Labels for unexplained language difficulties in children: We need to talk

The view from the Tower of Babel

This week saw the publication of a special issue of the International Journal of Language and Communication Disorders, focusing on labels for children with unexplained language difficulties. Two target articles, one by Sheena Reilly and colleagues, and one by me, are accompanied by an editorial by Susan Ebbels, twenty commentaries, and a final paper where Sheena and I join forces with Bruce Tomblin to try to synthesise the different viewpoints. These articles are free for anyone to access.

Terminological battles are often boring and seldom come to any consensus, so why are we putting time into this thorny issue? Quite simply, because it really matters. As we argue in the articles, having a label affects how a children are perceived, what help they are offered, and how seriously their problems are taken. 'Specific Language Impairment' has very poor name recognition compared to dyslexia and autism, despite being at least as common. Furthermore, unless we can agree on some common language, it's difficult to make progress in research, and to discover, for instance, the underlying causes of language difficulties, how common they are in different parts of the world, or what interventions work.

I was first confronted with the full extent of the problem when I tried to analyse the amount of research and research funding associated with different developmental disorders (Bishop, 2010). There are other conditions, notably autism and dyslexia, where there is plenty of debate about diagnostic criteria, or even about whether the condition exists. But even so, the terminology is reasonably consistent. For children's language difficulties, this is not the case - they can be described as cases of language difficulty, disorder, impairment, disability, needs or delay, with various prefixes such as 'developmental', 'specific' or 'primary'. Some researchers will use such labels with precise meanings, often excluding children who have co-existing conditions, whereas others use them more descriptively. This made it extremely difficult to do a sensible internet search to estimate the amount of research funding associated with children's language difficulties.  

The confusion over labels has, I think, also contributed to the lack of public recognition of language difficulties in children. A couple of years ago, I joined together with Courtenay Norbury, Maggie Snowling, Gina Conti-Ramsden and Becky Clark with the goal of remedying this situation. We started a campaign for Raising Awareness of Language Learning Impairments (RALLI) (Bishop et al., 2012), and set up a YouTube channel to provide basic information. We spent some time debating what terminology to use: "Language learning impairment" was our preferred choice, but many of our videos talk of Specific Language Impairment, simply because that is a more familiar label. The lack of an agreed label proved a real stumbling block for our attempts at public engagement, and we decided that, as well as producing videos, one of our goals would be to get the terminology issue discussed more widely, in the hope of achieving some consensus. It was a very happy coincidence that Sheena Reilly and colleagues were crystallizing their own position on this question in an article in IJLDC, and that they, and the Editors, were willing to include my article, and the commentaries of other RALLI founders, in the published debate.

One thing that came across when reading commentaries on our articles was the disconnect between research and practice. One point on which I agree with Sheena and colleagues is that there is no justification for drawing a distinction between children whose language problems are comparable with below average nonverbal ability, and those who have a mismatch between good nonverbal skills and low language. Research has failed to find any difference between children with uneven or even nonverbal-verbal profiles in terms of responsiveness to intervention or underlying causes. Such a distinction is, however, widely used in educational and clinical settings to decide which children gain access to extra support in school.  Another issue raised by the Reilly et al paper is whether it is logical to use other exclusionary criteria, and to distinguish, for instance, between children who do and don't have autistic features in association with a language problem.  

As Susan Ebbels noted in her editorial, in everyday settings "diagnostic labels and criteria were being used creatively in disputes over access to services both by those seeking to obtain services for children (often parents and their lawyers) who could be accused of ‘diagnostic shopping’ and also by those seeking to deny services (often due to financial constraints) who may use particularly restrictive criteria in order to reduce the number of children qualifying for services". 

We can't afford to ignore this confused situation any longer. The time has come to have a wider debate on these issues, with the aim of reaching a consensus about how terms are used. The Royal College of Speech and Language Therapists has set up a moderated discussion forum where people can give their views on the best way forward. Please do consider adding your voice: it is important that all those affected by this issue have a say, whether you are a speech-language therapist/pathologist, psychologist, teacher, health professional, legal expert, policymaker, a parent of a child with language difficulties, or someone who has experienced language difficulties. We'd also love to hear from those outside the UK - whether English-speaking or not. You can access the discussion forum here.

