EPG Therapy

Kathryn PatrickSpeech and Language Therapist

“Developing new and effective interventions for children with persistent speech sound disorders is challenging and one of the most neglected research areas in speech therapy”

Gibbon and Wood (2010)

“Speech and language therapists are reluctant to discharge these children from their caseloads because further improvements in articulation are highly desirable and often viewed as potentially achievable”

Gibbon and Paterson (2006)

Outline

• EPG practice in UK cleft centres• Evidence base• Underlying theoretical basis for EPG therapy• EPG case study• Conclusions

EPG therapy

• Custom made palate that fits on the roof of the mouth

• Tiny electrodes are embedded in the palate• Tongue touches electrodes – visual display• SLT use visual display to teach clients new

articulatory gestures

EPG therapy in the UK: A survey of practice

• 13/16 UK cleft centres responded to written survey (mid June 2013) (personal communication with 15)

• All centres have EPG equipment available for use, apart from one centre

• 14/15 offer (why 1 not offer – funding, children do well with traditional therapy)

• Number of patients seen per year– Range: 1 – 6 per year– Most commonly: 2 – 3 per year

Reasons for small numbers

• Funding (4)• Small number of eligible children (6)• Most children do well with traditional therapy (5)• SLT inexperience (2)• Restricted SLT time available for therapy (1)• Problems with generalisation (1)• EPG system difficult/temperamental to use (1)• Difficulty coordinating with orthodontics (1)

• Age range of patients– 6 to adults

• Criteria for EPG– Persistent speech difficulties which are impacting

on the individual– Speech difficulties that have not responded to

traditional therapy– Difficulties with lingual placement, pharyngeal

articulation, glottal productions, use of active nasal fricatives

Criteria continued

– Patients prepared to travel to centre– Patients prepared to commit to therapy– Dentition adequate to retain palate

• How are palates funded:– Cleft service– Speech and language therapy budget

• Where do you get palates from:– Incidental– Grove– In-house (Glasgow, Bristol)

• Outcomes– Good (10)– Mixed (3)

• Use of mirror neuron therapy– Yes (4)

• Use of ultrasound therapy– nil

• Interest in multicentre study – all yes, apart from two maybes

• Randomisation of patients – all but one centre happy to be involved in a RCT

Evidence base

• Substantial literature reporting EPG therapy for children with speech sound difficulties

• Used with cleft palate, functional articulation difficulties, neurological difficulties, hearing impairment

• 19 EPG cleft intervention studies, but lower levels of clinical effectiveness – most single case studies, case series, 1 RCT, 1 RCT with cross over design

• Case-studies – typically don’t report generalisation, changes to functional outcome (e.g. speech intelligibility/acceptability)

• Cochrane review: EPG for articulation disorders associated with cleft palate (Lee, Law and Gibbon, 2009): 1 RCT

• Lee et al’s conclusion “Current evidence supporting the efficacy of EPG is not strong and there remains a need for high quality randomised controlled trials to be undertaken in this area”

• Bessell et al (2013) review of SLT intervention for cleft palate speech – 1 EPG study meet their criteria. Concluded currently no robust evidence to support any speech and language therapy intervention for children with cleft palate speech.

• “Empty reviews do not mean that evidence for a given treatment does not exist, but that the strength of the evidence is of a moderate or low level. Empty (or near empty) reviews can bring attention to a research need and thus motive important investigative endeavours, particularly for low-incidence sub-speciality areas” Kelchner (2011)

Lee et al’s recommendations

• Further research on “active ingredients” of EPG therapy

• Development of treatment paradigm for enhancing generalisation and maintenance of treatment effect

Bessell et al’s recommendatons:

• Need for adequately designed studies• “Detailed information about the intervention

and its underlying approach”

Current predominant theoretical basis for EPG

• Principles of motor learning– Knowledge of results/performance – visual

feedback– Repetitive and intensive practice of new

articulatory gestures– Grading of motor complexityGibbon and Wood (2010)

Usage-based phonology

• Emergent model of language where language processing, acquisition and change comes about through language use and the subsequent generalisations / associations made following these usage events

Exemplar Theory

• Individuals make category judgements by comparing new stimuli with traces already stored in memory

• Similar memory traces are grouped together• A memory trace is more central or marginal

depending on the number and nature of shared features

Exemplar theory continued

• Frequency of use will impact on the core of a category

• The more frequent a memory trace, the more central that trace will become

• The core of the category can shift depending on the experience of the individual

