JCPSLP Vol 18 No. 1Mar 2016

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JCPSLP Volume 18, Number 1 2016 12
drawn from the study, for future research, a more
representative sample of participants ranging in severity of
PD and dysarthria would be valuable.
Future studies designed to investigate treatment
credibility and patient expectations should consider the
impact of other key participant variables. In particular it
would be worthwhile considering participants’ level of
education (schooling), depression, and treatment history
as literature is increasingly recognising relationships
between these factors and treatment credibility and patient
expectations (Constantino et al., 2014; Mooney et al.,
2014; Smeets et al., 2008). Furthermore, given that the
prevalence of depression in PD is estimated to be up
to 50% (Burn, 2002; van der Hoek et al., 2011) and the
related disorder of apathy at up to 36% (Pagonabarraga,
Kulisevsky, Strafella & Krack, 2015), it is reasonable to
hypothesise that the presence of depression and/or apathy
may impact upon perceptions of treatment credibility
and expectations (Tung, Cooke, & Moyle, 2013) and so
these variables should be considered in future studies. It
may also be important to measure patient expectations
and credibility at some point after the completion of
LSVT® LOUD when participants are more independent
and have sole responsibility over the maintenance of
their improvements. It may be hypothesised that patient
expectations and credibility correlate with outcomes in this
independent maintenance phase as the treatment process
may be more similar to those utilised in psychotherapies,
where correlations have often been established.
Clinical implications
The current study revealed that for LSVT ®LOUD, patient
expectations and treatment credibility were not associated
with treatment outcomes, nor were other participant
variables. The data from the current study supports
LSVT® LOUD as an efficacious treatment for persons with
hypokinetic dysarthria associated with PD. The findings of
this study suggest that patients undergoing LSVT ® LOUD
may significantly improve their communication, irrespective
of their expectations and perceptions of treatment
credibility. The findings of this study may assist in
broadening the eligibility criteria for candidates who are
considered for LSVT® LOUD. It is well established that a
large proportion of the population with PD suffer from
communicative limitations, critically reducing quality of life;
therefore it is vital that all people with PD are able to access
LSVT® LOUD (Duffy, 2005; Miller et al., 2006). The findings
from this study will be useful to speech-language
pathologists and other health professionals in ensuring that
all patients with PD have access to an efficacious speech
treatment regardless of their expectations, perceptions of
treatment credibility, age, time post onset of PD, severity of
dysarthria, and stage of PD.
References
Amanzio, M., Monteverdi, S., Giordano, A., Soliveri, P.,
Filippi, P., & Geminiani, G. (2010). Impaired awareness of
movement disorders in Parkinson’s disease. Brain and
Cognition, 72, 337–346.
Atkinson-Clement, C., Sadat, J., & Pinto, S. (2015).
Behavioural treatments for speech in Parkinson’s
disease: Meta-analyses and review of the literature.
Neurodegenerative Disease Management, 5(3), 233–248.
Borkovec, T. D., & Costello, E. (1993). Efficacy of applied
relaxation and cognitive-behavioral therapy in the treatment
of generalized anxiety disorder. Journal of Consulting and
and exercise outcome to small sample size and their
sampling method. The authors suggested that the high
mean scores for patient expectations may have raised the
possibility of a ceiling effect which occurs when close to
the highest possible score on the questionnaire is reached.
Few items remain to indicate whether the participant’s true
level of functioning has been measured accurately and
is discriminating between the functioning of participants
that are mostly all in the upper range is difficult (Taylor,
2010). This ceiling effect may explain the nil correlation
in the current study as patient expectation scores had a
moderately positive mean value.
The current study found that there was no association
between the participant variables of age, time post onset
of PD, severity of dysarthria or stage of PD, and the
treatment credibility or patient expectations. These findings
support those of Ramig et al. (1995) who were unable to
establish a relationship between participant characteristics
including age, stage of PD, time post onset and severity
of dysarthria, and LSVT®LOUD treatment outcomes. As
patients undergoing LSVT® LOUD typically achieve good
outcomes regardless of these variables, it may be expected
that these participant factors are not correlated with patient
expectations and treatment credibility. Nevertheless, it was
important to consider these variables as research in other
disciplines has established such associations (Constantino,
Penek, Bernecker, & Overtree, 2014; Curtis et al., 2011;
Mooney, Gibbons, Gallop, Mack, & Crits-Christoph, 2014).
The findings revealed that patients undergoing
treatment with LSVT®LOUD in this study made significant
improvements to their vocal volume and quality of life
irrespective of their own expectations and perceptions
of treatment credibility. Other participant variables – age,
time post onset of PD, severity of dysarthria, stage of
PD – did not influence patient expectations or treatment
credibility. These findings are important as people with
PD may have reduced insight and may appear apathetic
towards treatment (Amanzio et al., 2010; Mack et al.,
2013), yet this research shows that despite these potential
characteristics it is possible that they will make gains
through LSVT®LOUD. Therefore, the success that patients
achieve with LSVT®LOUD is likely to be due to the nature
of the speech treatment. The principles of neuroplasticity
embedded in LSVT®LOUD, such as the salience of tasks,
intensity of practice and personally rewarding tasks
(Kleim & Jones, 2008), are crucial for maximal and lasting
outcomes. Furthermore, there is evidence to suggest that
sensory calibration assists patients to recognise the need
to self-monitor the loudness of their speech and thus
enable generalisation into daily living (Fox et al., 2012). This
sensory calibration and motor learning is facilitated through
constant feedback and cueing from the clinician, who is
present throughout the 16 hours of therapy (Fox, Morrison,
Ramig, & Sapir, 2002). This treatment protocol is in contrast
to psychotherapies where the format may be less intensive
with more responsibility placed on the patient.
Limitations and future directions of the
current study
The findings of the current study may have been limited by
the sample which was primarily made up of participants in
the early stages of PD and experiencing mild dysarthria.
This sample bias may have contributed to the lack of
correlations found between treatment credibility and patient
expectations, and stage of PD and severity of dysarthria.
Although this limitation does not invalidate the conclusions