Finally, to raise awareness of this debate, during the week of 24th-31st August I will be taking over  the @WeSpeechies Twitter handle as guest curator. On Tuesday 26th at 8.a.m. BST there will be a live twitter debate on this topic. Feel free to join in, even if you aren't a regular tweeter.

References
Bishop, D. (2010). Which Neurodevelopmental Disorders Get Researched and Why? PLoS ONE, 5 (11) DOI: 10.1371/journal.pone.0015112  
Bishop, D., Clark, B., Conti-Ramsden, G., Norbury, C., & Snowling, M. (2012). RALLI: An internet campaign for raising awareness of language learning impairments Child Language Teaching and Therapy, 28 (3), 259-262 DOI: 10.1177/0265659012459467

Slides on this topic are available here.

Addendum Friday 29th August 2014

We've had a great week of interactions on Twitter. A transcript for the week is available here.

I'll look through this and aim to organise the material in due course, but meanwhile would encourage anyone who is interested to continue the discussion on Twitter. I'm appending below some tweets that I generated throughout the week to generate debate.

As noted above, the chat links in to a special issue of the Internat. J Lang. Comm Dis which is free to access here http://t.co/ncTUaYvyoI.  NB it is not all that obvious but there are 10 commentaries after each target article.

If you want to join the discussion on Twitter, feel free to comment at any time, but, please include the #WeSpeechies hashtag, so we can aggregate comments easily. Also if your comment relates to a numbered question, please add Q1, etc so we can relate them.

Monday started with my attempt to summarise each of the  twenty commentaries in a Tweet-length message.

Summaries from commentaries

Paediatricn Gillian Baird: ICD &DSM classifications talk of 'language disorder'; implies distinct from normal variation.  Disorder’ used for conditions without obvious aetiology; functional effect described separately in ICFDH.

Lauchlan/Boyle, ed psych view. Must ask: ‘Will label change the child's life for the better? Aetiology often irrelevant

Bellair et al: community SALTs. No one label works for both research & clinical. SLI has problems but we can manage them.

Mabel Rice: "SLI has yet to receive widespread adoption in clinical practice, in spite of the great need for it." critical of DSM5: excluded "well-researched category of SLI", included SCD, "with a minimal research base"

Kate Taylor SLP. SLI underidentified. Changing the term won't resolve the issue, which is one of measurement rather than label.

Conti-Ramsden: Any Consensus Panel on terminology must be international and include voices from different languages,

Hansson et al: ICD10 labels don't map on to use by researchers in Sweden . : Sweden: phonological & grammatical difficulties seen as part of language impairment. Soc comm probs separate

Clark & Carter: Survey:Scottish SALTs unclear re terms & diagnostic criteria. Move from exclusionary to inclusionary criteria.

Hüneke & Lascelles http://t.co/9rVKJzoBZV. Concern that watering down terminology will mean kids lose scarce resources. Prefer medical term 'developmental dysphasia' that gets problems taken seriously

Strudwick/Bauer http://t.co/GSY5Xwz283 Concern that labels don't capture comorbidities; most ch with 'SLI' have other problems

Michael Rutter, psychiatrist "both clinical & research classifications needed but they require a different approach"

Rutter: Specific’ implies ‘pure’ language impairment; "not supported by any of the available evidence"

Larry Leonard: Many researchers already use broader definition of SLI: do not use term to mean children have a pure profile. communicatn with the public/other disciplines will be even harder if we adopt generic label ‘language impairment.

Snowling: DSM5 treats Communication Disorders separately from Specific Learning Disorders, yet they often co-occur

Aoife Gallagher,SALT; ethical issue:"who owns diagnosis once it has been given.. who ultimately has the right to take it away"

Andrew Whitehouse: ‘SLI’ provides neat criteria for researchers but label hides behavioural & aetiological heterogeneity

Dockrell/Lindsay Educational perspective re SLI is missing yet day-to-day support of learning/development provided by teachers. in England ‘speech, language & communication needs’ (SLCN) indicates primary need is with language & communication

Grist & Hartshorne: http://t.co/QKeQbQFsdy Children & young people we work with rarely describe selves as having SLI or SLCN

Norbury @lilaccourt Relaxing diag criteria will increase demand for services.SALTs shld focus on severe & persistent impairmts

Parsons et al @wordaware Shockwaves through SALT profession if nonverbal IQ criteria and delay/disorder distinction removed .Use of marketing approaches to development of a new term, including consultation with parents & young people.

