Therapy outcome measures for children with dysarthria

A recent discussion with a parent and a speech and language therapist about how best to measure whether therapy has had an effect made me choose this article for this month’s blog post. 

I am not telling you anything new when I say that speech therapy can have a positive impact on a person’s communication and wellbeing. However, services are under increasing pressure to prove that their therapies are effective – from a clinical as well as cost-effective point of view. According to Pamela Enderby, one of the leading researchers on speech and language therapy and health interventions in the UK, outcome measures are important for evaluating and improving clinical services as they can measure communication changes in individuals, but also allow for comparison across services.  

Outcomes measures try to establish whether an individual has benefitted from therapy. There are several reasons why this is this difficult to find out for an area such speech and language therapy: 1) there are a wide range of therapy options for a child with dysarthria depending on the communication problem; 2) it is one thing to measure improvement in speech e.g. intelligibility, but how do you measure wellbeing, improved coping skills or increased confidence, which can all contribute to improved communication?

According to Enderby, Therapy Outcomes Measures or TOM (Enderby et al., 2006) can capture these more holistic aspects of therapy. TOM allows clinicians to describe the abilities of a child for impairment, communication activity, participation and wellbeing before and after therapy. The four features are rated on an 11 point scale (0 – severe to 5 – normal for age and sex) using the usual assessment procedures. I see TOMs strengths in the fact that they are a set of scales which are based on the International Classification of Functioning, Disability and Health framework (WHO). It is a quick tool that has proved reliable for a range studies, and can be applied irrespective of the various assessment procedures that exist in services. 

On the other hand, I think that in some cases a qualitative analysis of the data would be helpful to better understand results. For instance, no change in the rating could be considered a positive outcome in cases where the dysarthria is due to progressive disorders. Also, training may be needed to ensure consistency in the use of the scale. Being a member of review panels, I know how differently the same work can be viewed, with some judges, for instance, never exhausting the full scoring range available to them. After all, judging is the act or process of forming an opinion or making a decision after careful thought, i.e. it has a subjective element to it. This, however, should not stop us in our endeavour to improve the quality of the services we offer.

Enderby, P. (2014). Use of extended therapy outcome measure for children with dysarthria. International Journal of Speech-Language Pathology, 16(4), 436-444.

Production of consonants in school-aged children with CP

Detailed descriptions of speech features in children with CP are a prerequisite for providing suitable interventions for children with speech impairments. However, as Ann Nordberg and colleagues point out in their most recent article: thorough descriptions of speech impairment in children with CP are rare - and even non-existent for those with ataxic dysarthria. The aim of their study was therefore to investigate the production of consonants produced by 19 school-aged Swedish-speaking children with CP in order to fill some of the blank spaces.

The children participating in the study were about 11 years old, and - according to medical records -had some form of speech impairment. In addition, 9 of the 19 children were known to have cognitive problems. The children were asked to name 59 pictures of the Swedish Articulation and Nasality Test (SVANTE), which covers the whole range of Swedish oral consonants prone to articulation deficits. Two speech and language therapists then phonetically analysed the consonants to obtain the percentage of correctly articulated consonants, and describe the error patterns. They also rated the severity of the speech impairment, whether the children sounded nasal and whether anything about their breathing, voice quality and prosody was noticeable.

Results showed that more than 50% of the children had severe difficulties with articulation resulting in a mean score of correct consonants that was well below that of typically developing children. The authors also found that children with spastic and dyskinetic dysarthria did better than the kids with ataxic dysarthria. Voicing errors were the most frequent type of errors followed by substitutions and omissions, which might be a result of poorly controlled phonation.

The authors further found that most of the children had mild dysarthria, and nasality – as opposed to previous reports – was not a common feature of the children’s speech. However, 13 children had problems related to breathing including having low energy, being breathless and not having enough air for speech production. The same number of children was also found to have unusual voice features such as high pitch levels, harsh voice and creaky voice. A further 6 of the 19 children were described as having deviant prosodic speech characteristics such as monotonous speech. The authors conclude that these features are equally important for the perception of dysarthria as the articulation deficit, and listeners may rely on the whole range of speech changes when making judgements about the presence and severity of dysarthria.


Nordberg, A., Miniscalco, C. & Lohmander, A. (2014). Consonant production and overall speech characteristics in school-aged children with cerebral palsy and speech impairment. International Journal of Speech-Language Pathology, 16(4), 386-395.

Ways to advance speech treatment research in developmental dysarthria

We all are aware that speech treatment in developmental motor speech disorders is an under-researched area. We also know how important it is to find out whether current treatments help children to communicate more successfully. However, one of the main challenges we are facing is the lack of detailed information on how the few treatment studies that were conducted were designed and carried out. This lack does not just affect research by making it more difficult to repeat treatments to confirm its success for other speakers. It also means that speech and language therapists, who want to apply the approaches described in the literature, have very little information that could assist them in understanding what made those approaches successful.

