Introduction
Parkinson's disease is a progressive neurological disorder that is common under the elderly population [1]. The disease causes complications like failing motor systems, mental disorders and other dysfunctions, which all have a negative impact on the quality of life [2]. Even less apparent problems like memory management can be a problem for Parkinsonians [3].
There are multiple ways in which the regression of Parkinson's patients can be slowed. One of the effective methods is by using Neurologic Music Therapy [4,5,6].
The goal of this article is to get insight in the ways in which Neurologic Music Therapy can contribute to the rehabilitation of Parkinson's patients. The following research question is raised to reach this goal. How can neurologic music therapy contribute to the rehabilitation of Parkinson's patients? This question is answered by discussing the definition of neurologic music therapy, followed by an overview of the current state of research in rehabilitation methods by neurologic music therapy and how these methods can be applied to the rehabilitation of Parkinsonians.
Neurologic music therapy
The definition of neurologic music therapy is widely agreed upon among researchers.
Thaut [4] defined neurologic music therapy (NMT) as “The therapeutic application of music to cognitive, sensory and motor dysfunctions due to neurologic disease of the human nervous system”. Most researchers use that definition of neurologic music therapy since. According to Thaut [4] and Thaut and Hoemberg [5], the definition together with five other basic principles articulate the most important principles of NMT, being:
– “NMT is based on neuroscientific models of music perception and music production and influence of music on changes in non-musical brain and behaviour function.
– Treatment techniques are standardised in terminology and application, and are applied as therapeutic music exercises which are adaptable to a patient’s needs.
– The treatment techniques are based on data from translational scientific research, and are directed towards non-musical therapeutic goals.
– In addition to training in music and neurologic music therapy, practitioners are educated in the areas of neuroanatomy and physiology, neuropathology, medical terminology, and (re)habilitation of cognitive, motor, speech, and language functions.
– NMT is interdisciplinary. Music therapists can meaningfully contribute to and enrich the effectiveness of treatment teams. Non-music therapists who are trained in other allied health professions can effectively adapt the principles and materials of NMT for use in their own certified practice”
Thaut [4] divided the rehabilitation by NMT in three categories: Sensori motor rehabilitation, Cognitive rehabilitation and Speech and language rehabilitation. The division of rehabilitation has been widely agreed upon by researchers, and is done the same by Thaut and Hoemberg [5] and Pfeiffer[6].
Sensori motor rehabilitation
There are three methods of sensory motor rehabilitation in neurologic music therapy which can be used for the rehabilitation of Parkinson's patients.
Firstly, rhythmic auditory stimulation (RAS), which is defined by Thaut and Hoemberg [5] as: “The application of rhythmical (temporal) auditory stimuli associated with the initiation and ongoing facilitation of gait and gait related activities by providing a reference for the timing of movements”. This method has been proven effective for gait rehabilitation of Parkinsonians by
Thaut et al. [7] and Keus et al.[8]. On the other hand Lim et al. [9] also found evidence that RAS positively influences gait, but states that it is unclear whether positive effects identified in the laboratory can be generalized to improve activities of daily living.
Secondly, patterned sensory enhancement (PSE), explained by Thaut [1] as: “A technique that uses the rhythmic, melodic, harmonic, and dynamic-acoustical elements of music to provide temporal, spatial, and force cues for movements which reflect functional movements of activities of daily living or the fundamental motor patterns underlying these activities”. PSE, according to Pfeiffer et al. [3], has broader applications than RAS, because it can be used for movements that are not intrinsically or biologically rhythmic. Thaut and Hoemberg [5] agree with this statement, but add that the underlying neurologic mechanisms in RAS extend to the technique of PSE. Research by Freeman et al. [10] and Georgiou et al [11] has shown that PSE can be an effective method for the rehabilitation of Parkinsonians, especially for arm and hand movements.
Lastly, therapeutical instrumental music performance (TIMP). According to Thaut [4] it is the playing of musical instruments simulating functional nonmusical movement patterns for relearning functional movement skills. It shows results in increasing strength, endurance and motor control. Pfeiffer [6] states that the underlying mechanisms in RAS and PSE are shared with TIMP, but that TIMP has advantages. The instrument played by the patient provides a target for the movement and additional auditory feedback when the instrument target is accurately placed. The importance of placement of the instrumental target is also stated by Thaut and Hoemberg [5], but add that TIMP is also useful for overcoming unhealthy compensation strategies. Thaut [4] mentions the importance of the choice of instruments. Clack and Chadwick [12] and Elliot [13], who did extensive research on the importance of choice of instruments, agree with this statement.
In conclusion, RAS, PSE and TIMP are three effective methods for sensori motor rehabilitation of Parkinson's patients. The methods are based on the same underlying neurologic mechanisms, but focus on different motor functions.
Speech and language rehabilitation
There are two methods of speech and language rehabilitation in neurologic music therapy, that can be used for the rehabilitation of Parkinson's patients.