Wright: legal perspective Much time spent in tribunal appeals arguing re labels: eg is it delay or disorder, is it specific?

Questions for debate

On Tuesday we had a live twitter chat with four question topics, and later in the week, I added further numbered question. Here is the total list – we'd love to hear your thoughts on any or all of these:

Q1 What is your view on use of the diagnostic label SLI? Does it reflect a medical model and is this appropriate.

Q2 is What are appropriate criteria for identifying children's language problems

Q3; Should IQ, ASD features, hearing loss determine whether language-impaired children can access services?

Q4 What terminology is most appropriate for children who have unexplained language problems?

Q5 ICD11 will use'Developmental Language Disorder' and DSM5 uses 'Language Disorder'. What do people think of these terms?

Q6 In research SLI still widely used but without requiring IQ discrepancy. Should we retain SLI but with this broader meaning, or is it just confusing?

Q7 In UK education, Speech, Language and Communication Needs (SLCN) is popular term. Is it used outside UK? Is it useful?

Q8 In UK clinical practice, distinction between language 'delay' & 'disorder' is used, but it has no research support.  Where does delay/disorder distinction come from? How defined?

Q9 Is there any support for a return to the more medical term 'developmental dysphasia'?

Q10. Reilly et al and several commentators suggest we drop 'Specific' and use the term 'Language Impairment' instead .What wld be advantages (e.g. avoids unfair exclusion) and disadvantages (e.g. too broad)?

Q11 What do people think of terms 'Language Learning Impairment' or 'Primary language impairment'? '

Q12 Do diagnostic labels actually help children and families?

Q13 Shld terminology/diagnostic criteria be responsibility of speechies, or shld other professions & families have a say? Assumptions/practices seem v. different in education/medicine/psychology vs speech-language therapy/pathology

Q14 In yr area, who does intervention with kids whose language problems are associated with autism?

Q15 Some  people take pride in identifying themselves as dyslexic. Does this ever happen for kids with language problems? If not, why not?

Q16 Has anyone encountered situation where child not offered intervention bcs language problems attributed to social deprivation?

Q17 Insurance considerations seldom important in UK, but affect label use elsewhere. Do US insurers just require DSM?

Raising awareness of language learning impairments

A couple of years ago I did a Google search for ‘Specific language impairment’. I was  appalled by what I found. The top hit was a video by a chiropractor who explained he’d read a paper about neurological basis of language difficulties; he proceeded to mangle its contents, concluding that cranial osteopathy would help affected children.

I’ve previously described how I got together with colleagues in 2012 to try and remedy this situation, culminating in a campaign for Raising Awareness of Language Learning Impairments (RALLI). The practicalities have sometimes been challenging but I’m pleased to say that the collection of videos on our RALLI site has now attracted over 90,000 hits, providing an accessible and evidence-based source of information about developmental language impairments. As well as research-based films we have videos with practical information for parents, children and teachers.

So here, for those of you interested in this topic, is an index of what we have so far:

Background to RALLI

• What is RALLI?
• Why we've launched RALLI
• What is SLI?
• Meet Seb

Research topics

• Identification of Specific Language Impairment Video Slides References 
• How specific is SLI? Video Slides References 
• Speech, language and communication Video Slides 
• What is Pragmatic Language Impairment? Video Slides 
• How common is specific language impairment? Video Slides References 
• When should we be concerned about late-talkers? Video Slides References 
• SLI and Autism Video Slides References 
• Auditory processing disorder (APD) and language impairment Video Slides References 
• The causes of Specific Language Impairment Video Slides References 
• Specific language impairment and the brain Video Slides References 
• An extra X or Y chromosome: a rare cause of language impairment Video Slides References 
• SLI & reading: 1. Decoding (phonics) Video Slides References 
• SLI and reading: 2. Understanding written language Video Slides References 
•  Reading intervention for children with language impairments Video  References 
• Friendships in teenagers with SLI Video Slides 
• La Amistad y el TEL (Spanish) Video Slides 

Information for teachers

• Signs of SLI
• Literacy difficulties and SLI
• Looking behind behaviour
• Teacher tips: practical strategies
• Teacher tips: adapting your language
• What is the Better Communication Research Programme?

