JCPSLP Vol 18 No. 1Mar 2016

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

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

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JCPSLP Volume 18, Number 1 2016

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