“Lee Silverman Voice Treatment (LSVT)® LOUD is the first speech treatment with level 1 evidence and established efficacy for treating voice and speech disorders in individuals with Parkinson’s disease, with application to other neurological disorders” (Mater Health and Wellness, 2008).
History of the technique:
LSVT was developed by Dr. Lorraine Ramig in 1987 after a patient of hers, Mrs. Lee Silverman who was diagnosed with Parkinson’s disorder (PD) (LSVT Global, n.d). Speech and voice abnormalities that can arise from PD include reduction of loudness, breathy phonation, reduced prosody and imprecise articulation (Ramig, Sapir, Countryman, Pawlas, O’Brien, Hoehn, & Thompson, 2001). These symptoms are collectively termed hypokinetic dysarthria. Mrs. Silverman’s family expressed their concerns about her communication and this motivated Dr. Ramig to develop an effective treatment to help People with Parkinson’s (PwPs) improve their communication (LSVT Global, n.d).
LSVT is an intensive program that aims to improve and strengthen vocal fold adduction, supralaryngeal articulatory movements, laryngeal muscle synergy and activity, respiratory drive, vocal tract and laryngeal configuration. The program focuses on maximising phonatory and respiratory functions by only using a simple set of tasks such as reading (Ramig et al., 2001). The participants are guided to continuously “think loud” and produce a loud voice with maximum effort while completing a variety of speech tasks (Ramig et al., 2001). Guiding the participants to “think loud” helps to regulate their sensorimotor perception of their loud voice and it aids them to monitor their auditory-vocal behaviours (Fox, Ebersbach, Ramig & Sapir, 2012). Targeting loudness produces a ripple effect as it facilitates changes in articulation, vocal quality and intonation, and reduces rate of speech.
Participants need to attend 16 sessions spread out over four weeks. Therapy will be implemented four times a week consecutively for an hour by a certified LSVT therapist. In addition, each task will need to be repeated at a minimum of 15 times (Fox, Ebersbach, Ramig & Sapir, 2012). Finally, participants, within their own capacity will need to achieve an 8 or 9 on a 1-10 self-perceived maximum effort scale daily (Fox, Ebersbach, Ramig & Sapir, 2012).
Theoretical Foundation:
PD is a motor neuron disease that is caused by the degeneration of cells in the substantia nigra of the brain (Aldred, 2009, p. 257). These cells contain the neurotransmitter dopamine which transmits information to the muscles to initiate or control movement (Aldred, 2009, p. 257). Due to the nature of PD, patients with PD lack the ability to initiate desired movement or control movement. However, behavioural studies have revealed that PwPs are relatively able to acquire and retain motor learning with the help of additional sensory cues to consolidate their learning (Nieuwboer, Rochester, Müncks, & Swinnen, 2009). LSVT draws on the principle of motor learning and neuroplasticity by incorporating intensive and repetitive high effort exercises, providing feedback based on knowledge of performance and results and constantly reminding participants to monitor their auditory-vocal behaviours (Ramig et al., 2001).
Evidence of Efficacy:
Firstly, to provide the highest level of evidence of the effectiveness of the program, systematic reviews of RCT studies were reviewed as it is ranked the highest on the NHMRC Level of Evidence. Majority of the studies conducted revealed favourable outcomes following the LSVT treatment. A study that was aimed at providing an insight of the differences of delivering the program online versus face-to-face revealed that both modes were equally as effective in producing significant changes in perceptual and acoustic measures of speech (Herd, Tomlinson, Deane, Brady, Smith, Sackley & Clarke, 2012). In addition, participants from both group revealed positive changes in their quality of life post program. Another study revealed that LSVT helped to improve loudness and monotonicity better than the Respiratory Therapy (RT) (Herd et al., 2012). The participants from the study were able to maintain effects from the therapy up to 24 months for monotonicity and phonation loudness. In addition, they could, up to 12 months maintain loudness during a monologue and reading task whilst RT was not able to sustain long term results. Secondly, RCT studies were also reviewed as it provides the second highest level of evidence. An RCT study that compared the effectiveness of LSVT and Respiratory Effect Therapy (RET) in terms of hoarseness and breathiness showed that LSVT produced statistically significant changes whilst RSVT did not. Overall, all these studies noted an improvement in speech intelligibility of the participants.
The limitations of these studies were the limited number of participants. The researchers justified their decision based on avoiding the occurrence of false positive and false negatives conclusions and to reduce selection bias. In addition, one of the samples consisted of 72% of males and only 28% of females (Herd et al., 2012). This causes the sample to not be representative of the entire population of PwPs. Although all the studies stated the use of randomization methods, none of them provided evidence is concealment of allocations were carried out. This could have caused an increase in the chances of selection bias in the studies. These trials should have included some eligibility criteria that accounted for the severity of PD faced by the participants and their co-existing conditions. Without this information, physicians may find it challenging to apply the therapy as it could be irrelevant to their patient’s current presentation and concerns (Herd et al., 2012).
Facilitators and Barriers:
One of the facilitators of this program is that it can be delivered online as well as the eLOUD program. It was proven that delivering the program online vs face-to-face were equally as effective (Herd et al., 2012). However, there is a lack of qualified trained clinicians to deliver the program (Fox, Ramig, Halpern & McFarland, 2011). Upon searching the LSVT Global website, it was discovered that are no trained clinicians in Australia to deliver the online program which serves to be a barrier to patients with PD who live in regional/rural areas that do not have easy access to health care. In addition, patients who are in the advanced stages of the disease may not be able to access the program as well. The program costs a total of 2500 dollars and can place financial constraints on PwPs who are seeking treatment. Due to the lack of dopamine, PwPs are also likely to feel apathetic (Parkinson’s Victoria, n.d). Their motivation to complete the program might be affected and this may reduce their compliance in following the guidelines of the treatment. Therefore, reducing the effectiveness of the treatment.
ICF Applications:
The ICF is a framework created by WHO that address the consequences of the impairments caused by a disease on the individual’s ability to participate in activities of daily. It also takes into account personal and environmental aspects of the person’s life.
The impairment level focuses on the body structure or function that has been compromised by the disease. Activity limitation is the difficulties an individual experiences while executing a task. Participation restriction is the difficulties one faces while executing a task in everyday life situations. PwPs experience impairment of the function of their voice and speech. They often report an increase in social isolation as a result of poor speech intelligibility that causes frequent breakdown in communication. In addition, they may find it difficult to communicate with friends and family members over the telephone as they are not able to rely on gestural cues to help get their message across.
The aim of LSVT is to address the impairment caused by the disease to help facilitate improvements in their speech and their ability to participate in activities of daily living. By targeting aspects such as, vocal loudness (produces a ripple effect that address other symptoms of the dysarthria) the overall speech intelligibility of the individual improves. Therefore, allowing patients to overcome barriers they have been experiencing prior to the commencement of the treatment. This treatment is suitable for PwPs of all ages.