Support for parents and children

• Finding my strengths
• A Parent's Perspective of SLI: Meet Suzanne.
• You are not alone
• It's OK to ask for help
• Getting support
• Helping your child
• Sophie's Story: SLI in adulthood
• Talking about friendships: Megan and Eleshia
• Supporting families: the role of Afasic
• Speech and language therapy: Helping Michael  
• It's not your fault
• Things I wish I'd known: a parent's perspective 

International

• O que é o DEL? (Portuguese)
• 什麼是特定型語言障礙? (Mandarin)
• ¿Qué es el TEL? (Spanish)
• Qu'est-ce que le TSL? (French)
• Was sind spezifische Sprachentwicklungsstörungen? (German)
• Wat is een taalstoornis? (Dutch)
• 甚麽是特殊語言障礙（廣東話版）(Cantonese)
• Che cos'é il DSL? (Italian)
• Beth yw NIP? (Welsh)
• Τι είναι η Ειδική Γλωσσική Διαταραχή ( Greek)  

     Spanish translations/subtitled versions

• ¿Porqué hemos lanzado la campaña RALLI?
• Introducción a Spanish RALLI
• No es tu culpa para niños

Reference  
Bishop, D. V. M., Clark, B., Conti-Ramsden, G., Norbury, C., & Snowling, M. J. (2012). RALLI: An internet campaign for raising awareness of language learning impairments Child Language Teaching & Therapy, 28 (3), 259-262 DOI: 10.1177/0265659012459467

Vitamins, genes and language

Thiamine chloride  (source: Wikipedia)

In November 2003, a six-month-old boy was admitted to the emergency department of  a children’s hospital in Tel Aviv. He had been vomiting daily for two months, was apathetic, and had not responsed to anti-emetic drugs. The examining doctor noticed something odd about the child’s eye movements and referred him on to the neuro-ophthalmology department. A brain scan failed to detect any tumour. The doctors remembered a case they had seen 18 months earlier, where a 16-year-old girl had presented with episodic vomiting and abnormal eye movements due to vitamin B1 deficiency.  They injected the child with thiamine and saw improvement after 36 hours. The vomiting stopped, and over the next six weeks the eye movements gradually normalised. When followed up 18 months later he was judged to be completely normal.

This was not, however, an isolated case. Other babies in Israel were turning up in emergency departments with similar symptoms. Where thiamine deficiency was promptly recognised and treated, outcomes were generally good, but two children died and others were left with seizures and neurological impairment. But why were they thiamine deficient? All were being fed the same kosher, non-dairy infant formula, but it contained thiamine. Or did it? Analysis of samples by the Israeli Ministry of Health revealed that levels of thiamine in this product were barely detectable, and there was an immediate product recall. The manufacturer confirmed that human error had led to thiamine being omitted when the formula had been altered.

The cases who had been hospitalised were just the tip of the iceberg. Up to 1000 infants had been fed the formula. Most of these children had shown no signs of neurological problems. But a recent study reported in Brain describes a remarkable link between this early thiamine deprivation and later language development. Fattal and colleagues studied 59 children who had been fed thiamine-deficient formula for at least one month before the age of  13 months, but who were regarded as neurologically asymptomatic. Children who had birth complications or hearing loss were excluded. The authors stress that the children were selected purely on the basis of their exposure to the deficient formula, and not according to their language abilities. All were attending regular schools.  A control group of 35 children was selected from the same health centres, matched on age.

Children were given a range of language tests when they were 5 to 7 years of age. These included measures of sentence comprehension, sentence production, sentence repetition and naming. There were dramatic differences between the two groups of children, with the thiamine-deficient group showing deficits in all these tasks. The authors argued that the profile of performance was identical to that seem in children with a diagnosis of specific language impairment (SLI), with specific problems with certain complex grammatical constructions, and normal performance on a test of conceptual understanding that did not involve any language.

Figure 1 An example of a picture pair used in the comprehension task. 

The child is asked to point to the picture that matches a sentence, 

such as ‘Tar’e li et ha-yalda she-ha-isha mecayeret’ 

(Show me the girl that the woman draws). From Fattal et al, 2011.

