Non-speech oro-motor exercise use in acquired dysarthria
management: regimes and rationales.
Catherine Mackenzie
Margaret Muir
Carolyn Allen
Department of Educational and Professional Studies, University of
Strathclyde, Glasgow
Abstract
Background: Non-speech oro-motor exercises (NSOMExs) are described in speech
and language therapy (SLT) manuals, and are thought to be much used in acquired
dysarthria intervention, though there is no robust evidence of an influence on speech
outcome. Opinions differ as to whether, and for which dysarthria presentations,
NSOMExs are appropriate.
Aims: The investigation sought to collect development phase data, in accordance with
the Medical Research Council evaluation of complex interventions. The aims were to
establish the extent of NSOMExs use in acquired disorders, the exercise regimes in
use for dysarthria, with which dysarthric populations, and the anticipated clinical
outcomes. A further aim was to determine the influencing rationales where NSOMExs
were or were not used in dysarthria intervention.
Methods & Procedures: SLTs throughout Scotland, Wales and Northern Ireland,
working with adult acquired dysarthria, were identified by their service heads. They
received postal questionnaires comprising 21 closed and two open questions, covering
respondent biographics, use of NSOMExs, anticipated clinical outcomes, and practice
influencing rationales.
Outcome & Results: One hundred and ninety one (56% response) completed
questionnaires were returned. Eighty-one per cent of respondents used NSOMExs in
dysarthria. There was no association with years of SLT experience. Those who used
and those who did not use NSOMExs provided similar influencing rationales,
including evidence from their own practice, and Higher Education Institute (HEI)
teaching. More experienced SLTs were more likely than those more recently
qualified to be guided by results from their own practice. Input from the attended HEI
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was more influential for those less experienced than for those more experienced.
Clinical outcome aims were not confined to speech, but included also improvements
in movement, sensory awareness, appearance, emotional status, dysphagia and
drooling. NSOMExs were used with many neurological disorders, especially stroke,
all dysarthria classes, especially flaccid, and all severity levels. Tongue and lip
exercises were more frequent than face, jaw and soft palate. The most common
regimes were 4-6 repetitions of each exercise, during three practice periods daily,
each of 6-10 minutes.
Conclusions & Implications: NSOMExs are a frequent component of dysarthria
management in the UK devolved government countries. This confirmation, along with
the details of SLT practice, provides a foundation for clinical research which will
compare outcomes for people with dysarthria, whose management includes and does
not include NSOMExs. SLT practice may be guided by evidence that speech outcome
is or is not affected by NSOMExs
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Introduction
Many dysarthria treatment manuals include movement exercises for the oral speech
muscles, principally the tongue and lips (Robertson and Thomson 1987, Swigert
1997, Kaye 2000, Sugden –Best 2002). These non-speech oro-motor exercises
(NSOMExs), also known as speech mechanism exercises (Hustad and Weismer
2007), or subsumed within the broader category of neuromuscular treatments (Clark
2003), appear to have a long tradition in speech and language therapy (SLT) practice.
Publications in English, recommending and explaining NSOMExs for people with
acquired dysarthria, date from around 1940 (Robbins 1940, Froeschels 1943). As is
the case for many SLT treatments, no robust evidence base supports the use of
NSOMExs in acquired dysarthria (Clark 2003). Moreover, there is ongoing debate as
to whether the movement basis for such exercises is relevant to speech (Weismer
2006).
The rationale for NSOMExs is that these will increase levels of tension, endurance
and power of weak muscles, for example of the tongue (Clark 2003). Establishing that
weakness is actually present is seriously hindered by its clinical evaluation being
almost always subjective, lacking normative reference data and demonstrated
reliability, and involving activities which are not used in speech, such as pushing the
tongue into the cheek,. An additional reservation is that physiological capacity in
healthy individuals far exceeds speech requirements, so strength may not be a useful
measure for predicting speech capacity (Kent 2009). Research using laboratory
procedures for example the Iowa Oral Performance Instrument (Blaise Medical Inc),
indicates that significant deficit in muscle strength may accompany normal speech
(Rosenbek and Jones 2009). Wieismer’s review (2006) of the literature shows little or
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no relationship between NSOM performance and speech severity, thus demonstrating
that extent of speech involvement cannot be predicted from weakness assessment.
Therefore even if weakness can be reliably demonstrated in speech musculature, the
assumption that this causes dysarthria is not valid.
Those who advocate widespread use of NSOMExs think that they form an important
foundation for speech, and lead to enhancement of speech (Dworkin 1991, Kearns and
Simmons 1998). Speech is regarded as a motor skill which can be reduced to
components, as distinct from the view that speech is a highly specific activity, in
respect of its motor control. Froeschels (1943), one of the early proponents of this
approach, cautioned against initiating speech exercises in dysarthria ‘before the best
possible training of the muscles involved has been achieved’, because to contravene
this ‘rule’ ‘might increase the unbalanced condition’ (Froeschels 1943, P313). Some
authors adopt a more cautious approach, believing NSOMExs to be relevant only to
the most severely impaired patients (Darley, Aronson and Brown 1975), and used ‘as
a last resort’ (Rosenbek and Jones 2009, P281). Rosenbek and Jones (2009) conclude
that oral non- speech drills cannot be justified: ‘Practice wagging your tongue and this
skill will improve…..but speech will be uninfluenced.’ (P271).
Some writers judge NSOMExs to be appropriate only for particular classes of
dysarthria, but there is no consensus as to the relevant diagnostic groups. For Duffy
(2005), these are flaccid, spastic, unilateral upper motor neurone and hypokinetic
dysarthrias, and within these, only for occasional cases. Zraick and LaPointe (2009)
include hyperkinetic conditions. Murdoch, Ward and Thodoros (2009) exclude
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