Firstly, Vocal intonation therapy (VIT), defined by Thaut and Hoemberg [5] as: “The use of vocal exercises to train, maintain, develop and rehabilitate aspects of voice control due to structural, neurological, physiological, phycological, or functional abnormalities of the voice apparatus.” DeSteward et al [14] and Haneishi [15] both proved that VIT can contribute to the speech and language rehabilitation of Parkinson’s patients. These studies show the short term effects of VIT. The only research that focuses on long term effects has been done by Ramig et al. [16]. The study found positive improvements in vocal production parameters after two years by investigating an intensive therapy program. Bellaire et al. [17] and Tamplin [18] both researched dysarthric speakers and suggest a different method for rehabilitation. Bellaire et al. [17] suggest breath pattern modification, but Tamplin et al. [18] suggest vocal exercises and singing.
Secondly, Therapeutic Singing (TS), explained by Thaut [4] as: “A technique which involves the unspecified use of singing activities to facilitate initiation, development, and articulation in speech and language as well as to increase functions of the respiratory apparatus.” According to Thaut and Hoemberg [5], there has been very little research that has focused exclusively on its singular effectiveness. Though multiple studies have shown the effectiveness in combination of TS with other methods like VIT. DiBenedetto et al. [19] showed that vocal and choral singing treatment (VCST) can improve specific abnormalities and increase quality of speech rehabilitation. Ferriero et al. [20] found that Parkinsonians seem to benefit from singing speech. However, he also found that TS did not change the speech intelligibility.
In conclusion, research shows both VIT and TS can contribute to the speech rehabilitation of Parkinson’s patients. Research has shown that combination of the two gives the best results. But in order to have a clear view on the effectiveness of TS further research is needed.
Cognitive Rehabilitation
There are three methods of sensori motor rehabilitation in neurologic music therapy that can be used for the rehabilitation of Parkinson's patients.
Firstly, musical attention control training (MACT), defined by Thaut[4] as using structured active or receptive musical exercises to practice attention functions. There has been no research on MACT for Parkinson's patients specifically. Though according to Thaut and Hoemberg [5], MACT can be helpful in the management of cognitive difficulties for people with Parkinson's disease. Research by Manly et al.[21], O’connel and Robertson [22] and multiple studies by Sohlberg and Mateer [23],[24] show the effectiveness of attention control training for a more general group.Though the group included Parkinson’s patients, though these trainings are not music based.
Secondly, musical executive function training (MEFT) explained by Thaut and Hoemberg [5] as, using improvisation to focus on improving the executive function skills, which include problem solving, decision making and reasoning. This method has been tested by Miller and Cummings [25] and showed to be effective for children with attention deficit hyperactivity disorder. MEFT has also been tested by Bugos et al. [26] for normal adults between 60 and 85 years old. There is ,however, no research on this method for Parkinson's patients in particular. Although according to Thaut and Hoemberg [5], MEFT is likely to be useful for Parkinsonians. On the other hand Kudlicka et al. [27] state that more research is needed to find whether there is a need for specific support for Parkinson's patients who demonstrate executive function impairment.
Lastly, Musical mnemonics training (MMT). This is defined by Thaut [4] as: “A method that uses music as a mnemonic device to sequence and organise information and add meaning, pleasure, emotion, and motivation in order to enhance the person’s ability to learn and recall the information involved”. MMT is according to Thaut and Hoemberg [5] a useful method for improving memory for Parkinson's patients. A study by Berg et al. [28] showed that learning memory strategies is helpful for improving memory. Melody and rhyme have a positive effect on recall, according to a study by Rubin and Wallace [29]. Thaut and Hoemberg [5] state that MMT can be used for cognitive rehabilitation of Parkinson's disease, but there is no direct evidence it does.
In conclusion, MACT, MEFT and MMT can all be used for cognitive rehabilitation. Whether the methods also have positive effects on Parkinsonians remains to be seen. Therefore further research is needed to prove their effectiveness with Parkinson's patients.
Conclusion
From the research in the previous paragraphs can be concluded that neurologic music therapy can positively contribute to the rehabilitation of Parkinson's patients by utilizing different types of rehabilitation techniques. This is reflected by discussing the definition of neurologic music therapy and its different rehabilitation categories. These categories, sensori motor rehabilitation, cognitive rehabilitation, speech and language rehabilitation are all important parts of the rehabilitation of Parkinsonians and have different methods for targeting specific problems.
To have the most effective treatment in practice, a combination of the three rehabilitation types is suggested. A good diversity of exercises and regular therapy sessions in combination with good support and guidance will slow the regression of Parkinson's substantially.
Although, there is room for improvement. Further research should be done in the Cognitive rehabilitation for Parkinson's patients, because there is a lack of research that proves the effectiveness of cognitive rehabilitation in NMT for Parkinsonians. Here lies the big potential to increase the quality and effectiveness of rehabilitation by Neurologic Music Therapy.