Phonetic exemplars

Meanings

Contexts word used

• Neuromotor routines involve rapid sequenced movement

• This neuromotor activity is subject to overlapping and reduction

• Specific articulatory gestures will be influenced by surrounding articulatory gestures

• “stew” – “s” will be accompanied by lip rounding in anticipation of “ew”

Coarticulation

• Can occur within words • Can occur across words• One of the factors explaining the apparently

regular way many words are abutted together in continuous speech – connected speech processes

Connected speech processes

• Assimilaton• Coalescence• Elision

• “As adults we display our mastery of the phonology of the language as much as the ways in which we connect words up – our realisation of word junctions – as we do by our pronunciation of individual words”Howard et al (2008)

Connected speech exemplars

• e.g. “miss you” - /s/ becomes /ʃ/ whenever these combination of words is used (coalescence)

Clinical implications of usage-based phonology

• Intervention for older children and adults is more challenging because they have had many years using incorrect neuromotor traces

• Speech change is possible in older children and adults – use of new neuromotor routines (dosage important)

• Speech change is likely to be slow and gradual

Implications continued

• Coarticulation can be used to promote new articulatory gestures

• Capitalise on the principle of flexibility / gradience, ie gradual change in articulatory gestures

• Need to focus on new motor routines within connected speech – important for generalisat- ion and speech acceptability

Implications continued

• Therapy needs to promote use of new neuromotor routines in a variety of settings

Case Study

• Cleft palate• 22q11• Secondary speech surgery x 2(last surgery 15

months before start of EPG therapy)• History of speech and language difficulties

Speech pre-EPG

• Speech often difficult to follow• No signs of VPI• /t/, /d/ backed to uvular placement• /s/,/z/,/ʃ/, /ʒ/, /tʃ/, /dʒ/backed to velar or

uvular placement + active nasal airflow

ʃ

/t/

/s/

/ʃ/

/tʃ/

Therapy

• Articulatory placement for /t/ (from /n/)• Unable to add airflow to produce a stop

spound• Got interdental /t/ from a /p/• Interdental /s/ at word level• Alveolar /t/• Alveolar /d/

Therapy continued

• /tʃ/ from a /tj/• /dʒ/ from a /dj/• /ʃ/ from a /sj/• Alveolar /s/ from /st/ words

/t/

/s/

/tʃ/

Summary / Conclusions

• Older children and adults with significant and persistent cleft palate speech are a very neglected group

• EPG is a possible useful intervention for this group

• We need to develop our evidence based for EPG

• We need to develop our theoretical basis for treating this group of patients

Summary / Conclusions con’t

• Usage-based phonology is presented as a potential theory for developing and refining EPG treatment

• Case study – begun to apply some ideas from usage-based theory

References• Bessell, A., D. Sell, P. Whiting, S. Roulstone, L. Albery, M. Persson, A.

Verhoeven, M. Burke, and A. R. Ness, 2013, Speech and Language Therapy Interventions for Children With Cleft Palate: A Systematic Review: Cleft Palate-Craniofacial Journal, v. 50, p. E1-E17.

• Gibbon, F., E, and S. Wood, E, 2010, Visual feedback therapy with electropalatography, in L. Williams, A, S. McLeod, and R. McCauley, J, eds., Interventions for Speech Sound Disorders in Children: Baltimor, Maryland, Paul Brookes Publishing Co., p. 509 - 536.

• Gibbon, F. E., and L. Paterson, 2006, A Survey of Speech and Language Therapists' Views on Electropalatography Therapy Outcomes in Scotland: Child Language Teaching and Therapy, v. 22, p. 275-292.

References Continued• Howard, S., B. Wells, and J. Local, 2008, Connected Speech, in M. Ball, M.

Perkins, N. Muller, and S. Howard, eds., The Handbook of Clinical Linguistics: Oxford, Blackwell Publishing Ltd, p. 583 - 602.

• Kelchner, L. N., 2010, Near-empty review provides low-level support for use of Electropalatography (EPG) as a treatment for articulation disorders due to cleft palate, Psychology Press, p. 165-168.

• Lee ASY, Law J, Gibbon FE. Electropalatography for articulation disorders associated with cleft palate. Cochrane Database Syst Rev. 2009;(3):CD006854. doi:10.1002/14651858.CD006854.pub2.