This issue was the starting point for Erika Levy’s most recent article published in the International Journal of Speech-Language Pathology. Unlike most articles, which usually focus on outcome and improvements in speech, it details how speech treatments were carried out in the Speech Production and Perception Lab at Teachers College, Columbia University. In her article, Levy focuses on two approaches that were successfully used in the past to improve speech function in children with CP and dysarthria:

-Speech Systems Approach

-Lee Silverman Voice Treatment

Both approaches featured in previous blog entries. The former aims at improving the functioning, coordination and control of breathing, phonation and articulation, whereas the latter focuses on producing loud and clear speech. For both approaches Levy describes treatment protocols which include specific information on preparation and progression of treatment sessions, session structure, the tasks that were used, and how children can be motivated to do these tasks repeatedly.

The article also describes how best to record speech, and how these speech samples could be used for acoustic analyses. It further refers to a range of games and apps that could be used to keep children engaged in the therapy process as well as provide feedback on their performance.

By providing treatment specifics and strategies Levy intends to reduce some barriers that exist when it comes to researching speech treatment in developmental dysarthria. I do hope that this article will trigger further clinical research with the ultimate aim of designing treatments that will help children to be successful communicators.

Levy, E. S. (2014). Implementing two treatment approaches to childhood dysarthria. International Journal of Speech-Language Pathology, Early Online, 1–11. 

Intelligibility: Do sentence length and word structure matter?

Speech intelligibility is a complex construct and many aspects are known to influence intelligibility in motor speech disorders. This includes the way people pronounce words, but also how well listeners can tune into people’s speech. Context also helps, which is why connected speech is usually more intelligible than single words. In a recent study, Kristen Allison and Katie Hustad explored another important aspect influencing speech intelligibility: the linguistic properties of speech. Two aspects were of particular interest to them: sentence length and phonetic complexity, i.e. the motoric difficulty of a word’s sound structure (e.g. the word ”no” involves less complex motoric movements than the word “complex”). Both, longer sentences and higher phonetic complexity are known to increase the motoric demands of producing an utterance, which can affect intelligibility.

In order to quantify their contribution to intelligibility problems in children with CP the authors asked 119 listeners to orthographically transcribe speech samples of 24 5-year old children. 16 children had CP, of which 8 were diagnosed with dysarthria. The speech of 8 typically developing children was transcribed as well. The speech samples were sentences of 2 to 7 words in length. Each listener was asked to transcribe about 60 sentences.

Results showed that both factors had an effect on intelligibility, but the effect was found to be greater for children with dysarthria. They were best understood in short sentences of 2 to 3 words, whereas children without speech problems were easily understood up to a sentence length of 6 words. A similar result was observed for phonetic complexity: whilst the effect for children without speech problems was small, intelligibility of children with dysarthria was significantly reduced in sentences with words that required more complex motoric movements. The findings indicate that reducing length as well as phonetic complexity may enhance intelligibility. However, considerable individual variation suggests that for some children sentence length was more of an issue and for others complexity. This highlights the importance of a child’s individual motor profile when considering treatment options.

Allison, K. & Hustad, K. (2014). Impact of sentence length and phonetic complexity on intelligibility of 5-year-old children with cerebral palsy. International Journal of Speech-Language Pathology.

How does communication and social interaction develop in school-aged children with CP over time?

This was the central question Petra van Schie and colleagues addressed in their article published in Research in Developmental Disabilities. According to the authors communication becomes more important as children grow older, and they were keen to find out how cerebral palsy affects the development of communication and social interaction.

Over a period of 3 years, van Schie and colleagues monitored the development of 108 children with CP in the Netherlands. The children joined the study when they were about 6 years of age. Information on their communication was collected each year through an extensive parental questionnaire (the Vineland Adaptive Behaviour Scales).

Findings showed that more than half of the children (58%) had problems with communication and social interaction because of CP. This was particularly true for those children with a history of epilepsy, and – not surprisingly - speech problems. The results also showed that children who could not walk had greater problems with social interaction than those children who could walk or had walking aids. This shows that there is a link between motor abilities and communication, which mirrors findings from previous studies discussed here in this blog. However, even children in the latter group, i.e. who could walk, were not always successfully interacting with others. The authors thus conclude that a wide range of children with CP would benefit from intervention to support communication and social development.

This study highlights again how important intervention is to support communication development in children with CP…and how desperately needed intervention and intervention studies are to monitor progress…

Reference: van Schie et al. (2013). Development of social functioning and communication in school-aged (5-9) years children with cerebral palsy. Research in Developmental Disabilities, 34, 4485-4494.