I have some methodological quibbles with the paper. The authors excluded three control children who did poorly on the syntactic tests because they were outliers - this seems wrong-headed if the aim is to see whether syntactic problems are more common in children with thiamine-deficiency than in those without. The non-language conceptual tests were too easy, with both groups scoring above 95% correct. To convince me that the children had normal abilities they would need to demonstrate no difference between groups on a sensitive test of nonverbal IQ. My own experience of testing children’s grammatical abilities in English is that ability to do tests such as that shown in Figure 1 can be influenced by attention and memory as well as syntactic ability, and so I think we need to rule out other explanations before accepting the linguistic account offered by the authors. I’d also have liked a bit more information about how the control children were recruited, to be certain they were not a ‘supernormal’ group - often a problem with volunteer samples, and something that could have been addressed if a standarized IQ test had been used. But overall, the effects demonstrated by these authors are important, given that there are so few environmental factors known to selectively affect language skills. These results raise a number of questions about children’s language impairments.

The first question that struck me was whether thiamine deficiency might be implicated in other cases outside this rare instance. I have no expertise in this area, but this paper prompted me to seek out other reports. I learned that thiamine deficiency, also known as infantile beriberi, is extremely rare in the developed world, and when it does occur it is usually because an infant is breastfeeding from a mother who is thiamine deficient. It is therefore important to stress that thiamine deficiency is highly unlikely to be implicated in cases of specific language impairment in Western societies. However, a recent paper reported that it is relatively common in Vientiane, Laos, where there are traditional taboos against eating certain foods in the period after giving birth. The researchers suggested that obvious cases with neurological impairments may be the extreme manifestation of a phenomenon that is widespread in milder form. If so, then the Israeli paper suggests that the problem may be even more serious than originally suggested, because there could be longer-term adverse effects on language development in those who are symptom-free in infancy.

The second question concerns the variation in outcomes of thiamine-deficient infants. Why, when several hundred children had been fed the deficient formula, were only some of them severely affected? An obvious possibility is the extent to which infants were fed foods other than the deficient formula. But there may also be genetic differences between children in how efficiently they process thiamine.

This brings us to the third question: could this observed link between thiamine deficiency and language impairment have relevance for genetic studies of language difficulties? Twin and family studies have indicated that specific language impairment is strongly influenced by genes. However, one seldom finds genes that have a major all-or-none effect. Rather, there are genetic risk variants that have a fairly modest and probabilistic impact on language ability.

Robinson Crusoe Island

A recent study by Villanueva et al illustrates this point. They analysed genetic variation in an isolated population on Robinson Crusoe Island, the only inhabited island in the Juan Fernandez Archipelago, 677 km to the west of Chile. At the time of the study there were 633 inhabitants, most of whom were descended from a small number of founder indviduals. This population is of particular interest to geneticists as there is an unusually high rate of specific language impairment.  A genome-wide analysis failed to identify any single major gene that distinguished affected from unaffected individuals. However, there was a small region of chromosome 7 where there genetic structure was statistically different between affected and unaffected cases, and which contained genetic variants that had previously been found linked to language impairments in other samples. One of these, TPK1 is involved in the catalysis of the conversion of thiamine to thiamine pyrophosphate. It must be stressed that the genetic association between a thiamine-related genetic variant and  language impairment is probabilistic and weak, and far more research will be needed to establish whether it is generalises beyond the rare population studied by Villanueva and colleagues. But this observation points the way to a potential mechanism by which a genetic variant could influence language development.

To sum up: the importance of the study by Fattal and colleagues is two-fold. First, it emphasises the extent to which there can be adverse longer-term consequences of thiamine deficiency in children who may not have obvious symptoms, an observation which may assume importance in cultures where there is inadequate nutrition in breast-feeding mothers. Second, it highlights a role of thiamine in early neurodevelopment, which may prove an important clue to neuroscientists and geneticists investigating risks for language impairment.

References

Fattal I, Friedmann N, & Fattal-Valevski A (2011). The crucial role of thiamine in the development of syntax and lexical retrieval: a study of infantile thiamine deficiency. Brain : a journal of neurology, 134 (Pt 6), 1720-39 PMID: 21558277  

Villanueva P, Newbury DF, Jara L, De Barbieri Z, Mirza G, Palomino HM, Fernández MA, Cazier JB, Monaco AP, & Palomino H (2011). Genome-wide analysis of genetic susceptibility to language impairment in an isolated Chilean population. European journal of human genetics : EJHG, 19 (6), 687-95 PMID: 21248734