technique they used is called electropalatography (EPG). EPG allows to record when and where the tongue makes contact with the roof of the mouth, the hard palate, during speech. An artificial palate with electrodes - which looks a bit like a dental brace - records the tongue movements. That means the client gets direct feedback where the tongue is and can try and change its position to produce a sound that is closer to the desired sound. Using EPG the authors examined how children with CP produce dental and alveolar targets sounds (t, d, n and s) in different positions in single words before and after therapy.

Five children (mean age 9.4 years) with CP and mild or severe dysarthria took part in the study. The majority of them practiced at home for 15 minutes a day for 5 days a week over a period of 8 weeks. Weekly EPG exercises included the production of target sounds in syllables, words and short sentences. Speech materials to monitor progress consisted of 70 pictures from a Swedish Articulation Test.

A detailed analysis of the EPG patterns revealed that before therapy the children had unusual articulation patterns such as producing sounds far back in the mouth (retracted articulation). After therapy, EPG analysis and perceptual evaluation revealed that the tongue made more precise contact in dental and alveolar positions leading to an improvement in articulation. This improvement was observed for sounds in word-initial and -medial positions but not in word-final positions. Overall, the authors conclude that EPG can be valuable for the description of articulation patterns in CP and to document changes after speech therapy. Due to the instrumental nature of the intervention EPG may not be readily available everywhere as a therapy approach, but seems worthwhile pursuing for children who have not responded to conventional articulation therapy.


Nordberg, A., Carlsson, G. & Lohmander, A. (2011). Electropalatography in the description and treatment of speech disorders in five children with cerebral palsy. Clinical Linguistics & Phonetics, 25(10), 831-852

LSVT Loud versus systems approach

As indicated in earlier blogs there is a desperate need for intervention research in developmental dysarthria to find out which interventions lead to meaningful changes in speech, and if so why.

Hot off the press is an article by Erika Levy and colleagues that compares the effects of two interventions:  LSVT Loud and speech subsystems approach (what they termed traditional approach). Levy and colleagues recruited three girls with spastic type CP (aged 3-9 years) with mild to moderate dysarthria. The allocation to intervention was somewhat arbitrary with those girls who could commit to therapy 4 days a week getting LSVT Loud, whereas one girl received therapy following the traditional approach twice a week. LSVT focused on increasing loudness; the traditional approach targeted posture, speech clarity and breath control.

Changes - measured by means of caregiver questionnaires, articulation tests and listener perception tests of single words and spontaneous speech – were positive: caregivers reported a positive impact of therapy on speech, articulation tests showed greater articulatory precision, and listeners preferred the post-therapy speech samples. Interestingly, LSVT seemed to increase speech function and loudness, whereas the traditional approach resulted in better speech but had no effect on loudness.

Although overall results suggest an improvement in speech function, individual performances show a highly variable picture. For instance, in terms of loudness one girl undergoing LSVT treatment improved at word level, whereas the other one showed improvements in spontaneous speech. This is not the only reason why the results of the study should be interpreted carefully:

• The interventions were administered by different therapists/students
• It is unclear whether the frequency of intervention had an effect
• The allocation to intervention was arbitrary
• Relation of the findings to intelligibility were not examined
• Results were not tested for statistical significance

The study is a step into the right direction, and raises one important issue: How can we predict which intervention approach is the best for a particular child?

Levy, E. S., Ramig, L. O. & Camarata, S. (2012) The Effects of Two Speech Interventions on Speech Function in Pediatric Dysarthria. Journal of Medical Speech-Language Pathology, 20(4), 82-87.